JPH09196739A - Method and implement for detection of liquid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily detect a liquid in a trace amount by a method wherein light is made incident in a specific angle range with reference to a normal line on the surface of a flow passage, reflected light or transmitted light is received on the surface of the flow passage so as to measure its intensity and the existence of the liquid inside the flow passage is detected. SOLUTION: An upper plate 11 and a lower plate 12 are formed of a transparent material, a flow passage 8 is formed on the plate 12, and an incident face 14 and a radiant face 15 are formed on the plate 11. Light at an incident angle 17 in a range of about 42 to 60 deg. with reference to the normal line 16 of the flow passage 8 is transmitted vertically through the incident face 14, it is reflected on the surface 13 of the flow passage, it is transmitted vertically through the radiant face 15 so as to be received by a photodetector, and the existence of a liquid inside the flow passage 8 is detected. When the flow passage is filled with the air and the liquid flows into a part on which the light is incident inside the flow passage at an angle at which the light is reflected totally, the light is not reflected totally. Consequently, when a change in reflected light is detected, the existence of the liquid even in a trace amount inside the flow passage can be detected easily.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for detecting the presence or absence of a trace amount of liquid by an optical method, an instrument used for the method, and a trace amount liquid metering device using them. Particularly, it is useful for providing a minute amount of biological liquid sample for analysis.

[0002]

2. Description of the Related Art In the analysis of components in liquids, especially in the analysis of components in body fluids, the use of disposable dry analytical instruments that can be easily measured is widespread. In order to reduce the burden on patients or animals, the analysis of bodily fluids is usually performed with as little sample as possible.To prevent biological hazards, etc., the sample is trapped in the flow path of the analytical instrument and aspirated by a pump. A method is used in which a sample is moved and a reaction or measurement is performed in a channel. Further, in the case of a sample containing bacteria or the like, it is particularly desired to reduce the number of operations such as pipetting for dropping the sample to the sample receiving port or the like.

Conventionally, a liquid detecting method is generally a method of detecting a change in conduction at the time of liquid contact using electrodes, a method of irradiating ultrasonic waves to detect the presence or absence of liquid, the presence or absence of liquid. For example, there is a method of detecting a change in electrostatic capacity in the presence. However, a thin instrument with high airtightness for measuring a minute amount of a biological liquid sample is structurally difficult to construct an electrode therein, and a minute amount of a thin layer is necessary. It is difficult to detect a biological liquid sample by ultrasonic waves or a minute change in capacitance, and it is not easy to accurately control the sample transfer amount.

Optically, a method of transmitting light and detecting the presence or absence of a liquid from the change in the transmittance is conventionally used. However, in detecting the presence or absence of a thin layer of liquid in a channel having a thickness of 0.05 to 0.5 mm, the change in the transmittance is weak and it is difficult to use it as a detectable signal.

[0005]

In view of the above situation, the present invention provides a method for easily detecting a liquid in a trace amount and a thin analytical instrument, an instrument used in the method, an analytical instrument and a trace amount liquid. An object is to provide a quantification device.

[0006]

Means for Solving the Problems That is, the first aspect of the present invention is to provide a molded article having a flow path in which at least an upper part of the flow path from an upper surface thereof is made of a transparent material, and a top surface through which a trace amount of liquid flows is a flat surface. Liquid detection that detects the presence or absence of liquid in the flow channel by receiving light incident on the upper surface normal line in the range of 42 to 62 °, reflected or transmitted by the flow channel upper surface, and measuring the intensity thereof. Is the way.

A second aspect of the present invention is a molded article having a flow path in which at least a portion above the flow path upper surface is made of a transparent material, and the upper surface through which a small amount of liquid flows is a flat surface, and the flow path upper surface is 42 It is an instrument having a liquid detection part for detecting the presence or absence of liquid in a flow channel in which an entrance surface and an exit surface are formed on the outer surface of a molded body at an angle of ˜62 °.

