Blood Testing Devices

Abstract

Provided is a blood testing device which can be used in a simple manner, has satisfactory reliability and reproducibility, and can produce a stable determination result. The blood testing device is provided with: a first substrate which has, formed therein, a first opening through which blood is added; a second substrate which is placed facing the first substrate and has, formed therein, a second opening for observing a color reaction therethrough; a dry reagent phase which is laminated between the first and second substrates in such a manner that a portion of the dry reagent phase is exposed on the second substrate through the second opening; a plasma separation unit which is formed from a porous sheet material and is laminated on the dry reagent phase; and a diffusion layer which is formed from a sheet material composed of hydrophilic fibers and is arranged on the plasma separation unit in such a manner that a portion of the diffusion layer is exposed through the first opening. In the blood testing device, an outside region of a dry-reagent-layer-contacting part of a dry-reagent-layer-side surface of the plasma separation unit is adhered to the second substrate.

Description

[Technical Field]

[0001] The present invention relates to a blood testing device for measuring the presence or concentration of a specific substance in blood. [Background technology]

[0002] Blood tests that analyze the presence or concentration of specific substances in blood are widely used to diagnose the health condition of a subject. For example, by analyzing the content of various components in blood plasma, the organ function of the subject can be diagnosed.

[0003] In a typical blood test, the blood sample is separated into liquid components, such as plasma or serum, and solid components, such as cells, using a centrifuge or a suction / pressure pump. A certain amount of blood (e.g., 5 mL or more) is typically required for centrifugation, so a doctor, nurse, or clinical laboratory technician must draw blood from the subject. Therefore, typical blood tests can only be performed at medical institutions or specialized testing facilities equipped with expensive analytical equipment, such as centrifuges, and the power supplies required to operate them. Furthermore, the burden on medical professionals who draw the blood is significant. In other words, typical blood tests place a heavy burden not only on the subject but also on the medical institution, resulting in high costs.

[0004] Meanwhile, from the perspective of preventive medicine and extending healthy life expectancy, awareness of taking responsibility for one's own health is spreading throughout society, and along with this, there is a growing need for simple testing devices that can perform quick tests and allow results to be determined visually.

[0005] If a simple testing device could be developed that could separate plasma or serum from blood without using expensive analytical equipment or a power source and that could accurately test for the presence or concentration of specific substances contained in the separated plasma or serum, even those not in well-equipped medical institutions or testing laboratories, or even ordinary people without specialized skills, could easily and inexpensively perform testing themselves using a small amount of self-collected blood. This would be useful not only for the daily health management of ordinary people, but also for the health management of people at home who have difficulty going out. Furthermore, testing would be possible even in countries or regions with weak medical systems or in areas where it is difficult to secure power, such as disaster areas. Therefore, there is a great social demand for the development of an easy-to-use and highly accurate testing device.

[0006] Patent document 1 discloses a reagent strip comprising a test pad formed from an anisotropic membrane containing a color-developing reagent system specific to the analyte and having a side with relatively small pores defining a test surface and an opposite side with relatively large pores defining a sample receiving surface, and a porous sample transfer medium attached to the sample receiving surface of the test pad, the transfer medium being capable of receiving a whole blood sample and transferring a detectable portion of the sample to the sample receiving surface. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Publication No. 6-74953 Summary of the Invention [Problem to be solved by the invention]

[0008] In a test device in which a plasma separation section made of a porous material that separates plasma by passing blood through it and a reagent phase made of a dry reagent phase impregnated with a reagent are stacked, the plasma separated by the plasma separation section is allowed to soak into one side of the reagent phase, and the color reaction caused by the plasma that reaches the other side of the reagent phase is observed. Such simple test devices have the following problems.

[0009] To obtain reliable and reproducible test results, a necessary and sufficient amount of plasma must be brought into contact with the entire surface of the reagent phase. If the amount of plasma is insufficient, the sensitivity of the color reaction resulting from contact between the plasma and the reagent phase may be reduced, potentially making the reaction impossible to observe. Alternatively, if the amount of plasma is insufficient, the reaction may become uneven in the reagent phase, reducing the reproducibility of the test. On the other hand, if the amount of plasma is too large, the plasma may overflow the reagent phase and wrap around the sides of the reagent phase, resulting in an uneven reaction. In other words, it is important to supply an appropriate amount of plasma to the reagent phase. This allows for an accurate color reaction corresponding to the concentration of a specific substance contained in the blood, with good reproducibility. To achieve this, a certain range of blood volumes must be added to the test device.

