Test strip

Abstract

The test strip (12) includes: a flow path (26) formed in the main body (20), a reagent part (22b) provided in the flow path (26), and a placement part (24) provided at the start end of the flow path (26) for introducing a sample into the flow path (26). In the main body (20), there are provided: a buffer space (28) communicating with the terminal of the flow path (26), and an exhaust hole (30) opening on the outer surface of the main body (20) and communicating with the buffer space (28). In the region where the buffer space (28) is spatially connected to the flow path (26), the cross-sectional area (Sb) of the buffer space (28) is larger than the cross-sectional area (S) of the flow path (26).

Description

Technical Field

[0001] The present invention relates to a test strip. Background Art

[0002] For example, Japanese Unexamined Patent Application Publication No. 2007-10558 discloses a test strip including: a main body portion in which a flow path for blood (sample) to flow is formed, a reagent portion disposed in the flow path, an exhaust hole for discharging air in the flow path, and a volume expansion material provided at the exhaust hole. When blood is guided to the end of the flow path, the volume expansion material expands due to the blood and blocks the exhaust hole. Thereby, leakage of the blood flowing in the flow path to the outside of the main body portion can be suppressed.

[0003] In a test strip such as that disclosed in Japanese Unexamined Patent Application Publication No. 2007-10558, since it is necessary to provide a volume expansion material, the cost of the test strip may increase. Summary of the Invention

[0004] The present invention has been made in consideration of such problems, and an object thereof is to provide a test strip that can suppress an increase in cost and suppress leakage of a sample in a flow path from an exhaust hole to the outside of a main body portion.

[0005] A test strip according to one aspect of the present invention includes a flow path formed in a main body portion, a reagent portion disposed in the flow path, and a loading portion provided at a start end of the flow path for introducing a sample into the flow path. In the main body portion, a buffer space communicating with a terminal end of the flow path and an exhaust hole opening on an outer surface of the main body portion and communicating with the buffer space are provided. In a region where the buffer space is spatially connected to the flow path, a cross-sectional area of the buffer space is larger than a cross-sectional area of the flow path.

[0006] According to the present invention, in a region where the buffer space is spatially connected to the flow path, the cross-sectional area of the buffer space is larger than the cross-sectional area of the flow path. Therefore, in a connection portion between the buffer space, which is a terminal end of the flow path, and the flow path, an interfacial tension component in a flow direction is reduced for blood in the flow path. Therefore, it is difficult to generate a capillary force such that the blood is sucked into the buffer space. In addition, even if it is assumed that a sample in the flow path flows into the buffer space, the sample can be stored in the buffer space. Thereby, an increase in cost can be suppressed, and leakage of the sample from the exhaust hole to the outside of the main body portion can be suppressed. Brief Description of the Drawings

[0007] Figure 1 is a plan view showing an overall structure of a component measurement system including a test strip according to one embodiment of the present invention.

[0008] Figure 2 is Figure 1 a perspective view of the test strip.

[0009] Figure 3 is Figure 2 exploded perspective view of the test strip.

[0010] Figure 4 is Figure 2 longitudinal sectional view of the test strip.

[0011] Figure 5A is along Figure 4 cross-sectional view along the VA-VA line of Figure 5B is along Figure 4 cross-sectional view along the VB-VB line of

[0012] Figure 6 is observed from one side in the thickness direction of Figure 2 top view of the test strip.

[0013] Figure 7 is showing Figure 2 flow chart of the manufacturing process of the test strip.

[0014] Figure 8 is sectional explanatory view for explaining the deviation amount of the test strip.

[0015] Figure 9 is sectional view omitting a part of Figure 1 the component measurement system.

[0016] Figure 10A is longitudinal sectional view of the test strip of Example 1, Figure 10B is from Figure 10A top view observed in the thickness direction of the test strip.

[0017] Figure 11A is longitudinal sectional view of the test strip of Comparative Example 1, Figure 11B is from Figure 11A top view observed in the thickness direction of the test strip.

[0018] Figure 12A is longitudinal sectional view of the test strip of Comparative Example 2, Figure 12B is from Figure 12A top view observed in the thickness direction of the test strip.

[0019] Figure 13A is longitudinal sectional view of the test strip of Comparative Example 3, Figure 13B is from Figure 13A top view observed in the thickness direction of the test strip.

[0020] Figure 14A is longitudinal sectional view of the test strip of Comparative Example 4, Figure 14B is from Figure 14A top view observed in the thickness direction of the test strip.

[0021] Figure 15 It is a table showing the first test results.

[0022] Figure 16 It is a diagram showing the second test results. Detailed implementation

[0023] Hereinafter, preferred embodiments of the test strip of the present invention will be listed and described with reference to the accompanying drawings.

[0024] As Figure 1 shown, the analyte measurement system 10 of an embodiment of the present invention includes: a test strip 12 capable of holding a sample, and an analyte measurement device 14 that measures the amount of analyte contained in the sample by attaching the test strip 12.

[0025] A sample is introduced into the test strip 12. The test strip 12 is configured to be held at a detection target position in the analyte measurement device 14 in a state where the sample and the reagent react and develop color inside it (color development state). On the other hand, the analyte measurement device 14 optically detects the reaction product of the sample and the reagent at the detection target position of the test strip 12. In addition, the test strip 12 is sometimes also referred to as a contact, a sensor, etc. The "sample" can be whole blood (blood) or separated plasma. In addition, the sample can also be other body fluids or an aqueous solution containing an analyte.

[0026] Hereinafter, the analyte measurement system 10 (blood glucose measurement system) for measuring the amount of an analyte (here, glucose) when the sample is blood will be described representatively. In particular, the analyte measurement device 14 includes a measurement unit 18 that irradiates the detection target position with measurement light of a specified wavelength and detects the measurement light (transmitted light) after passing through the detection target, and thus is configured as a blood glucose meter 16 for measuring blood glucose levels.

[0027] The test strip 12 is provided with a reagent. The reagent contains a chromogenic reagent that dissolves in the sample and reacts according to the amount of the analyte in the sample. Therefore, when the reagent comes into contact with the analyte, a chromogenic reaction occurs in which the chromogenic reagent develops color, generating a chromogenic component (reaction product). The reagent of the present embodiment reacts specifically with glucose. As the reagent of the present embodiment, for example, a mixed reagent of (i) glucose oxidase (GOD), (ii) peroxidase (POD), (iii) 1-(4-sulfophenyl)-2,3-dimethyl-4-amino-5-pyrazolone, (iv) N-ethyl-N-(2-hydroxy-3-sulfopropyl)-3,5-dimethylaniline, sodium salt, monohydrate (MAOS), or a mixed reagent of glucose dehydrogenase (GDH) and a tetrazolium salt, etc. are exemplified. Also, a buffer such as a phosphate buffer, a medium, and an additive may be contained in the reagent. The type and composition of the reagent are not limited to these. In the present embodiment, the blood glucose meter 16 uses the mixture of the chromogenic component (reaction product) and the sample as the detection target. Particularly, when measuring light of a specified wavelength is irradiated to the detection target position and the transmitted light (transmitted light) after passing through the detection target is detected, instead of using a porous member or a carrier, it is preferable to directly apply the prepared mixed reagent solution to a specified position inside the test strip 12 and dry it.

[0028] In addition, the component measurement system 10 is used as a measurement system for personal use operated by a user (patient). For example, the user uses the test strip 12 and the blood glucose meter 16 to measure the blood glucose level and perform self-blood glucose management. In addition, the component measurement system 10 can also be used in a medical facility or the like as a device for a medical practitioner to measure the blood glucose level of a patient.