A third aspect of the present invention is an analytical instrument for measuring the optical characteristics of a sample equipped with at least one of the above-mentioned liquid detecting portions to analyze a body fluid component, which has a sample receiving port and a pump connecting port. At least one sample processing chamber and at least one photometric chamber, or at least one sample processing chamber / photometric chamber are provided between the sample receiving port and the pump connection port, and if necessary, a blood cell separating portion, a sample reservoir, and a waste liquid. A body fluid component analyzing instrument comprising a reservoir, each of which is connected by a flow path having at least one air hole, wherein a sample is quantitatively divided from one sample receiving port into a plurality of flow paths to perform a plurality of measurements. Is configured to be supplied with the sample.

In a fourth aspect of the present invention, a body fluid component analyzing instrument having the above-mentioned liquid detecting portion is mounted, an air valve for opening and closing an air hole of the body fluid component analyzing instrument, a light source for making light incident on an incident surface, and a reflected light. Alternatively, it is a trace amount liquid quantification device provided with a liquid detection means including a light receiver for receiving transmitted light and an air opening / closing means for opening / closing an air hole at the same time as fluid detection.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Generally, when light enters a substance having a refractive index n ₀ from a substance having a refractive index n, the incident angle is θ and the refraction angle is θ.
_{If 0} , then the refraction law of n sin θ = n ₀ sin θ ₀ holds. When light goes from a place with a large refractive index to a place with a small refractive index, n> n ₀ , and when the incident angle is considerably large, n sin θ / n ₀ > 1, which means that the above law cannot be satisfied regardless of the refractive index. reflect. The incident angle in this case is the critical angle. For example, if the refractive index of glass with respect to air is n / n ₀ = 1.52, then nsin θ
The angle satisfying the condition of / n ₀ = 1 is about 42 °.
Therefore, when the incident angle of the light passing through the inside of the glass at the interface with the air is 42 ° or more, the light is totally reflected inside the glass and does not go out to the air side. In this case, the value obtained by dividing the intensity of the reflected light by the intensity of the incident light is the reflectance, and this value generally increases with the incident angle.

When light is incident at an angle of total reflection when the flow path is filled with air as described above, if, for example, water flows into the air side (refractive index of glass = 1.5
2) / (refractive index of water = 1.33) = 1.14, and n
Since the angle satisfying sin θ / n ₀ = 1 is about 62 °, the incident angle is not totally reflected and the reflectance is reduced. Therefore, the presence or absence of the liquid in the flow path can be easily detected by detecting the change in the reflected light.

Glass, acrylic resin, polystyrene resin, or the like is used as the transparent material at least above the upper surface of the flow path, and its refractive index is about 1.5. On the other hand, the refractive index of plasma, which is a biological liquid that fills the channel, is about 1.35. Therefore, 4 to the upper surface of the flow path with respect to the normal to the upper surface of the flow path.
The presence or absence of the liquid can be detected by injecting the light of 2 to 62 ° and measuring the change in the intensity of the reflected light generated according to the presence or absence of the liquid. In this case, the portion below the flow path does not necessarily need to be a transparent material.

Instead of measuring the change in the intensity of the reflected light, the change in the intensity of the transmitted light of the liquid may be measured. When measuring transmitted light, it is necessary that the lower part of the channel is also made of a transparent material.

The analytical instrument of the present invention, which has a liquid detection mechanism for detecting the presence or absence of liquid in the flow channel, has a flow channel in which a trace amount of liquid flows, in which at least the upper portion of the flow channel upper surface is made of a transparent material. In the molded body, the incident surface and the injection surface are formed on the outer surface of the molded body at an angle of 42 to 62 ° with respect to the upper surface of the flow path. The upper part of the flow path is arranged between the entrance surface and the exit surface. When measuring the reflected light on the upper surface of the channel, the incident surface and the exit surface are formed on the same plane as the outer surface of the molded body, and when measuring the transmitted light on the upper surface of the channel, the incident surface and the exit surface are formed on the outer surface of the molded body. Formed on opposite surfaces.

