EP2967374A1

EP2967374A1 - Method and device for monitoring vital functions

Info

Publication number: EP2967374A1
Application number: EP14707772.1A
Authority: EP
Inventors: Axel Kulcke
Original assignee: Senspec GmbH
Current assignee: Sentec GmbH
Priority date: 2013-03-11
Filing date: 2014-03-04
Publication date: 2016-01-20
Also published as: US20160022147A1; WO2014139830A1; EP2777491A1

Abstract

Disclosed is a method for monitoring vital parameters of a living being, wherein broad-band light is beamed into the tissue of a living being, a spectrum of the beamed-in light is recorded, and absorption is evaluated, wherein at least one first parameter is determined on the basis of the absorption values of a first spectral range, and at least one second parameter is determined on the basis of the absorption values of a second spectral range (13), the first parameter is compared to the second parameter, and at least one vital parameter is determined with the aid of the comparison.

Description

Method and device for monitoring vital signs

The present invention relates to a method and a

Device for monitoring vital functions of patients.

From the prior art are various methods and

Devices are known to record and / or monitor the vital signs of patients. Especially in emergencies, during first aid, in surgery or for a

Long-term monitoring or sleep monitoring are preferably used non-invasive devices and methods. Such devices and methods should provide fast and accurate results in order to be informed as quickly as possible about the health status of a patient or to make decisions about further measures.

From the prior art, for example, pulse oximeters are known which measure the oxygen saturation of blood.

Typically, light is emitted into a tissue and the

Absorbtion measured. For example, an earlobe or a finger is received in a holder of such a device. The measurements will be in both the red and the near

infrared region of the light is performed, typically one measurement is carried out at a wavelength of 660nm and 940nm.

In addition, pulse spectrometers are known which are suitable for carrying out an amplitude-based evaluation of the pulse by means of spectroscopy, such as e.g. disclosed in WO 2011/161102 Al.

A common problem of such methods and devices is that measurements are inaccurate or that the measurements or results are corrupted. Since the measurements at individual Wavelengths are carried out, they are extremely sensitive to changes, for example

Ambient conditions of the DUT. There is also one

such amplitude-based evaluation prone to

Motion artifacts. If a patient moves, for example, the blood can be accelerated or decelerated, or a sensor attached to the body can slip. There is also the risk of external influences, especially of electrical

Devices, magnetic or electric fields or

Voltage fluctuations within the devices. The worse the vital functions of a patient are, the more difficult it is to obtain accurate results, because the background noise, so-called artifacts, becomes relatively large in proportion.

There are different approaches, such

Exclude motion artifacts from the measurement signal. The

US 2011/0245654, for example, discloses a method which uses an adaptive filter to determine the motion artifacts

tried to filter out. Near infrared light (NIR) as well

Red light is applied and the optical density is measured. In a numerical method, measured values are included

Comparison values are compared and the oxygen saturation of the blood determined by the maximum rashes. This

Procedure is complicated and complicated and requires a high computing power.

It is therefore an object of the invention to overcome the disadvantages of the prior art. In particular, a should

Method and apparatus are provided, which reduces complicated computing operations, is less prone to motion artifacts and thus avoids false alarms. This task is carried out by the independent

Claims defined defined methods and devices. Other embodiments will be apparent from the dependent

Claims.

The inventive method is for monitoring of

Vital parameters of a living being provided. A vital parameter is in particular the pulse rate or the oxygen saturation of the blood. But it is also conceivable, the process for

Monitoring other parameters such as blood sugar or other chemical constituents of the blood or other liquids. The method comprises the following steps.