[0029] When the test strip 12 is assembled to the blood glucose meter 16, a part thereof protrudes to the outside of the blood glucose meter 16. The test strip 12 has an opening (insertion portion 24) in the part protruding from the blood glucose meter 16. Blood is introduced into the test strip 12 through the insertion portion 24, thereby performing the blood glucose level measurement using the blood glucose meter 16. The test strip 12 is a disposable device that is discarded after each measurement.

[0030] As Figure 2As shown, the test strip 12 has a strip-shaped (flat plate-shaped) main body 20 and a reagent piece 22 (reagent component) provided on the main body 20. The long axis direction (arrow X direction) of the main body 20 is the insertion and removal direction with respect to the blood glucose meter 16. Here, when the main body 20 is assembled to the blood glucose meter 16, one end side (arrow X1 direction) of the main body 20 is exposed from the blood glucose meter 16, and the other end side (arrow X2 direction) of the main body 20 is housed inside the blood glucose meter 16. When viewed from the thickness direction of the main body 20 (viewed from the arrow Z direction), one end portion (the end portion in the arrow X1 direction) of the main body 20 is formed in a substantially semicircular shape. When viewed from the thickness direction of the main body 20 (viewed from the arrow Z direction), the other end portion (the end portion in the arrow X2 direction) of the main body 20 is formed in a rectangular shape. That is, when viewed from the thickness direction, the outer shape of the main body 20 is a substantially rectangular shape with one side bulging in an arc shape. In addition, when the main body 20 is assembled to the blood glucose meter 16, at least the area from the other end (the end portion in the arrow X2 direction) of the main body 20 to the reagent piece 22 is housed inside the blood glucose meter 16.

[0031] As Figures 2 to 4 shown, the main body 20 is formed by laminating and integrating a plurality of plate bodies 32 in the thickness direction of the plate bodies 32 (arrow Z direction). Hereinafter, from Figure 3 above (arrow Z1 direction) to below (arrow Z2 direction) in, the plurality of plate bodies 32 are referred to as a first plate body 32A, a second plate body 32B, a third plate body 32C, a fourth plate body 32D, a fifth plate body 32E, and a sixth plate body 32F. The outer edges of the first to sixth plate bodies 32A to 32F are formed in substantially the same shape when viewed from above in the arrow Z direction. More specifically, the outer edges of the plurality of plate bodies 32 are formed in a substantially rectangular shape with an arc at one end portion when viewed from above in the arrow Z direction. In addition, in the plurality of plate bodies 32, space portions such as the later-described cutout portions 24a to 24d and vent holes 30 are appropriately cut out. A bonding layer (not shown) made of an adhesive or the like is provided between the mutually adjacent plate bodies 32. Through this bonding layer, the adjacent plate bodies 32 are firmly bonded to each other.

[0032] In the main body 20, there are provided a loading portion 24 for loading blood into the main body 20, a flow path 26 for guiding the blood loaded into the loading portion 24 to the reagent strip 22, a buffer space 28 communicating with the flow path 26, and an exhaust hole 30 communicating with the buffer space 28. When viewed from above in the arrow Z direction, the loading portion 24 is provided at one end side (in the arrow X1 direction) of the main body 20 formed in an arc shape. The flow path 26 transfers blood by capillary force. One surface of the loading portion 24 in the arrow Z1 direction is open, and the other surface of the loading portion 24 in the arrow Z2 direction is covered by the fifth plate body 32E. However, the surface of the loading portion 24 in the arrow Z2 direction may be covered by the sixth plate body 32F instead of the fifth plate body 32E, or may be covered by both the fifth plate body 32E and the sixth plate body 32F. One end side (in the arrow X1 direction) of the flow path 26 is open in the loading portion 24. The length of the loading portion 24 in the width direction is longer than the length of the flow path 26 in the width direction. The loading portion 24, the flow path 26, and the buffer space 28 are formed by stacking space portions formed in the respective plate bodies 32.

[0033] The plurality of plate bodies 32 may be made of resin materials such as polyethylene terephthalate (PET), polymethyl methacrylate (PMMA), polyester, polycarbonate, polystyrene, polypropylene, acrylonitrile-butadiene-styrene copolymer (ABS), cycloolefin polymer (COP), cycloolefin copolymer (COC). When the component measuring device 14 is of a type that detects the measurement light (transmitted light) that has passed through the object to be detected, the passage of the measurement light is made of a transparent material. The plate body 32 may also be mixed with pigments according to the purpose. When the plate body 32 is used as a light-shielding member, a resin material containing carbon black is used. In addition, according to the measurement method of JIS K7605; 1976 (withdrawn standard), the light-shielding rate of the light-shielding member is preferably 90% or more, and a black thin plate member having a light-shielding rate of 99% or more can be preferably used. As the thickness of each of the plate bodies 32, it is preferably 20 μm to 50 μm, and more preferably 20 μm to 100 μm.

[0034] As Figure 3 and Figure 4 shown, the first plate body 32A is a planar member disposed at the end (the end in the arrow Z1 direction) on one side in the thickness direction of the test strip 12. A first cutout portion 24a and an exhaust hole 30 are formed in the first plate body 32A.

[0035] The first cutout portion 24a forms a part of the loading portion 24. The first cutout portion 24a is formed at the end of the first plate body 32A in the arrow X1 direction. The first cutout portion 24a is formed in a rectangular shape that is open on one side when viewed from above in the arrow Z direction.

[0036] As the first plate body 32A, a black sheet member having light-shielding properties can also be used. When a light-shielding member is used as the first plate body 32A, a first opening 36 (aperture diameter) is also formed in the first plate body 32A. Thus, the first plate body 32A constitutes a light-shielding portion 34 that blocks part of the measurement light in the test strip 12. The first opening 36 is independently provided at a position that is a predetermined distance away from the first cutout portion 24a in the direction of arrow X2. The first opening 36 is a through hole of the first plate body 32A that allows the measurement light to pass through in the thickness direction of the test strip 12. The first opening 36 is located approximately at the center in the width direction (direction of arrow Y) of the first plate body 32A. The first opening 36 is formed in a circular shape. Additionally, instead of the first opening 36, a transparent portion (light guide portion) through which the measurement light can pass may be provided in the first plate body 32A. Through the first opening 36, a measurement light amount required for optical detection of the reaction product (measurement target) of the sample and the reagent can pass through the first opening 36 and reach the detection target. Furthermore, by using a light-shielding member for the first plate body 32A, stray light that affects the detection accuracy can be reduced.

[0037] The space of the exhaust hole 30 is connected to the buffer space 28, and the exhaust hole 30 opens on the surface of the first plate body 32A in the Z1 direction (outer surface of the test strip 12). The exhaust hole 30 is a hole for discharging the air in the flow path 26 and the buffer space 28 to the outside of the main body portion 20 when guiding blood from the placement portion 24 to the flow path 26. The exhaust hole 30 is independently provided at a position that is a predetermined distance away from the first opening 36 in the direction of arrow X2. The exhaust hole 30 is located approximately at the center in the width direction (direction of arrow Y) of the first plate body 32A.

[0038] The second plate body 32B is a sheet-like member laminated on the other side (direction of arrow Z2) of the first plate body 32A in the thickness direction of the test strip 12. A second cutout portion 24b and a first buffer hole 28a are formed in the second plate body 32B.

[0039] The second cutout portion 24b forms a part of the placement portion 24. The second cutout portion 24b is formed at the end of the second plate body 32B in the direction of arrow X1. The second cutout portion 24b is formed in a rectangular shape when viewed from above in the direction of arrow Z. The second cutout portion 24b communicates with the first cutout portion 24a in the direction of arrow Z2. The second cutout portion 24b is formed to have the same size and the same shape as the first cutout portion 24a.

[0040] The first buffer hole 28a forms a part of the buffer space 28. The first buffer hole 28a is a rectangular through hole that penetrates the second plate body 32B in the thickness direction. Specifically, the first buffer hole 28a is formed in a square shape when viewed from above in the direction of arrow Z. However, the first buffer hole 28a may be a rectangle extending in the direction of arrow X or a rectangle extending in the direction of arrow Y.