The incident surface or the exit surface may be formed so that the surface through which the light is transmitted forms an angle of 42 to 62 ° with respect to the upper surface of the flow path, and the surface is external to the outer surface of the molded body. It may be provided as a protrusion or as a concave shape. Further, masking the periphery of the entrance surface and the exit surface with black ink or the like can prevent stray light in the molded body.

By providing the liquid detecting portion of the present invention in the body fluid component analyzing instrument, a minute amount of biological liquid can be quantitatively supplied. FIG. 1 shows a plan view of a body fluid component analyzing instrument according to a first embodiment of the present invention. An example is shown where the sample is whole blood and blood cells are separated and plasma is used for analysis. This analytical instrument includes a sample receiving port (1), a blood cell separation area (2), a first air hole (3), a second air hole (4), a liquid detecting portion (5), a sample processing chamber and a photometric chamber (6). , A pump connection port (7) and a flow path (8) connecting them. When whole blood is supplied from the sample receiving port (1) and aspirated from the pump connecting port (7), the plasma separated in the blood cell separation region (2) is guided to the flow channel (8). When the blood plasma is detected to reach the liquid detection portion (5), the pump connection port (7) is once opened and the depressurization in the flow path (8) is released. At this time, the plasma retreats only slightly toward the sample receiving port (1) side. Next, the first air hole (3) is opened and sucked, and the tip of the plasma is transferred to the liquid detection portion (5). When the first air hole (3) is closed and the second air hole (4) is opened and suctioned, only the blood plasma between the second air hole (4) and the liquid detection portion (5) is used as the sample processing chamber and photometry. It can be transferred to the chamber (6) for analysis.

FIG. 2 shows a plan view of another embodiment of the body fluid component analyzing instrument according to the first embodiment of the present invention. Also in this body fluid component analysis instrument, a case where whole blood is used as a sample and blood cells are separated to analyze plasma will be described as an example. This analytical instrument includes a sample receiving port (101), a blood cell separation region (102), a first air hole (103), a second air hole (105), a first liquid detecting portion (104), and a second liquid detecting portion (106). ), Sample processing chamber and photometric chamber (107), pump connection port (108)
And a flow path (109) connecting them. When whole blood is supplied from the sample receiving port (101) and aspirated from the pump connecting port (108), the blood cell separation region (10
The plasma separated in 2) is led to the channel (109). When the blood plasma is detected to reach the first liquid detection portion (104), the second air hole (105) is once opened and the decompression in the flow path (109) is released. At this time, the flow path (1
The plasma in 09) recedes slightly toward the sample receiving port (101) side. Then open the first air hole (103),
The air hole (105) is suctioned in a closed state, and the tip of the plasma is transferred to the second liquid detection portion (106). When the first air hole (103) is closed and the second air hole (105) is opened and sucked, only the plasma between the second air hole (105) and the second liquid detection portion (106) is processed. It can be transferred to the chamber / photometric chamber (107) and used for analysis.

FIG. 3 is a sectional view of the liquid detecting portion (5, 104, 106) of the body fluid component analyzing instrument of FIGS. 1 and 2. In this case, the molded body is composed of an upper plate (11) and a lower plate (12) made of a transparent material, the flow paths (8, 109) are formed in the lower plate (12), and the incident surface (14) is formed. ) And the exit surface (15) are formed on the upper plate (11). Channel (8,109)
The incident angle (17) in the range of 42 to 62 ° with respect to the normal line (16) of (1) passes vertically through the incident surface (14), is reflected by the flow path upper surface (13), and is perpendicular to the exit surface (15). After passing through, the light is measured by a light receiver (not shown), and the presence or absence of liquid in the flow paths (8, 109) can be detected by the value.