Broadband light, preferably pulsed light, is irradiated into tissue of a living being. The light preferably comprises wavelengths in a spectral range from 400 nm to 850 nm. A spectrum of the light returned from the tissue becomes

added. The light in the tissue may either have been reflected or transmitted. Finally, a

Evaluation of the recorded spectrum performed. to

Evaluation of the absorption will be at least a first parameter on the basis of a first spectral range within the

Spectrum determined. In addition, at least a second

Parameter based on at least one second

Spectral range determined. The second spectral range is greater than the first spectral range and contains the first spectral range at least partially. The first parameter is compared with the second parameter and at least one

Vital parameters determined by comparison.

Both oxygenated hemoglobin (Hb02) and reduced

Hemoglobin (HHb) has several in this waveband

isosbestic points on. Especially in the wave range of 500nm to 600nm are such points. In this Range, the absorption coefficients of hemoglobin are higher and the relative proportion between absorption of hemoglobin and scattering of light in the tissue is increased. The pulse increases and / or continuously alters the proportion of arterial blood in the tissue as well as the oxygen saturation in the tissue. However, a basic absorption by the non-or only slowly variable components of the tissue, such as skin and bone, remains.

The spectra typically show the absorption of the

radiated light in the blood and tissues. The parameter, which is determined from the first, smaller spectral range, experiences significant fluctuations as a function of the pulse, or the oxygen saturation in the blood, especially if the range of wavelengths with increased absorption of oxygenated

Hemoglobin Hb02 between two isosbestic points. The second parameter, derived from a broader spectral range, provides a basis that undergoes little and / or slow change. By comparing these two parameters, a value can be determined

For example, a statement about the saturation of the blood with oxygen allowed. If the evaluation is carried out over a broad spectral range with several wavelengths, the influence of the respective change of individual components is smaller. With the inventive method is therefore not pure

Measured amplitude-based. Rather, one will

Amplitude-based measurement in a partial region of the spectrum normalized by a measurement over a broader range. The sub-range refers to wavelengths in which the absorption changes in a similar manner depending on the oxygen saturation, typically increasing at higher saturation. The second area includes sections where absorption increases at higher oxygen saturation and sections where the Absorbtion at higher saturation decreases. Therefore, the measured parameter of the second region reflects more the scattering in the tissue or the absorption in the non-oxygenated blood than the measurement in the first region. The measurement over the larger range is therefore to a much lesser extent dependent on the oxygen saturation than the measurement over the first, narrower range. By comparing these values, an oxygen-based rather than an amplitude-based measurement can be achieved.

Preferably, the first region is selected so that the absorption increases with prolonged oxygen saturation, that is, that the absorption coefficient Hb02 is greater than that

Absorption coefficient HHb. In a preferred embodiment, the first spectral range substantially corresponds to one

Range between at least two adjacent isosbestic points where the absorption depends on the

Oxygen saturation behaves the same, for example, increases.

Isosbestic points are for example at 505nm, 522nm, 548nm, 570nm and 586nm (see Fig. 2).

The first spectral range can be composed of at least two subregions. Each of these subareas preferably has absorption coefficients which behave, for example increase, as a function of the oxygen saturation. If the subregions are selected accordingly, the absorption adds up. Thus, a statement can be made even at low oxygen saturation.

A particularly advantageous possibility of comparing the first parameter with the second parameter results from the formation of a quotient of the first and the second

Parameter. Such a quotient can be scaled arbitrarily and represents a dimensionless quantity. The formation of a quotient causes a basic absorption, for example caused by the hemoglobin absorption, absorption of the skin, of the tissue or of the bone, or of the measurement

locked out .

The second spectral range may comprise at least twice the wavelength range as the first

Spectral range. By such a broad measurement of the second spectral range, a value is reached, which, depending on the oxygen saturation, only slight fluctuations

is subject to or changes only slowly.

Preferably, the second spectral range comprises a

Wave area, which has several isosbestic points. This promotes a value that is subject to less fluctuation.

Both the first and second parameters may be determined by integrating the absorption curve over the first and second regions, respectively. The integration results in individual values that can be easily linked with each other.