[0041] The first buffer hole 28a is independently provided at a position that is separated from the second cutout portion 24b by a predetermined distance in the direction of arrow X2. The first buffer hole 28a is located approximately at the center in the width direction of the second plate body 32B. On both sides of the first buffer hole 28a in the direction of arrow Y, there are wall portions of the second plate body 32B. The first buffer hole 28a is formed at a position facing the exhaust hole 30. That is, the first buffer hole 28a communicates with the exhaust hole 30 in the direction of arrow Z2. The first buffer hole 28a is formed to be larger in size than the exhaust hole 30 when viewed from above in the direction of arrow Z.

[0042] The wall portion 38 between the second cutout portion 24b and the first buffer hole 28a in the second plate body 32B covers the side in the direction of arrow Z2 of the first opening 36 (see Figure 4 ). The wall portion 38 is formed transparently so that the light passing through the first opening 36 can pass through. The entire second plate body 32B is formed to be transparent (colorless transparent or colored transparent). Only a part of the wall portion 38 of the second plate body 32B may be formed to be transparent, and the portion other than the wall portion 38 may be formed to be opaque.

[0043] The third plate body 32C is a sheet-like member laminated on the second plate body 32B in the direction of arrow Z2. A third cutout portion 24c, a first flow path groove 26a, and a second buffer hole 28b are formed in the third plate body 32C.

[0044] The third cutout portion 24c forms a part of the insertion portion 24. The third cutout portion 24c is formed at the end of the third plate body 32C in the direction of arrow X1. The third cutout portion 24c is formed to be rectangular when viewed from above in the direction of arrow Z. The third cutout portion 24c communicates with the second cutout portion 24b in the direction of arrow Z2. The third cutout portion 24c is formed to have the same size and the same shape as the first cutout portion 24a and the second cutout portion 24b, respectively.

[0045] The first flow path groove 26a forms a part of the flow path 26. The first flow path groove 26a extends linearly along the length direction of the third plate body 32C. The first flow path groove 26a penetrates the third plate body 32C in the thickness direction. The first flow path groove 26a is located approximately at the center in the width direction of the third plate body 32C. One end (the end in the direction of arrow X1, the starting end) of the first flow path groove 26a communicates with the third cutout portion 24c. The other end (the end in the direction of arrow X2, the terminal end) of the first flow path groove 26a communicates with the second buffer hole 28b. That is, the third cutout portion 24c, the first flow path groove 26a, and the second buffer hole 28b form a continuous space.

[0046] The first flow path groove 26a is formed to be narrower in width than the third cutout portion 24c. The first flow path groove 26a is covered in the direction of arrow Z1 by the wall portion 38 of the second plate body 32B (see Figure 4)。That is, the wall portion 38 of the second plate body 32B liquid-tightly blocks the liquid between the first flow path groove 26a and the first opening 36. The wall portion 38 of the second plate body 32B is the top surface of the flow path 26 in the arrow Z1 direction.

[0047] The second buffer hole 28b forms a part of the buffer space 28. The second buffer hole 28b is a rectangular through hole that penetrates the third plate body 32C in the thickness direction. Specifically, the second buffer hole 28b is formed as a square when viewed from above in the arrow Z direction. However, the second buffer hole 28b may be a rectangle extending in the arrow X direction or a rectangle extending in the arrow Y direction.

[0048] The second buffer hole 28b is located approximately at the center in the width direction of the third plate body 32C. On both sides of the second buffer hole 28b in the arrow Y direction, there are wall portions of the third plate body 32C. The second buffer hole 28b is formed at a position opposed to the first buffer hole 28a. That is, the second buffer hole 28b communicates with the first buffer hole 28a in the arrow Z2 direction. The second buffer hole 28b is formed to have the same size and the same shape as the first buffer hole 28a. The second buffer hole 28b is formed to be wider than the first flow path groove 26a. In other words, when viewed from above in the arrow Z direction, the width of the second buffer hole 28b expands toward both sides in the arrow Y direction with respect to the first flow path groove 26a.

[0049] The fourth plate body 32D is a thin plate-like member laminated on the arrow Z2 direction side with respect to the third plate body 32C. A fourth cutout portion 24d, a second flow path groove 26b, a reagent dispensing hole 40, and a third buffer hole 28c are formed in the fourth plate body 32D.

[0050] The fourth cutout portion 24d forms a part of the insertion portion 24. The fourth cutout portion 24d is formed at the end in the arrow X1 direction of the fourth plate body 32D. The fourth cutout portion 24d is formed as a rectangle when viewed from above in the arrow Z direction. The fourth cutout portion 24d communicates with the third cutout portion 24c in the arrow Z2 direction. The fourth cutout portion 24d is formed to have the same shape and the same size as the first cutout portion 24a, the second cutout portion 24b, and the third cutout portion 24c, respectively.

[0051] The second flow path groove 26b forms a part of the flow path 26. The second flow path groove 26b extends linearly along the length direction of the fourth plate body 32D. The second flow path groove 26b penetrates the fourth plate body 32D in the thickness direction. The second flow path groove 26b is located approximately at the center in the width direction of the fourth plate body 32D. One end (the end in the arrow X1 direction, the starting end) of the second flow path groove 26b communicates with the fourth cutout portion 24d. The second flow path groove 26b terminates at the position of the reagent dispensing hole 40.

[0052] The second flow path groove 26b is formed to be narrower in width than the fourth cutout portion 24d. The second flow path groove 26b is formed at a position opposed to the first flow path groove 26a. That is, the second flow path groove 26b communicates with the first flow path groove 26a in the arrow Z2 direction. The width of the second flow path groove 26b in the arrow Y direction is the same as the width of the first flow path groove 26a in the arrow Y direction. In the arrow X direction, the overall length of the second flow path groove 26b is shorter than the overall length of the first flow path groove 26a (see Figure 4 ).

[0053] The reagent dispensing hole 40 is a space where the reagent sheet 22 can be dispensed, and is provided between the second flow path groove 26b and the third buffer hole 28c. The reagent dispensing hole 40 penetrates the fourth plate body 32D in the thickness direction and extends in a rectangle over the entire width (the overall length in the arrow Y direction) of the fourth plate body 32D. The reagent dispensing hole 40 is opposed to the end portion of the first flow path groove 26a in the arrow X2 direction.

[0054] The fourth plate body 32D is divided into a first member 42a, a second member 42b, and a third member 42c by the fourth cutout portion 24d, the second flow path groove 26b, and the reagent dispensing hole 40. The first member 42a and the second member 42b are disposed on both sides in the arrow Y direction of the second flow path groove 26b. The side surfaces on the central axis side of the first member 42a and the second member 42b form a part of the wall of the flow path 26. The third member 42c is disposed in the arrow X2 direction of the first member 42a and the second member 42b with the reagent dispensing hole 40 therebetween.

[0055] The third buffer hole 28c forms a part of the buffer space 28. The third buffer hole 28c is a rectangular through hole that penetrates the fourth plate body 32D in the thickness direction. Specifically, the third buffer hole 28c is formed as a square when viewed from the arrow Z direction. However, the third buffer hole 28c may be a rectangle extending in the arrow X direction or a rectangle extending in the arrow Y direction.

[0056] The third buffer hole 28c is located approximately at the center in the width direction of the fourth plate body 32D. On both sides in the arrow Y direction of the third buffer hole 28c, there are wall portions of the fourth plate body 32D. The third buffer hole 28c is formed at a position opposed to the second buffer hole 28b. That is, the third buffer hole 28c communicates with the second buffer hole 28b in the arrow Z2 direction. The third buffer hole 28c is formed to have the same size and the same shape as the first buffer hole 28a and the second buffer hole 28b, respectively.