FIG. 4 shows a sample of the body fluid component analyzing instrument having the liquid detecting portion, which is provided with a sample reservoir and which has three flow paths having air holes branched from the sample reservoir. It is a body fluid component analysis instrument of 2 embodiment. The case of a whole blood sample will be described as an example. Whole blood supplied to the sample receiving port (20) is separated into blood cells and plasma in the blood cell separating region (21) by suction from the third pump connecting port (35). After the plasma fills the sample reservoir (23), the third liquid sensing portion (2
Reach 9). Therefore, the first, second and third pump connection ports (33, 34, 35) are once opened to return to atmospheric pressure, and then the first air hole (22) is opened. The second, third and fourth air holes (24, 25, 26) provided in the branched flow paths (36, 37, 38) are sucked by the respective pumps while being closed, and plasma is introduced into the flow paths. To do. Plasma is 3
When the presence of liquid is detected in the first, second and third liquid detecting portions (27, 28, 29), the second, third and fourth air holes (24 Two
Opening (5, 26) means that a certain amount of plasma is measured in each flow path. Then, in the first, second and third sample processing chambers / photometric chambers (30, 31, 32),
If necessary, sample pretreatment, reaction, photometry, etc. are performed to analyze various body fluid components.

Table 1 below shows a specific process for dividing and collecting plasma using the body fluid component analyzer of FIG.

[Table 1] Process of divided collection of plasma ◯: Open state ×: Closed state S: Pump is stopped while being connected to the pump connection port M: Pump is operating while being connected to the pump connection port L: Pump connection port Open to return the flow path to atmospheric pressure

In step 1, the first and second pumps are
The third pump connected to the third pump connection port (35) is operated while the operation of the first and second pump connection ports (33, 34) is stopped. Second, third and fourth air holes (22, 24, 25, 2)
When 6) is closed, the third pump connection port (3
By suction via 5), the liquid flows through the third flow path (38) to the third liquid detection portion (29), where the liquid is detected. In step 2, first, second and third
The pump connection ports (33, 34, 35) are separated from the first, second and third pumps and opened to the atmosphere, the first air holes (22) are opened, and the third flow path (38) is opened. Atmospheric pressure. In step 3, the first pump and the second pump are first
While being connected to the second pump connection port (33, 34), the operation is stopped, the third pump is connected to the third pump connection port (35) to operate, and
The first air hole (22) is opened so that the tip of the liquid reaches the third liquid detecting portion (29). In step 4,
When the liquid is detected by the third liquid detecting portion (29), the first air hole (22) is closed and the fourth air hole (26) is opened. As a result, the liquid from the fourth air hole (26) to the third liquid detecting portion (29) is allowed to flow into the third sample processing chamber / photometering chamber (3
It flows into the third flow path (38) toward 2). That is, a fixed amount of liquid is flown into the third flow path (38) just before the third sample processing chamber / photometric chamber (32). When the third liquid detecting portion (29) stops detecting liquid, the operation of the third pump is stopped. In step 5, the fourth air hole (26) is closed and the first pump and the third pump are connected to the first and third pump connection ports (33, 35), but the operation is stopped. A second pump is connected to the second pump connection port (34) to operate, and a first air hole (2
2) is opened so that the tip of the liquid is the second liquid detecting portion (28).
To reach. In step 6, when the liquid is detected by the second liquid detecting portion (28), the first air hole (22) is closed and the third air hole (25) is opened. As a result, the liquid from the third air hole (25) to the second liquid detecting portion (28) is made to flow into the second flow path (37) just before the second sample processing chamber / photometric chamber (31). Second liquid detection part (2
When 8) no longer detects the liquid, the operation of the second pump is stopped. In step 7, the third air hole (25) is closed and the second pump and the third pump are connected to the second and third pump connection ports (34, 35), but the operation is stopped. The first pump is connected to the first pump connection port (33) to operate, and the first air hole (22) is opened so that the tip of the liquid reaches the first liquid detection portion (27). In step 8, the first liquid sensing portion (2
When the liquid is detected in 7), the first air hole (22) is closed and the second air hole (24) is opened. As a result, the liquid from the second air hole (24) to the first liquid detection portion (27) is allowed to flow into the first sample processing chamber / photometering chamber (3) in the first flow path (36).
Inflow until just before 0). First liquid detection part (27)
Stops the operation of the first pump when no longer detects liquid. In step 9, the first, second and third pumps are respectively connected to the first, second and third pump connection ports (33, 34,
35) to activate all pumps and to close the first air vent (22) to the second, third and fourth
The air holes (24, 25, 26) are opened so that a fixed amount of liquid in the first, second and third flow paths (36, 37, 38) can be used for the first, second and third sample processing chambers and photometry. Room (30, 31,
The reaction is carried out through 32), and the mixture is optically measured. In addition, step 1 is a step for introducing plasma into the flow channel, and includes the first, second and third pump connection ports (33, 34,
Suction may be performed by any of 35).