Preference is given to the inventive method

Oxygen signal generated, which maps the evaluation time-resolved. Such an image can be recorded at a frequency of 50 to 150 Hz. This can be the

Oxygen saturation can be mapped over time. For example, it is possible to detect hypoxia.

Oxygen levels in the tissue decrease, the comparison values

experienced a significant change, because for example the

Basic absorption deviates from a longer-term value. It is also possible to determine the pulse rate from the oxygen signal, since the oxygen saturation in the tissue directly from the pulse, or from the freshly delivered arterial ie

Oxygen-enriched blood is affected. Thus, both a statement about the oxygen saturation and the pulse can be made. A combination of the evaluation in a display device or the further processing of the values in relation to each other is now possible.

The proportion of pulses in the absorption makes only a small part, in a healthy person about 1% to 5% of the total

optical signal off. For critical patients, this percentage may decrease by a factor of 10 or more. By means of the method according to the invention, however, it is also possible to detect a pulse or an oxygen saturation, which is to be classified as critical, or a pulse can be obtained from the change in temperature

Oxygen saturation can be calculated. This is according to

Present method possible because not the absolute signal is evaluated, but in forming a quotient the

Ratio of the different absorption of the individual waves of the respective spectral ranges.

The result of the comparison of the first parameter with the second parameter, which may for example be present as a vital parameter, can be compared with a purely amplitude-based signal. It is conceivable that such a

Signal is determined by the absorption of irradiated light, wherein the absorption is measured for example at a certain wavelength. Common wavelengths of the prior art, for example, 660nm or 940nm for measuring the oxygen saturation of the blood, other wavelengths for other properties of the blood are conceivable and the Specialist known. Typically, for the generation of an amplitude-based signal, a wavelength or an area of the irradiated light is selected which comprises a plurality of wavelengths, for example the waveband between two

isosbestic points. Such a signal can

for example, from the first or second according to the

obtained parameters obtained in these methods. However, it is also conceivable to carry out the comparison with a second, independent amplitude-based signal,

for example, with the signal of a pulse oximeter.

With the solution according to the invention, an oxygen-based signal and an amplitude-based signal are available. From a comparison of these two signals, or from the degree of agreement of these signals can measure the

Trustworthiness of the signals are determined. For example, it is possible to set alarms that are an indication when the response between the signals changes, for example that the one signal is no longer detected correctly, for example if the light is no longer radiated correctly into the tissue. It is also conceivable to time-based these two signals

record. In this way, longer-term changes or deviations can also be determined, or different mean values, in particular mean values over individual intervals or time segments, can be compared with one another.

Another aspect of the invention relates to a device for monitoring vital parameters of a living being, in particular for monitoring the pulse. Preferably, the

Apparatus for carrying out the presently described

Process. Such a device comprises at least one light source for irradiating light in tissue. The light source preferably emits a broadband light spectrum. In particular, the spectrum includes light having a wavelength in the range of 400nm to 850nm. Furthermore, the device has a receiver for the light radiation from the tissue. The receiver also comprises means for fanning the light and a detector, so that a light spectrum of the light returned from the tissue is detectable. The device has evaluation means. These evaluation means are suitable for at least a first one within the spectrum

Determine parameters based on a first spectral range and at least one second parameter on the basis of at least one second spectral range. The second

Spectral range is greater than the first spectral range.

In addition, the evaluation are suitable to a

Perform comparison of the first parameter with the second parameter and perform a determination of a vital parameter based on the comparison. This favors the processing of the vital parameter, or its evaluation.

The evaluation means preferably comprise means for integrating at least the first and the second spectral range. As a result, at least the first and second parameters can be determined. Such specific values may, for example, be in one

Processor of the measuring device further processed.