[0057] The fifth plate body 32E is a thin plate-like member laminated on the fourth plate body 32D in the arrow Z2 direction. A reagent insertion hole 44 and a fourth buffer hole 28d are formed in the fifth plate body 32E.

[0058] The reagent insertion hole 44 faces the reagent preparation hole 40 and is formed in the same shape. The reagent insertion hole 44 faces the reagent preparation hole 40 in the direction of arrow Z2. That is, the reagent insertion hole 44 penetrates the fifth plate body 32E in the thickness direction and extends along the entire width of the fifth plate body 32E (the entire length in the direction of arrow Y).

[0059] The fifth plate body 32E is divided into a first component 46a and a second component 46b by the reagent insertion hole 44. The first component 46a is arranged in the direction of arrow X1 so as to sandwich the reagent insertion hole 44 with respect to the second component 46b. The first component 46a hermetically covers the fourth cutout portion 24d and the second flow path groove 26b from the direction of arrow Z2 (refer to Figure 4 ). The end of the first component 46a in the direction of arrow X1 is formed in a semicircular shape.

[0060] The fourth buffer hole 28d forms part of the buffer space 28. The fourth buffer hole 28d is a rectangular through-hole that penetrates the fifth plate body 32E in the thickness direction. Specifically, the fourth buffer hole 28d is formed in a square shape when viewed from the direction of arrow Z. However, the fourth buffer hole 28d may be a rectangle extending in the direction of arrow X or a rectangle extending in the direction of arrow Y.

[0061] The fourth buffer hole 28d is located approximately at the center in the width direction of the fifth plate body 32E. On both sides of the fourth buffer hole 28d in the direction of arrow Y, there are wall portions of the fifth plate body 32E. The fourth buffer hole 28d is formed at a position facing the third buffer hole 28c. That is, the fourth buffer hole 28d communicates with the third buffer hole 28c in the direction of arrow Z2. The fourth buffer hole 28d is formed to have the same size and the same shape as the first buffer hole 28a, the second buffer hole 28b, and the third buffer hole 28c respectively.

[0062] The sixth plate body 32F is a thin plate-like component laminated on the fifth plate body 32E in the direction of arrow Z2. The sixth plate body 32F is a planar component arranged at the end in the thickness direction of the test strip 12 (the end in the direction of arrow Z2). The sixth plate body 32F forms one surface of the test strip 12. The sixth plate body 32F hermetically covers the fourth buffer hole 28d from the direction of arrow Z2 (refer to Figure 4 ). A second opening 48 is formed in the sixth plate body 32F.

[0063] The second opening 48 is a circular through-hole that allows the measurement light to pass through in the thickness direction of the test strip 12. The second opening 48 is located in the direction of arrow Z2 with respect to the first opening 36. The diameter of the second opening 48 is larger than the diameter of the first opening 36 (refer to Figure 6)。In other words, when viewed from the direction of arrow Z, the second opening 48 is arranged such that the entirety of the first opening 36 is located inside the second opening 48. In addition, a transparent portion (light guide portion) through which measurement light can pass may be provided in the sixth plate body 32F instead of the second opening 48.

[0064] In the main body portion 20 configured as described above, the placement portion 24 is formed by a first cutout portion 24a, a second cutout portion 24b, a third cutout portion 24c, and a fourth cutout portion 24d. The flow path 26 is formed by a first flow path groove 26a and a second flow path groove 26b. The length of the placement portion 24 in the width direction is longer than the length of the flow path 26 in the width direction. The buffer space 28 is formed by a first buffer hole 28a, a second buffer hole 28b, a third buffer hole 28c, and a fourth buffer hole 28d. The surface on one end side (in the direction of arrow Z2) of the buffer space 28 is sealed by the sixth plate body 32F, and the surface on the other end side (in the direction of arrow Z1) of the buffer space 28 is covered by the first plate body 32A having the exhaust hole 30. The length of the buffer space 28 in the width direction is longer than either the length of the flow path 26 in the width direction or the length of the placement portion 24 in the width direction.

[0065] In Figure 4 , the start end of the flow path 26 communicates with the placement portion 24. The end of the flow path 26 (the end of the first flow path groove 26a) communicates with the buffer space 28. A reagent for analyte detection is disposed at an arbitrary position between the start end and the end of the flow path 26. That is, the buffer space 28 exists on the downstream side of the reagent in the flow path 26. The flow path 26 is connected to the buffer space 28 substantially perpendicularly. The buffer space 28 is formed in a rectangular parallelepiped shape (hexahedron shape). In the case where blood leaks from the end of the flow path 26 (the first flow path groove 26a), the buffer space 28 can store the blood. The volume of the buffer space 28 is larger than the volume of the flow path 26. Thereby, leakage of blood from the exhaust hole 30 can be suppressed by the buffer space 28.

[0066] As Figure 4 , Figure 5A and Figure 5BAs shown, the buffer space 28 expands in cross-sectional area compared to the cross-sectional area S of the flow path 26 at the connection portion with the flow path 26. In a cross-section along the arrow X direction passing through the center of the width direction of the flow path 26, in the region where the flow path 26 and the buffer space 28 are spatially connected, it is preferred that the overall thickness (length along the arrow Z direction) of the buffer space 28 be 3 to 10 times the thickness (length along the arrow Z direction) of the flow path 26. Regarding the increase in the thickness of the buffer space 28 relative to the thickness of the end cross-section of the flow path 26, it is preferred to increase by 1.1 to 10 times the thickness of the end cross-section of the flow path 26 in the Z1 direction and the Z2 direction respectively, and more preferably to increase by 3.3 to 5 times the amount. In other words, in the region where the flow path 26 and the buffer space 28 are spatially connected (the boundary region between the flow path 26 and the buffer space 28), it is preferred that the buffer space 28 extend in the arrow Z1 direction relative to the flow path 26 by a length of 1 to 10 times the length of the flow path 26 in the arrow Z direction, and more preferably by a length of 3.3 to 5 times the length of the flow path 26 in the arrow Z direction. In addition, in the region where the flow path 26 and the buffer space 28 are spatially connected, it is preferred that the buffer space 28 extend in the arrow Z2 direction relative to the flow path 26 by a length of 1 to 10 times the length of the flow path 26 in the arrow Z direction, and more preferably by a length of 3.3 to 5 times the length of the flow path 26 in the arrow Z direction.

[0067] It is preferred that the overall length of the buffer space 28 in the width direction (arrow Y direction) be 2 to 5 times the length of the end of the flow path 26 in the width direction (arrow Y direction). As the increase in the width of the buffer space 28 relative to the width direction of the end of the flow path 26, it is preferred that either direction in the Y direction be 0.5 to 2 times the width direction of the end of the flow path 26. In other words, in the region where the flow path 26 and the buffer space 28 are spatially connected, it is preferred that the buffer space 28 extend in the arrow Y direction relative to the flow path 26 by a length of 0.5 to 2 times the length of the flow path 26 in the width direction on one side. In addition, in the region where the flow path 26 and the buffer space 28 are spatially connected, it is preferred that the buffer space 28 extend in the arrow Y direction relative to the flow path 26 by a length of 0.5 to 2 times the length of the flow path 26 in the width direction on the other side.

[0068] In the boundary region where the buffer space 28 and the flow path 26 are spatially connected, when comparing cross-sections in a direction orthogonal to the arrow X direction, the cross-sectional area Sb of the buffer space 28 is larger than the cross-sectional area S of the flow path 26. In addition, the cross-sectional area Sb of the buffer space 28 is larger than the maximum flow path cross-sectional area Sa of the flow path 26. Here, the maximum flow path cross-sectional area Sa of the flow path 26 is the sum of the flow path cross-sectional area of the first flow path groove 26a and the flow path cross-sectional area of the second flow path groove 26b.