FIG. 5 is a plan view of another embodiment of the body fluid component analyzing instrument according to the second embodiment of the present invention. A case where whole blood is used as a sample will be described as an example. Whole blood supplied to the sample receiving port (119) is separated into blood cells and plasma in the blood cell separating region (120) by suction from the third pump connecting port (135). The plasma reaches the first liquid sensing portion (123) after filling the sample reservoir (122). Then, the second, third and fourth air holes (124, 125, 126) provided in the flow paths (136, 137, 138) once branched, respectively.
Is opened and returned to atmospheric pressure, and then the first air hole (121) is opened. Then the second, third and fourth air holes (124, 1
25, 126) closed and sucked with each pump,
The plasma is introduced into the branched flow paths (136, 137, 138). Plasma travels through each of the three flow paths to the second, third and fourth liquid sensing portions (127, 128, 129).
When the presence of liquid is detected at, the first air hole (12
1) is opened and the second, third and fourth air holes (124,
When 125, 126) are opened, a certain amount of plasma is metered into the respective flow paths (136, 137, 138). Thereafter, in the first, second, and third sample processing chambers / photometric chambers (130, 131, 132), if necessary, sample pretreatment, reaction, photometry, etc. are performed to analyze various body fluid components.

A specific process of dividing and collecting plasma using the body fluid component analyzer of FIG. 5 will be described below. In step 1, the first and second pumps were connected to the first and second pump connection ports (133, 134), but were connected to the third pump connection port (135) with their operation stopped. Actuating the third pump, the first, second, third and fourth
When the air holes (121, 124, 125, 126) are closed, the liquid flows to the first liquid detection portion (123) by suction through the third pump connection port (135), and the liquid is here. Is detected. The second by this detection,
The third and fourth air holes (124, 125, 126) are opened to bring the inside of the flow path to atmospheric pressure. In step 2, the first air hole (121) is opened and the first and second pumps are connected to the first and second pump connection ports (133, 134), but the operation is stopped. A third pump is connected to the third pump connection port (135) to operate, and the second, third and fourth air holes (124, 125, 1
The tip of the liquid reaches the fourth liquid detecting portion (129) in the state in which 26) is closed. Step 3, 4th
When the liquid is detected by the liquid detecting portion (129), the first air hole (121) is closed and the fourth air hole (126) is opened. As a result, the liquid from the fourth air hole (126) to the fourth liquid detection portion (129) flows into the third flow path (138) toward the third sample processing chamber / photometric chamber (132). That is, a fixed amount of liquid is made to flow into the third flow path (138) just before the third sample processing chamber / photometric chamber (132). In step 4, the fourth air hole (126) is closed and the first and third pumps are connected to the first and third pump connection ports (133, 1).
35), the second pump is connected to the second pump connection port (134) for operation while the operation is stopped, and the first air hole (121) is opened to store the liquid. The tip should reach the third liquid sensing portion (128). In step 5, the third liquid sensing portion (128)
When liquid is detected in, close the first air hole (121),