In a preferred embodiment, the evaluation means comprise means for forming a quotient of the first and second parameters. As a dimensionless variable, a quotient is particularly advantageous in the evaluation or further processing. With the formation of a quotient, a basic absorption can be excluded from the further processed signal. Thus, only values are considered that change and are of interest. In addition, the evaluation means may comprise means for generating an oxygen signal, so that the evaluation can be imaged in a time-resolved manner. Such a mapping over time allows conclusions about the course of the vital signs. In particular, the temporal change of the value can be seen.

The device may comprise attachment means, preferably attachment means for securing the device to a

Finger, forehead, earlobe or on one

Skin surface. This is particularly advantageous in the event that measurements must be taken over a longer period of time.

Advantageously, the light detector comprises a 2-dimensional sensor array, in particular a CMOS sensor, preferably a monolithic CMOS pixel array. Such a sensor allows a direct detection of the light spectrum, for example, each area or pixel, or each pixel array is assigned a different wavelength and allows direct integration by adding adjacent sensor cells.

In addition, a direct amplification and further processing of the signal is possible.

On the basis of figures, which represent only embodiments, the invention will be explained in more detail below. Show it :

FIG. 1 a: typical measurement profiles of pulse oximeters from the

State of the art;

FIG. 1b: typical noise ratios in blood measurements in vitro;

FIG. 1c: typical real signals of pulse oximeters; Figure 2: absorption curve of hemoglobin between

500nm and 600nm;

Figure 3: the course of Figure 2 with therein

marked measuring ranges;

Figure 4a: undisturbed pulse curve at low frequency;

FIG. 4b: undisturbed pulse curve at high frequency;

FIGS. 5a and 5b: pulse curves with disturbances;

Figures 6 and 7: Two pleth signals over a longer period of time; FIG. 8: frequency spectrum of the pleth signal from FIG. 7;

FIG. 9 shows a device for carrying out the method according to the invention;

Figure 10: Schematic representation of the device

FIG. 9.

Figure la shows typical sequences of light shots of

various pulse oximeters available on the market. There are devices that emit alternately infrared and red light, with intermediate dark phases (first curve). Alternative measuring instruments show successive gradients (curve 3) or gradients with repeating single phases (curve 2).

Figure lb shows typical noise ratios in technical

Abutments, for example a measurement on a blood tube. Each of these graphs is a specific wavelength of the

Assigned light spectrum. Common to all is a superimposed noise and a pulsatile change, caused here by a roller pump.

FIG. 1c now shows the real signals for the same wavelengths as in FIG. 1b, the measurement being based on a healthy one

Subjects was performed. The measurement was performed on the middle finger of the right arm. FIG. 2 shows an absorption spectrum of the hemoglobin in the wavelength range from 500 nm to 600 nm for exemplary saturations of the hemoglobin with oxygen between 0% and 100%. The isosbestic points at 505nm, 522nm, 548nm, 570nm and 586nm are clearly visible. In an isosbestic point, the relationship between increasing absorption coefficient and increasing oxygen saturation changes to decreasing

Absorption coefficients with increasing oxygen saturation and vice versa. For example, the absorption coefficient of the curves between the isosbestic points at 522nm and 548nm and the curves between the isosbestic points at 570nm and 586nm higher, the higher the oxygen concentration.

FIG. 3 now shows the selected measuring ranges for the

present method. The areas designated II and 12 are the areas in which the absorption coefficient of the

Oxygenated blood Hb02 is higher than that of the deoxygenated blood HHb. These areas together form a first subregion of the absorption spectrum. The 13th

designated area shows a second area to the

Determination of a second parameter is used.

Illustrated by way of example is the range between 505 nm and 600 nm (see FIG

Oxygen saturation.

The curves of subsections II and 12 are each integrated separately at the same time or offset. The coefficients are added to a single value. In a further step, which can take place simultaneously or with a time delay, the curve of the second subarea is integrated. Simultaneous operation, however, precludes serial sampling of the individual

Wavelengths are not enough. From the values of these two integrals a quotient can be formed, shown by way of example in the following formula.

