JP2021067652A - Absorbance measuring device, biological information measuring device, and absorbance measuring method - Google Patents

Abstract

To accurately measure the absorbance of light in a specific wavelength region.SOLUTION: An absorbance measuring device according to an embodiment of the present invention comprises: a light source that emits a plurality of beams of probe light different in wavelength in a specific wavelength region; a total reflection member that totally reflects the beams of probe light to be incident in a state of being in contact with an object to be measured; an incident control unit that controls the incidence of the beams of probe light on the total reflection member so as to provide at least a period during which all the plurality of beams of probe light are not incident on the total reflection member; a light intensity detection unit that is provided to able to detect the light intensity of the beams of probe light emitted from the total reflection member; and an absorbance output unit that outputs an absorbance acquired based on a detected value from the light intensity detection unit in a state where the beams of probe light are incident on the total reflection member, and a detected value therefrom in a state where all the plurality of beams of probe light are not incident on the total reflection member.SELECTED DRAWING: Figure 1

Description

The present application relates to an absorbance measuring device, a biological information measuring device, and an absorbance measuring method.

In recent years, the number of diabetic patients is increasing all over the world, and non-invasive blood glucose measurement without blood sampling is desired. As a method for measuring biological information such as blood glucose level using light, various methods such as a method using near infrared, a method using mid-infrared, and a method using Raman spectroscopy have been proposed. Of these, the mid-infrared region is a fingerprint region in which glucose is largely absorbed, and the measurement sensitivity can be increased as compared with the near-infrared region.

A light emitting device such as a Quantum Cascade Laser (QCL) can be used as a light source in the mid-infrared region, but laser light sources are required for the number of wavelengths used. From the viewpoint of miniaturization of the device, it is desirable to narrow down the wavelength in the mid-infrared region to several wavelengths.

As a device for measuring biological information based on the absorbance of probe light in a specific wavelength region such as the mid-infrared region, a wavelength-variable light source and light emitted from the light source are intensity-modulated by an attenuator to detect lock-in. Those that detect the differential spectral signal of absorbance are disclosed (see, for example, Patent Document 1).

However, in the apparatus of Patent Document 1, the absorbance may not be accurately measured because the measurement conditions change every moment due to the environment around the apparatus, the temperature change of the living body, the output fluctuation of the light source, and the like.

An object of the present invention is to accurately measure the absorbance of light in a specific wavelength region.

The absorptiometry device according to one aspect of the present invention includes a light source that emits a plurality of probe lights having different wavelengths in a specific wavelength region, and a total reflection member that totally reflects the incident probe light in contact with an object to be measured. And the incident control unit that controls the incident of the probe light on the total reflective member and the emission from the total reflective member so that at least a period during which all of the plurality of probe lights are not incident on the total reflective member is provided. A light intensity detecting unit provided so as to be able to detect the light intensity of the probe light, a value detected by the light intensity detecting unit in a state where the probe light is incident on the total reflection member, and a plurality of probe lights. It is provided with the detection value in a state where all of the above is not incident on the total reflection member, and an absorbance output unit that outputs the absorbance obtained based on the detection value.

According to the present invention, the absorbance of light in a specific wavelength region can be accurately measured.

It is a figure which shows the whole configuration example of the blood glucose level measuring apparatus which concerns on 1st Embodiment. It is a figure which shows the operation of the ATR prism. It is a perspective view which shows the structure of the ATR prism. It is a perspective view which shows the structure of a hollow fiber. It is a block diagram of the hardware configuration example of the processing part which concerns on embodiment. It is a block diagram which shows the functional structure example of the processing part which concerns on 1st Embodiment. It is a figure which shows the switching operation example of a probe light, (a) is a case where a 1st probe light is used, (b) is a case where a 2nd probe light is used, (c) is a case where a 3rd probe light is used. Is. It is a timing chart which shows the switching timing example of a probe light, (a) is a state of a 1st shutter, (b) is a state of a 2nd shutter, (c) is a state of a 3rd shutter, (d) is a photodetector. It is a figure which shows the output signal of. It is a flowchart which shows the operation example of the blood glucose level measuring apparatus which concerns on 1st Embodiment. It is a figure which shows the probe light intensity changed in 3 or more steps, (a) is the probe light intensity of a comparative example, and (b) is the probe light intensity changed in 3 or more steps. It is a figure which shows the misalignment correction example of a probe light, (a) is a figure which shows the cross-sectional light intensity distribution of a probe light, (b) is a figure which shows the cross-sectional light intensity distribution of (a) after the misalignment, (c). ) Is a diagram showing the cross-sectional light intensity distribution of the probe light including the speckle, and (d) is a diagram showing the cross-sectional light intensity distribution of (c) after the misalignment. It is a figure which shows the action of the incident surface in the ATR prism, (a) is the figure which shows the total reflection of the probe light when the incident surface is a flat surface, (b) is the figure which shows the total reflection of the probe light when the incident surface is a diffused surface. The figure showing reflection, (c) is an incident surface of a diffusion surface, (d) an incident surface of a concave surface, and (e) is an incident surface of a convex surface. It is a figure which shows the relative positional deviation of the 1st and 2nd hollow optical fibers and an ATR prism, (a) is the living body when the ATR prism is not in contact with a living body, (b) is a living body on the 1st total reflection surface of the ATR prism. (C) is the case where the living body comes into contact with the second total reflection surface of the ATR prism. It is a figure which shows the support member of the 1st and 2nd hollow optical fibers, ATR prism. It is a figure which shows the example of the visual appearance method of the contact state between an ATR prism and a lip. It is a figure which shows the whole configuration example of the blood glucose level measuring apparatus which concerns on 2nd Embodiment. It is an enlarged view explaining the contact part between a piezoelectric drive part and a 1st hollow optical fiber. It is a figure which shows the operation of the piezoelectric drive part, (a) is the probe light image which concerns on a comparative example, (b) is the AA cross-section light intensity distribution of (a), (c) is the probe which concerns on 2nd Embodiment. The optical image, (d) is the BB cross-sectional light intensity distribution of (c). It is a figure which shows the whole structure example of the blood glucose level measuring apparatus which concerns on 1st modification. It is a figure which shows the driving example of a lens. It is a figure which shows the whole structure example of the blood glucose level measuring apparatus which concerns on 2nd modification. It is a figure which shows the driving example of a mirror. FIG. It is a figure which shows an example of the light source drive current which concerns on 3rd modification, (a) is the light source drive current of the comparative example, (b) is the light source drive current which was high frequency modulated. It is a figure which shows the ATR prism which concerns on 3rd Embodiment, (a) is the center of the 2nd total reflection surface (b) when there is a measurement sensitivity region on both the 1st total reflection surface and the 2nd total reflection surface. When there is a measurement sensitivity region at only one location, (c) there is a measurement sensitivity region at a plurality of locations on the second total reflection surface. It is a figure which shows the structural example of the pressure detection part which concerns on 4th Embodiment, (a) is the case where one pressure detection part is provided, (b) is the case where the pressure detection part is provided at both ends of the ATR prism. (C) is a case where a plurality of pressure detection units are provided. 4th embodiment is a diagram showing the arrangement of an ATR prism on the lips of a living body, in which (a) is before the ATR prism comes into contact with the lips and (b) is a state in which the living body is holding the ATR prism. It is a block diagram which shows the functional structure example of the processing part which concerns on 4th Embodiment. It is a figure which shows the example of the correspondence relationship between the contact pressure of ATR prism and the lip, and the absorbance. It is a figure which shows the arrangement example to the support part of a pressure sensor, (a) is a case where one pressure sensor is provided, (b) is a case where a pressure sensor is provided on both ends side of an ATR prism, (c) is a figure. This is a case where a plurality of pressure sensors are provided. It is a figure of the thickness direction positional relationship example of a pressure sensor, a support part, and an ATR prism. It is a figure which shows other example of the positional relationship in the thickness direction of a pressure sensor, a support part, and an ATR prism, (a) is the case where the pressure sensor is arranged on the 2nd total reflection surface side, (b) is the 1st total reflection. This is a case where pressure sensors are arranged on both the surface side and the second total reflection surface side. It is a block diagram which shows the functional structure example of the processing part which concerns on 5th Embodiment. It is a figure explaining an example of the temperature detection result and the acquisition result of the blood glucose level data before correction. It is a figure which shows the correlation between the sublingual body temperature and the blood glucose level. It is a figure explaining an example of the temperature detection result and the acquisition result of the blood glucose level data after correction. It is a block diagram which shows the functional structure example of the processing part which concerns on 6th Embodiment. It is a figure which shows the correlation of the reference absorbance and the 2nd absorbance and the 3rd absorbance. It is a figure which shows the absorbance in one absorbance measurement. It is a figure which shows the correlation of the reference absorbance and the 2nd absorbance and the 3rd absorbance in one absorbance measurement.

Hereinafter, modes for carrying out the invention will be described with reference to the drawings. In each drawing, the same components may be designated by the same reference numerals and duplicate description may be omitted.

<Explanation of terms of the embodiment>
(Mid-infrared region)
The mid-infrared region refers to a wavelength region of 2 to 14 μm, and is an example of a specific wavelength region.

(Probe light)
Probe light refers to light used for absorbance measurement and biological information measurement. In the embodiment, it corresponds to the light that is totally reflected by the total reflection member, attenuated by the living body, and then detected by the light intensity detection unit.

(ATR method)
The ATR (Attenuated Total Reflection) method is a method of total reflection or total reflection, which exudes from the total reflection surface when total reflection occurs in a total reflection member such as an ATR prism arranged in contact with an object to be measured. It is a method to acquire the absorption spectrum of the object to be measured by using the field (evanescent wave).

(Absorbance)
Absorbance is a dimensionless quantity that indicates how much the light intensity decreases when light passes through an object. In the embodiment, the attenuation by the living body of the field exuded from the total reflection surface is measured as the absorbance by the ATR (Attenuated Total Reflection) method.

(Blood glucose level)
The blood sugar level refers to the concentration of glucose contained in the blood.

(Detected value)
In the embodiment, it refers to the value detected by the light intensity detection unit.

Hereinafter, the embodiment will be described by taking as an example a blood glucose level measuring device (an example of a biological information measuring device) that measures a blood glucose level (an example of biological information) based on the absorbance measured using an ATR prism (an example of a total internal reflection member). explain.

(Wave number)
The relationship between the wavelength λ (μm) and the wave number k (cm-1) is k = 10000 / λ.

[First Embodiment]
First, the blood glucose level measuring device 100 according to the first embodiment will be described.

In the present embodiment, a plurality of probe lights having different wavelengths in the mid-infrared region are incident on a total reflection member provided in contact with a living body, and the absorbance of each of the plurality of probe lights is measured based on the ATR method. To do.

Further, a light intensity detecting unit provided so as to be able to detect the light intensity of the probe light emitted from the total reflection member is provided so that at least a non-incident period during which all of the plurality of probe lights are not incident on the total reflection member is provided. , Controls the incident of probe light on the total internal reflection member. Then, the mid-infrared region is based on the detection value by the light intensity detection unit when the probe light is incident on the total reflection member and the detection value when all of the plurality of probe lights are not incident on the total reflection member. Obtain the absorbance data of the light of. This reduces the influence on the measurement such as the environment around the device and the temperature change of the living body, and accurately measures the absorbance.

<Overall configuration example of blood glucose level measuring device 100>
FIG. 1 is a diagram showing an example of the overall configuration of the blood glucose level measuring device 100. As shown in FIG. 1, the blood glucose level measuring device 100 includes a measuring unit 1 and a processing unit 2.

The measuring unit 1 is an optical head for performing the ATR method, and outputs a detection signal of the probe light attenuated by the living body to the processing unit 2. The processing unit 2 is a processing device that acquires absorbance data by calculation based on the detection signal and acquires and outputs the blood glucose level by calculation based on the absorbance data.

The measuring unit 1 includes a first light source 111, a second light source 112, a third light source 113, a first shutter 121, a second shutter 122, and a third shutter 123. It also includes a first half mirror 131, a second half mirror 132, a coupling lens 14, a first hollow optical fiber 151, an ATR prism 16, a second hollow optical fiber 152, and a photodetector 17.

The processing unit 2 includes an absorbance acquisition unit 21 and a blood glucose level acquisition unit 22. As shown by being surrounded by a broken line, the absorbance measuring device 101 includes a measuring unit 1 and an absorbance acquiring unit 21.

The first light source 111, the second light source 112, and the third light source 113 in the measuring unit 1 are electrically connected to the processing unit 2, respectively, and emit laser light in the mid-infrared region according to the control signal from the processing unit 2. It is a quantum cascade laser.

In the embodiment, the first light source 111 emits a laser beam having a wave number of 1050 cm-1 as the first probe light, the second light source 112 emits a laser beam having a wave number of 1070 cm-1 as the second probe light, and the third light source 113 emits the laser light. Emits a laser beam having a wave number of 1100 cm-1 as a third probe light.

The wave numbers of 1050 cm-1, 1070 cm-1 and 1100 cm-1 correspond to the wave numbers of the absorption peaks of glucose, respectively, and by measuring the absorbance using these wave numbers, the glucose concentration based on the absorbance can be measured. It can be done with high accuracy.

Further, the first shutter 121, the second shutter 122, and the third shutter 123 are electromagnetic shutters that are electrically connected to the processing unit 2 and are opened and closed according to a control signal from the processing unit 2.

When the first shutter 121 is opened, the first probe light from the first light source 111 passes through the first shutter 121 and reaches the first half mirror 131. On the other hand, when the first shutter 121 is closed, the first probe light is blocked by the first shutter 121 and does not reach the first half mirror 131.

When the second shutter 122 is opened, the second probe light from the second light source 112 passes through the second shutter 122 and reaches the first half mirror 131. On the other hand, when the second shutter 122 is closed, the second probe light is blocked by the second shutter 122 and does not reach the first half mirror 131.

Similarly, when the third shutter 123 is opened, the third probe light from the third light source 113 passes through the third shutter 123 and reaches the second half mirror 132. On the other hand, when the third shutter 123 is closed, the third probe light is blocked by the third shutter 123 and does not reach the second half mirror 132.

The first half mirror 131 and the second half mirror 132 are optical elements for transmitting a part of the incident light and reflecting the rest. Such an optical element can be configured by providing an optical thin film that transmits a part of the incident light and reflects the rest on a substrate that is transparent to the incident light.

However, the present invention is not limited to an optical thin film, and a diffraction structure that transmits a part of the incident light and reflects (diffracts) the rest may be formed on a substrate that is transparent to the incident light. Good. The use of a diffraction structure is preferable in that light absorption can be suppressed.

The first half mirror 131 transmits the first probe light that has passed through the first shutter 121 and reflects the second probe light that has passed through the second shutter 122. Further, the second half mirror 132 transmits the first probe light and the second probe light, respectively, and reflects the third probe light that has passed through the third shutter 123.

It is preferable that the light intensity ratio of the transmitted light and the reflected light in each of the first half mirror 131 and the second half mirror 132 is set to be approximately 1: 1, but it depends on the probe light intensity and the like emitted by each light source. Therefore, the above-mentioned light intensity ratio can be adjusted.

The first to third probe lights that have passed through the first half mirror 131 or the second half mirror 132 are guided into the first hollow optical fiber 151 via the coupling lens 14 and propagate in the first hollow optical fiber 151. Then, the light is guided into the ATR prism 16 through the incident surface 161 of the ATR prism 16.

The ATR prism 16 is an optical prism that propagates the first to third probe lights incident from the incident surface 161 toward the exit surface 164 while totally reflecting them, and emits the light from the exit surface 164. As shown in FIG. 1, the ATR prism 16 is arranged so that the first total reflection surface 162 is in contact with the living body S (an example of an object to be measured).

The first to third probe lights guided into the ATR prism 16 are repeatedly totally reflected by each of the first total reflection surface 162 and the second total reflection surface 163 facing the first total reflection surface 162, and are emitted. It is guided into the second hollow optical fiber 152 via the surface 164.