The third air hole (125) is opened. As a result, the liquid from the third air hole (125) to the third liquid detecting portion (128) flows into just before the second sample processing chamber / photometric chamber (131). In step 6, the third air hole (125) is closed and the second and third pumps are connected to the second and third pump connection ports (134, 135), but their operation is stopped. The first pump is connected to the first pump connection port (133) to operate, and the first air hole (12
1) is opened so that the tip of the liquid is the second liquid detection portion (12
Try to reach 7). In step 7, when the liquid is detected by the second liquid detecting portion (127), the first air hole (1
21) is closed and the second air hole (124) is opened. As a result, the liquid from the second air hole (124) to the second liquid detecting portion (127) is allowed to flow into the first sample processing chamber / photometering chamber (13).
Inflow until just before 0). In step 8, the first, second and third pumps are respectively connected to the first, second and third pump connection ports (133, 134, 135) to operate all the pumps, and the second and third pumps are operated. And the fourth air holes (124, 125, 126) are opened to allow the liquids in the first, second and third flow paths (136, 137, 138) to serve as the first, second and third sample processing chambers and photometric chambers. (130, 13
1, 132) to cause a reaction, and after completion of the reaction, it is optically measured. It should be noted that step 1 is a step for introducing plasma into the flow channel, and suction is performed simultaneously from any of the first, second and third pump connection ports (133, 134, 135) and / or by combining these. You may go.

[0024]

EXAMPLES Specific examples using the liquid detection method according to the present invention will be described below. Example 1 Comparison of Light Transmission and Reflection Light Amounts in Thin-Layer Cell Flow of a plate having a channel having a depth of 0.1 mm and a width of 1.0 mm sandwiched between two 1.5 mm-thick polystyrene resins. The liquid was poured into the passage, and the change in the light quantity of the light receiver of the liquid detection part was examined. An incident surface was provided on the light irradiation side of the polystyrene resin so that the incident angle on the upper surface of the flow channel was 52 °. An exit surface was also provided on the light receiver side so that reflected light at an angle of 52 ° could be received. The entrance and exit surfaces are 1 mm long and 0.6 mm wide
It formed so that it might become. The light source is a light-emitting diode L630 manufactured by Epitex, and the light receiver is a phototransistor T manufactured by Toshiba.
PS613C was used. Liquid transfer rate in the flow path is 0.3
It was controlled so that it was μl / sec. FIG. 6 shows the output of the light receiver converted and recorded in the recorder. One scale on the X-axis representing a change in time corresponds to one second. From FIG. 6, 3.25 V is shown when there is no liquid, but the voltage sharply decreases when the liquid flows into the flow channel, and drops to 0.19 V when the liquid fills the flow channel. I can see it. This means that the reflected light to the light receiver on the upper surface of the flow channel decreases as the liquid enters the flow channel, and the reflected light almost disappears when the flow channel is filled with the liquid. From this, the level for detecting the presence or absence of liquid is set to 1
When the voltage is set to 1 volt, it can be known that the liquid is filled in the liquid detecting portion if the voltage is 1 volt or less, and that the liquid is not in the liquid detecting portion if the voltage is 1 volt or more. In addition, the level for detecting the presence or absence of liquid is, for example, 1 volt and 2 volt.
By setting the point, it is possible to know whether the liquid is not filling the liquid detecting portion, the moment when the liquid reaches the liquid detecting portion, or the state where the liquid is filling the liquid detecting portion.