II and 12 are the subregions of the first spectral range, 13 denotes the second spectral range. P is a

dimensionless coefficient, for further processing

can be used.

Of course, it is also conceivable, alternatively, that the first measurement takes place in a partial region which has lower absorption coefficients with higher oxygen saturation of the hemoglobin. Thus, further different parameter profiles could be generated. For example, it is also conceivable to use the coefficients of integration

To form difference.

Figure 4a shows an example of the comparison

dimensionless coefficient with an amplitude-based measurement of a low and undisturbed pulse over time. The instantaneous measurements carried out as described herein can be carried out, for example, at a frequency of 50 to 150 Hz. The values thus obtained make it possible to replicate the oxygen saturation as a function of time and to display it in a pleth diagram. The

Comparison of this oxygen-based evaluation (recognizable as a solid line) with the amplitude-based measurement (dashed line in the present plot) shows a clear agreement. FIG. 4b shows corresponding measurement results for a fast pulse for FIG. 4a.

FIGS. 5a and 5b show pulse curves with interference

Motion artifacts, the curves corresponding to those of Figure 4a and 4b. The expression of the curve, which from the

dimensionless coefficient is formed is more pronounced in comparison with the amplitude-based measurement.

FIG. 6 shows a plethat over a longer period of time. The clearly visible frequency is the respiratory rate. The

Pulse frequency is no longer displayed in this resolution. The amplitude-based curve (shown in dashed lines) has no noticeable features. By contrast, the oxygen-based evaluation (solid line) shows a clear change in contrast to the amplitude-based evaluation. About off

Second 225, the signals of the two curves begin to

diverge. From about second 310, the falls

Oxygen-based curve markedly off. The behavior in the range between 200 and 300 seconds is a clear sign of hypoxia. The oxygen depletion is indicated by the increase in the curve. The significant drop in the curve at about 310 sec shows a rapid improvement in oxygen supply.

The pulse signals of these two curves can also be compared with each other in a finer resolution, such as shown in Fig. 7, and thus against each other

be because both signals must show a consistent pulse width over a wide range. Disturbances of the individual measurement signals can thus be detected. FIG. 7 shows a detail of a plethrough with a higher resolution and over a shorter period of time. Clearly visible is the pulse. The superimposed low frequency is the respiratory rate. The correlation between the amplitude-based (dashed) and the oxygen-based (solid) signal can be clearly recognized.

A frequency analysis of the oxygen based, i. shown in solid line in Figure 7 is shown in Figure 8. The respiratory rate is about 0.2 Hz, the pulse rate at about 2.2 Hz. In general, in adults that the

Respiratory rate is significantly less than the pulse rate. The pulse rate is also recognizable by the fact that harmonic upper frequencies are recognizable. The existence of such

Upper frequencies can be used to verify the pulse rate

be used.

FIG. 9 shows an exemplary embodiment of a

Device according to the invention, as described, for example, in WO2011 / 161102 for the measurement of blood sugar. The device 1 has a housing in which the various optical and

electronic components are arranged. The measurement is done on a finger. The finger is guided into the measuring range 3 or brought to the measuring range 3. As a light source, a broadband LED 20 is provided, which typically emits light in the spectral range of 400 to 850 nm against the measuring range 3. The housing 16 has an opening for the exit of the light. The opening may be provided with a transparent cover 19 for the exiting light. The reflected or transmitted by the finger light is passed through a second opening in the housing 16, which is also provided with a transparent cover 19 for the light, in the housing 16. To lead and fanning the light is a Mirror assembly 5, a slit 7 and a first imaging optics 8 are provided which the light on

Steer diffraction grating 9. By the diffraction grating 9, the light is fanned depending on the wavelength and passed through a second imaging optics 10 on the sensor surface 11 of a light detector, in particular an image sensor 12. The image sensor 12 and the LED 20 are arranged on a common printed circuit board 18 in the housing 16. The printed circuit board 18 is also provided with electronic components for controlling the LED 20 and the

Image sensor 12 provided. In particular, the printed circuit board 18 also has a USB controller 36 and USB ports not shown in detail. This USB interface allows one hand

Power supply to the device 1. On the other hand, it allows data exchange with an external computer or display device.