[0069] In other words, the buffer space 28 is connected to the flow path 26 at a portion where the buffer space 28 is connected to the flow path 26 as a space that expands on both sides in the Y-arrow direction and both sides in the Z-arrow direction of the flow path 26. That is, as Figure 6 shown, the width W1 of the buffer space 28 in the Y-arrow direction is wider than the width W2 of the flow path 26 in the Y-arrow direction. As Figure 5A well as Figure 5B shown, the length L1 of the buffer space 28 in the Z-arrow direction is longer than the maximum length L2 of the flow path 26 in the Z-arrow direction. The volume of the buffer space 28 is larger than the volume of the flow path 26. In Figure 6 , the exhaust hole 30 is located at the end of the buffer space 28 in the X2-arrow direction and is located approximately at the center in the Y-arrow direction of the buffer space 28.

[0070] In Figure 4 , a hydrophilic treatment (not shown) is performed on the surface of the second plate body 32B in the Z2-arrow direction and the surface of the fifth plate body 32E in the Z1-arrow direction. As a result, blood can easily flow in the flow path 26 sandwiched between the second plate body 32B and the fifth plate body 32E.

[0071] As Figure 3 well as Figure 4 shown, the reagent sheet 22 includes a support substrate 22a and a reagent portion 22b provided on the support substrate 22a. When viewed from above in the Z-arrow direction, the support substrate 22a is formed in a rectangular shape. The reagent portion 22b is located approximately at the center in the longitudinal direction of the support substrate 22a. On both sides of the reagent portion 22b in the longitudinal direction of the support substrate 22a, the reagent portion 22b is pasted on the surface of the third plate body 32C in the Z2-arrow direction in such a manner that the reagent portion 22b is located within the first flow path groove 26a.

[0072] The support substrate 22a is formed in a rectangular shape that extends longer in the width direction (the width direction is the Y-arrow direction) of the test strip 12 and extends shorter in the longitudinal direction (the X-arrow direction). The support substrate 22a is the same as the plate body 32 and can use a film material having transparency. Also, by adjusting the thickness of the support substrate 22a, the thickness of the flow path 26 in the Z-arrow direction can be changed in the middle of the flow path 26. In the present embodiment, in the portion where the reagent portion 22b is disposed within the flow path 26, the thickness of the flow path 26 in the Z-arrow direction becomes smaller. Therefore, the area of the cross section of the flow path 26 orthogonal to the X-arrow direction is the narrowest on the support substrate 22a.

[0073] In addition, the reagent preparation holes 40 extend across the entire width of the fourth plate body 32D, and the reagent insertion holes 44 extend across the entire width of the fifth plate body 32E. Therefore, in the present embodiment, without narrowing the width of the reagent preparation holes 40 and the reagent insertion holes 44 in the arrow Y direction, the width of the test strip 12 in the arrow Y direction can be narrowed. That is, the bonding area of the support substrate 22a with respect to the third plate body 32C can be sufficiently ensured, and the test strip 12 can be miniaturized. More specifically, the length of the support substrate 22a in the arrow Y direction is longer than the width dimension of the flow path 26 in the arrow Y direction, and is the same as or less than the length of the test strip 12 in the width direction. Thus, even if the length of the test strip 12 in the arrow Y direction is miniaturized to 10 mm or less, the support substrate 22a can be reliably bonded to the third plate body 32C.

[0074] The reagent part 22b carries a reagent that reacts with the sample in at least a part of the flow path 26. The reagent part 22b does not block the inside of the flow path 26 and is coated on the support substrate 22a. Various polymers and carriers may also be arranged on the support substrate 22a according to the properties of the reagent and the measurement system. In a state where the support substrate 22a is arranged in the reagent preparation hole 40, when viewed from the arrow Z direction, the reagent part 22b overlaps with the first opening 36 (refer to Figure 6 ). Therefore, the measurement light of the blood glucose meter 16 is irradiated toward the reagent part 22b. In addition, when detecting the measurement light (transmitted light) that has passed through the object to be detected, it is preferable not to use a carrier such as a porous member. In this case, a reagent solution is directly coated on the support substrate 22a by a known means such as inkjet and dried to form the reagent part 22b.

[0075] The reagent piece 22 and the plate body 32 are configured as different components, but are not limited thereto. For example, the reagent part 22b may be formed by coating a reagent at an appropriate position on a specified plate body 32 (for example, the surface of the second plate body 32B in the arrow Z2 direction). The reagent may be coated at any position in the second flow path groove 26b or in the region between the second flow path groove 26b and the third buffer hole 28c. Alternatively, the reagent may be coated on any wall surface of the region where the flow path 26 and the reagent preparation hole 40 face each other to form the reagent part 22b. In this case, the reagent part 22b is provided on a part of the surface of the second plate body 32B in the Z2 direction that faces the reagent preparation hole 40. In addition, even when the reagent piece 22 is not used, it is preferable that the thickness of the space above the portion coated with the reagent is smaller than the thickness of the flow path 26. Thus, blood can quickly flow from the flow path 26 into the space above the reagent part 22b.

[0076] As Figure 7As shown, the manufacturing method of the above test strip 12 includes a plate body forming process, a first laminating process, a reagent sheet disposing process, and a second laminating process. In the plate body forming process (step S1), the first plate body 32A, the second plate body 32B, the third plate body 32C, the fourth plate body 32D, the fifth plate body 32E, and the sixth plate body 32F are respectively formed by processing (such as blanking) a thin sheet member. In the present embodiment, at least six layers of plate bodies 32 are laminated to form the test strip 12.

[0077] In the first laminating process (step S2), the first plate body 32A, the second plate body 32B, the third plate body 32C, the fourth plate body 32D, and the fifth plate body 32E are laminated and bonded using a double-sided tape or an adhesive. In the reagent sheet disposing process (step S3), the reagent sheet 22 is inserted into the reagent dispensing hole 40 through the reagent insertion hole 44 of the fifth plate body 32E. At this time, both sides of the reagent portion 22b in the support base 22a are adhered to the surface of the third plate body 32C in the arrow Z2 direction. Thereby, the reagent sheet 22 is fixed relative to the third plate body 32C. In the second laminating process (step S4), the sixth plate body 32F is adhered to the fifth plate body 32E. Thereby, the test strip 12 is manufactured.

[0078] In the test strip 12 manufactured in this way, as Figure 8 shown, in the first laminating process, when the plate bodies 32 are adhered, the plate bodies 32 may deviate from each other in the arrow X direction. That is, the end (the first buffer end 50) of the first buffer hole 28a of the second plate body 32B in the arrow X1 direction and the end (the second buffer end 52) of the third buffer hole 28c of the fourth plate body 32D in the arrow X1 direction may deviate from each other in the arrow X direction by a first distance D1.

[0079] In addition, in the reagent sheet disposing process, when the support base 22a is adhered to the surface of the third plate body 32C in the arrow Z2 direction, the reagent sheet 22 may deviate from the fourth plate body 32D in the arrow X direction. That is, the end face 54 of the reagent sheet 22 in the arrow X2 direction and the second buffer end 52 may deviate from each other in the arrow X direction by a second distance D2.

[0080] In this case, the first buffer end 50 deviates from the end face 54 of the reagent sheet 22 by a specified deviation amount ΔD (ΔD = D1 + D2). The deviation amount ΔD is the deviation in the arrow X direction generated at the connection end of the flow path 26 in the region where the buffer space 28 and the flow path 26 are spatially connected. More specifically, it corresponds to the deviation length in the arrow X direction generated between the upper and lower surfaces of the flow path 26 at the terminal of the flow path 26. In the present embodiment, it is preferably set such that the deviation amount ΔD is less than 0.24 mm, more preferably 0.22 mm or less, and still more preferably 0.10 mm or less.