(Example 2) Measurement by an analytical instrument having a plurality of flow paths Using the biological fluid component analytical instrument of the present invention shown in FIG. 4, the sample was divided and quantified according to the above-mentioned operation steps. A membrane filter (10 mm × 10 mm) having an asymmetric pore size was attached to the blood cell separation region (21) by pressing the peripheral portion so that blood cells did not leak from the periphery of the filter.
First, second and third sample processing chambers and photometric chambers (30, 3
1, 32) food dye blue No. 1 0.5 g / l (0.0
1.5 μl of 5% Triton X-405 aqueous solution) was added dropwise as a reagent and dried. The height of the entire flow path is 0.1 mm, the width of the flow path is 1 mm, the volume of the sample reservoir (23) is 5 μl, the width of the sample processing chamber / photometric chamber is 3 mm, and the second, third, and fourth air holes are provided. The distance from (24, 25, 26) to the first, second and third liquid sensing portions (27, 28, 29) is 1 each.
5 mm. 20 μl of blood is dripped into the sample receiving port (20), and all the air holes except the third pump connecting port (35) and the pump connecting ports are closed (step 1), and then the third pump connecting port (35) is used. When aspirated, the internal pressure drops and plasma fills the channel and sample reservoir (23) one after another.
The liquid detection part (29) is reached. Next, steps 2 to 9 are performed to dissolve the edible blue dye in the first, second, and third sample processing chambers and photometric chambers (30, 31, 32), and absorb the blue dye at a wavelength of 630 nm. It was measured at. The air hole was opened and closed by driving a rubber plate provided on the machine side with a solenoid, and the pump connection port was opened and closed by providing a mechanism for opening a passage to the atmosphere between the pump connection port and the pump.
The same experiment was performed 5 times. The results are shown in Table 2 below.

[Table 2] Absorbance measurement with an analytical instrument with multiple channels From Table 2, in each experiment, the sample concentrations of the first, second and third sample processing chambers / photometric chambers (30, 31, 32) are almost the same, and the plurality of flow paths (36, 37, 38) are It can be seen that a fixed amount of sample could be sent through.

Comparative Example Liquid Detection in the Vertical Direction The same experiment as in Example 1 was conducted by irradiating light perpendicularly to the flow channel and measuring the transmitted light. As a result, even if the liquid fills the liquid detection portion, the value of the light receiver is 3.
The output of 2 volts remained unchanged and no signal was obtained to detect the presence or absence of liquid. This is because the light that enters vertically is transmitted as it is, and the amount of light that can be caught by the light receiver hardly changes.

[0027]

According to the present invention, it is possible to provide a method for easily detecting a liquid in a trace amount and a thin analytical instrument, an instrument used in the method, an analytical instrument and a trace amount liquid quantification device. .

[Brief description of drawings]

FIG. 1 is a plan view of a body fluid component analyzer according to a first embodiment of the present invention.

FIG. 2 is a plan view of a body fluid component analyzer according to another aspect of the first embodiment of the present invention.

FIG. 3 is a cross-sectional view taken along the line AA of the body fluid component analysis instrument of FIGS. 1 and 2.

FIG. 4 is a plan view of a body fluid component analyzer according to a second embodiment of the present invention having a plurality of flow paths.

FIG. 5 is a plan view of a body fluid component analyzer according to another aspect of the second embodiment of the present invention.

FIG. 6 is a diagram showing a voltage change when a liquid is detected.

[Explanation of symbols]

 1, 101 Sample receiving port 2, 102 Blood cell separation area 3, 103 First air hole 4, 105 Second air hole 5 Liquid detection part 6, 107 Sample processing chamber / photometric chamber 7, 108 Pump connection port 8, 109 Flow path 9, 110 Reagents 10, 111 Photometric part 11 Upper plate 12 Lower plate 13 Channel upper part 14 Incident surface 15 Exit surface 16 Normal line of channel upper surface 17 Incident angle 20, 119 Sample receiving port 21, 120 Blood cell separation area 22, 121 First air hole 23,122 Sample reservoir 24,124 Second air hole 25,125 Third air hole 26,126 Fourth air hole 27,123 First liquid detecting portion 28,127 Second liquid detecting portion 29,128 3 Liquid Detecting Parts 30, 130 First Sample Processing Room / Photometry Room 31, 131 Second Sample Processing Room / Photometry Room 32, 132 Third Sample Processing Room / Photometry Room 33 133 first pump connection port 34, 134 second pump connection port 35, 135 third pump connection port 36, 136 first flow path 37, 137 second flow path 38, 138 third flow path 104 first liquid detection portion 106 Second liquid detection part 129 Fourth liquid detection part