In the photodetector 17, the first to third probe lights guided by the second hollow optical fiber 152 reach the photodetector 17. The photodetector 17 is a detector capable of detecting light having a wavelength in the mid-infrared region. The received first to third probe lights are photoelectrically converted, and an electric signal corresponding to the light intensity is processed as a detection signal. Output to part 2. The photodetector 17 is composed of a PD (Photo Diode) for infrared rays, an MCT (Mercury Cadmium Telluride) detection element, a bolometer, and the like. Here, the photodetector 17 is an example of a light intensity detecting unit. In the following, when the first to third probe lights are not distinguished, they may be simply referred to as probe lights.

The processing unit 2 is constructed by an information processing device such as a PC (Persdonal Computer). The absorbance acquisition unit 21 in the processing unit 2 acquires the absorbance data of each probe light based on the detection signal of the photodetector 17 and outputs the absorbance data to the blood glucose level acquisition unit 22. The blood glucose level acquisition unit 22 acquires the blood glucose level data (blood glucose level information) of the living body based on the absorbance data of each probe light.

In FIG. 1, in order to clearly show the configuration of the measuring unit 1 and the components included in the absorbance measuring device 101, the measuring unit 1 is surrounded by a solid line frame and the absorbance measuring device 101 is surrounded by a broken line frame. However, these do not indicate a housing. The ATR prism 16 is not housed in the housing, and at least one of the first total reflection surface 162 or the second total reflection surface 163 can be brought into contact with an arbitrary part of the living body.

<Action and configuration of ATR prism 16 etc.>
Next, the operation of the ATR prism 16 will be described with reference to FIG. As shown in FIG. 2, the ATR prism 16 of the measuring unit 1 is arranged in contact with the living body S. Each probe light incident on the ATR prism 16 is attenuated corresponding to the infrared absorption spectrum of the living body S. The attenuated probe light is received by the photodetector 17, and the light intensity is detected for each probe light. The detection signal is input to the processing unit 2, and the processing unit 2 acquires and outputs the absorbance data and the blood glucose level data based on the detection signal.

The infrared attenuated total reflection (ATR) method is effective for spectroscopic detection in the mid-infrared region where the absorbed light intensity of glucose can be obtained. In the infrared ATR method, probe light, which is infrared light, is incident on an ATR prism 16 having a high refractive index, and a "stain" of a field that appears when total reflection occurs at the interface between the ATR prism 16 and the outside world (for example, living body S). It uses "out". If the measurement is performed in a state where the living body S, which is the object to be measured, is in contact with the ATR prism 16, the exuded field is absorbed by the living body S.

If infrared light having a wide wavelength range of 2 to 12 μm is used as the probe light, the light having a wavelength due to the molecular vibration energy of the living body S is absorbed, and the light is absorbed at the corresponding wavelength of the probe light transmitted through the ATR prism 16. Appears as a dip. In this method, since a large amount of energy of the detection light transmitted through the ATR prism 16 can be obtained, infrared spectroscopy using a probe light having a weak power is particularly advantageous.

When infrared light is used, the depth of light exuding from the ATR prism 16 to the living body S is only about a few microns, and the light does not reach the capillaries existing at a depth of about several hundred microns. However, it is known that components such as plasma in blood vessels ooze out as tissue fluid (interstitial fluid) in skin and mucosal cells. By detecting the glucose component present in the tissue fluid, the blood glucose level can be measured.

The concentration of the glucose component in the tissue fluid is considered to increase as it gets closer to the capillaries, and the ATR prism is always pressed with a constant pressure during measurement. In favor of such pressing, the embodiment employs a multi-reflective ATR prism with a trapezoidal cross section.

Here, FIG. 3 is a perspective view showing the structure of the ATR prism according to the embodiment. As shown in FIG. 3, the ATR prism 16 is a trapezoidal prism. As the number of multiple reflections in the ATR prism 16 increases, the glucose detection sensitivity increases. Further, since the contact area with the living body S can be made large, the fluctuation of the detected value due to the change in the pressure for pressing the ATR prism 16 can be suppressed to be small. The length L of the bottom surface of the ATR prism 16 is, for example, 24 mm. The thickness t is set thin so as to cause multiple reflections, such as 1.6 mm and 2.4 mm.

As a material for the ATR prism 16, a material that is not toxic to the human body and exhibits high transmission characteristics in the vicinity of a wavelength of 10 μm, which is an absorption band of glucose, is a candidate. As an example, a ZnS (zinc sulfide) prism having a large exudation of light, capable of detecting deeper parts, and a refractive index of 2.2 can be used from materials satisfying these conditions. Unlike ZnSe (zinc selenide), which is generally used as an infrared material, ZnS has been shown to have no carcinogenicity, and is also used as a non-toxic dye (lithopone) in dental materials.

In a general ATR measuring device, since the ATR prism is fixed to a relatively large device, the part of the living body to be measured is limited to the body surface such as the fingertip or the forearm. However, since the skin of these parts is covered with a stratum corneum having a thickness of about 20 μm, the detected glucose concentration becomes small. In addition, the stratum corneum is affected by the state of sweat and sebum secretion, which limits the reproducibility of measurements. Therefore, in the blood glucose level measuring device 100, a first hollow optical fiber 151 and a second hollow optical fiber 152 capable of transmitting infrared probe light with low loss are used, and one end of each is brought into contact with the ATR prism 16. Use.

One end of the first hollow optical fiber 151 is brought into contact with the ATR prism 16 to be optically connected to the incident surface 161 of the ATR prism 16, and the light emitted from the first hollow optical fiber 151 is emitted from the ATR prism 16. It is designed to be incident on the incident surface 161.

Further, the second hollow optical fiber 152 is optically connected to the exit surface 164 of the ATR prism 16 by contacting one end with the ATR prism 16, and the light emitted from the exit surface 164 of the ATR prism 16 is the second. 2 The light is guided into the hollow optical fiber 152.

By using the ATR prism 16, capillaries are present relatively close to the skin surface, and it is possible to perform measurement on the earlobe, which is less affected by sweat and sebum, and the oral mucosa, which does not have keratin.

FIG. 4 is a perspective view showing an example of the structure of the hollow optical fiber used in the blood glucose level measuring device 100. Mid-infrared light with a relatively long wavelength used for glucose measurement cannot be transmitted because the light is absorbed by the glass in the quartz glass optical fiber. So far, various optical fibers for infrared transmission using special materials have been developed, but it has been difficult to use them in the medical field due to problems such as toxicity, hygroscopicity and chemical durability of the materials. ..

On the other hand, in the first hollow optical fiber 151 and the second hollow optical fiber 152, a metal thin film 242 and a dielectric thin film 241 are arranged in this order on the inner surface of a tube 243 formed of a harmless material such as glass or plastic. There is. The metal thin film 242 is formed of a material having low toxicity such as silver, and is coated with the dielectric thin film 241 to impart chemical and mechanical durability. Further, since the core 245 is air that does not absorb the mid-infrared light, low-loss transmission of the mid-infrared light is possible in a wide wavelength range.

<Structure of processing unit 2>
Next, the configuration of the processing unit 2 will be described with reference to FIGS. 5 and 6.

FIG. 5 is a block diagram showing an example of the hardware configuration of the processing unit 2 according to the embodiment. As shown in FIG. 5, the processing unit 2 includes a CPU (Central Processing Unit) 501, a ROM (Read Only Memory) 502, a RAM (Random Access Memory) 503, an HD (Hard Disk) 504, and an HDD (Hard). It includes a Disk Drive) controller 505 and a display 506. In addition, an external device connection I / F (Interface) 508, a network I / F 509, a data bus 510, a keyboard 511, a pointing device 512, a DVD-RW (Digital Versatile Disk Rewritable) drive 514, and a media I / It includes an F516, a light source drive circuit 517, a shutter drive circuit 518, and a detection I / F519.

Of these, the CPU 501 controls the operation of the entire processing unit 2. The ROM 502 stores a program used for driving the CPU 501 such as an IPL (Initial Program Loader). The RAM 503 is used as a work area of the CPU 501.

The HD504 stores various data such as programs. The HDD controller 505 controls reading or writing of various data to the HD 504 according to the control of the CPU 501. The display 506 displays various information such as cursors, menus, windows, characters, or images.

The external device connection I / F 508 is an interface for connecting various external devices. The external device in this case is, for example, a USB (Universal Serial Bus) memory, a printer, or the like. The network I / F 509 is an interface for performing data communication using a communication network. The bus line 510 is an address bus, a data bus, or the like for electrically connecting each component such as the CPU 501 shown in FIG.

Further, the keyboard 511 is a kind of input means including a plurality of keys for inputting characters, numerical values, various instructions and the like. The pointing device 512 is a kind of input means for selecting and executing various instructions, selecting a processing target, moving a cursor, and the like. The DVD-RW drive 514 controls reading or writing of various data to the DVD-RW 513 as an example of the removable recording medium. In addition, it is not limited to DVD-RW, and may be DVD-R or the like. The media I / F 516 controls reading or writing (storage) of data to a recording medium 515 such as a flash memory.

The light source drive circuit 517 is electrically connected to each of the first light source 111, the second light source 112, and the third light source 113, and outputs a drive voltage for emitting infrared light to each of them in response to a control signal. It is an electric circuit. The shutter drive circuit 518 is an electric circuit that is electrically connected to each of the first shutter 121, the second shutter 122, and the third shutter 123, and outputs a drive voltage that drives the opening and closing of these according to a control signal.

The detection I / F519 is an electric circuit such as an A / D (Analog / Digital) conversion circuit that serves as an interface for acquiring a detection signal of the photodetector 17. The detection I / F 519 has a function as an interface for acquiring detection signals not only by the photodetector 17 but also by various sensors such as a pressure sensor and a temperature sensor (not shown in FIG. 5).

Next, FIG. 6 is a block diagram showing an example of the functional configuration of the processing unit 2 according to the first embodiment. As shown in FIG. 6, the processing unit 2 includes an absorbance acquisition unit 21 and a blood glucose level acquisition unit 22.

The absorbance acquisition unit 21 includes a light source drive unit 211, a light source control unit 212, a shutter drive unit 213, a shutter control unit 214, a data acquisition unit 215, a data recording unit 216, and an absorbance output unit 217. ..

Of these, the function of the light source drive unit 211 is performed by the light source drive circuit 517 or the like, the function of the shutter drive unit 213 is performed by the shutter drive circuit 518 or the like, and the function of the data acquisition unit 215 is performed by the detection I / F 319 or the like. The functions of are realized by HD504 and the like. Further, each function of the light source control unit 212, the shutter control unit 214, and the absorbance output unit 217 is realized by the CPU 501 executing a predetermined program or the like.

The light source driving unit 211 outputs a driving voltage based on the control signal input from the light source control unit 212, and emits infrared light to each of the first light source 111, the second light source 112, and the third light source 113. The light source control unit 212 controls the emission timing and light intensity of infrared light by the control signal.

The shutter drive unit 213 outputs a drive voltage based on the control signal input from the shutter control unit 214 to open and close each of the first shutter 121, the second shutter 122, and the third shutter 123. The shutter control unit 214 controls the timing and period for opening the shutter by a control signal. Here, the shutter control unit is an example of the incident control unit.

The data acquisition unit 215 outputs the detection value of the light intensity acquired by sampling the detection signals continuously output by the photodetector 17 at a predetermined sampling cycle to the data recording unit 216. The data recording unit 216 records the detection value input from the data acquisition unit 215.

The absorbance output unit 217 executes a predetermined arithmetic process based on the detected value read from the data recording unit 216 to acquire the absorbance data, and outputs the acquired absorbance data to the blood glucose level acquisition unit 22.

However, the absorbance output unit 217 may output the acquired absorbance data to an external device such as a PC via the external device connection I / F508, or output the acquired absorbance data to an external server or the like through the network I / F509 and the network. May be good. Alternatively, the display 506 (see FIG. 5) may be output for display.

Further, the blood glucose level acquisition unit 22 includes a biological information output unit 221. The biological information output unit 221 executes a predetermined arithmetic process based on the absorbance data input from the absorbance acquisition unit 21 to acquire blood glucose level data, and outputs the acquired blood glucose level data to a display 506 or the like for display.

However, the biological information output unit 221 may output the blood glucose level data to an external device such as a PC via the external device connection I / F508, or output the blood glucose level data to the external server or the like through the network I / F509 and the network. You may. In addition, the biological information output unit 221 may be configured so as to output the reliability of blood glucose measurement at the same time.

Since the technique disclosed in Japanese Patent Application Laid-Open No. 2019-037752 can be applied to the process for acquiring the blood glucose level data from the absorbance data, further detailed description will be omitted here.

<Operation example of blood glucose measuring device 100>
Next, the operation of the blood glucose level measuring device 100 will be described with reference to FIGS. 7 to 9.

(Example of probe light switching operation)
FIG. 7 is a diagram for explaining an example of the switching operation of the probe light. (A) shows the state of the measuring unit 1 when the first probe light is used, (b) shows the state of the measuring unit 1 when the second probe light is used, and (c) shows the state when the third probe light is used. ..

In the present embodiment, since the incident of the probe light by each light source on the ATR prism 16 is controlled by opening and closing each shutter, the first light source 111, the second light source 112, and the third light source 113 are used when measuring the absorbance and the blood glucose level. It constantly emits infrared light.

In FIG. 7A, the first shutter 121 is opened in response to the control signal. The first probe light emitted by the first light source 111 passes through the first shutter 121, passes through each of the first half mirror 131 and the second half mirror 132, and passes through the first hollow light through the coupling lens 14. The light is guided to the fiber 151. Then, after propagating through the first hollow optical fiber 151, it is incident on the ATR prism 16.

On the other hand, since the second shutter 122 and the third shutter 123 are closed, the second probe light and the third probe light do not enter the ATR prism 16. Therefore, in this state, the absorbance of the first probe light due to the attenuation at the ATR prism 16 is measured.

In FIG. 7B, the second shutter 122 is opened in response to the control signal. The second probe light emitted by the second light source 112 passes through the second shutter 122, is reflected by the first half mirror 131, passes through the second half mirror 132, and passes through the first hollow through the coupling lens 14. The light is guided to the optical fiber 151. Then, after propagating through the first hollow optical fiber 151, it is incident on the ATR prism 16.

On the other hand, since the first shutter 121 and the third shutter 123 are closed, the first probe light and the third probe light do not enter the ATR prism 16. Therefore, in this state, the absorbance of the second probe light due to the attenuation at the ATR prism 16 is measured.

In FIG. 7C, the third shutter 123 is opened in response to the control signal. The third probe light emitted by the third light source 113 passes through the third shutter 123, is reflected by the second half mirror 132, and is guided to the first hollow optical fiber 151 via the coupling lens 14. Then, after propagating through the first hollow optical fiber 151, it is incident on the ATR prism 16.

On the other hand, since the first shutter 121 and the second shutter 122 are closed, the first probe light and the second probe light do not enter the ATR prism 16. Therefore, in this state, the absorbance of the third probe light due to the attenuation at the ATR prism 16 is measured.

When all of the first shutter 121, the second shutter 122, and the third shutter 123 are closed, none of the first probe light, the second probe light, and the third probe light is incident on the ATR prism 16, and the light is emitted. It does not reach the detector 17.

In this way, the shutter control unit 214 (see FIG. 6) as the incident control unit controls the opening and closing of each shutter, and the first to third probe lights are sequentially incident on the ATR prism 16 and the first. It is possible to switch the state in which all of the third probe light does not enter the ATR prism 16.

(Example of probe light switching timing)
Next, FIG. 8 is a timing chart for explaining an example of switching timing of the first to third probe lights. 8 (a) shows the state of the first shutter 121, (b) shows the state of the second shutter 122, (c) shows the state of the third shutter 123, and (d) shows the output signal of the photodetector 17. ing. Further, in each figure, when the signal level is 0, the shutter is closed, and when the signal level is 1, the shutter is open. Further, the signals shown by diagonal hatching indicate those related to the first probe light, the signals shown by lattice hatching indicate those related to the second probe light, and the signals shown without hatching indicate those related to the third probe light. There is.

In FIG. 8A, the shutter control unit 214 opens the first shutter 121 and closes the second shutter 122 and the third shutter 123. As shown in FIG. 8D, during the period 81 when the first shutter 121 is opened, the photodetector 17 outputs a detection signal in a state where the first probe light is incident on the ATR prism 16.

After that, the shutter control unit 214 opens the second shutter 122 at the timing when the first shutter 121 is closed at the timing when the predetermined time elapses (FIG. 8B). As shown in FIG. 8D, during the period 82 when the second shutter 122 is open, the photodetector 17 outputs a detection signal in a state where the second probe light is incident on the ATR prism 16.