[0010] However, in the case of test devices that allow general subjects to test themselves, a simple method of use is assumed in which the subject punctures a fingertip or the like to directly add (drop or spot) blood collected from the subject's fingertip or the like to the test device. For such test devices, it is not practical to have the subject measure the amount of blood using a pipette or other instrument in order to keep the amount of blood constant.

[0011] Furthermore, in the above-mentioned simple test device, as time passes after the start of the color reaction, the plasma evaporates from the surface of the reagent phase, causing the color of the reagent phase to change. Therefore, if colorimetric determination takes time, it becomes difficult to obtain stable test results.

[0012] The present invention has been made in view of the above, and aims to provide a blood testing device that can be used in a simple manner, has good reliability and reproducibility, and is capable of obtaining stable determination results. [Means for solving the problem]

[0013] In order to solve the above problems, one embodiment of the present invention provides a blood testing device for measuring the presence or concentration of a specific substance contained in blood based on a color reaction that occurs in a dry reagent phase impregnated with a reagent by bringing plasma separated from blood into contact with the dry reagent phase, the blood testing device comprising: a first substrate having a first opening formed therein to which blood is added; a second substrate disposed opposite the first substrate and having a second opening formed therein for observing the color reaction; a dry reagent phase laminated on the second substrate between the first and second substrates so that a portion of the dry reagent phase is exposed from the second opening; a plasma separation section formed from a porous sheet material and laminated on the dry reagent phase; and a diffusion layer formed from a sheet material made of hydrophilic fibers and disposed on the plasma separation section so that a portion of the diffusion layer is exposed from the first opening, and the area of ​​the surface of the plasma separation section facing the dry reagent phase outside the portion that contacts the dry reagent phase is adhered to the second substrate.

[0014] In the above blood test device, the ratio of the volume of the plasma separation section to the volume of the dry reagent phase may be 1.6 times or more and 3.7 times or less.

[0015] In the above-mentioned blood test device, a plurality of the second openings may be provided, a plurality of the dry reagent phases may be provided, and the ratio of the volume of the plasma separation section to the sum of the volumes of the plurality of dry reagent phases may be 1.6 times or more and 3.7 times or less.

[0016] In the above blood test device, the ratio may be 2.0 times or more and 3.1 times or less.

[0017] The blood testing device may further include a spacer that is disposed between the first substrate and the second substrate and that forms a space of a predetermined height between the first substrate and the second substrate, and the dry reagent phase, the plasma separation section, and the diffusion layer are disposed in the space, and the height of the spacer may be smaller than the sum of the thickness of the diffusion layer, the thickness of the plasma separation section, and the thickness of the dry reagent phase before the blood testing device is assembled.

[0018] In the above blood test device, the height of the spacer may be 0.65 to 0.9 times the sum.

[0019] In the above blood test device, the plasma separation section may include a polysulfone membrane or an asymmetric polysulfone membrane. [Effects of the Invention]

[0020] According to the present invention, it is possible to realize a blood testing device that can be used in a simple manner, has good reliability and reproducibility, and is capable of obtaining stable determination results. [Brief explanation of the drawings]

[0021] [Figure 1] 1 is a perspective view showing a blood test device according to an embodiment of the present invention (observation unit side). [Figure 2] FIG. 1 is a perspective view (blood addition section side) showing a blood test device according to an embodiment of the present invention. [Figure 3] FIG. 3 is an exploded perspective view of the blood test device shown in FIG. 2. [Figure 4] FIG. 3 is a partially enlarged cross-sectional view of the blood test device shown in FIG. 2. [Figure 5] 1 is a graph showing the average colorimetric sensitivity values ​​for experimental test devices. [Figure 6] 1 is a graph showing CV values ​​of colorimetric sensitivity in an experimental test device. [Figure 7] FIG. 10 is an exploded perspective view of a blood test device according to a modified example of an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0022] Hereinafter, blood test devices according to embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to these embodiments. In addition, in the description of each drawing, the same parts are designated by the same reference numerals.

[0023] The drawings referred to in the following description merely show the shapes, sizes, and positional relationships in a schematic manner to enable the understanding of the contents of the present invention. That is, the present invention is not limited to the shapes, sizes, and positional relationships exemplified in each drawing. Furthermore, there may be parts in which the dimensional relationships and ratios differ between the drawings. Here, in this specification, a trace amount refers to an amount of about several μL to several tens of μL.