[0081] Next, the blood glucose meter 16 for assembling the test strip 12 will be described. As Figure 1 shown, the blood glucose meter 16 is configured as a reusable type that can repeatedly perform blood glucose measurement. The housing 60 of the blood glucose meter 16 has: a box portion 64 that houses the control portion 62 of the blood glucose meter 16 inside with a size that is easy for the user to hold and operate; and a cylindrical light measurement portion 66 that protrudes from the box portion 64 and houses the measurement portion 18 of the optical system inside.

[0082] On the upper surface of the box portion 64, a power button 68, an operation button 70, and a display 72 are provided. On the upper surface of the light measurement portion 66, a discharge lever 74 serving as an operation portion for removing the used test strip 12 is provided. The discharge lever 74 is provided so as to be movable in the extending direction of the light measurement portion 66 and is connected to a discharge pin 76 provided inside the light measurement portion 66 (refer to Figure 9 ).

[0083] As Figure 9 shown, an insertion hole 78 for inserting the test strip 12 is provided in the light measurement portion 66. The measurement portion 18 optically detects glucose in the blood. The measurement portion 18 includes a light emitting portion 80 and a light receiving portion 82. The light emitting portion 80 and the light receiving portion 82 are arranged to face each other across the insertion hole 78.

[0084] As the light emitting portion 80, an LED, an organic EL, a laser diode, etc. are used. In a state where the test strip 12 is assembled in the insertion hole 78, the light emitting portion 80 irradiates light of a specified wavelength toward the first opening portion 36 of the test strip 12. As the light receiving portion 82, for example, a photodiode is used. The light receiving portion 82 receives the light that has passed through the test strip 12 (reagent portion 22b).

[0085] The control portion 62 of the blood glucose meter 16 is constituted by a control circuit (computer) having a converter, a processor, a memory, and an input / output interface (not shown). The control portion 62, for example, drives the measurement portion 18 under the operation of the user and calculates the blood glucose value based on a signal corresponding to the amount (or concentration) of glucose in the blood. The calculated blood glucose value is displayed on the display 72.

[0086] Next, the measurement of the blood glucose value using the test strip 12 of the present embodiment will be described.

[0087] As Figure 9 shown, the user inserts the test strip 12 into the insertion hole 78 of the blood glucose meter 16 so that the reagent portion 22b of the test strip 12 is located between the light emitting portion 80 and the light receiving portion 82. Next, the user attaches a small amount of blood to the placing portion 24 of the test strip 12. The blood flows toward the detection target position in the flow path 26 by capillary force.

[0088] Next, the user operates the operation button 70 of the blood glucose meter 16 to start the measurement of the blood glucose value. In this case, the measurement light emitted from the light emitting unit 80 passes through the first opening 36, the wall portion 38 of the second plate body 32B, the first flow path groove 26a, the reagent portion 22b, the support substrate 22a, the reagent insertion hole 44, and the second opening 48 and is received by the light receiving unit 82. The control unit 62 of the blood glucose meter 16 calculates the blood glucose value based on the output signal from the light receiving unit 82 and displays it on the display 72. Thus, the measurement of the blood glucose value is completed.

[0089] As the blood advances in the flow path 26, the air in the flow path 26 and the buffer space 28 is discharged to the outside of the main body 20 through the exhaust hole 30. The blood reaching the reagent strip 22 flows into the space on the reagent portion 22b. When the blood reaches the reagent portion 22b, the reagent portion 22b quickly dissolves in the blood and the reaction between glucose and the reagent occurs. In the connecting portion between the buffer space 28 and the flow path 26, the cross-sectional area Sb of the buffer space 28 is larger than the maximum flow path cross-sectional area Sa of the flow path 26. In other words, in the region where the buffer space 28 and the flow path 26 are spatially connected, the cross-sectional area Sb of the buffer space 28 is larger than the cross-sectional area S of the flow path 26. Therefore, it is difficult for the blood in the flow path 26 to be sucked into the buffer space 28 by capillary action. Therefore, the inflow of blood from the flow path 26 into the buffer space 28 is suppressed. This is because, when the sample reaches the end of the flow path 26, the action of the surface tension of the blood applied from the buffer space 28 side to the end cross-section of the flow path 26 suppresses the leakage of blood beyond the end of the flow path 26 into the buffer space 28. Thus, by providing the buffer space 28, special surface treatments such as a volume expansion material, a plugging material, the configuration of a micro flow path, and a waterproof treatment for suppressing the leakage of the sample from the test strip 12 can be omitted.

[0090] The volume of the buffer space 28 is 2 to 5 times the volume of the flow path 26. If the blood in the flow path 26 flows into the buffer space 28, in this case, the blood can also be sufficiently stored in the buffer space 28. Therefore, the leakage of blood from the exhaust hole 30 is suppressed. As a result, the inside of the blood glucose meter 16 is prevented from being contaminated by blood. The area of the exhaust hole 30 is 10 to 30 times the maximum flow path cross-sectional area Sa. By making the area of the exhaust hole 30 sufficiently larger than the maximum flow path cross-sectional area Sa, the air can be quickly exhausted through the exhaust hole 30 when the blood flows into the flow path 26.

[0091] The test strip 12 of the present embodiment has the following effects.

[0092] In the main body 20, a buffer space 28 communicating with the end of the flow path 26 and an exhaust hole 30 opening on the outer surface of the main body 20 and communicating with the buffer space 28 are provided. In the region where the buffer space 28 and the flow path 26 are spatially connected, the cross-sectional area Sb of the buffer space 28 is larger than the cross-sectional area S of the flow path 26.

[0093] According to this structure, in the region where the buffer space 28 and the flow path 26 are spatially connected, the cross-sectional area Sb of the buffer space 28 is larger than the cross-sectional area S of the flow path 26. Therefore, in the connection portion between the buffer space 28, which is the terminal of the flow path 26, and the flow path 26, the interfacial tension component in the flow direction with respect to the blood in the flow path 26 is reduced. Thus, it is difficult to generate capillary force such that the blood is sucked into the buffer space 28. Additionally, even if the blood in the flow path 26 flows into the buffer space 28, the blood can be stored in the buffer space 28. Thereby, it is possible to suppress the soaring of costs and suppress the leakage of blood from the vent hole 30 to the outside of the main body portion 20.

[0094] The buffer space 28 is formed in a rectangular parallelepiped shape.

[0095] According to this structure, it is possible to effectively suppress the leakage of blood from the vent hole 30 to the outside of the main body portion 20.

[0096] The flow path 26 is connected to the buffer space 28 substantially perpendicularly.

[0097] According to this structure, in the connection portion between the buffer space 28 and the flow path 26, the surface tension of the blood reaching the cross-section of the flow path 26 can act uniformly in the cross-section of the flow path 26. Thereby, it is possible to effectively suppress the inflow of blood from the flow path 26 into the buffer space 28.

[0098] The main body portion 20 is formed by laminating a plurality of sheet members. In the direction in which the flow path 26 and the buffer space 28 are arranged, the deviation amount ΔD between the end (end face 54) on the buffer space 28 side of the reagent portion 22b and the end (first buffer end 50) on the flow path 26 side of the buffer space 28 is 0.22 mm or less.

[0099] According to this structure, it is possible to more effectively suppress the inflow of blood from the flow path 26 into the buffer space 28, and the test strip 12 can be manufactured by a plurality of plate bodies 32.

[0100] In the direction in which the flow path 26 and the buffer space 28 are arranged, the maximum deviation amount between the terminal on the upper surface of the flow path 26 and the terminal on the lower surface of the flow path 26 is less than 0.24 mm.