After that, the shutter control unit 214 opens the third shutter 123 at the timing when the second shutter 122 is closed at the timing when the predetermined time elapses (FIG. 8C). As shown in FIG. 8D, during the period 83 when the third shutter 123 is opened, the photodetector 17 outputs a detection signal in a state where the third probe light is incident on the ATR prism 16.

After that, when the shutter control unit 214 closes the third shutter 123 at the timing when a predetermined time elapses, all of the first shutter 121, the second shutter 122, and the third shutter 123 are closed. The photodetector 17 outputs a detection signal in a state where all of the first to third probe lights are not incident on the ATR prism 16 as in the non-incident period 84 shown in FIG. 8 (d).

After that, at the timing when the predetermined period elapses, the shutter control unit 214 sequentially opens the first shutter 121, the second shutter 122, and the third shutter 123 for a predetermined time, and then closes all of them. Then, such an operation is repeated.

As described above, the shutter control unit 214 as the incident control unit is provided with at least a non-incident period 84 in which all of the first to third probe lights are not incident on the ATR prism 16. The incident on the ATR prism 16 can be controlled.

Here, the cycle 85 in FIG. 8D shows one cycle of the control operation by the shutter control unit 214. In this one cycle, as shown in FIG. 8D, the period in which the first to third probe lights are sequentially incident on the ATR prism 16 and the entire first to third probe lights are all in the ATR prism. A non-incident period in which the light is not incident on 16 is included.

During each period within the cycle 85, the photodetector 17 outputs a light intensity detection signal to the data recording unit 216 via the data acquisition unit 215. The data recording unit 216 includes a first detection value based on the detection signal of the first probe light, a second detection value based on the detection signal of the second probe light, a third detection value based on the detection signal of the third probe light, and non-incident. Each of the fourth detection values based on the detection signal of the period is recorded separately.

Here, the action of the fourth detection value based on the detection signal during the non-incident period will be described. The detection signal by the photodetector 17 includes the light intensity of the background light around the device of the blood glucose level measuring device 100 as a bias signal, and in the mid-infrared region, the photodetector 17 also includes radiation (heat rays) due to heat. Since it is detected as the light intensity, the bias signal includes a large amount of the light intensity of this heat ray.

When the bias signal level changes due to a change in background light intensity, a change in temperature around the apparatus, or the like, the absorbance data acquired based on the detection signal of the photodetector 17 changes, causing a measurement error. In particular, the temperature changes from moment to moment due to the environment around the device, the heat generated by the living body, the heat generated by the configuration of the light source, the photodetector, and the like, and thus changes the bias signal level, which is a major factor in lowering the measurement accuracy.

On the other hand, the detection signal of the photodetector 17 in the non-incident period 84 in FIG. 8 represents a bias signal that does not include the first to third probe light intensities. Therefore, in the present embodiment, the first to third detection values are obtained by subtracting the fourth detection value in the non-incident period 84 from the first to third detection values based on each of the first to third probe lights. The bias signal component contained in each is removed. This makes it possible to acquire absorbance data with reduced effects such as the environment around the device and temperature changes of the living body by using the detected values of the first to third probe lights from which the bias signal component has been removed.

Further, if the time difference between the period in which the probe light is detected and the non-incident period becomes large, the change in the bias signal level due to the temperature or the like due to the time difference becomes large, and the influence of the bias signal may not be corrected appropriately. .. Therefore, in the present embodiment, the influence of the bias signal is corrected by using the detected value in the non-incident period most recent to the period in which the detected value of the probe light is acquired.

For example, in FIG. 8, the first detection value in the period 86 for detecting the first probe light is corrected by using the fourth detection value in the latest non-incident period 84 instead of the non-incident period 88 after the period 86. To do. Further, the second detection value in the period 87 for detecting the second probe light is corrected by using the fourth detection value in the latest non-incident period 84 or the non-incident period 88. By doing so, the influence of time changes such as temperature is more preferably reduced.

Here, the period 86 is an example of the first incident period, and the period 87 is an example of the second incident period. Further, these period 86, period 87, and non-incident period 88 are periods included in one cycle. In this way, the absorbance output unit 217 can output the absorbance data corrected for the influence of the bias signal.

(Operation example of blood glucose measuring device 100)
FIG. 9 is a flowchart showing an example of the operation of the blood glucose level measuring device 100.

First, in step S91, all of the first light source 111, the second light source 112, and the third light source 113 emit infrared light in response to the control signal of the light source control unit 212. However, in this initial state, the first shutter 121, the second shutter 122, and the third shutter 123 are all closed.

Subsequently, in step S92, the shutter control unit 214 opens the first shutter 121 and closes the second shutter 122 and the third shutter 123.

Subsequently, in step S93, the data recording unit 216 records the detection value (first detection value) by the photodetector 17 acquired by the data acquisition unit 215.

Subsequently, in step S94, the shutter control unit 214 opens the second shutter 122 and closes the first shutter 121 and the third shutter 123.

Subsequently, in step S95, the data recording unit 216 records the detection value (second detection value) by the photodetector 17 acquired by the data acquisition unit 215.

Subsequently, in step S96, the shutter control unit 214 opens the third shutter 123 and closes the first shutter 121 and the second shutter 122.

Subsequently, in step S97, the data recording unit 216 records the detection value (third detection value) by the photodetector 17 acquired by the data acquisition unit 215.

Subsequently, in step S98, the shutter control unit 214 closes all of the first shutter 121, the second shutter 122, and the third shutter 123.

Subsequently, in step S99, the data recording unit 216 records the detection value (fourth detection value) by the photodetector 17 acquired by the data acquisition unit 215.

Subsequently, in step S100, the absorbance output unit 217 subtracts the latest fourth detected value for each period from each of the first to third detected values read from the data recording unit 216 to correct the value.

Subsequently, in step S101, the absorbance output unit 217 acquires the absorbance data of the first to third probe lights based on the corrected first to third detection values and outputs the absorbance data to the biological information output unit 221.

Subsequently, in step S102, the biological information output unit 221 executes a predetermined arithmetic process based on the absorbance data of the first to third probe lights to acquire the blood glucose level data, and displays the acquired blood glucose level data on the display 506 ( Output to (see FIG. 5) and displayed.

In this way, the blood glucose level measuring device 100 can acquire and output the blood glucose level data.

<Action and effect according to the first embodiment>
The mid-infrared region is a finger print region (fingerprint region) in which glucose is largely absorbed, and is advantageous in that the measurement sensitivity is improved as compared with the near-infrared region. However, since the mid-infrared region is a wavelength region that matches the emission spectrum of an object at room temperature, the ambient environment of the measuring device, the heat generated by the living body, the heat generated by the light source used in the measuring device, the heat generated by the photodetector, etc. As a result, the detection signal of the photodetector changes from moment to moment. In particular, in the method of bringing a living body into contact with a total reflection member such as an ATR prism, the temperature of the total reflection member or the living body changes in a short time due to heat transfer from the living body, so that accurate absorbance may not be measured.

Further, when light having a single wavelength or a narrow band wavelength near a single wavelength is used, the measurement accuracy of the blood glucose level may decrease (for example, Kasahara.R, Kino.S, Soyama.S, Matsuura. Y. "Noninvasive glucos neighborhood measuring mid-infrared absorption spectrum spectrum spectrum based on a five wavelengths", Biomedical optics9, 20) (20), 20).

In the present embodiment, the first to third probe lights having different wavelengths in the mid-infrared region are incident on the ATR prism 16 provided in contact with the living body S, and the first to third probes light are incident on the ATR prism 16 based on the ATR method. Measure the absorbance of each probe light.

Further, the photodetector 17 is provided so as to be able to detect the light intensity of the first to third probe lights emitted from the ATR prism 16, and all of the first to third probe lights are not incident on the ATR prism 16. The incident of the first to third probe lights on the ATR prism 16 is controlled so that the incident period is at least provided. Then, the first to third detection values by the photodetector 17 in the state where each of the first to third probe lights is incident on the ATR prism 16 and the fourth detection value by the photodetector 17 in the non-incident period are set. Based on this, the absorbance data of light in the mid-infrared region is acquired.

Since this fourth detection value is based on the bias signal due to the environment around the device, the heat of the living body S, etc., the environment around the device is corrected by subtracting the fourth detection value from the first to third detection values. It is possible to reduce the influence on the measurement such as the temperature change of the living body. As a result, the absorbance can be measured accurately.

Here, in the above correction process, any correction process can be executed based on the first to third detection values and the fourth detection value, but the fourth detection value is subtracted from the first to third detection values. By performing the processing, the correction processing can be executed more easily.

Further, in the present embodiment, in the shutter control unit 214 as the incident control unit, the period during which the first to third probe lights are sequentially incident on the ATR prism 16 and the entire first to third probe lights are ATR. The non-incident period during which the prism 16 is not incident is periodically controlled so as to be included in one cycle.

As a result, the absorbance data corrected based on the first to third detection values and the fourth detection value can be repeatedly acquired, and the absorbance that changes with time can be accurately measured for each time.

Further, when the time difference between the period in which the first to third detection values are acquired and the non-incident period in which the fourth detection value is acquired becomes large, the change in temperature and the like due to the time difference becomes large, and the influence of the bias signal is affected. It may not be possible to correct properly.

Therefore, in the present embodiment, the shutter control unit 214 as the incident control unit has a period 86 (first incident period) in which the first probe light of the first to third probe lights is incident on the ATR prism 16 and a first. The period 87 (second incident period) in which the second probe light of the first to third probe lights is incident on the ATR prism 16 and the non-incident period 88 are periodically controlled so as to be included in one cycle.

Then, the absorbance output unit 217 acquires the first absorbance data based on the first detection value in the period 86 and the fourth detection value in the non-incident period 84 most recent to the period 86, and the second detection value in the period 87. The second absorbance data is acquired based on the fourth detected value in the non-incident period 84 most recent to the period 87 or the non-incident period 88. Here, the first absorbance data is an example of the first absorbance, and the second absorbance data is an example of the second absorbance.

As a result, the detection value based on the latest bias signal can be obtained at the time when the detection value by the probe light is acquired, the influence of the temperature change of the living body or the like can be minimized, and the absorbance can be measured more accurately.

In this embodiment, an example is shown in which the electromagnetic shutters, the first shutter 121, the second shutter 122, and the third shutter 123, are controlled to switch the incident of the probe light on the ATR prism 16, but the present invention is limited to this. It is not something that is done. The incident of the probe light on the ATR prism 16 may be switched by controlling to switch the plurality of light sources on (injection) and off (non-injection). Further, one light source that emits light having a plurality of wavelengths may be used, and the light source may be switched on and off for each wavelength.

Further, in the present embodiment, an example in which the first half mirror and the second half mirror are used as an element that transmits a part of the probe light and reflects the rest is shown, but the present invention is not limited to this, and the beam splitter is not limited to this. Or a polarizing beam splitter or the like may be used.

Further, a high refractive index material that transmits probe light, such as germanium, has a high surface reflectance due to the material characteristics. For example, when light (s-polarized light) polarized in the direction perpendicular to the surface direction of the substrate is incident on the substrate at an incident angle of 45 degrees, the ratio of transmission to reflection becomes approximately 1: 1. Taking advantage of this, the germanium plate can be installed so as to have an incident angle of 45 degrees to replace the half mirror. Since the back surface also has a 50% antireflection component, an antireflection film is applied to the back surface.

<Various modifications according to the first embodiment>
Here, since each component in the present embodiment can be deformed in various ways, various deformation examples will be described below.

(Timing of non-incident period)
First, in the above-described embodiment, an example is shown in which a period in which the first to third probe lights are incidentally incident on the ATR prism 16 one by one is provided, and a non-incident period is provided at a subsequent timing.

On the other hand, a non-incident period is provided after the period in which the first probe light is incident on the ATR prism 16, a non-incident period is provided after the period in which the second probe light is incident on the ATR prism 16, and the third probe light is in the ATR. A non-incident period may be provided after the period of incident on the prism 16. By doing so, it becomes easier to acquire the detected value based on the latest bias signal at the time when the detected value by the probe light is acquired, and the influence of the temperature change of the living body or the like can be corrected more accurately.

(Suppression of the influence of linearity error of photodetector 17)
The photodetector 17 used in the blood glucose level measuring device 100 may include a linearity error, and the linearity error of the photodetector 17 causes a blood glucose level measurement error. Therefore, the influence of the linearity error can be reduced by changing the probe light intensity to three or more predetermined steps and comparing the probe light intensity with the value detected by the photodetector 17.

10A and 10B are diagrams for explaining an example of probe light intensity changed in three or more stages, FIG. 10A is a diagram showing probe light intensity according to a comparative example, and FIG. 10B is a diagram showing three. It is a figure which shows the probe light intensity changed in the above-mentioned steps. In FIG. 10, the portion indicated by diagonal hatching indicates the light intensity of the first probe, the portion indicated by lattice hatching indicates the light intensity of the second probe, and the portion shown without hatching indicates the light intensity of the third probe.

In FIG. 10A, the light intensity of each probe is constant, whereas in FIG. 10B, the light intensity of each probe is gradually reduced in three or more stages. By changing the drive voltage or drive current of the light source in three or more predetermined stages (six stages in FIG. 10B), the emitted probe light intensity can be changed in three or more stages. .. The light intensity of the probe light in this case changes in a cycle shorter than the probe light switching control cycle (for example, the cycle from steps S92 to S94 in FIG. 9) by the shutter control unit 214. The probe light switching control cycle by the shutter control unit 214 corresponds to the “control cycle by the incident control unit”.

When the photodetector 17 does not include the linearity error, the value detected by the photodetector 17 changes linearly with respect to the change in the probe light intensity. On the other hand, when the photodetector 17 includes a linearity error, the value detected by the photodetector 17 changes non-linearly with respect to the change in the probe light intensity.

Therefore, the probe light is emitted while changing the light intensity in three or more stages, the detection value by the photodetector 17 at each stage is acquired, and the emitted probe light intensity data and the detection value by the photodetector 17 are obtained. To identify the light intensity range where linearity is ensured. Then, the absorbance and the blood glucose level are measured using only the portion of the probe light intensity that changes in three or more stages and whose linearity is ensured. As a result, the absorbance and the blood glucose level can be measured by reducing the influence of the linearity error of the photodetector 17.

The operation of specifying the light intensity range in which the linearity is ensured may be performed prior to the blood glucose measurement, or may be performed in real time during the blood glucose measurement.

Further, since there is one photodetector 17 while there are a plurality of probe lights, the processing for reducing the influence of the linearity error of the photodetector 17 does not have to be performed using all of the plurality of probe lights. Often, this may be done with at least one of a plurality of probe lights.

(Detection of probe light by image sensor)
The photodetector 17 is not limited to one that uses one pixel (light receiving element), but is not limited to a line-shaped image sensor in which pixels are arranged in a line shape, or an area shape in which pixels are arranged two-dimensionally. An image sensor can also be used.

Here, since the detection signal of the light detector 17 is an integrated value of the received probe light intensity, if the optical path of the incident light or the emitted light in the ATR prism 16 changes when the living body S comes into contact with the ATR prism 16. The probe light intensity before and after the change may be integrated to cause a detection error, making it impossible to obtain accurate absorbance data.

11 (a) and 11 (b) show such a misalignment of the probe light, and the region 171 is a light receiving region of the probe light by the photodetector 17. When the probe light shifts in the direction of the white arrow in FIG. 11B, the probe light intensity distribution in the region 171 changes, and the detection signal by the photodetector 17 changes.

On the other hand, when an image sensor is used for the photodetector 17, the amount of misalignment of the probe light can be known from the probe light image captured by the image sensor. Therefore, the integrated value of the light intensity distribution of the probe light after the misalignment is detected as a detection signal. By doing so, the influence of the positional deviation of the probe light can be corrected. The region 172 of FIG. 11B shows a region in which the integrated value of the light intensity distribution is acquired by the probe light after the misalignment.

Further, when coherent light such as laser light is used as the probe light, a fine mottled light intensity distribution called speckle may be superimposed on the probe light. FIG. 11C shows an example of the cross-sectional light intensity distribution of the probe light including the speckle. Reference numeral 174 indicates a singular point of light intensity that may be included in the speckle image, and the singular point 174 is included in the region 173.