[0024] The blood testing device described below measures the presence or concentration of a specific substance contained in plasma based on a color reaction that occurs in a dry reagent phase by contacting plasma separated from blood with a dry reagent phase impregnated with a reagent. Measurable test items are not particularly limited as long as they are components contained in plasma and exhibit a color reaction with a specific reagent. Specific examples of test items include AST, ALT, γ-GT, triglycerides, HDL cholesterol, LDL cholesterol, blood glucose, HbA1c, and minerals such as zinc and magnesium.

[0025] (Test device configuration) Figures 1 and 2 are perspective views showing a blood test device according to a first embodiment of the present invention. Of these, Figure 1 shows the blood test device as seen from the observation section side, and Figure 2 shows it as seen from the blood addition section side. Figure 3 is an exploded perspective view of the blood test device. Figure 4 is a partially enlarged cross-sectional view of the blood test device.

[0026] As shown in Figures 1 to 4, the blood test device (hereinafter also simply referred to as the test device) 10 of this embodiment comprises a first substrate 11 and a second substrate 12 arranged opposite each other, a diffusion layer 13 laminated between the first substrate 11 and the second substrate 12, a plasma separation section 14, and a reagent phase 15.

[0027] The first substrate 11 and the second substrate 12 are formed from a thin sheet material made of a resin material such as PET (polyethylene terephthalate). However, the material of the first substrate 11 and the second substrate 12 is not limited to resin, and may be any material that can maintain the shape of the testing device 10 and has a surface that is treated so as not to be penetrated by the sample blood or plasma or to react with these liquids. For example, the first substrate 11 and the second substrate 12 may be formed from cardboard with a water-repellent surface.

[0028] The first substrate 11 is formed with a blood addition section 111, which is an opening into which blood, which is a sample, is added. In this embodiment, the shape of the blood addition section 111 is elliptical, but this shape is not particularly limited and may be any shape that allows the addition of blood. Specific examples include rectangular and oval shapes. An alignment opening 112 may also be formed in the first substrate 11.

[0029] The second substrate 12 is formed with an observation section 121, which is an opening for observing the color reaction of the reagent phase 15. In this embodiment, the shape of the observation section 121 is square, but this shape is not particularly limited and may be circular, elliptical, or the like. From the viewpoint of ease of observation of the color reaction, it is preferable that the shape of the observation section 121 is similar to the shape of the reagent phase 15 and that the area of ​​the reagent phase 15 exposed from the observation section 121 is made as large as possible. Furthermore, an alignment opening 122 may be formed in the second substrate 12.

[0030] Providing such first substrate 11 and second substrate 12 prevents deformation of diffusion layer 13, plasma separation section 14, and reagent phase 15, and allows these three layers to maintain contact with each other. Note that first substrate 11 and second substrate 12 may be formed from two separate plates as shown in Figure 3, or may be formed by bending a single elongated plate.

[0031] A spacer 16 is disposed between the first substrate 11 and the second substrate 12. The spacer 16 forms a space 10a of a predetermined height between the first substrate 11 and the second substrate 12. In this space 10a, a reagent phase 15, a plasma separation section 14, and a diffusion layer 13 are stacked in this order from the second substrate 12 side.

[0032] The spacer 16 is formed from a plate material that is difficult to deform (compress) when pressed in the thickness direction, such as a resin material such as PET, and that does not penetrate the sample such as blood or plasma or react with these liquids.

[0033] 4, in this embodiment, the spacer 16 is adhered to the first substrate 11 and the second substrate 12 by double-sided tape 17. However, the method for fixing the spacer 16 to the first substrate 11 and the second substrate 12 is not limited to double-sided tape 17, and a liquid or paste adhesive may be used, or thermocompression bonding may be used. The key point is that the spacer 16 should be able to maintain the height of the space 10a constant.