[0101] According to this structure, in the connection portion between the buffer space 28 and the flow path 26, the surface tension of the blood reaching the terminal of the flow path 26 can act uniformly in the cross-section of the flow path 26. Also, the interfacial tension of the blood reaching the terminal of the flow path 26 can act uniformly in the cross-section of the flow path 26.

[0102] In the direction in which the flow path 26 and the buffer space 28 are arranged, the maximum deviation amount between the end on the buffer space 28 side of the reagent portion 22b and the end on the flow path 26 side of the buffer space 28 is less than 0.24 mm.

[0103] According to this structure, by reducing the positional deviation between the first buffer end 50 and the end face 54, it is possible to suppress the reduction in the action of the interfacial tension acting on the interface of the blood-channel cross-section. Thereby, it is possible to effectively suppress the inflow of blood from the flow path 26 into the buffer space 28.

[0104] Next, the first test conducted to confirm the effects of the present invention will be described.

[0105] [Sample]

[0106] One test strip 12A (Example 1) of the present invention was prepared, and four test strips 102A to 102D (Comparative Examples 1 to 4) of comparative examples were prepared. The dimensions of the test strip were a width of 6 mm, a length of 24 mm, and a thickness of about 550 μm. The volume inside the flow path was about 0.9 μL. As Figure 10A and Figure 10B shown, a flow path 92 and a buffer space 94 communicating with the flow path 92 were formed in the main body portion 90 of the test strip 12A of Example 1. The starting end of the flow path 92 opened at the end face in the arrow X1 direction of the main body portion 90. The terminal end of the flow path 92 communicated with the buffer space 94. In addition, a stepped portion 96 was formed on the inner surface of the flow path 92. Through the stepped portion 96, the thickness of the flow path 92 in the arrow Z direction was reduced. A reagent portion 98 was coated on the stepped portion 96. The reagent portion 98 was the same as the above-described reagent portion 22b.

[0107] In Example 1, the buffer space 94 penetrated the main body portion 90 in the thickness direction. When viewed from the thickness direction of the main body portion 90, the buffer space 94 was formed in a rectangular shape. In other words, the buffer space 94 had a cuboid shape. The width of the buffer space 94 in the arrow Y direction was wider than the width of the flow path 92 in the arrow Y direction (refer to Figure 10B ). The length of the buffer space 94 in the arrow Z direction was longer than the length of the flow path 92 in the arrow Z direction (refer to Figure 10A ). In other words, in the connection portion between the buffer space 94 and the flow path 92, the maximum flow path cross-sectional area of the flow path 92 was enlarged. Both opening portions of the buffer space 94 that opened on the outer surface of the main body portion 90 functioned as air discharge holes 100 for discharging air.

[0108] In Comparative Examples 1 to 4, the shape and size of the buffer space 94 of the test strip 12A of Example 1 were changed. As Figure 11A and Figure 11BAs shown, in the test strip 102A of Comparative Example 1, the buffer space 94a expands only on the arrow Z1 direction side in the connection portion between the flow path 92 and the buffer space 94a. The buffer space 94a opens only on the surface side in the arrow Z1 direction of the main body portion 90. The opening portion of the buffer space 94a functions as the exhaust hole 100. When observed from the thickness direction (arrow Z1 direction) of the main body portion 90, the buffer space 94a is formed in a rectangular shape. The width of the buffer space 94a (the length in the arrow Y direction) is the same as the width of the flow path 92 (refer to Figure 11B ). The buffer space 94 is in a cuboid shape.

[0109] As Figure 12A and Figure 12B shown, in the test strip 102B of Comparative Example 2, when observed from the thickness direction (arrow Z1 direction) of the main body portion 90, the buffer space 94b is formed in a rectangular shape. The buffer space 94b expands only in the arrow Z1 direction in the connection portion between the flow path 92 and the buffer space 94b. The difference in thickness in the arrow Z direction between the end portion in the arrow X1 direction of the buffer space 94 and the end portion in the arrow X2 direction of the buffer space 94b forms the amount of the thickness of the plate body of the surface in the arrow Z1 direction of the main body portion 90. The width of the buffer space 94b is the same as the width of the flow path 92 (refer to Figure 12B ). An open space 104 communicating with the buffer space 94b is provided in the main body portion 90. The open space 104 is formed by cutting off a part of the portion of the main body portion 90 on the arrow X2 direction side of the flow path 92. The open space 104 is located on the side opposite to the flow path 92 with the reagent portion 98 in between. The connection portion of the buffer space 94b with respect to the open space 104 functions as the exhaust hole 100.

[0110] As Figure 13A and Figure 13B shown, in the test strip 102C of Comparative Example 3, the buffer space 94c extends and protrudes from the terminal of the flow path 92 to the end face in the arrow X2 direction of the main body portion 90. In other words, the buffer space 94c opens only on the end face in the arrow X2 direction of the main body portion 90. The end face in the arrow X2 direction of the buffer space 94c functions as the exhaust hole 100. In Figure 13B , a constriction portion 106 having a cross-sectional area smaller than the maximum flow path cross-sectional area of the flow path 92 is provided in the buffer space 94c. The constriction portion 106 is formed by bulging the inner surface in the arrow Y direction of the buffer space 94c inward.

[0111] As Figure 14A and Figure 14BAs shown, in test strip 102D of Comparative Example 4, buffer space 94d extends and protrudes from the terminal of flow path 92 to the end face of main body 90 in the direction of arrow X2. In other words, buffer space 94d only opens at the end face of main body 90 in the direction of arrow X2. The opening at the end of buffer space 94d in the X2 direction functions as vent hole 100. In Figure 14B a contraction portion 108 with a cross-sectional area smaller than the maximum cross-sectional area of flow path 92 is provided in buffer space 94d. Contraction portion 108 is a narrow flow path formed by bulging the inner surface of buffer space 94d towards the inner surface of flow path 92.

[0112] [Test Method]

[0113] For Example 1 and Comparative Examples 1 - 4, samples were spotted on the end face of main body 90 in the direction of arrow X1, and the behavior of the samples was confirmed by a CCD camera. As samples, three kinds of liquids (RO water, albumin aqueous solution, blood) were used. For easy visual inspection, RO water stained with nitro red (1 mg / ml) was used. Albumin aqueous solution with 7 wt% albumin was used. Blood with a hematocrit value (Ht) of 20 was used. RO water mimicked the sample most likely to leak from main body 90. Albumin aqueous solution simulated plasma. The spotting volume of the sample was 5 μL. In Example 1 and Comparative Examples 1 - 4, the volume inside flow path 92 was about 0.9 μL. Samples in excess of the actual sample volume used were employed. In addition, the test mimicked conditions harsher than the actual usage method, and main body 90 was fixed in a state where the insertion port of main body 90 faced vertically upward.

[0114] [Results]

[0115] In Figure 15 the test results of Example 1 and Comparative Examples 1 - 4 are shown. As Figure 15 shown, for the evaluation of the test, A indicates that the sample did not leak from vent hole 100. B indicates that although the sample did not leak outside from vent hole 100 (did not flow out outside vent hole 100), a bulge of the sample liquid droplet caused by interfacial tension was visually confirmed in vent hole 100. C indicates that the sample leaked from vent hole 100.

[0116] In Example 1, RO water, albumin solution, and blood were all evaluated as A. On the other hand, in Comparative Example 1 and Comparative Example 2, RO water, albumin solution, and blood were all evaluated as B. In Comparative Example 3 and Comparative Example 4, RO water, albumin solution, and blood were all evaluated as C. In addition, when the evaluation was B, in all cases, if the vent hole 100 was touched with a finger, the sample adhered to the finger.