FIG. 11D shows a case where the probe light of FIG. 11C is displaced in the direction of the white arrow. In this state, the singular point 174 is not included in the region 173, and the change in the detection signal before and after the misalignment becomes remarkable. On the other hand, by using the integrated value of the light intensity distribution in the region 175 as the detection signal according to the amount of the position shift of the probe light detected from the probe light image, the influence of the position shift of the probe light can be more preferably obtained. Can be corrected.

Further, the contact region between the living body S and the ATR prism 16 is estimated based on the probe light intensity distribution on the image sensor, and the sensitivity distribution in the ATR prism 16 plane acquired and stored in advance before the start of measurement is used. By correcting the detection value based on the detection signal of the image sensor, it is possible to reduce the measurement variation error.

(Incident surface to total reflection member)
In the above-described embodiment, the incident surface 161 of the ATR prism 16 is a flat surface, but the present invention is not limited to this, and the incident surface 161 is formed into various shapes such as a diffusion surface and a surface having a curvature. You may.

As shown in FIG. 12A, when the incident surface 161 is a flat surface, the traveling direction of the probe light in the ATR prism 16 becomes a uniform state according to the incident angle to the incident surface 161. Therefore, on the total reflection surface of the ATR prism 16 with which the living body S comes into contact, there may be a region dependence in which the measurement sensitivity differs for each region.

The detection signal of the photodetector 17 depends on the contact state such as the size of the contact area of the living body S with respect to the ATR prism 16. In particular, when the living body S such as a lip or a finger is an object to be measured, the reproducibility of the contact state tends to be low, so that the measurement variation may increase due to the region dependence of the measurement sensitivity.

On the other hand, by using the incident surface 161 as the diffusing surface, the traveling direction of the probe light in the ATR prism 16 is randomly changed, so that the region dependence of the measurement sensitivity is increased as shown in FIG. 12 (b). It can be relaxed and the measurement variation can be reduced.

Further, the incident surface 161 may be a concave surface shown in FIG. 12 (d) or a convex surface shown in FIG. 12 (e) in addition to the diffusion surface shown in FIG. 12 (c). The concave surface of FIG. 12 (d) and the convex surface of FIG. 12 (e) are examples of an incident surface having a curvature. In this case as well, the optical path of the probe light can be made different as in the diffusion surface, the region dependence of the measurement sensitivity can be relaxed, and the measurement variation can be reduced.

The same effect can be obtained by arranging a diffuser plate, a lens, or the like on the optical path before the probe light is incident on the ATR prism 16, but in this case, the device is assembled by increasing the number of component parts. Differences in measured values (machine differences) between devices due to errors and high costs may occur. It is more preferable to make the incident surface 161 of the ATR prism 16 a diffusion surface or a curved surface because such a difference in machine size and high cost can be suppressed.

(Light guide part and support part of total reflection member)
When the living body S comes into contact with the ATR prism 16, if the relative positions of the first hollow optical fiber 151 and the second hollow optical fiber 152 and the ATR prism 16 are displaced, the incident efficiency and emission efficiency of the probe light with respect to the ATR prism 16 will increase. It may fluctuate and the measurement variation may increase.

FIG. 13 is a diagram illustrating the relative positional deviation between the first hollow optical fiber 151 and the second hollow optical fiber 152 and the ATR prism 16. (A) is when the ATR prism 16 is not in contact with the living body S, (b) is when the living body S is in contact with the first total reflection surface 162 of the ATR prism 16, and (c) is the second total of the ATR prism 16. The cases where the living body S comes into contact with the reflecting surface 163 are shown.

As shown in FIG. 13B, when the living body S comes into contact with the first total reflection surface 162 of the ATR prism 16, a pressing force is applied downward as indicated by the white arrow, and the ATR prism 16 is displaced downward. As a result, the relative positions of the first hollow optical fiber 151 and the second hollow optical fiber 152 and the ATR prism 16'change in the state shown in the ATR prism 16'.

Further, as shown in FIG. 13C, when the living body S comes into contact with the second total reflection surface 163 of the ATR prism 16, a pressing force is applied upward as indicated by the white arrow, and the ATR prism 16 shifts upward. As a result, the relative positions of the first hollow optical fiber 151 and the second hollow optical fiber 152 and the ATR prism 16 "change in the state shown in the ATR prism 16".

Due to such relative positional deviation, the incident efficiency and emission efficiency of the probe light with respect to the ATR prism 16 fluctuate. In particular, when the object to be measured is a living body, it is not easy to keep the contact pressure constant, so that the measurement variation due to the relative positional deviation is particularly likely to increase.

Therefore, in order to suppress the relative positional deviation, it is preferable that the first hollow optical fiber 151, the second hollow optical fiber 152, and the ATR prism 16 are supported by the same supporting member.

FIG. 14 is a diagram illustrating an example of the configuration of a member that supports the first hollow optical fiber 151, the second hollow optical fiber 152, and the ATR prism 16. The light guide support member 153 in FIG. 14 is a member that integrally supports the first hollow optical fiber 151 and the ATR prism 16. Further, the emission support member 154 is a member that integrally supports the second hollow optical fiber 152 and the ATR prism 16.

By integrally supporting the first hollow optical fiber 151 and the ATR prism 16, even when the living body S is brought into contact with the ATR prism 16, both move integrally, so that relative positional deviation does not occur. Further, by integrally supporting the second hollow optical fiber 152 and the ATR prism 16, even when the living body S is brought into contact with the ATR prism 16, the two move integrally, so that the relative positional deviation does not occur. As a result, fluctuations in the incident efficiency and the exit efficiency of the probe light due to the contact of the living body S with the ATR prism 16 can be suppressed, and measurement variations can be reduced.

In the above-mentioned example, the light guide support member 153 and the exit support member 154 are made into separate members, but the first hollow optical fiber 151, the second hollow optical fiber 152, and the ATR prism 16 are combined into one. It may be configured to be supported by a support member.

Further, even when the light guide portion is composed of an optical element such as a mirror or a lens without using the first hollow optical fiber 151 as the light guide portion, the optical element and the ATR prism 16 are integrally supported. The same effect as described above can be obtained.

Further, not only the light guide unit but also the first light source 111, the second light source 112, the third light source 113, and the photodetector 17 are integrally supported by the same support member, so that the effect of reducing the measurement variation can be obtained. Be done.

(Detection and display of contact status)
When the ATR prism 16 is brought into contact with the living body part (lips, etc.) of the subject who is out of the field of view of the subject who measures the blood glucose level, the contact state between the living body part and the ATR prism 16 cannot be visually recognized. Therefore, the contact state may change for each measurement, and the measurement variation may increase.

On the other hand, as shown in FIG. 15, a camera 40 that captures the contact portion between the lips of the subject, which is the living body S, and the ATR prism 16, and a display unit such as a liquid crystal display that displays an image captured by the camera 40. 41 can be added to the configuration of the blood glucose level measuring device 100.

By adjusting the contact state between the lips and the ATR prism 16 while the subject visually recognizes the image displayed on the display unit 41, the reproducibility of the contact state can be improved and the measurement variation can be reduced.

[Second Embodiment]
Next, the blood glucose level measuring device 100a according to the second embodiment will be described.

In the present embodiment, the first hollow optical fiber 151 (an example of the light guide unit) that guides the probe light to the ATR prism 16 is driven by the drive unit. As a result, by averaging the detection signal of the probe light by the photodetector 17, the absorbance due to the speckle of the probe light, the output fluctuation of the light source, the position fluctuation of each component due to the vibration of the blood glucose level measuring device, and the like. Reduce the measurement variation of.

FIG. 16 is a diagram illustrating an example of the overall configuration of such a blood glucose level measuring device 100a. As shown in FIG. 16, the blood glucose level measuring device 100a includes a measuring unit 1a and a processing unit 2a. Further, the measurement unit 1a includes a piezoelectric drive unit 181 (an example of a drive unit) for driving the first hollow optical fiber 151, and the processing unit 2a includes a drive control unit 23 for controlling the piezoelectric drive unit 181. Here, the absorbance measuring device 101a includes a measuring unit 1a, a drive control unit 23, and an absorbance acquisition unit 21 as shown by being surrounded by a broken line.

The piezoelectric drive unit 181 includes a piezoelectric element that expands and contracts in a predetermined direction according to an input drive voltage. The piezoelectric drive unit 181 is arranged in contact with an intermediate portion in the length direction of the first hollow optical fiber 151 so as to expand and contract in a direction intersecting the propagation direction of the probe light by the first hollow optical fiber 151. .. Here, the first hollow optical fiber 151 is an example of an "optical fiber", and a place where one end of the first hollow optical fiber 151 is attached to the ATR prism 16 is an example of a "predetermined place".

The drive control unit 23 is an electric circuit that outputs a drive signal for driving the piezoelectric drive unit 181 to the piezoelectric drive unit 181. The drive control unit 23 outputs a drive voltage modulated in a predetermined cycle shorter than the detection cycle of the probe light intensity by the photodetector 17 to the piezoelectric drive unit 181.

Here, FIG. 17 is an enlarged view for explaining a contact portion between the piezoelectric drive unit 181 and the first hollow optical fiber 151.

As shown in FIG. 17, the piezoelectric drive unit 181 expands and contracts in the direction intersecting the propagation direction of the probe light (the direction of the white arrow), and the position of the intermediate portion in the length direction of the first hollow optical fiber 151 is white. Change in the direction of the pull-out arrow. More specifically, the piezoelectric drive unit 181 vibrates the intermediate portion in the length direction of the first hollow optical fiber 151 in the direction of the white arrow by repeating expansion and contraction according to the drive voltage input from the drive control unit 23. It is (driven), and the position of the intermediate portion is periodically and finely changed.

On the other hand, since one end of the first hollow optical fiber 151 is attached to the ATR prism 16, the intermediate portion of the first hollow optical fiber 151 in the length direction does not move even if it vibrates. Therefore, the piezoelectric drive unit 181 periodically finely changes the position of the intermediate portion in the length direction of the first hollow optical fiber 151 while maintaining the incident position and the incident angle of the probe light incident on the ATR prism 16. be able to.

If the position of the intermediate portion can be changed, the tip portion of the piezoelectric drive unit 181 and the intermediate portion may be connected by adhesion or the like, or may be vibrated by periodically contacting each other without being connected. It may be made possible.

The frequency of vibration by the piezoelectric drive unit 181 is 130 Hz as an example. However, the present invention is not limited to this, and the vibration may be performed at a frequency sufficiently higher than the detection frequency of the probe light intensity by the photodetector 17, and it is preferable to determine an appropriate frequency according to the weight of the driving target. A lightweight object such as the first hollow optical fiber 151 can have a high frequency of 100 kHz or more. The detection frequency of the probe light intensity by the photodetector 17 is, for example, 2 to 3 Hz.

Further, the vibration amplitude of the piezoelectric drive unit 181 is preferably about 1/10 of the beam diameter of the probe light to about the same size as the beam diameter. By vibrating the first hollow optical fiber 151 with this amplitude, the pattern of the probe light on the photodetector 17 changes, and the light intensity is integrated by the photodetector 17 to obtain a time averaging effect. Can be done.

FIG. 18 is a diagram for explaining the operation of such a piezoelectric drive unit 181. (A) is a probe light image according to a comparative example, (b) is an AA cross-sectional light intensity distribution of (a), (c) is a probe light image according to the present embodiment, and (d) is B of (c). -B Cross-sectional light intensity distribution is shown.

The probe light images in FIGS. 18A and 18C are obtained by capturing the probe light emitted from the second hollow optical fiber 152 with an infrared camera, and the light intensity of the probe light detected by the photodetector 17. It is for explaining the distribution.

In the probe optical image shown in FIG. 18A, the piezoelectric drive unit 181 is not driven, and the first hollow optical fiber 151 is not vibrating. In this state, a mottled pattern due to speckle is remarkably generated in the probe optical image. The AA cross-sectional light intensity distribution of (a) shown in FIG. 18 (b) includes fluctuations in light intensity corresponding to speckles, and the light in the detection area 176 corresponding to the detection area by the photodetector 17. The variation width 177 of the intensity distribution is relatively large, 140 to 240 gradations.

On the other hand, in the probe optical image according to the present embodiment shown in FIG. 18C, the piezoelectric drive unit 181 is driven and the first hollow optical fiber 151 is vibrating. In this state, the probe optical image fluctuates finely due to the vibration of the first hollow optical fiber 151 within the imaging cycle of the infrared camera, and the probe optical image time-averaged in the imaging cycle of the infrared camera is captured. The light intensity distribution is smoothed by the action of this time averaging, and the variation width 178 of the light intensity distribution within the detection region 176 shown in FIG. 18D is reduced to 180 to 230 gradations. Since the first hollow optical fiber 151 is vibrated while maintaining the incident position and incident angle of the probe light on the ATR prism 16, the time averaging action is obtained without changing the position of the probe light on the photodetector 17. be able to.

By reducing the variation width of the light intensity distribution, the variation of the value detected by the photodetector 17 is also reduced.

On the other hand, the value detected by the photodetector 17 may fluctuate due to the output fluctuation of the light source that emits the probe light, and the measurement variation may increase. In addition, the position of each component of the blood glucose measuring device fluctuates due to vibration of the device or the like, and the position of the probe light on the photodetector 17 fluctuates, which may increase the measurement variation. In these cases as well, the variation in the detected value can be reduced by the time averaging action of the probe light due to the vibration of the first hollow optical fiber 151.

<Action and effect according to the second embodiment>
As described above, in the present embodiment, the first hollow optical fiber 151 that guides the probe light to the ATR prism 16 is driven by the piezoelectric drive unit 181. As a result, the detection signal by the photodetector 17 is time-averaged to measure the absorbance due to the speckle of the probe light, the output fluctuation of the light source, the position fluctuation of each component due to the vibration of the blood glucose level measuring device, and the like. The variation can be reduced. Then, the absorbance can be accurately measured and the blood glucose level can be accurately measured.

If probe light with low coherence is used, the variation in the detected value due to the speckle becomes small, but even in this case, it is caused by the output fluctuation of the light source, the position fluctuation of each component due to the vibration of the blood glucose level measuring device, and the like. The effect of reducing measurement variation can be obtained.

In the present embodiment, an example of vibrating the intermediate portion of the first hollow optical fiber 151 in the length direction is shown, but the present invention is not limited to this, and the position of at least a part of the first hollow optical fiber 151 is not limited to this. May be changed. However, if the position of the intermediate portion is changed, the incident position and the incident angle of the probe light on the ATR prism 16 can be maintained. Therefore, the probe light intensity fluctuates due to the fluctuation of the incident position and the incident angle of the probe light on the ATR prism 16. It is preferable because the measurement error caused by the above can be suppressed.

Further, the direction changed by the piezoelectric drive unit 181 is not limited to the direction orthogonal to the propagation direction of the probe light by the first hollow optical fiber 151, and the position of at least a part of the first hollow optical fiber 151 is changed. If possible, it may be in any direction. Further, the present invention is not limited to one direction, and may be changed in a plurality of directions, or the changing direction may be two-dimensionally changed over time.

Further, in the present embodiment, an example of the piezoelectric drive unit is shown as the drive unit, but the present invention is not limited to this. If at least one of the positions or angles of the light guide unit can be changed, an ultrasonic vibrator, a voice coil motor, or the like can be used as the drive unit.

The effects other than the above are the same as those described in the first embodiment.

<Various modifications according to the second embodiment>
Here, since each component in the present embodiment can be deformed in various ways, various deformation examples will be described below.

(First modification)
In this modification, the light guide portion that guides the probe light to the ATR prism 16 includes a mirror (an example of a deflection portion) and a lens (an example of a condensing portion). Further, the lens included in the light guide unit is driven to time-average the detection signal by the photodetector 17. As a result, the measurement variation of the absorbance due to the speckle of the probe light, the output variation of the light source, the position variation of each component due to the vibration of the blood glucose level measuring device, and the like can be reduced.