[0034] The thickness of the spacer 16, i.e., the height of the space 10a, is smaller than the sum of the thicknesses of the diffusion layer 13, the plasma separation section 14, and the reagent phase 15 before the test device 10 is assembled. In other words, when the test device 10 is assembled, the first substrate 11 and the second substrate 12 apply a certain amount of pressure to the diffusion layer 13, the plasma separation section 14, and the reagent phase 15, maintaining the adjacent layers in close contact. The thickness of the spacer 16 is preferably 0.65 to 0.9 times the sum, and more preferably 0.7 to 0.85 times the sum. If the thickness of the spacer 16 is too small relative to the sum (e.g., less than 0.65 times), the plasma separation section 14 and the reagent phase 15 may be excessively compressed, potentially resulting in clogging. Furthermore, if the thickness of the spacer 16 is too large relative to the sum (e.g., more than 0.9 times), it may be difficult to maintain the diffusion layer 13, the plasma separation section 14, and the reagent phase 15 in close contact.

[0035] Diffusion layer 13 is formed from a member obtained by weaving hydrophilic fibers into a sheet, and is disposed so that a portion of it is exposed from blood addition section 111 provided on first substrate 11. Diffusion layer 13 quickly guides blood added to blood addition section 111 over a wide area in the planar direction by capillary action, causing the blood to be uniformly absorbed into one surface of plasma separation section 14. In this embodiment, diffusion layer 13 is made of a plain-woven hydrophilic polyester member. Also, in this embodiment, diffusion layer 13 is adhered to first substrate 11 with double-sided tape 17 attached around the periphery of blood addition section 111. Of course, diffusion layer 13 may be adhered to first substrate 11 using an adhesive or the like instead of double-sided tape 17.

[0036] The plasma separation unit 14 is formed of a porous sheet material and separates plasma by trapping cellular components from blood that has soaked into one surface and allowing liquid components to pass through in the membrane thickness direction. The plasma separation unit 14 can be made of a porous polymer membrane such as a polysulfone (PS) membrane or an asymmetric PS membrane. Among these, an asymmetric PS membrane has excellent blood separation performance, and even when the membrane is as thin as a few millimeters, it can produce colorless, transparent plasma that is free of whole blood or hemolyzed matter. In this embodiment, an asymmetric PS membrane is used as the plasma separation unit 14. The asymmetric PS membrane has directionality and is arranged in a direction that allows liquid to pass from the first substrate 11 to the second substrate 12. Alternatively, a multilayer structure in which a PS membrane or the like is combined with a glass fiber membrane may be used as the plasma separation membrane 14.

[0037] The plasma separation unit 14 is disposed so that its surface (first surface) facing the first substrate 11 is in contact with the diffusion layer 13, and its surface (second surface) facing the second substrate 12 is in contact with the reagent phase 15. Furthermore, of the second surface of the plasma separation unit 14, an area outside the portion in contact with the reagent phase 15 is adhered to the second substrate 12 with double-sided tape 17. This prevents plasma from seeping out from the outside area, preventing uneven reaction in the reagent phase 15 due to plasma seepage, and enabling plasma to be efficiently supplied from the plasma separation unit 14 to the reagent phase 15.

[0038] Note that instead of double-sided tape 17, an adhesive or the like may be used to adhere plasma separation unit 14 to second substrate 12. In either case, by adhering the outer region to second substrate 12 and eliminating any gap between them, unintended seepage of plasma from plasma separation unit 14 can be suppressed.

[0039] The reagent phase 15 is a dry reagent phase made by impregnating filter paper (chromatography paper, etc.) with a reagent appropriate for the test item and drying it, and is arranged so that a portion of the reagent phase 15 is exposed from the observation section 121. In this embodiment, the reagent phase 15 is adhered to the second substrate 12 by double-sided tape 17 attached to the periphery of the observation section 121. Of course, an adhesive or the like may be used instead of the double-sided tape 17.

[0040] The reagent phase 15 reacts with a predetermined substance contained in the plasma that has permeated the plasma separation section 14 and develops a color. This color reaction can be visually observed from the observation section 121 side when the plasma has sufficiently permeated the reagent phase 15.

[0041] The ratio of the volume of the plasma separation section 14 to the volume of the reagent phase 15 is preferably 1.6 to 3.7 times, and more preferably 2.0 to 3.1 times, before the test device 10 is assembled. If this volume ratio is too small (for example, less than 1.6 times), the amount of plasma held in the plasma separation section 14 will be small relative to the volume of the reagent phase 15, and the plasma supplied to the reagent phase 15 will be quickly depleted. This will cause the reagent phase 15 to dry out, making it difficult to observe a stable color reaction. On the other hand, if the volume ratio is too large (for example, more than 3.7 times), excessive plasma will be supplied to the reagent phase 15, which may cause uneven color reaction in the reagent phase 15 or liquid leakage, thereby reducing the reliability and reproducibility of the test results.