[0117] Thus, when the cross-sectional area of the buffer space 94 is larger than that of the flow path 92 at the connection portion between the buffer space 94 and the flow path 92 provided downstream of the reagent section 98, and when the terminal cross-section of the flow path 92 is connected to the buffer space 94 in either the arrow Y direction or the arrow Z direction, it is found that the sample does not leak from the vent hole 100. That is, it is preferable that the buffer space 94 and the flow path 92 are connected in the extending direction of the flow path 92 (arrow X direction), and the terminal cross-section of the flow path 92 is connected to the cross-section of the buffer space 94 within the space. In addition, when the shape is such that a larger area is open on one side in the Z direction at the terminal of the flow path 26 (Comparative Examples 1 and 2), the sample may leak. When the portion corresponding to the buffer space is narrower than the width of the flow path 92 (Comparative Examples 3 and 4), it is found that the sample easily leaks. According to the above description, it is shown that by providing the buffer space 94 having the characteristics shown in Example 1 between the terminal of the flow path 92 and the vent hole 100, the leakage of blood can be effectively suppressed.

[0118] Next, a second test conducted to confirm the effects of the present invention will be described.

[0119] [Sample]

[0120] Fifty test strips 12 manufactured by the above manufacturing method were prepared. For these test strips 12 in Figure 8 , the deviation of the deviation amount ΔD of the first buffer end 50 and the end face 54 of the reagent piece 22 in the arrow X direction was set in the range of 0.02 mm to 0.26 mm.

[0121] [Test method]

[0122] With the test strip 12 fixed in such a manner that the insertion portion 24 faces vertically upward, the sample was spotted on the insertion portion 24, and it was confirmed with a CCD camera whether the sample flowed into (leaked) the buffer space 28 from the flow path 26. The above RO water was used as the sample. The spotting amount of the sample was 5 μL. The volume within the flow path 26 was about 0.9 μL.

[0123] [Results]

[0124] In Figure 16 , the test results of 50 test strips 12 are shown. Figure 16 is a bar graph showing the number of test strips 12 in which leakage of the sample from the flow path 26 to the buffer space 28 occurred (number of leaks generated), and the number of test strips 12 in which no leakage of the sample from the flow path 26 to the buffer space 28 occurred (number of no leaks). In Figure 16In this figure, the horizontal axis represents the magnitude of the deviation ΔD, and the vertical axis represents the number of test strips 12. In the bar graph, the occurrence of leakage of the sample from the flow path 26 to the buffer space 28 is indicated by hatched lines. The deviation amount ΔD corresponds to the deviation length in the direction of arrow X generated between the end of the upper surface and the end of the lower surface of the flow path 26 at the terminal of the flow path 26. In the present embodiment, since the lower surface of the flow path 26 is the reagent sheet 22 at the terminal of the flow path 26 (the space connection portion between the flow path 26 and the buffer space 28), the deviation amount ΔD between the end of the reagent sheet 22 on the buffer space 28 side and the end of the buffer space 28 on the flow path 26 side is evaluated.

[0125] As Figure 16 shown, when the deviation amount ΔD is 0.24 mm or more, leakage of the sample from the flow path 26 to the buffer space 28 is confirmed. On the other hand, when the deviation amount ΔD is 0.22 mm or less, almost no leakage of the sample from the flow path 26 to the buffer space 28 occurs. When the deviation amount ΔD is 0.12 mm, there is 1 case of sample leakage and 14 cases where no sample leakage occurs. When the deviation amount ΔD is 0.10 mm or less, no sample leakage occurs in all the test strips 12.

[0126] In this way, in the test strip 12 where the deviation amount ΔD (maximum deviation amount) between the end of the reagent part 22b (reagent sheet 22) on the buffer space 28 side and the end of the buffer space 28 on the flow path 26 side is 0.22 mm or less, leakage of the sample from the flow path 26 to the buffer space 28 can be effectively suppressed. In the test strip 12 where the deviation amount ΔD is less than 0.12 mm, leakage of the sample from the flow path 26 to the buffer space 28 can be more effectively suppressed. In the test strip 12 where the deviation amount ΔD is 0.10 m or less, leakage of the sample from the flow path 26 to the buffer space 28 can be further effectively suppressed.

[0127] The present invention is not limited to the above-described embodiment, and various changes can be made without departing from the gist of the present invention.

[0128] The test strip 12 of the present invention is not limited to being applied to a blood glucose measurement system for measuring blood glucose levels, and can be applied to various systems for optically measuring the components of an analyte. For example, as analytes to be measured at the medical site, in addition to blood, solutions of samples obtained from organisms such as urine (ketone bodies, etc.), interstitial fluid, and saliva can be cited, and they can be either the original solutions or experimental products that have been chemically treated, etc. Alternatively, the component measurement system 10 can also be applied to devices for measuring the components of analytes such as drainage water and industrial samples.

[0129] The above embodiments are summarized as follows.

[0130] The above-described embodiment discloses a test strip (12, 12A) including a flow path (26, 92) formed in a main body portion (20, 90), a reagent portion (22b, 98) provided in the flow path, and a placement portion (24) provided at the start end of the flow path for introducing a sample into the flow path. In the main body portion, a buffer space (28, 94) communicating with the terminal of the flow path and an exhaust hole (30, 100) opening on the outer surface of the main body portion and communicating with the buffer space are provided. In a region where the buffer space and the flow path are spatially connected, the cross-sectional area (Sb) of the buffer space is larger than the cross-sectional area (S) of the flow path.

[0131] In the above test strip, the buffer space may be formed in a rectangular parallelepiped shape.

[0132] In the above test strip, the flow path may be connected to the buffer space substantially perpendicularly.

[0133] In the above test strip, the main body portion may be formed by laminating a plurality of thin sheet members.

[0134] In the above test strip, in the arrangement direction of the flow path and the buffer space, the maximum deviation amount (ΔD) between the terminal of the upper surface of the flow path and the terminal of the lower surface of the flow path may be less than 0.24 mm.

[0135] In the above test strip, in the arrangement direction of the flow path and the buffer space, the maximum deviation amount between the end portion of the reagent portion on the buffer space side and the end portion of the buffer space on the flow path side may be less than 0.24 mm.

Claims

1. A test strip, comprising a flow path formed in a main body portion, a reagent portion provided in the flow path, and a loading portion provided at a starting end of the flow path for introducing a sample into the flow path, characterized in that a buffer space communicating with a terminal of the flow path and an exhaust hole communicating with the buffer space and opening on an outer surface of the main body portion are provided in the main body portion; in a region where the buffer space is spatially connected to the flow path, a cross-sectional area of the buffer space is larger than a cross-sectional area of the flow path; the main body portion is formed by laminating a plurality of thin sheet members; the exhaust hole is provided on an upper surface of the main body portion so as to open to the outside; in an arrangement direction of the flow path and the buffer space, a maximum deviation amount between a terminal of an upper surface of the flow path and a terminal of a lower surface of the flow path is 0.02 mm or more and less than 0.24 mm.

2. The test strip according to claim 1, characterized in that the buffer space is formed in a rectangular parallelepiped shape.

3. The test strip according to claim 2, characterized in that the flow path is connected to the buffer space substantially perpendicularly.

4. A test strip, comprising a flow path formed in a main body portion, a reagent portion provided in the flow path, and a loading portion provided at a starting end of the flow path for introducing a sample into the flow path, characterized in that a buffer space communicating with a terminal of the flow path and an exhaust hole communicating with the buffer space and opening on an outer surface of the main body portion are provided in the main body portion; in a region where the buffer space is spatially connected to the flow path, a cross-sectional area of the buffer space is larger than a cross-sectional area of the flow path; the main body portion is formed by laminating a plurality of thin sheet members; the exhaust hole is provided on an upper surface of the main body portion so as to open to the outside; in an arrangement direction of the flow path and the buffer space, a maximum deviation amount between an end portion of the reagent portion on the buffer space side and an end portion of the buffer space on the flow path side is 0.02 mm or more and less than 0.24 mm.

Images