FIG. 19 is a diagram illustrating an example of the overall configuration of the blood glucose level measuring device 100b according to this modified example. As shown in FIG. 19, the blood glucose level measuring device 100b includes a measuring unit 1b and a processing unit 2b. Further, the measuring unit 1b includes a deflection mirror 191 that deflects the first to third probe lights toward the ATR prism 16 and a first condensing lens 192 and a second condensing lens 193 that condense the deflected light by the deflection mirror 191. And a piezoelectric drive unit 181b for driving the second condenser lens 193. Here, the configuration including the deflection mirror 191 and the first condensing lens 192 and the second condensing lens 193 is an example of the light guide unit. Further, it is preferable to use a deflection mirror 191 made of a gold or silver material having a high reflectance of infrared light. It is preferable to use the first condensing lens 192 and the second condensing lens 193 also having high light condensing efficiency in the mid-infrared region.

Further, the processing unit 2b includes a drive control unit 23b that controls the piezoelectric drive unit 181b. The absorbance measuring device 101b includes a measuring unit 1b, a drive control unit 23b, and an absorbance acquisition unit 21 as shown by being surrounded by a broken line.

The piezoelectric drive unit 181b includes a piezoelectric element that expands and contracts in a predetermined direction according to an input drive voltage. The piezoelectric drive unit 181b is arranged in contact with the side portion of the second condenser lens 193 so as to expand and contract in a direction intersecting the optical axis of the second condenser lens 193.

The drive control unit 23b is an electric circuit that outputs a drive voltage for driving the piezoelectric drive unit 181b to the piezoelectric drive unit 181b. The drive control unit 23b outputs a drive voltage modulated in a predetermined cycle shorter than the detection cycle of the probe light intensity by the photodetector 17 to the piezoelectric drive unit 181b.

Here, FIG. 20 is an enlarged view for explaining a driving example of the second condenser lens 193. As shown in FIG. 20, the piezoelectric drive unit 181b expands and contracts in the direction intersecting the optical axis of the second condenser lens 193 (in the direction of the white arrow), and the position of the second condenser lens 193 is moved in the direction of the white arrow. Change. More specifically, the piezoelectric drive unit 181b vibrates (drives) the side portion of the second condenser lens 193 in the direction of the white arrow by repeating expansion and contraction according to the drive voltage input from the drive control unit 23b. , The position of the second condenser lens 193 is changed periodically and finely. As a result, the position of the probe light incident on the ATR prism 16 changes periodically, so that the position of the probe light on the photodetector 17 changes finely periodically.

If the position of the second condensing lens 193 can be changed, the tip portion of the piezoelectric drive unit 181b and the side portion of the second condensing lens 193 may be connected by adhesion or the like, or may not be connected. The vibration may be made possible by periodically contacting the lens.

The frequency of vibration by the piezoelectric drive unit 181b is 130 Hz as an example. However, the present invention is not limited to this, and the vibration may be performed at a frequency sufficiently higher than the detection frequency of the probe light intensity by the photodetector 17, and it is preferable to determine an appropriate frequency according to the weight of the driving target.

Since the second condenser lens 193 is heavier than the first hollow optical fiber 151 (see FIG. 16) according to the second embodiment, it is preferable that the frequency is lower than the frequency at which the first hollow optical fiber 151 is vibrated.

Here, in the second embodiment described above, since the probe light is vibrated while maintaining the incident position and the incident angle on the ATR prism 16, the probe on the photodetector 17 is vibrated even if the first hollow optical fiber 151 vibrates. The position of the light did not change. However, in this modification, the position of the probe light incident on the ATR prism 16 changes due to the vibration of the second condenser lens 193, and the position of the probe light on the photodetector 17 changes with this change. ..

On the other hand, by making the amplitude of the vibration by the piezoelectric drive unit 181b from 1/10 of the beam diameter of the probe light to about the same size as the beam diameter, the photodetector 17 even if the second condenser lens 193 vibrates. A part of the probe light overlaps above. As a result, the time averaging effect can be obtained in the region where the probe lights on the photodetector 17 overlap.

Since the action and effect of the blood glucose level measuring device 100b according to this modification is the same as that described in the second embodiment, duplicate description will be omitted here.

In this modification, an example is shown in which the piezoelectric drive unit 181b contacts the side portion of the second condenser lens 193 to vibrate the second condenser lens 193, but the piezoelectric drive unit 181b is the second condenser. The second condenser lens 193 may be vibrated in contact with a holding portion (not shown) that holds the lens 193.

Further, in this modification, an example of a piezoelectric drive unit is shown as a drive unit, but the present invention is not limited to this. If at least one of the positions or angles of the light guide unit can be changed, an ultrasonic vibrator, a voice coil motor, or the like can be used as the drive unit.

(Second modification)
In the first modification, the second condenser lens 193 included in the light guide is driven, but in this modification, the deflection mirror 191 included in the light guide is driven to drive the probe light by the photodetector 17. The detection signal of is time-averaged. As a result, the measurement variation of the absorbance due to the speckle of the probe light, the output variation of the light source, the position variation of each component due to the vibration of the blood glucose level measuring device, and the like can be reduced.

FIG. 21 is a diagram illustrating an example of the overall configuration of the blood glucose level measuring device 100c according to this modified example. As shown in FIG. 21, the blood glucose level measuring device 100c includes a measuring unit 1c and a processing unit 2c. Further, the measuring unit 1c includes a deflection mirror 191 that deflects the first to third probe lights toward the ATR prism 16 and a first condensing lens 192 and a second condensing lens 193 that condense the deflected light by the deflection mirror 191. , A piezoelectric drive unit 1820 for driving the deflection mirror 191 is provided.

Further, the processing unit 2c includes a drive control unit 23c that controls the piezoelectric drive unit 181c. As shown by being surrounded by a broken line, the absorbance measuring device 101c includes a measuring unit 1c, a drive control unit 23b, and an absorbance acquisition unit 21.

The piezoelectric drive unit 181c includes a piezoelectric element that expands and contracts in a predetermined direction according to an input drive voltage. The piezoelectric drive unit 181c is arranged in contact with the back portion of the deflection mirror 191 so as to expand and contract in a direction perpendicular to the mirror surface of the deflection mirror 191.

The drive control unit 23c is an electric circuit that outputs a drive voltage for driving the piezoelectric drive unit 1820 to the piezoelectric drive unit 1820. The drive control unit 23c outputs a drive voltage modulated in a predetermined cycle shorter than the detection cycle of the probe light intensity by the photodetector 17 to the piezoelectric drive unit 1820.

Here, FIG. 22 is a diagram illustrating a driving example of the deflection mirror 191. (A) shows the case where the piezoelectric drive unit 1820 is vibrated by the drive source, (b) is the case where the motor 1821 is vibrated by the drive source, and (c) is the case where the motor 1821 is vibrated by the MEMS (Micro Mechanical Electro System) mirror 1822. There is.

As shown in FIG. 22A, the piezoelectric drive unit 1820 expands and contracts in the direction perpendicular to the mirror surface of the deflection mirror 191 (in the direction of the white arrow), and changes the position of the deflection mirror 191 in the direction of the white arrow. The piezoelectric drive unit 1820 vibrates (drives) the deflection mirror 191 in the direction of the white arrow by repeating expansion and contraction according to the drive voltage input from the drive control unit 23c, and periodically finely changes the position of the deflection mirror 191. Let me. As a result, the incident position of the probe light on the ATR prism 16 changes, and the position of the probe light on the photodetector 17 changes periodically and finely.

If the position of the second condensing lens 193 can be changed, the tip portion of the piezoelectric drive unit 181b and the side portion of the second condensing lens 193 may be connected by adhesion or the like, or may not be connected. The vibration may be made possible by periodically contacting the lens.

Further, as shown in FIG. 22B, the motor 1821 vibrates in a direction perpendicular to the mirror surface of the deflection mirror 191 (direction of the white arrow) to change the position of the deflection mirror 191 in the direction of the white arrow. Here, the motor 1821 is a motor such as a ring (hollow) shaped voice coil motor. The motor 1821 holds the deflection mirror 191 inside the annulus and vibrates in the direction of the white arrow according to the drive voltage input from the drive control unit 23c, thereby causing the deflection mirror 191 to vibrate in the direction of the white arrow. The position of the deflection mirror 191 is changed periodically and finely. As a result, the incident position of the probe light on the ATR prism 16 changes, and the position of the probe light on the photodetector 17 changes periodically and finely.

Further, as shown in FIG. 22 (c), the MEMS mirror 1822 is a mirror in which a driving unit such as a piezoelectric driving unit is integrally formed by a semiconductor process. The piezoelectric drive unit is deformed according to the drive voltage input from the drive control unit 23c, and the deflection mirror 191 is rotated around an axis parallel to the mirror surface (for example, an axis perpendicular to the paper surface in FIG. 22). The angle of the deflection mirror 191 is changed. As a result, the deflection angle of the probe light by the deflection mirror 191 changes, the incident position of the probe light on the ATR prism 16 changes, and the position of the probe light on the photodetector 17 changes periodically and finely.

Since these drive frequencies, drive amplitudes, and effects are the same as those described in the first modification, redundant description will be omitted here.

In this modification, examples of a piezoelectric drive unit, a voice coil motor, a MEMS mirror, and the like are shown as the drive unit, but the drive unit is not limited to this. An ultrasonic vibrator, an acoustic optical element, a polygon mirror, or the like may be used as the driving unit as long as at least one of the positions or angles of the light guide unit can be changed.

(Third modification example)
In the first and second modifications, an example is shown in which the light guide unit is driven to reduce the measurement variation caused by the speckle of the probe light and the like. Since this speckle is generated by the interference of scattered light of the probe light and the like, the generation of speckle can be suppressed by reducing the coherence of the probe light. Therefore, in this modification, by superimposing a high-frequency modulation component on the current that drives the light source, the coherence of the light source included in the blood glucose level measuring device is reduced, and the measurement variation in absorbance due to the speckle of the probe light. To reduce.

FIG. 23 is a diagram for explaining an example of the light source drive current according to the present modification, (a) shows the light source drive current according to the comparative example, and (b) is a high-frequency modulated light source drive current according to the present modification. Is shown.

The light source control unit 212 (see FIG. 6) periodically outputs a pulsed drive current as shown in FIG. 23A to each of the first light source 111, the second light source 112, and the third light source 113. This causes them to emit pulsed probe light.

In this modification, the high-frequency modulation component is superimposed on the pulsed drive current of FIG. 23A and output to the first light source 111, the second light source 112, and the third light source 113. The waveform of the high-frequency modulation component may be sinusoidal or rectangular. Any modulation frequency from 1 MHz (megahertz) to several GHz (gigahertz) can be selected.

By superimposing the high-frequency modulation component, the first light source 111, the second light source 112, and the third light source 113 can each emit pseudo multimode laser light as probe light, and the coherence of the probe light is possible. Can be reduced. As a result, the speckle of the probe light is reduced due to the decrease in coherence, and the measurement variation caused by the speckle is reduced.

Although the second embodiment and the first to third modifications have been described above, a absorbance measuring device or a blood glucose level measuring device can be realized by combining some of them.

Further, in the above-described example, an example in which the present embodiment is applied to a blood glucose level measuring device has been shown, but the present invention is not limited thereto. The embodiment is also applicable to a light guide device including a light guide unit that guides the probe light, a drive unit that drives the light guide unit, and a control unit that controls the drive unit. With such a light guide device, the same effect as that of the above-mentioned absorbance measuring device can be obtained.

[Third Embodiment]
Next, the blood glucose level measuring device according to the third embodiment will be described.

In the present embodiment, by limiting the measurement sensitivity region of the ATR prism 16, the measurement variation of the absorbance due to the fluctuation of the contact region (contact area) between the ATR prism 16 and the living body S is reduced for each measurement.

Here, the measurement sensitivity region refers to a region having measurement sensitivity for measurement based on the ATR method on the total reflection surface. More specifically, it refers to a region where the field is exuded from the total reflection surface to obtain the damping action of the field by the living body.

FIG. 24 is a diagram illustrating a configuration example of the ATR prism 16d in which the measurement sensitivity region according to the present embodiment is defined. Each of FIGS. 24 (a) to 24 (c) shows three examples in which the measurement sensitivity regions are different. In (a) to (c), the probe light P indicated by the broken line arrow is incident from the incident surface 161 of the ATR prism 16d, is totally reflected four times by the first total reflection surface 162, and is 3 by the second total reflection surface 163. After total internal reflection, the light is emitted from the exit surface 164.

A part of the first total reflection surface 162 in each figure is provided with a reflection film 162 m made of gold or silver having a high reflectance with respect to infrared rays. Similarly, a part of the second total reflection surface 163 is also provided with a reflection film 163 m made of a gold material or a silver material having a high reflectance with respect to infrared rays. Such reflective films 162 m and 163 m can be formed by depositing gold or silver on all reflective surfaces. Further, by using a mask at the time of vapor deposition, gold or silver can be vapor-deposited in a region other than the masked region.

In the region of the first total reflection surface 162 and the second total reflection surface 163 where the reflection films 162 m and 163 m are provided, total reflection does not occur and the field does not exude, so that the field attenuation effect by the living body S cannot be obtained. It does not correspond to the measurement sensitivity range. In other words, each of the reflective films 162 m and 163 m has a function of defining a measurement sensitivity region on the total reflection surface. The reflective films 162m and 163m are examples of the region defining portion. The regions of the first total reflection surface 162 and the second total reflection surface 163 in which the reflection films 162m and 163m are provided are examples of "regions other than the measurement sensitivity region", and the reflection films 162m and 163m are not provided. The region is an example of a "region other than the edge".

FIG. 24A shows a case where the measurement sensitivity region is provided on both the first total reflection surface 162 and the second total reflection surface 163. Reflective films 162 m and 163 m are provided on any surface in a region excluding the central portion. The central portion where the reflective films 162 m and 163 m are not provided corresponds to the measurement sensitivity region.

The field 162k shown by the diagonal hatching represents the field exuded from the first total reflection surface 162. Since it is totally reflected twice, a boundary is generated at two places. Similarly, the field 163k represents a field exuded from the second total reflection surface 163. Since it is totally reflected once, a boundary is generated at one place.

FIG. 24B shows a case where the measurement sensitivity region is located at one position in the center of the second total reflection surface 163. Since the first total reflection surface 162 is provided with the reflection film 162 m on the entire surface, the first total reflection surface 162 does not have a measurement sensitivity region. The second total reflection surface 163 is provided with a reflection film 163 m except for the central portion. A boundary 163k is generated in the central portion, and this portion becomes the measurement sensitivity region.

FIG. 24C shows a case where there are measurement sensitivity regions at a plurality of locations (here, three locations) of the second total reflection surface 163. Since the first total reflection surface 162 is provided with the reflection film 162 m on the entire surface, the first total reflection surface 162 does not have a measurement sensitivity region. The second total reflection surface 163 is provided with a reflection film 163 m except for three places. Fields 163k are generated at three locations where the reflective film 163m is not provided, and these portions serve as measurement sensitivity regions.

Here, in the blood glucose measurement using the ATR prism, the subject ATR so that the first total reflection surface 162 contacts the upper lip of the living body S and the second total reflection surface 163 touches the lower lip of the living body S. The measurement may be performed by holding the prism 16d. In this case, since the central portion of the lips is likely to apply a gripping force, the lips can be brought into contact with the ATR prism relatively stably. On the other hand, in the vicinity of both ends of the lips, it is relatively difficult to apply a holding force, and the size of the mouth varies from person to person, so that the contact area may fluctuate and the measurement variation may increase.

On the other hand, in the example of FIG. 24A, the measurement sensitivity region near both ends of the ATR prism 16d that contacts both ends of the lips is defined by the reflective films 162 m and 163 m, and the contact region is likely to fluctuate. Can be avoided for measurement.

The region provided with the reflective film 162 m in FIG. 24 (a) corresponds to both ends of the first total internal reflection surface 162. However, a reflective film 162 m may be provided at either end. Further, the region provided with the reflective film 163 m in FIG. 24 (a) corresponds to both ends of the second total reflection surface 163. However, a reflective film 163 m may be provided at either end.

Further, since the lower lip is easier to apply the holding force to the ATR prism 16d than the upper lip, it may be possible to reduce the measurement variation of the absorbance by using only the second total reflection surface 163 in which the lower lip is in contact. ..