FIG. 10 now shows the schematic structure and the FIGS

Operation of the arrangement of Figure 9. The device 1 has one or more light sources 2 (only one shown here), which generate measuring light. In this case, the light source 2 serves as a measuring area 3 to be examined, typically a skin and tissue area, as substantially

Illuminate two-dimensional area with a relatively narrow extent perpendicular to its surface. The linear one

Measurement range 3 is thus illuminated either reflexively or transmissively in the various embodiments by the illumination devices and emits analysis light 4 in accordance with its transmission or reflection behavior. The

Analysis light 4 is a deflection mirror 5 in a

Spectrometer unit coupled for fanning the light, wherein such a spectrometer unit at least one aperture 7, a first imaging optics 8 and a diffraction grating 9th

includes. The analysis light 4 is here to determine the oxygen saturation in the blood and other blood levels in Wavelength range between 400nm and 850nm and has a spectral distribution according to the substance composition. Thus, the analysis light contains spectra in the relevant

Wavelength range for identification of quantitative

Substance composition in the measuring range 3, so typically the composition of the arterial blood and the substance

Fabric.

The analysis light 4 passes through a deflection mirror 5 and a third imaging optics 6 on a diaphragm 7. The third

Imaging optics 6 serves as an input lens for the

Spectrometer unit. The aperture 7 is elongated, preferably as a gap or slot, for. B. with a width of typically 10 ym to 30 ym, and extending in the horizontal direction or z-direction (perpendicular to the plane in Figure 10). In the beam path other optical elements such. As filters or other mirrors may be used to filter or direct the light.

The transmitted by the aperture 7 stripes of the image of the measuring area 3 is thrown as light over a first imaging optics 8 on a diffraction grating 9. The grid is for

Monitoring blood counts typically include a transmissive "Volume Phase Holographic" lattice with a blaze wavelength in the range of 500nm to 800nm and approximately 300 1 / mm to 6001 / mm The grating 9 is constructed and arranged such that a

Wavelength dispersive fanning of the analysis light 4

perpendicular to the direction of the gap of the aperture 7, d. H. in the transverse direction or Y direction; Here, according to modified embodiments are possible. About a second

Imaging optics 10, the diffracted light is imaged as a diffraction image on a sensor surface 11 of an image sensor 12. On the sensor surface 11 is thus a diffraction pattern of the diaphragm 7 and whose gap is shown, with the longitudinal extent of the gap (the z-direction) in one direction and the wavelength-dispersive fanning of the diffraction pattern in the other direction. The image sensor is in monitoring for blood value measurements

typically a CMOS Aptina MT9m032 (1.6 Mpixel) or MT9P031 (5 Mpix) camera sensor.

Such a mapping allows for easy readout integration. Each row or column can have the value of one

capture specific wavelength. By simply adding the individual optical values we completed the integration. For example, only the values from preferred

Regions of the sensor 12, for example with certain

Wavelengths, read out and added. This optical value can be digitized directly on the sensor 12, for example. Electrical disturbances can thus largely be excluded or at least reduced. The so

Calculated value can be forwarded to a processor for processing or further processing.

The value can be evaluated in the processor or in further evaluation means, wherein the processor can be in a correspondingly programmed computer. It is also possible that the evaluation means are part of the device 1 and are located completely therein. An external arrangement is conceivable. This arrangement can, for example, via output means such as

For example, have a screen or an acoustic display.