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yuki Umehara 45, Takeda Okenoi-cho, Fushimi-ku, Kyoto, Kyoto Prefecture 3 Within Terramex Co., Ltd. (72) Inventor Shigeru Fujioka 1-13-5 Kudankita, Chiyoda-ku, Tokyo Nihon Mediphysics Co., Ltd. (72) Tadao Yamaguchi 9 Techno Park, Sanda City, Hyogo Prefecture No. 1 day Inside the Hyogo Factory of Meiji Physics Co., Ltd.

Claims (8)

[Claims] 1. A molded body having a flow path in which at least an upper part of the flow path upper surface is formed of a transparent material, and the upper surface through which a small amount of liquid flows is a flat surface, and the flow path upper surface is 42 to 62 ° with respect to a normal line. The liquid detection method of detecting the presence or absence of the liquid in the flow channel by receiving the light that has entered in the range, reflected or transmitted through the upper surface of the flow channel, and measuring the intensity thereof. 2. A molded body having a flow path in which at least an upper part of the flow path is formed of a transparent material, and the upper surface through which a trace amount of liquid flows is a flat surface.
An instrument having a liquid detection part for detecting the presence or absence of liquid in the flow channel, which has an incident surface and an emission surface of light formed on the outer surface of the molded body at an angle of ˜62 °. 3. A light entrance surface and an exit surface are formed on the same surface of the molded body, a flow path upper surface is disposed between the entrance surface and the exit surface, and reflected light on the flow path upper surface is An instrument having a liquid sensing portion according to claim 2, wherein the instrument is arranged so as to pass through the exit surface. 4. A light incident surface and a light emitting surface are formed on opposing flat surfaces of a molded body, a flow path upper surface is located between the light incident surface and the light emitting surface, and transmitted light on the flow path upper surface. An apparatus having a liquid sensing portion according to claim 2, wherein the device is arranged so as to pass through the ejection surface. 5. An analytical instrument having at least one liquid detecting part according to claim 2, 3 or 4 for measuring optical characteristics of a sample to analyze a body fluid component, which comprises a sample receiving port. A pump connection port, and at least one sample processing chamber and at least one photometric chamber or at least one sample processing chamber / photometric chamber between the sample receiving port and the pump connection port, and if necessary A body fluid component analysis instrument comprising a blood cell separation portion, a sample reservoir, and a waste fluid reservoir, each of which is connected by a flow path having at least one air hole. 6. The body fluid component analyzing instrument according to claim 5, wherein a plurality of channels having air holes branched from the sample reservoir and each channel are provided. A body fluid component analysis instrument having the liquid detection part according to the above paragraph. 7. A sample to be analyzed is dropped into the sample receiving port of the body fluid component analyzing instrument according to claim 6, the sample is once stored in the sample reservoir, and then the air holes are opened and closed to allow the sample to pass through a plurality of channels. A method for multi-item analysis of body fluid, in which each of which is branched and transferred, and a predetermined analysis is performed. 8. A body fluid component analyzing instrument according to claim 5 is mounted, and an air valve for opening and closing an air hole of the body fluid component analyzing instrument, a light source for making light incident on an incident surface, and a reflected light or a transmitted light are provided. A trace amount liquid metering device comprising a liquid detecting means composed of a light receiving device for receiving light and an air valve opening / closing means for opening / closing an air hole at the same time as liquid detection.