On the other hand, in the example of FIG. 24B, the measurement sensitivity region of the entire surface of the first total reflection surface 162 in contact with the upper lip and the measurement sensitivity regions near both ends of the second total reflection surface 163 in contact with both ends of the lower lip is defined. It is defined by the reflective films 162 m and 163 m, and only the region where the contact region is hard to fluctuate is used for the measurement.

Further, the greater the number of total reflections on the total reflection surface, the greater the attenuation due to the living body S, and the higher the sensitivity of measurement. On the other hand, in the example of FIG. 24C, regions where the reflective film 163 m is not formed are provided at three locations where total reflection occurs on the second total reflection surface 163 in which the lower lip contacts. As a result, the blood glucose level can be measured with a larger total number of reflections (3 times) than the total number of total reflections (1 time) in FIG. 24 (b), and highly accurate measurement with higher measurement sensitivity becomes possible.

The blood glucose level measuring device 100 according to the first embodiment can be applied to the overall configuration of the blood glucose level measuring device according to the present embodiment by replacing the ATR prism 16 with the ATR prism 16d.

Further, the region where total reflection occurs on the first total reflection surface 162 and the second total reflection surface 163 can be specified by experiment or simulation based on the angle of incidence of the probe light on the ATR prism 16. Reflective films 162 m and 163 m can be provided in addition to the specified area where total reflection occurs.

<Action and effect according to the third embodiment>
Depending on the contact area (contact area) of the living body with the ATR prism, the generation area of the field exuding from the total reflection surface of the ATR prism changes. When measuring the blood glucose level, it is preferable that the contact area is constant, but in reality, it is difficult to exactly match the contact area of the living body with the ATR prism for each measurement, so the contact area is set for each measurement. It may change and the measurement variation of absorbance may increase due to the change of the contact area. In particular, when the lip is used as the measurement site, the contact area around the edge of the lip is likely to change depending on the individual difference in the size of the lip and the degree of force applied to hold the ATR prism, and measurement variation is likely to occur. ..

In the present embodiment, the measurement sensitivity region of the ATR prism 16d is defined by the reflective films 162m and 163m as the region defining portion. As a result, the measurement can be performed using only the region in which the contact region of the ATR prism 16d is likely to fluctuate and the region in which the contact region is relatively fluctuating. As a result, the measurement variation of the absorbance due to the fluctuation of the contact region between the ATR prism 16d and the living body S can be reduced, and the measurement variation of the blood glucose level can be reduced.

[Fourth Embodiment]
Next, the blood glucose level measuring device according to the fourth embodiment will be described.

In the present embodiment, the contact pressure (pressure) of the living body S with respect to the ATR prism 16 is detected by a pressure sensor (an example of a pressure detection unit). By acquiring the absorbance data of the probe light based on the light intensity of the probe light and the contact pressure detected by the pressure sensor, it is possible to reduce the measurement variation of the absorbance due to the contact pressure fluctuating from measurement to measurement. Reduce the measurement variation of blood glucose level.

<Arrangement example of pressure sensor 30>
FIG. 25 is a diagram illustrating an example of arrangement of the pressure sensor 30 on the ATR prism 16. Each figure of FIGS. 25 (a) to 25 (c) shows three examples in which the arrangement position and the number of pressure sensors 30 are different. 25 (a) shows a case where one pressure sensor 30 is provided, (b) shows a case where the pressure sensor 30 is provided at both ends of the ATR prism 16, and (c) shows a plurality of (here, three) pressure sensors 30. Is shown.

As shown in each figure, the total reflection support portion 31 contacts one side surface portion (a surface other than the incident surface and the exit surface of the probe light) of the ATR prism 16 to support the ATR prism 16 and also supports the first total reflection. A pressure sensor 30 is placed on the surface 162 to support the pressure sensor 30.

The pressure sensor 30 is in contact with at least one of the ATR prism 16 and the pressure sensor 30 and is fixed by adhesion or the like. The pressure sensor 30 is a sensor that detects the contact pressure Pr received by the ATR prism 16 from the lips when the subject as the living body S holds the ATR prism 16. As the pressure sensor 30, various types of sensors such as a capacitance type sensor, a strain gauge type sensor, a pressure sensitive resistance type sensor whose resistance value changes depending on pressure, and a pressure sensor using MEMS technology can be applied.

FIG. 25 shows an example in which the pressure sensor 30 is arranged only on the first total reflection surface 162 of the ATR prism 16, but the pressure sensor 30 is the first total reflection surface 162 or the second total of the ATR prism 16. It can be arranged on at least one of the reflecting surfaces 163.

As shown in FIG. 25 (b), if pressure sensors 30 are provided near both ends of the ATR prism 16, it is difficult to apply a relatively holding force, or the size of the mouth varies from person to person, resulting in contact pressure. Can detect pressure near both ends of the lips, which is liable to fluctuate. Further, as shown in FIG. 25 (c), if three pressure sensors 30 are provided, the distribution of contact pressure can be detected.

When the pressure sensor 30 is arranged on the total reflection surface, the field does not exude from the total reflection surface in the region where the pressure sensor 30 is arranged, and the damping action of the field by the living body S cannot be obtained, so that the pressure sensor 30 is arranged. The region is no longer the measurement sensitivity region.

Therefore, the pressure sensor 30 can be provided with the function as the region defining portion described in the third embodiment, and the pressure sensor 30 is arranged in a region where the contact region is likely to fluctuate, such as near both ends of the ATR prism 16. Therefore, it is possible to reduce the measurement variation of the absorbance due to the fluctuation of the contact region.

However, if the pressure sensor 30 is arranged in all the regions where total reflection occurs in the ATR prism 16, measurement based on the ATR method cannot be performed. Therefore, the pressure sensor 30 should not be arranged in at least a part of the region where total reflection occurs. Therefore, it is preferable to secure a measurement sensitivity region.

26A and 26B are views for explaining an example of arranging the ATR prism 16 and the pressure sensor 30 on the lips. FIG. 26A shows a state in which a person holds the ATR prism 16 before contacting the lips, and FIG. 26B shows a state in which a person holds the ATR prism 16. ing.

As can be seen from FIG. 26, the size of the ATR prism 16 is smaller than that of the subject's lips as the living body S. Therefore, when the subject holds the ATR prism 16, the lips are in a state where they can come into contact with both the ATR prism 16 and the total reflection support portion 31. Therefore, although FIG. 25 shows an example in which the pressure sensor 30 is arranged so as to straddle both the total reflection surface of the ATR prism 16 and the total reflection support portion 31, the pressure sensor 30 is arranged only on the total reflection support portion 31. May be fixed.

<Functional configuration of processing unit 2d>
Next, the functional configuration of the processing unit 2d provided in the blood glucose level measuring device according to the present embodiment will be described. FIG. 27 is a block diagram illustrating an example of the functional configuration of the processing unit 2d. As shown in FIG. 27, the processing unit 2d includes an absorbance acquisition unit 21d, and the absorbance acquisition unit 21d includes a data acquisition unit 215d, a notification unit 218, and an absorbance output unit 217d. Further, the absorbance output unit 217d includes a pressure correction unit 219.

Of these, the function of the data acquisition unit 215d is realized by the detection I / F519 (see FIG. 5) and the like, and the function of the notification unit 218 is realized by the display 506 and the like. Further, the functions of the absorbance output unit 217d and the pressure correction unit 219 are realized by the CPU 501 executing a predetermined program or the like.

The data acquisition unit 215d samples the detection signals continuously output by the photodetector 17 at a predetermined sampling cycle and outputs the detected value of the light intensity acquired to the data recording unit 216. At the same time, the detection signal continuously output by the pressure sensor 30 is sampled at a predetermined sampling cycle, and the contact pressure data acquired is output to the notification unit 218. However, the data acquisition unit 215d may output the contact pressure data to the notification unit 218 via the data recording unit 216.

The notification unit 218 displays the contact pressure data on the display 506 and notifies the subject so that the subject holding the ATR prism 16 can visually recognize the contact pressure data. The subject holding the ATR prism 16 can adjust the contact pressure between the ATR prism 16 and his / her lips while visually recognizing the contact pressure data displayed on the display 506.

However, the notification of the contact pressure by the notification unit 218 is not limited to this. When the contact pressure data exceeds a predetermined contact pressure threshold value, a beep sound is emitted or a message notifying that the contact pressure exceeds the threshold value is displayed on the display 506 to notify the user. May be good.

The absorbance output unit 217d acquires the absorbance data by executing a predetermined arithmetic process based on the detected value of the probe light intensity read from the data recording unit 216. Further, the pressure correction unit 219 in the absorbance output unit 217d corrects the absorbance data with reference to a table showing the correspondence between the contact pressure and the absorbance acquired in advance. The absorbance output unit 217d outputs the corrected absorbance data to the blood glucose level acquisition unit 22. The absorbance output unit 217d is an example of "an absorbance output unit that outputs the absorbance of the probe light acquired based on the light intensity and pressure of the probe light".

Either one of the notification by the notification unit 218 and the correction of the absorbance data by the pressure correction unit 219 may be executed, or both may be executed in combination.

FIG. 28 is a diagram showing an example of the correspondence between the contact pressure between the ATR prism 16 and the lips and the absorbance. The horizontal axis of FIG. 28 shows the contact pressure, and the vertical axis shows the absorbance. Moreover, this correspondence is the data acquired in advance by the experiment. The pressure sensor used in this experiment is a pressure-sensitive resistance type.

A table corresponding to the data shown in FIG. 28 is stored in a storage device such as HD504 (see FIG. 5), and the pressure correction unit 219 corrects the absorbance data with reference to this table based on the contact pressure data. ..

Further, as shown in FIG. 28, since there is a linear relationship between the two, a linear equation corresponding to this linear relationship is stored in the HD504, and the pressure correction unit 219 uses this linear equation based on the contact pressure data. The absorbance data may be corrected with reference to.

<Example of placement of pressure sensor on total reflection support 31>
As described above, since the ATR prism 16 is small with respect to the lips of the subject, when the subject holds the ATR prism 16, the lips can come into contact with both the ATR prism 16 and the total reflection support portion 31. .. Therefore, the pressure sensor is not arranged so as to straddle both the ATR prism 16 and the total reflection support portion 31, but the pressure sensor 30 is arranged only on the total reflection support portion 31 to apply the contact pressure between the lip and the ATR prism 16. It can also be detected.

FIG. 29 is a diagram illustrating an example in which the pressure sensor 30 is arranged only on the total reflection support portion 31. Each figure of FIGS. 29 (a) to 29 (c) shows three examples in which the arrangement position and the number of pressure sensors 30 are different. 29 (a) shows a case where one pressure sensor 30 is provided, (b) shows a case where the pressure sensor 30 is provided on both ends of the ATR prism 16, and (c) shows a plurality of (here, three) pressure sensors. The case where 30 is provided is shown.

If pressure sensors 30 are provided on both ends of the ATR prism 16 as shown in FIG. 29 (b), it is difficult to apply a relatively holding force, or the size of the mouth varies from person to person. It is possible to detect the contact pressure near both ends of the lips where the pressure is liable to fluctuate. Further, as shown in FIG. 29 (c), if three pressure sensors 30 are provided, the distribution of contact pressure can be detected.

Next, FIG. 30 is a diagram illustrating an example of the positional relationship of the pressure sensor 30, the total reflection support portion 31, and the ATR prism 16 in the thickness direction. FIG. 30 shows a state in which the pressure sensor 30 is placed on the total reflection support portion 31 and one side surface portion of the ATR prism 16 is brought into contact with the total reflection support portion 31 and fixed in the lateral direction (longitudinal direction of the ATR prism 16). The figure seen from (direction along) is shown.

In FIG. 30, t _atr represents the thickness of the ATR prism 16, t _sen represents the thickness of the pressure sensor 30, and t _sup represents the thickness of the total reflection support portion 31.

In this case, it is preferable to determine the thickness of each part so as to satisfy the following equation (1).

この関係を満たすことで、唇とＡＴＲプリズム１６の全反射面との接触を全反射支持部３１が阻害せず、唇とＡＴＲプリズム１６の全反射面を密着させることができる。

By satisfying this relationship, the total reflection support portion 31 does not hinder the contact between the lips and the total reflection surface of the ATR prism 16, and the lips and the total reflection surface of the ATR prism 16 can be brought into close contact with each other.

Further, when the center line 16c of the ATR prism 16 in the thickness direction and the center line 21c of the total reflection support portion 31 in the thickness direction are matched, the thickness of each portion is determined so as to satisfy the following equation (2). Then it is suitable.

この関係を満たすことで、圧力センサ３０のセンサ面をＡＴＲプリズム１６の第１全反射面１６２に対して、厚み方向にわずかに突出させることができ、唇のＡＴＲプリズム１６への接触圧を圧力センサ３０により好適に検出可能になる。

By satisfying this relationship, the sensor surface of the pressure sensor 30 can be slightly projected in the thickness direction with respect to the first total reflection surface 162 of the ATR prism 16, and the contact pressure of the lip with respect to the ATR prism 16 is pressured. The sensor 30 enables suitable detection.

However, if the amount of protrusion is too large, the lips cannot properly contact the ATR prism 16, so it is more preferable to determine the thickness of each part so as to satisfy the following equation (3).

この関係を満たすことで、圧力センサ３０のセンサ面がＡＴＲプリズム１６の第１全反射面１６２に対して厚み方向に突出しすぎることを防ぎ、唇のＡＴＲプリズム１６への接触圧を圧力センサ３０によりさらに好適に検出可能になる。

By satisfying this relationship, the sensor surface of the pressure sensor 30 is prevented from protruding too much in the thickness direction with respect to the first total reflection surface 162 of the ATR prism 16, and the contact pressure of the lip with the ATR prism 16 is applied by the pressure sensor 30. More preferably, it becomes detectable.

FIG. 31 is a diagram illustrating another example of the positional relationship of the pressure sensor 30, the total reflection support portion 31, and the ATR prism 16 in the thickness direction. FIG. 31 shows a state in which the pressure sensor 30 is placed on the total reflection support portion 31 and one side surface portion of the ATR prism 16 is brought into contact with the total reflection support portion 31 and fixed in the same manner as in FIG. The view from the direction along the longitudinal direction of the ATR prism 16) is shown.

FIG. 31 (a) shows a case where the pressure sensor 30 is arranged on the second total reflection surface 163 side, and FIG. 31 (b) shows a case where the pressure sensor 30 is arranged on both sides of the first total reflection surface 162 side and the second total reflection surface 163 side. The case where the pressure sensor 30 is arranged is shown.

Also in the arrangement of FIG. 31, it is preferable to determine the thickness of each part so as to satisfy the equations (1) to (3) in the same manner as described above.

<Action and effect according to the fourth embodiment>
As described above, in the present embodiment, the contact pressure of the living body S with respect to the ATR prism 16 is detected by the pressure sensor 30, and the probe is based on the detection value of the probe light intensity by the photodetector 17 and the contact pressure. Obtain light intensity data.

More specifically, in the present embodiment, the contact pressure data is displayed on the display 506 and notified so that the subject holding the ATR prism 16 can see it. As a result, the subject holding the ATR prism 16 can adjust the contact pressure between the ATR prism 16 and his / her lips while visually recognizing the contact pressure data displayed on the display 506. As a result, it is possible to suppress the fluctuation of the contact pressure for each measurement, reduce the measurement variation of the absorbance due to the contact pressure fluctuation, and reduce the measurement variation of the blood glucose level.

Further, in the present embodiment, the absorbance data is corrected with reference to the data showing the correspondence between the contact pressure and the absorbance acquired in advance, and the corrected absorbance data is output to the blood glucose level acquisition unit 22. Thereby, it is possible to suppress the fluctuation of the contact pressure for each measurement, reduce the measurement variation of the absorbance due to the fluctuation, and reduce the measurement variation of the blood glucose level.

Furthermore, by both notifying the contact pressure and correcting the absorbance data based on the contact pressure data, it is possible to reduce the measurement variation of the absorbance due to the fluctuation of the contact pressure for each measurement, and to reduce the measurement variation of the blood glucose level. Can be reduced. By performing both, it is possible to secure the correction accuracy by reducing the amount to be corrected while shortening the adjustment time of the contact pressure by the subject.

The pressure sensor 30 may be provided on at least one of the ATR prism 16 and the total reflection support portion 31.

[Fifth Embodiment]
Next, the blood glucose level measuring device according to the fifth embodiment will be described.