[0042] (How to use the inspection device) First, a fingertip or the like is punctured to induce bleeding and form a blood pool. Next, the blood addition section 111 of the test device 10 is faced downward, and the blood addition section 111 is brought into direct contact with the blood pool formed on the fingertip or the like. Then, when the entire surface of the reagent phase 15 exposed from the observation section 121 becomes wet, the test device 10 is removed from the fingertip or the like. After a predetermined time has passed, the color of the reagent phase 15 is compared with a reference color to estimate the concentration of the test item.

[0043] As another method of use, instead of directly contacting the testing device 10 with the blood pool, a simple liquid collection tool may be used. For example, the tip of a cylindrical liquid collection tool is brought into contact with the blood pool to hold the blood, and the tip is then brought into contact with the blood addition section 111 to transfer the blood. In this case, it is also possible to further add a diluent after adding the blood.

[0044] As described above, in the test device 10 according to this embodiment, the blood addition section 111 is provided with the diffusion layer 13. Therefore, when blood is added to the blood addition section 111, the blood spreads quickly along the diffusion layer 13 in the planar direction. Therefore, even if blood is added to only a portion of the blood addition section 111, the blood can be quickly and uniformly permeated over the entire surface of the plasma separation section 14. This allows plasma separation to proceed almost simultaneously in the planar direction of the plasma separation section 14, and allows a substantially uniform amount of plasma to permeate the entire surface of the reagent phase 15 in contact with the plasma separation section 14. As a result, variation in the reaction in the reagent phase 15 is suppressed, making it possible to obtain test results with good reliability and reproducibility.

[0045] Furthermore, in this embodiment, the region of the second surface of the plasma separation section 14 outside the portion in contact with the reagent phase 15 is adhered to the second substrate 12, which keeps the plasma in the reaction region and also makes the plasma separation membrane 14 adhere closely to the reagent phase 13, thereby promoting the penetration of the plasma into the reagent phase 15. This makes it possible to suppress unintended seepage of plasma from the plasma separation section 14, prevent uneven reaction in the reagent phase 15, and efficiently supply plasma from the plasma separation section 14 to the reagent phase 15 without waste.

[0046] Furthermore, according to this embodiment, the ratio of the volume of the plasma separation section 14 to the volume of the reagent phase 15 is preferably 1.6 to 3.7 times, more preferably 2.0 to 3.1 times, so that after being separated from the blood in the plasma separation section 14, the plasma retained in the plasma separation section 14 is continuously supplied to the reagent phase 15. In other words, even if the plasma evaporates from the surface of the reagent phase 15, new plasma is successively supplied from the back surface of the reagent phase 15, so that a stable color reaction can be observed in the observation section 121 for a certain period of time (at least several minutes to several tens of minutes).

[0047] Furthermore, in this embodiment, the spacer 16 is disposed between the first substrate 11 and the second substrate 12, so that the diffusion layer 13, the plasma separation section 14, and the reagent phase 15 can be disposed in the space 10a in a slightly compressed state. This allows these layers to adhere to each other, allowing plasma to be supplied uniformly in the planar direction from the plasma separation section 14 to the reagent phase 15. This suppresses reaction irregularities in the reagent phase 15, improving the reliability and reproducibility of test results. Furthermore, by applying a constant pressure to the plasma separation section 14 and the reagent phase 15, the plasma held in the plasma separation section 14 is continuously supplied to the reagent phase 15 at a substantially constant speed, thereby enabling stable determination results to be obtained.

[0048] Furthermore, in this embodiment, the volume ratio between the plasma separation section 14 and the reagent phase 15 is appropriately set, so that an appropriate amount of plasma can be supplied to the reagent phase 15 without accurately measuring the amount of blood to be added. In other words, even by a simple method such as directly contacting the blood addition section 111 with a blood pool formed on a fingertip or the like, reliable and reproducible test results can be stably obtained based on a small amount of blood. Therefore, even in regions or countries where testing facilities are not available, subjects can perform tests themselves, which can be useful for health management.

[0049] (Example) In a device having the same configuration as the test device 10, an experiment was carried out as follows to measure the colorimetric sensitivity of the reagent phase by changing the ratio of the volume of the plasma separation section to the volume of the reagent phase.