Claims

claims

1. A method for monitoring vital signs of a

Living thing, especially for monitoring the pulse rate

and / or oxygen saturation, including the following

Steps :

Injection of broadband light, preferably pulsed

Light, in tissue of a living being, wherein the light preferably comprises wavelengths in a spectral range from 400 nm to 850 nm;

Capturing a spectrum of the light reflected back from the tissue, wherein the light in the tissue has either been reflected or transmitted;

Performing an evaluation of the recorded spectrum, characterized in that the evaluation comprises the following steps:

Determining at least a first parameter based on a first spectral range within the spectrum;

Determining at least one second parameter on the basis of at least one second spectral range (13) which is greater than the first spectral range and at least partially contains the first spectral range;

Comparing the first parameter with the second parameter

Determining at least one vital parameter based on the comparison.

2. The method according to claim 1, characterized in that the first spectral range substantially a range between at least two adjacent isosbestischen points

corresponds, wherein in the first spectral range preferably the absorption coefficient Hb02 is greater than that Absorption coefficient HHb.

3. The method according to claim 2, characterized in that the first spectral range of at least two subregions (II, 12) is composed, preferably in each

Subregion (II, 12) is an absorption coefficient Hb02 greater than an absorption coefficient HHb.

4. The method according to any one of the preceding claims, characterized in that the comparison of the first parameter with the second parameter corresponds to the formation of a quotient of the first and second parameters.

5. The method according to any one of the preceding claims, characterized in that the second spectral range (13) comprises at least twice as large wavelength range as the first spectral range.

6. The method according to any one of the preceding claims, characterized in that the second spectral range (13) comprises a wavelength range having a plurality of isosbestische points.

7. The method according to any one of the preceding claims, characterized in that both the first and the second parameter are determined by an integral of the absorption over the first and the second region (13).

8. The method according to any one of the preceding claims, characterized in that an oxygen signal is generated, which images the time-resolved evaluation, preferably with a frequency of 50-150 Hz.

9. The method according to any one of the preceding claims, characterized in that from the oxygen signal, the pulse rate is determined.

10. The method according to any one of the preceding claims, characterized in that a result of the comparison of the first parameter with the second parameter, in particular the at least one determined by the comparison

Vital parameters, with an amplitude-based signal, in particular a signal due to the absorption of irradiated light of a certain wavelength or a certain wavelength range, or the signal of a pulse oximeter, is compared.

11. Device (1) for monitoring vital parameters of a living being, in particular for monitoring the pulse,

preferred for carrying out a process according to the preceding claims, comprising at least one

Light source (2) for irradiating light in tissue,

Preferably, a broadband light source (2), in particular a light source (2) having a wavelength in the range of 400-850nm, a receiver for the light radiation from the tissue, wherein the receiver preferably comprises at least means for fanning the light and a light detector, so that a light spectrum of the light reflected by the tissue is detectable, characterized in that the device comprises evaluation means adapted to determine at least one first parameter on the basis of a first spectral range within the spectrum and at least one second parameter on the basis of at least one second Spectral range (13) to determine, wherein the second spectral range (13) is greater than the first spectral range and wherein the evaluation means to are formed, a comparison of the first parameter with the second parameter for determining a

Vital parameters on the basis of the comparison.

12. Device (1) according to claim 11, characterized in that the evaluation means comprise means for integrating at least the first and the second spectral range (13).

13. Device (1) according to any one of claims 11 to 12, characterized in that the evaluation means comprise means for forming a quotient of the first and the second parameter.

14. Device (1) according to any one of claims 11 to 13, characterized in that the evaluation means comprise means for generating an oxygen signal, so that the evaluation is time-resolved imaged.

15. Device (1) according to one of claims 11 to 14, characterized in that the device (1) has fastening means, preferably fastening means for fastening the device to a finger, an earlobe or on a skin surface.

16. Device (1) according to one of claims 11 to 15, characterized in that the light detector comprises a 2-dimensional sensor array (12), in particular a CMOS sensor, preferably a monolithic CMOS pixel array.