In the present embodiment, by acquiring blood glucose level data based on the light intensity of the probe light and the temperature of at least one of the living body S and the ATR prism 16, the influence of the heat of the ATR prism 16 on the living body S and the living body The effect of the heat of S on the ATR prism 16 is suppressed, and the blood glucose level is accurately measured.

<Functional configuration of processing unit 2e>
The functional configuration of the processing unit 2e provided in the blood glucose level measuring device according to the present embodiment will be described with reference to FIG. 32. FIG. 32 is a block diagram illustrating an example of the functional configuration of the processing unit 2e. As shown in FIG. 32, the processing unit 2e includes an absorbance acquisition unit 21e and a blood glucose level acquisition unit 22e. The absorbance acquisition unit 21e includes a data acquisition unit 215e, and the blood glucose level acquisition unit 22e includes a biological information output unit 221e. Further, the biological information output unit 221e includes a temperature correction unit 222.

Of these, the functions of the data acquisition unit 215e are realized by the detection I / F519 (see FIG. 5) and the like, and the functions of the biological information output unit 221e and the temperature correction unit 222 are such that the CPU 501 executes a predetermined program. Is realized by.

The data acquisition unit 215e samples the detection signals continuously output by the photodetector 17 at a predetermined sampling cycle and outputs the detected value of the light intensity acquired to the data recording unit 216. At the same time, the temperature data obtained by sampling the detection signals continuously output by the temperature sensor 50 at a predetermined sampling cycle is output to the data recording unit 216. Here, the temperature sensor 50 is arranged under the tongue of the subject corresponding to the living body S, and can output the detection signal of the sublingual body temperature to the data acquisition unit 215e. The temperature sensor 50 is an example of a temperature detection unit.

The biological information output unit 221e executes a predetermined arithmetic process based on the absorbance data input from the absorbance output unit 217 to acquire blood glucose level data. Further, the temperature correction unit 222 corrects the blood glucose level data based on the correspondence between the temperature and the blood glucose level acquired in advance. The biological information output unit 221e is an example of "a biological information output unit that outputs biological information acquired based on the light intensity of the probe light and the temperature of at least one of the object to be measured or the total reflection member".

<Temperature-based correction action>
Here, the action of correcting the blood glucose level data based on the temperature will be described. First, the correlation between the temperature detected by the temperature sensor 50 (here, the sublingual body temperature) and the blood glucose level will be described.

In order to investigate this correlation, an experiment was conducted to detect the sublingual body temperature by measuring the absorbance of the subject from about 1 hour before the meal to about 5 hours after the meal of the subject. It was.

A normalized MLR (Multiple Linear Regression) model that normalizes with a certain wave number was used as a model for acquiring (calculating) the blood glucose level based on the measurement result of the absorbance. Moreover, 1000 cm-1 was used as the normalized wavenumber in the normalized MLR model. The calculation formula of the normalized MLR model is shown in the following formula (4).

（４）式において、ｙは、温度補正部２２２による補正を行っていない血糖値データ（補正前の血糖値データ）を表し、ｘ（ｋ）は波数ｋで測定された正規化前の吸光度データを表している。血糖値データは、吸光度データに基づいて上記の（４）式を用いて取得できる。

In the equation (4), y represents the blood glucose level data (blood glucose level data before correction) that has not been corrected by the temperature correction unit 222, and x (k) is the absorbance data before normalization measured with the wave number k. Represents. The blood glucose level data can be obtained by using the above equation (4) based on the absorbance data.

FIG. 33 is a diagram illustrating an example of a temperature detection result and an acquisition result of blood glucose level data. The horizontal axis of FIG. 33 indicates time, the first axis (left axis) of the vertical axis indicates the blood glucose level, and the second axis (right axis) of the vertical axis indicates the temperature detected by the temperature sensor 50. ing. The time on the horizontal axis represents the time when the subject ate a meal, the negative side representing the time before the meal, and the positive side representing the time after the meal.

Further, the “◯” mark in FIG. 33 indicates the acquired blood glucose level, and the small “•” mark indicates the detected sublingual body temperature. The “◯” mark in FIG. 33 is the blood glucose level data before correction.

The blood glucose level is generally considered to be low on an empty stomach before a meal and high after a meal, but in FIG. 33, the blood glucose level is relatively high before a meal. On the other hand, the sublingual body temperature before meals is low. Therefore, FIG. 33 suggests that there is a correlation between sublingual body temperature and blood glucose level.

FIG. 34 shows the results of investigating the correlation between sublingual body temperature and blood glucose level using the data of FIG. 33. The horizontal axis of FIG. 34 shows the sublingual body temperature, and the vertical axis shows the blood glucose level. Blood glucose and sublingual body temperature should be irrelevant, but it can be seen that there is a negative correlation as shown in FIG. The slope of the regression line in this negative correlation is -21 (mg / dl / deg). Therefore, by correcting the blood glucose level data acquired based on the absorbance data by using the slope of this regression line, more accurate blood glucose level data can be acquired. The correction formula for the blood glucose level data using the slope of the regression line is as follows (5).

（５）式におけるｙ_ｃは補正後の血糖値データ、ｙは補正前の血糖値データ、Ｔは検出された舌下体温を表している。なお、切片の「−７６５」は、補正後の血糖値データが温度によらずほぼ同じ値になるように調整されている。

In equation (5), y_c represents the corrected blood glucose level data, y represents the uncorrected blood glucose level data, and T represents the detected sublingual body temperature. The section "-765" is adjusted so that the corrected blood glucose level data has substantially the same value regardless of the temperature.

FIG. 35 is a diagram illustrating an example of a temperature detection result and an acquisition result of the blood glucose level data when the blood glucose level data is corrected using the equation (5). Since the view of FIG. 35 is the same as that of FIG. 33, a duplicate description will be omitted here.

In FIG. 35, the blood glucose level data at the time before the meal is smaller than that in FIG. 33 before the correction, and the blood glucose level data is smaller even after a long time has passed after the meal. Therefore, it can be seen that the blood glucose level data is corrected so as to follow the tendency that the blood glucose level becomes low on an empty stomach before a meal or on an empty stomach after a long time after a meal.

In this embodiment, a correction example based on the correlation between the sublingual body temperature of the living body S and the blood glucose level data is shown, but the temperature of the ATR prism 16 is detected instead of the body temperature of the living body S, and the ATR prism 16 is used. A similar effect was obtained by making corrections based on the correlation between temperature and blood glucose level data.

<Action and effect according to the fifth embodiment>
When the ATR prism 16 is brought into contact with the living body S to measure the blood glucose level, the acquired blood glucose level data may change depending on the temperature of the portion of the living body S in contact with the ATR prism 16 or the temperature of the ATR prism 16.

As a factor for this, it is considered that the ATR prism 16 itself is warmed by the temperature of the part of the living body S in contact with the living body S, and the amount of mid-infrared light emitted by the ATR prism 16 itself changes, which affects the measurement. It is also conceivable that the contact of the ATR prism 16 changes the temperature of the part of the living body S, and the metabolism in the body and the radiation of mid-infrared light from the part of the living body S change.

In the prior art, since the optical measuring unit such as the ATR prism 16 is configured to measure without contacting the object to be measured, it is caused by the influence of the temperature of the part of the living body S in which the ATR prism 16 is in contact and the temperature of the ATR prism 16. As a result, it may not be possible to measure the blood glucose level accurately.

In this embodiment, blood glucose level data is acquired based on the light intensity of the probe light and the temperature of at least one of the living body S and the ATR prism 16. More specifically, the blood glucose level data is acquired based on the absorbance data acquired based on the light intensity of the probe light, and the blood glucose level data is corrected based on the temperature of the living body S detected by the temperature sensor 50.

For the correction of the blood glucose level data, a correction formula based on the correspondence between the temperature and the blood glucose level acquired in advance is used. Thereby, the influence of the heat of the ATR prism 16 on the living body S and the influence of the heat of the living body S on the ATR prism 16 can be suppressed, and the blood glucose level can be accurately measured.

In the present embodiment, an example in which the temperature sensor 50 detects the sublingual body temperature of the subject corresponding to the living body S is shown, but the present invention is not limited to this. The temperature sensor 50 may be placed at any part of the subject's body to detect the temperature of that part, or the temperature sensor 50 may be placed on the ATR prism 16 and the temperature of the ATR prism 16 or the ATR prism 16 The temperature of the part of the subject in contact with the subject may be detected. However, it is preferable to acquire a correction formula based on the correspondence between the temperature and the blood glucose level in advance for each arrangement position of the temperature sensor 50, and use the correction formula corresponding to the arrangement position of the temperature sensor 50 at the time of measurement.

When the temperature sensor 50 is arranged on the ATR prism 16, if it is arranged at the end of the total reflection surface where the living body S and the ATR prism 16 are in contact with each other, the temperature sensor 50 prevents the probe light from blocking the absorbance measurement. It is suitable because it can be used.

Further, when the body temperature data of the living body S is used, it is preferable to detect the temperature of the part of the living body S in contact with the ATR prism 16 because the blood glucose level data can be corrected more accurately. For example, when the ATR prism 16 is brought into contact with the lips for measurement, it is preferable to arrange the temperature sensor 50 so as to detect the temperature of the lips. However, the blood glucose level can be measured by bringing the ATR prism 16 into contact with various parts such as ear lobes and fingers in addition to the lips.

Further, in the present embodiment, an example of correction using a correction formula based on the correspondence between the temperature and the blood glucose level is shown, but the correction is not limited to this. A table showing the correspondence between the temperature and the blood glucose level is created in advance and stored in a storage device such as HD504, and the corrected blood glucose level data is acquired by referring to this table based on the temperature detected at the time of measurement. It may be.

Further, although the example in which the linear correction formula is used is shown in the present embodiment, the correction may be performed by using a non-linear polynomial as the correction formula. By using a non-linear polynomial, more detailed correction is possible.

[Sixth Embodiment]
Next, the blood glucose level measuring device according to the sixth embodiment will be described.

In the present embodiment, among a plurality of probe lights including the first probe light and the second probe light having a wavelength different from that of the first probe light, the first absorbance of the first probe light and the second probe light of the second probe light. The second absorbance is converted to the converted absorbance based on the relationship with the second absorbance. Then, blood glucose level data is acquired based on the absorbance of a plurality of probe lights including this converted absorbance. As a result, the blood glucose level can be accurately measured by suppressing the influence of the environment around the device and the temperature change of the living body without acquiring the data for conversion (correction) in advance.

<Functional configuration of processing unit 2f>
First, the functional configuration of the processing unit 2f included in the blood glucose level measuring device according to the present embodiment will be described with reference to FIG. 36. FIG. 36 is a block diagram illustrating an example of the functional configuration of the processing unit 2f. As shown in FIG. 36, the processing unit 2f includes a blood glucose level acquisition unit 22f. Further, the blood glucose level acquisition unit 22f includes a data holding unit 223 and an absorbance conversion unit 224.

Of these, the function of the data holding unit 223 is realized by HD504 (see FIG. 5) or the like, and the function of the absorbance conversion unit 224 is realized by the CPU 501 executing a predetermined program or the like.

The data holding unit 223 temporarily holds each of the first absorbance data of the first probe light, the second absorbance data of the second probe light, and the third absorbance data of the third probe light input from the absorbance output unit 217. When the predetermined period elapses, the data holding unit 223 can overwrite and hold the newly input first to third absorbance data.

The absorbance conversion unit 224 reads out the first to third absorbance data temporarily held by the data holding unit 223, uses the first absorbance data as the reference absorbance data, and uses the second absorbance data as the reference absorbance data based on the relationship between the reference absorbance data and the second absorbance data. The absorbance data is converted into the second conversion absorbance data. Further, the third absorbance data is converted into the third converted absorbance data based on the relationship between the reference absorbance data and the third absorbance data. Here, the second conversion absorbance data and the third conversion absorbance data are examples of the conversion absorbance, respectively.

Further, in the present embodiment, as an example, the probe light having a wave number of 1100 cm-1 is used as the first probe light, the probe light having a wave number of 1050 cm-1 is used as the second probe light, and the probe light having a wave number of 1070 cm-1 is used as the first probe light. 3 Use probe light.

After that, the absorbance conversion unit 224 outputs each of the first absorbance data, the second conversion absorbance data, and the third conversion absorbance data to the biological information output unit 221. The biological information output unit 221 acquires blood glucose level data based on the normalized MLR model of the above-mentioned equation (4) using these as input data. The normalized MLR model of Eq. (4) is an example of a linear model.

<Action of absorbance converter 224>
Next, the operation of the absorbance conversion unit 224 will be described. First, the correlation between the second absorbance and the third absorbance with respect to the reference absorbance will be described.

In order to investigate this correlation, the first to third absorbances were measured several tens of times from before the meal to 3 hours after the meal, using the lips of the subject corresponding to the living body S as the object to be measured. did. FIG. 37 is a diagram showing the correlation between the second absorbance and the third absorbance with respect to the reference absorbance. The horizontal axis of FIG. 37 shows the reference absorbance. The black dot plot shows the second absorbance, and the white dot plot shows the third absorbance.

The measured absorbance fluctuates depending on the contact state between the living body S and the ATR prism 16 and the fluctuation of the detection sensitivity of the photodetector 17, but on average, the second absorbance and the third absorbance are proportional to the reference absorbance, respectively. It is thought that. However, as shown in FIG. 37, the regression line 371 of the second absorbance with respect to the reference absorbance (regression line of the solid line) and the regression line 372 of the third absorbance with respect to the reference absorbance (regression line of the broken line) have different section values. There is. Specifically, the intercept of the regression line of the second absorbance is 0.187, and the intercept of the regression line of the third absorbance is 0.217.

It is considered that such a deviation of the intercept is caused by the temperature of the environment around the device, the sensitivity difference of the photodetector 17 due to the difference in wavelength, the drift of 0 point, and the like. Therefore, in the present embodiment, the second and third absorbance data are converted so as to correct the deviation of the intercept.

Further, in the normalized MLR model, if the measurement sensitivity is different for each wavelength of the probe light, the blood glucose level data acquired based on the absorbance changes. This measurement sensitivity corresponds to the slope of the regression line. In the example of FIG. 37, the slope of the regression line 371 is 0.883 and the slope of the regression line 372 is 0.872, and the measurement sensitivities are different. .. Therefore, in the present embodiment, the second and third absorbance data are converted so as to correct the deviation of the inclination.

The conversion formulas for performing the conversion processing for correcting the deviation between the intercept and the inclination are shown in the following equations (6) and (7).

但し、（６）式におけるａ１０５０_ｃは変換後の第２吸光度データ（第２変換吸光度データ）、ａ_１０５０は変換前の第２吸光度データ、ｃ１０５０は回帰直線３７１の切片、ｋ１０５０は回帰直線３７１の傾きをそれぞれ表している。また、（７）式におけるａ１０７０_ｃは変換後の第３吸光度データ（第３変換吸光度データ）、ａ_１０７０は変換前の第３吸光度データ、ｃ１０７０は回帰直線３７２の切片、ｋ１０７０は回帰直線３７２の傾きをそれぞれ表している。

However, in equation (6), a1050_c is the second absorbance data after conversion (second conversion absorbance data), a_1050 is the second absorbance data before conversion, c1050 is the intercept of the regression line 371, and k1050 is the slope of the regression line 371. Each is represented. Further, in equation (7), a1070_c is the third absorbance data after conversion (third conversion absorbance data), a_1070 is the third absorbance data before conversion, c1070 is the intercept of the regression line 372, and k1070 is the slope of the regression line 372. Each is represented.

The second conversion absorbance data and the third conversion absorbance data are input to the normalized MLR model. The coefficients of each term in the normalized MLR model of Eq. (4) are predetermined so as to correspond to the absorbance data after conversion.

Here, in FIG. 37, in order to obtain the correlation data of the second absorbance and the third absorbance with respect to the reference absorbance, the absorbance was measured several tens of times from before the meal until 3 hours after the meal. Indicated. However, even if the absorbance is measured a smaller number of times, it is possible to obtain the correlation data of the second absorbance and the third absorbance with respect to the reference absorbance.