[0050] 1. Creation of experimental testing devices Nine experimental test devices were fabricated for each size of plasma separation section, with a reagent phase, plasma separation section, and diffusion layer made of the following materials placed between two substrates each having an opening for the blood addition section and an opening for the observation section. The spacer separating the two substrates was 0.5 mm thick. (1) Reagent phase Materials: Test paper impregnated with reagents for measuring glucose concentration (components: piperazine-1,4-bis(2-ethanesulfonic acid) (PIPES), N-ethyl-N-(2-hydroxy-3-sulfopropyl)-3,5-dimethoxyaniline sodium (DAOS), 4-aminoantipyrine (4-AA), mutarotase, peroxidase (POD), glucose oxidase) and dried. Size: 5mm x 5mm, thickness 0.17mm (volume: 4.25mm 3 ) (2)Plasma separation section Material: Asymmetric polysulfone Sizes: 5mm x 4mm, 5mm x 5mm, 5mm x 6mm, 5mm x 7mm, 5mm x 8mm, 5mm x 9mm, 5mm x 10mm, 6 types, thickness is only 0.33mm (volume: 6.6mm 3 ~16.5mm 3 ) (3) Diffusion layer Material: Hydrophilic polyester plain weave sheet Size: 5mm x 10mm, thickness: 0.12mm

[0051] 2. Liquid Samples Control blood (55% plasma, 45% blood cells) 10μL

[0052] 3. Experimental Method (1) 10 μL of control blood was added to the blood addition section of the test device. (2) Three minutes after the sample was added, the exposed reagent phase in the observation area was photographed with an optical camera, and the RGB values ​​of the reagent phase in the image were measured. (3) After another 2 minutes (5 minutes after the addition of the sample), the reagent phase exposed in the observation area was photographed with an optical camera, and the RGB values ​​of the reagent phase portion in the image were measured. (4) The ratio of the RGB values ​​of the reagent phase 3 minutes after the addition of the sample to the RGB values ​​of the reagent phase 5 minutes after the addition of the sample (RGB values ​​after 5 minutes / RGB values ​​after 3 minutes) was calculated. This ratio was defined as the colorimetric sensitivity. (5) The average value and CV value of the colorimetric sensitivity were calculated for each size of the plasma separation section.

[0053] 4. Experimental Results Figure 5 is a graph showing the average value of colorimetric sensitivity (in the case of R values) in the experimental test device. Figure 6 is a graph showing the CV value of colorimetric sensitivity (in the case of R values) in the experimental test device. In Figures 5 and 6, the horizontal axis shows the ratio of the volume of the plasma separation section to the volume of the reagent phase.

[0054] Here, the closer the colorimetric sensitivity value is to 1, the less the RGB values ​​change over time, meaning that more stable test results can be obtained. Also, the smaller the CV value of colorimetric sensitivity, the less variability there is in the results, meaning that the results are more reproducible and therefore more reliable.

[0055] 5 and 6, when the volume ratio is in the range of about 1.6 to about 3.7 times, the CV value of the colorimetric sensitivity is about 5% or less, which is a relatively small variation, and the average value of the colorimetric sensitivity is also within a range of about 1 (±0.1). Furthermore, when the volume ratio is in the range of about 2.0 to about 3.1 times, the CV value of the colorimetric sensitivity is about 3% or less, which is an even smaller variation.

[0056] From the above experimental results, it was found that in the test device, by setting the ratio of the volume of the plasma separation section to the volume of the reagent phase to be 1.6 to 3.7 times, stable test results with little variability could be obtained. Furthermore, it was found that by setting the above volume ratio to be 2.0 to 3.1 times, variability in test results could be further suppressed. Here, in this specification, the ratio of the volume of the plasma separation section to the volume of the reagent phase is not strictly limited to the above ratio, and may include a range of approximately ±10%.

[0057] (Variation) Figure 7 is an exploded perspective view of a blood testing device according to a modified embodiment of the present invention. As shown in Figure 7, blood testing device 20 according to this modified embodiment is a device for testing multiple items, and includes first substrate 21 and second substrate 22 arranged opposite each other via spacer 26, diffusion layer 23 arranged between first substrate 21 and second substrate 22, plasma separation section 24, and multiple reagent phases 25a, 25b, and 25c. The materials and functions of these components are similar to those of first substrate 11, second substrate 12, diffusion layer 13, plasma separation section 14, reagent phase 15, and spacer 16 in the first embodiment, respectively.