FIG. 38 is a diagram showing a reference absorbance, a second absorbance, and a third absorbance in one absorbance measurement. The absorbance data is sampled a plurality of times in one absorbance measurement. The horizontal axis of FIG. 38 indicates the number of samplings, and the vertical axis indicates the absorbance. In the example shown in FIG. 38, the number of samplings in one absorbance measurement is about 120 times. In addition, the graph of FIG. 38 shows the measurement results of the reference absorbance, the second absorbance, and the third absorbance in a mixed manner.

When the number of samplings is about 15, the ATR prism 16 comes into contact with the lips, and then the absorbance increases. However, the absorbance does not become constant after contact, but gradually increases. This is due to a change in the contact state between the ATR prism 16 and the lips, and a change in the temperature of the ATR prism 16 or the lips due to the contact of the ATR prism 16 with the lips. The time required for this one measurement is about 1 minute.

The correlation between the second absorbance and the third absorbance with respect to the reference absorbance obtained by using the measurement result of FIG. 38 is shown in FIG. 39. Since the view of FIG. 39 is the same as that of FIG. 37, a duplicate description will be omitted here.

As shown in FIG. 39, the regression line 371 of the second absorbance and the regression line 372 of the third absorbance can be obtained by one absorbance measurement. Then, the second conversion absorbance data can be obtained by using the slope and intercept of the regression line 371, and the third conversion absorbance data can be obtained by using the slope and intercept of the regression line 372.

In the blood glucose level measurement in the present embodiment, the absorbance conversion unit 224 reads out a plurality of first to third absorbance data temporarily held by the data holding unit 223. Then, the second converted absorbance data is acquired by using the slope and intercept of the regression line 371 of the second absorbance data obtained by using the first absorbance data as the reference absorbance data. Further, the third converted absorbance data is acquired by using the slope and intercept of the regression line 372 of the third absorbance data obtained by using the first absorbance data as the reference absorbance data.

In this way, without acquiring data for conversion (correction) in advance, the influence of the temperature of the ambient environment of the device, the sensitivity difference of the photodetector 17 due to the difference in wavelength, the drift of 0 points, etc. Absorbance data can be converted to correct.

<Action and effect according to the sixth embodiment>
As described above, in the present embodiment, among the plurality of probe lights including the first probe light and the second probe light having a wavelength different from that of the first probe light, the first probe light is the first. Using the absorbance data and the second absorbance data of the second probe light, a regression line 371 as an example of the first absorbance and the second absorbance is obtained. Then, the second absorbance data is converted into the second converted absorbance data using the slope and intercept of the regression line 371, and the blood glucose level is measured based on the absorbance data of a plurality of probe lights including the second converted absorbance data.

Since the data for conversion (correction) acquired in advance is not used, even if the measurement conditions change momentarily due to changes in the environment around the device or the temperature of the living body, the temperature of the environment around the device or the temperature of the living body changes. The second absorbance data can be converted into the second conversion absorbance data so as to correct changes and the like. As a result, the influence of the environment around the device and the temperature change of the living body can be suppressed, and the blood glucose level can be measured accurately.

Here, in the present embodiment, an example of the conversion process using the slope of the regression line and the intercept is shown, but the present invention is not limited to this. Since some photodetectors 17 have non-linear sensitivity characteristics, in such a case, conversion is performed using at least one of the coefficients of each term in a regression polynomial such as a quadratic equation or a cubic equation. Processing can also be performed. As a result, even when the photodetector 17 has a non-linear sensitivity characteristic, the influence of the environment around the device, the temperature change of the living body, and the like can be suppressed in more detail, and the blood glucose level can be accurately measured.

Further, in the present embodiment, an example in which the blood glucose level acquisition unit 22f includes the data holding unit 223 is shown, but the present invention is not limited to this, and the functions of the data holding unit 223 can be added to the data recording unit 216 or an external storage device. Etc. may be prepared.

Further, in the present embodiment, an example in which the conversion process is performed using both the slope and the intercept is shown, but the conversion process may be performed using at least one of the slope and the intercept.

Although the embodiments have been described above, the present invention is not limited to the above-described embodiments specifically disclosed, and various modifications and changes can be made without departing from the scope of claims. is there.

In the embodiment, an example is shown in which one processing unit 2 realizes the functions of the absorbance acquisition unit 21, the blood glucose level acquisition unit 22, the drive control unit 23, and the like, but the present invention is not limited thereto. These functions may be realized by separate processing units, or the functions of the absorbance acquisition unit 21 and the blood glucose level acquisition unit 22 may be dispersed and realized in a plurality of processing units. Further, it is also possible to configure the function of the processing unit and the function of the storage device such as the data recording unit 216 to be realized by an external device such as a cloud server.

Further, in the embodiment, an example is shown in which the first light source 111, the second light source 112, and the third light source 113 are provided as a plurality of light sources, and each emits light having a different wavelength in the mid-infrared region. It is not limited. One light source may emit light of a plurality of wavelengths.

Further, although an example of a quantum cascade laser is shown as a light source, the light source is not limited to this, and a light source other than a laser such as an infrared lamp, an LED (Light Emitting Diode), and an SLD (Super Luminescent Ddiode) can be used. it can. In this case, it is preferable that the probe light is incident on the total reflection member such as the ATR prism 16 through a wavelength filter that extracts only the desired wavelength as appropriate. Alternatively, it is preferable that the photodetector 17 receives the probe light through the wavelength filter.

Further, in the embodiment, an example of measuring the blood glucose level as biological information is shown, but the present invention is not limited to this, and the embodiment can be applied to the measurement of other biological information if the measurement can be performed based on the absorbance. it can.

Further, an optical element such as a beam splitter that branches a part of the probe light after being emitted by a light source or after being emitted from a hollow optical fiber, and a detection element that detects a part of the branched probe light intensity. The drive voltage or drive current of the light source may be feedback-controlled so as to suppress fluctuations in the probe light intensity. This suppresses output fluctuations of the light source and enables more accurate measurement of biological information.

Further, although an example in which the total reflection member is composed of the ATR prism 16 is shown, the present invention is not limited to this. A parallel flat plate, an optical fiber, or the like may be used to form the total reflection member as long as it can be totally reflected and the field can be exuded at the time of total reflection.

Further, although examples of applying the second to sixth embodiments to the configuration of the blood glucose level measuring device 100 according to the first embodiment have been described, the present invention is not limited thereto. Each of the second to fourth embodiments can be applied even when the blood glucose level measuring device includes one light source and emits the first to third probe lights having different wavelengths from the one light source for measurement. In that case, since it is not necessary to switch the incident of the first to third probe lights on the ATR prism 16, the blood glucose level measuring device has the first shutter 121, the second shutter 122, the third shutter 123, and the first half mirror 131. And the second half mirror 132 may not be provided.

Further, each of the second to fifth embodiments can be applied when the blood glucose level measuring device includes one light source and emits probe light having one wavelength from one light source for measurement.

The second to sixth embodiments are also applied to the absorbance measurement and the biological information measurement when the light intensity of the first to third probe lights is not corrected by using the value detected by the photodetector 17 in the non-incident period. be able to.

Further, the blood glucose level measuring device may be configured by combining a plurality of the first to sixth embodiments.

The embodiment also includes a method for measuring absorbance. For example, the absorbance measuring method includes a step of emitting a plurality of probe lights having different wavelengths in a specific wavelength region, a step of totally reflecting the incident probe light in a state of being in contact with an object to be measured by a total reflection member, and the above-mentioned. A step of controlling the incident of the probe light on the total reflection member and the probe light emitted from the total reflection member so that at least a period during which all of the plurality of probe lights are not incident on the total reflection member is provided. The process by the light intensity detection unit provided so as to be able to detect the light intensity of the above, the value detected by the light intensity detection unit in a state where the probe light is incident on the total reflection member, and all of the plurality of probe lights. A step of outputting the absorptivity obtained based on the detected value in a state where the light is not incident on the total internal reflection member is performed. By such an absorbance measuring method, the same effect as that of the absorbance device according to the first embodiment can be obtained.

Further, the absorbance measuring method includes a step of emitting probe light in a specific wavelength region, a step of totally reflecting the incident probe light in a state of being in contact with an object to be measured by a total reflecting member, and a light guide unit. A step of guiding each probe light to the all-reflection member, a step of driving the light guide portion, a step of controlling the drive of the light guide portion, and light of the probe light emitted from the all-reflection member. A detection step of detecting the intensity and a step of outputting the absorbance of the probe light acquired based on the light intensity are performed. By such an absorbance measuring method, the same effect as that of the absorbance device according to the second embodiment can be obtained.

Further, the biological information measurement method includes a step of emitting probe light in a specific wavelength region, a step of totally reflecting the incident probe light in contact with an object to be measured by a total reflection member, and a total reflection member. A step of detecting the light intensity of the emitted probe light and a step of outputting biological information acquired based on the light intensity and the temperature of at least one of the object to be measured or the total internal reflection member. Do. By such a biometric information measuring method, the same effect as that of the biometric information measuring apparatus according to the fifth embodiment can be obtained.

Further, the biological information measuring method includes a step of emitting a plurality of probe lights including a first probe light and a second probe light having a wavelength different from that of the first probe light, and the light is absorbed by the object to be measured. A step of detecting the light intensity of the probe light, a step of acquiring the absorbance of the probe light based on the light intensity, a first absorbance of the first probe light, and a second absorbance of the second probe light. Based on the above relationship, the step of converting the second absorbance into the converted absorbance and the step of outputting the biological information acquired based on the absorbance of the plurality of probe lights including the converted absorbance are performed. By such a biological information measuring method, the same effect as that of the biological information measuring device according to the sixth embodiment can be obtained.

Further, each function of the embodiment described above can be realized by one or a plurality of processing circuits. Here, the "processing circuit" in the present specification is a processor programmed to execute each function by software such as a processor implemented by an electronic circuit, or a processor designed to execute each function described above. It shall include devices such as ASIC (Application Specific Integrated Circuit), DSP (digital signal processor), FPGA (field programmable gate array) and conventional circuit modules.

1 Measuring unit 100 Blood glucose level measuring device (an example of biological information measuring device)
101 Absorbance measuring device 111 First light source (example of light source)
112 Second light source (an example of a light source)
113 Third light source (an example of a light source)
121 1st shutter 122 2nd shutter 123 3rd shutter 131 1st half mirror 132 2nd half mirror 14 Coupling lens 151 1st hollow optical fiber (example of light guide unit)
152 Second hollow optical fiber 153 Light guide support member 154 Emission support member 16 ATR prism (example of total reflection member)
161 Incident surface 162 First total internal reflection surface 162m, 163m Reflective film (example of region defining part)
162k, 163k field 163 2nd total reflection surface 164 Exit surface 17 Photodetector (example of light intensity detector)
181 Piezoelectric drive unit (an example of drive unit)
1820 Piezoelectric drive unit (an example of drive unit)
1821 motor (an example of drive unit)
1822 MEMS mirror (an example of drive unit)
191 Deflection mirror (example of deflection part)
192 1st condensing lens 193 2nd condensing lens (example of condensing unit)
2 Processing unit 21 Absorbance acquisition unit 211 Light source drive unit 212 Light source control unit 213 Shutter drive unit 214 Shutter control unit (an example of incident control unit)
215 Data acquisition unit 216 Data recording unit 217 Absorption output unit 218 Notification unit 219 Pressure correction unit 22 Blood glucose level acquisition unit 221 Biometric information output unit 222 Temperature correction unit 223 Data retention unit 224 Absorption conversion unit 23 Drive control unit 30 Pressure sensor (pressure) Example of detection unit)
31 Total internal reflection support 50 Temperature sensor (an example of temperature detection unit)
501 CPU
506 Display 519 Detection I / F
85 cycles (an example of 1 cycle)
86 period (an example of the first incident period)
87 period (an example of the second incident period)
84, 88 Non-incident period S Living body (example of the object to be measured)
P probe light Pr contact pressure (example of pressure)
y Blood glucose level data before correction y_c Blood glucose level data after correction T Sublingual body temperature

Japanese Patent No. 3649291

Claims (17)

A light source that emits multiple probe lights with different wavelengths in a specific wavelength region,
A total reflection member that totally reflects the incident probe light in contact with the object to be measured, and
An incident control unit that controls the incident of the probe light on the total internal reflection member so that at least a period during which all of the plurality of probe lights are not incident on the total internal reflection member is provided.
A light intensity detecting unit provided so as to be able to detect the light intensity of the probe light emitted from the total reflection member, and
Obtained based on the detection value by the light intensity detection unit when the probe light is incident on the total reflection member and the detection value when all of the plurality of probe lights are not incident on the total reflection member. An absorbance measuring device including an absorbance output unit that outputs the absorbance to be generated. The incident control unit has one cycle of a period in which the plurality of probe lights are sequentially incident on the total reflection member one by one and a non-incident period in which all of the plurality of probe lights are not incident on the total reflection member. The absorbance measuring device according to claim 1, wherein the absorbance measuring device is periodically controlled so as to include the inside. The incident control unit has a wavelength different from that of the first incident period in which the first probe light of the plurality of probe lights is incident on the total reflection member and the first probe light of the plurality of probe lights. Periodically controlled so that the second incident period in which the second probe light is incident on the total reflection member and the non-incident period in which all of the plurality of probe lights are not incident on the total reflection member are included in one cycle. And
The absorbance output unit is
The first absorbance obtained based on the detected value in the first incident period and the detected value in the non-incident period closest to the first incident period.
The first or second claim which outputs the detected value in the second incident period, the detected value in the non-incident period closest to the second incident period, and the second absorbance obtained based on the second incident period. Absorbance measuring device. The absorbance output unit is
The first absorbance obtained by subtracting the detected value in the non-incident period from the detected value in the first incident period.
The absorbance measuring apparatus according to claim 3, wherein the second absorbance obtained by subtracting the detected value in the non-incident period from the detected value in the second incident period is output. The absorbance measuring device according to any one of claims 1 to 4, wherein at least one of the plurality of probe lights has a light intensity that changes in a cycle shorter than the control cycle by the incident control unit. The absorbance measuring device according to claim 5, wherein at least one of the plurality of probe lights has the light intensity changed in three or more steps. The total reflection member includes an incident surface on which the probe light is incident.
The absorbance measuring device according to any one of claims 1 to 6, wherein the incident surface is a diffusion surface. The total reflection member includes an incident surface on which the probe light is incident.
The absorbance measuring device according to any one of claims 1 to 7, wherein the incident surface has a curvature. A light guide unit that guides the probe light to the total reflection member,
A drive unit that drives the light guide unit and
The absorbance measuring device according to any one of claims 1 to 8, further comprising a drive control unit that controls the drive unit. The absorbance measuring device according to claim 9, wherein the driving unit changes at least one of the positions or angles of the light guide unit. The absorbance measuring device according to claim 9 or 10, further comprising a light guide support portion that supports the total reflection member and the light guide portion. A pressure detecting unit for detecting the pressure of the object to be measured with respect to the total reflection member is provided.
The absorbance output unit includes the detection value in a state where the probe light is incident on the total reflection member, the detection value in a state where all of the plurality of probe lights are not incident on the total reflection member, and the pressure. The absorbance measuring device according to any one of claims 1 to 11, which outputs the absorbance obtained based on the above. The absorbance measuring device according to any one of claims 1 to 12, wherein the total reflection member includes a region defining portion that defines a measurement sensitivity region of the absorbance on the total reflecting surface. The absorbance measuring device according to any one of claims 1 to 13.
A biological information measuring device including a biological information output unit that outputs biological information acquired based on the absorbance. The biological information measuring device according to claim 14, wherein the biological information is blood glucose level information. The biometric information measuring device according to claim 15, wherein the wave number includes at least one of 1050 cm-1, 1070 cm-1, or 1100 cm-1. The process of emitting multiple probe lights with different wavelengths in a specific wavelength region,
The step of totally reflecting the incident probe light in contact with the object to be measured by the total reflection member, and
A step of controlling the incident of the probe light on the total internal reflection member and a step of controlling the incident of the probe light on the total internal reflection member so that at least a period during which all of the plurality of probe lights are not incident on the total reflection member is provided.
A process by a light intensity detecting unit provided so as to be able to detect the light intensity of the probe light emitted from the total reflection member, and
Obtained based on the detection value by the light intensity detection unit when the probe light is incident on the total reflection member and the detection value when all of the plurality of probe lights are not incident on the total reflection member. A step of outputting the absorbance to be obtained, and a method of measuring the absorbance.

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