[0058] A blood addition section 211, which is an opening into which blood as a sample is added, is formed on first substrate 21. The shape of blood addition section 211 is not particularly limited, and may be rectangular as shown in Fig. 7, or may be elliptical or oblong.

[0059] Furthermore, a plurality of observation portions 22a, 22b, and 22c, which are openings for observing a color reaction, are formed on the second substrate 22. The plurality of reagent phases 25a, 25b, and 25c are arranged so that a portion thereof is exposed from the observation portions 22a, 22b, and 22c, respectively. Note that alignment openings 212 and 222 may be formed in the first substrate 21 and the second substrate 22, respectively.

[0060] The surface of the plasma separation unit 24 facing the reagent phases 25a, 25b, and 25c, excluding the areas in contact with the reagent phases 25a, 25b, and 25c, including the areas between the reagent phases 25a, 25b, and 25c, is adhered to the second substrate 22 with double-sided tape, adhesive, or the like. This prevents plasma leakage from the surface of the plasma separation unit 24 facing the reagent phases 25a, 25b, and 25c, excluding the areas in contact with the reagent phases 25a, 25b, and 25c. Furthermore, the flow of liquid between adjacent reagent phases 25a, 25b, and 25c through these passages can be prevented, thereby preventing plasma seepage between adjacent reagent phases. This prevents uneven reactions in the reagent phases 25a, 25b, and 25c and color transfer between adjacent reagent phases due to plasma seepage, and enables plasma to be efficiently supplied from the plasma separation unit 24 to the reagent phases 25a, 25b, and 25c without waste.

[0061] In this modified example, as in the above embodiment, the ratio of the volume of the plasma separation section 24 to the sum of the volumes of the multiple reagent phases 25a, 25b, 25c is preferably 1.6 times or more and 3.7 times or less, and more preferably 2.0 times or more and 3.1 times or less. [Explanation of symbols]

[0062] 10, 20... Blood test device (test device), 10a... Space, 11, 21... First substrate, 12, 22... Second substrate, 13, 23... Diffusion layer, 14, 24... Plasma separation section, 15, 25a, 25b, 25c... Reagent phase, 16, 26... Spacer, 17... Double-sided tape, 111, 211... Blood addition section, 112, 122, 212, 222... Opening, 121, 22a, 22b, 22c... Observation section

Claims

1. A blood testing device for measuring the presence or concentration of a specific substance contained in blood based on a color reaction that occurs in a dry reagent layer by bringing plasma separated from the blood into contact with the dry reagent layer, the device comprising: a first substrate having a first opening formed therein to which blood is added; a second substrate disposed opposite the first substrate and having a second opening formed therein for observing a color reaction; a dry reagent layer laminated on the second substrate between the first and second substrates so that a portion of the dry reagent layer is exposed through the second opening; a plasma separation unit formed of a porous sheet material and laminated on the dry reagent layer; a diffusion layer formed of a sheet material made of hydrophilic fibers and disposed on the plasma separation unit so that a portion of the diffusion layer is exposed from the first opening; Equipped with a region of the surface of the plasma separation unit facing the dry reagent layer, outside the portion in contact with the dry reagent layer, that is bonded to the second substrate.

2. 2. The blood test device according to claim 1, wherein the ratio of the volume of the plasma separation section to the volume of the dry reagent layer is 1.6 times or more and 3.7 times or less.

3. a plurality of the second openings are provided; A plurality of the dry reagent layers are provided, 2. The blood test device according to claim 1, wherein a ratio of the volume of the plasma separation section to the sum of the volumes of the plurality of dry reagent layers is 1.6 times or more and 3.7 times or less.

4. The blood test device according to claim 2 or 3, wherein the ratio is 2.0 times or more and 3.1 times or less.

5. a spacer disposed between the first substrate and the second substrate to form a space of a predetermined height between the first substrate and the second substrate; the dry reagent layer, the plasma separation section, and the diffusion layer are disposed in the space; The blood test device according to any one of claims 1 to 4, wherein the height of the spacer is smaller than the sum of the thickness of the diffusion layer, the thickness of the plasma separation section, and the thickness of the dry reagent layer before the blood test device is assembled.

6. The blood test device according to claim 5 , wherein the height of the spacer is 0.65 to 0.9 times the sum.

7. The blood test device according to any one of claims 1 to 6, wherein the plasma separation section includes a polysulfone membrane or an asymmetric polysulfone membrane.

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