Secretion component measuring device

Abstract

This secretion component measuring device comprises a first flow passage, a measuring instrument, and a second flow passage. The first flow passage is disposed on the skin, and liquid flowing in from a first flow inlet flows toward a first flow outlet together with secretions from the skin. The measuring instrument measures a component within the secretions. In the second flow passage, the liquid flows from a second flow inlet connected to the first flow outlet toward a second flow outlet. A portion of the measuring instrument is disposed inside the second flow passage. The second flow inlet is disposed directly above the first flow outlet.

Description

Secretion component measuring device

[0001] The present invention relates to the assessment of the amount of a substance in a secretion from a living body, in particular in sweat.

[0002] Conventionally, techniques for measuring the amount of substances (e.g., lactic acid) in sweat have been known.

[0003] For example, there is known a technology in which a device is attached to the skin of the human body to absorb sweat and measure substances in the absorbed sweat using a sensor (see, for example, Patent Document 1 and Patent Document 2 (e.g., wicking layer 500)).

[0004] However, with such conventional technology, the sweat remains absorbed in the sweat-absorbing layer, and therefore, sweat that was produced before the sweat to be measured is released remains in the sweat-absorbing layer, making the measurement of the amount of substance in the sweat inaccurate.

[0005] There is also known a technique in which a device is attached to the skin of a human body, sweat is collected through a flow path, and substances in the collected sweat are measured by a sensor (see, for example, Patent Document 3 and Non-Patent Document 1).

[0006] However, with such conventional techniques, if the amount of sweat produced is small, the sweat evaporates before reaching the sensor, resulting in an inaccurate measurement of the amount of substance in the sweat.

[0007] Therefore, a technique (hereinafter referred to as "flow measurement") is known in which phosphate buffered saline is flowed over the skin surface and guided to a sensor, and substances in sweat are measured by the sensor (see, for example, Non-Patent Document 2). Flow measurement does not cause the problem of sweat remaining in the sweat-absorbing layer. Moreover, with flow measurement, even if the amount of sweat produced is small, the phosphate buffered saline allows sweat to reach the sensor.

[0008] Jonghyun Son et al., "Cactus-Spine-Inspired Sweat-Collecting Patch for Fast and Continuous Monitoring of Sweat", Advanced Materials, 2021, 2102740, pp. 1-9 Keigo Enomoto and two others, "Real-time Measurement System for Lactic Acid Secretion on the Skin Surface for the Purpose of Evaluating Exercise Load", Transactions of the Institute of Electrical Engineers of Japan (Sensor and Micromachine Division), Vol. 137, No. 12, pp. 450-454, 2017

[0009] However, with the flow-type measurement described above, it is necessary to connect the flow path for the phosphate-buffered saline solution flowing over the skin surface with the flow path for guiding the sweat-containing phosphate-buffered saline solution to the sensor using a tube.

[0010] Therefore, the time it takes for the sweat-containing phosphate buffered saline to reach the sensor increases depending on the length of the tube.

[0011] Therefore, an object of the present invention is to shorten the time required for secretions from a living body to be guided to a sensor.

[0012] The secretion component measuring device of the present invention comprises a first flow path that is placed on the skin and through which liquid flowing in from a first inlet flows toward a first outlet together with secretions from the skin, a measuring instrument that measures the components in the secretions, and a second flow path through which the liquid flows from a second inlet connected to the first outlet toward a second outlet, with a portion of the measuring instrument being placed inside the second flow path and the second inlet being placed directly above the first outlet.

[0013] In the secretion component measuring device configured as described above, the first flow path is placed on the skin, and liquid flowing in from the first inlet flows toward the first outlet together with secretions from the skin. A measuring device measures the components in the secretions. The second flow path allows the liquid to flow from a second inlet connected to the first outlet toward the second outlet. A portion of the measuring device is placed inside the second flow path. The second inlet is placed directly above the first outlet.

[0014] In the secretion component measuring device according to the present invention, the second inlet may be directly connected to the first outlet.

[0015] In the secretion component measuring device according to the present invention, the secretion may be sweat.

[0016] In the secretion component measuring device according to the present invention, the component may be lactic acid, sugar, uric acid, a mineral component, or active oxygen.

[0017] In the secretion component measuring device according to the present invention, the measuring device may be an electrochemical sensor, a calorimetric sensor, or a quartz crystal microbalance sensor.

[0018] In the secretion component measuring device according to the present invention, the first flow path may have three or more straight flow paths, and the extending directions of adjacent straight flow paths may be different from each other.

[0019] In the secretion component measuring device according to the present invention, the second flow path may be branched.

[0020] In the secretion component measuring device according to the present invention, the second flow path may be disposed at a location other than directly above the first flow path.

[0021] In addition, the secretion component measuring device of the present invention may be configured so that the first flow path has a linear first outlet-side flow path connected to the first outlet, the second flow path has a linear second inlet-side flow path connected to the second inlet, and the second inlet-side flow path is located directly above the first outlet-side flow path.

[0022] In addition, the secretion component measuring device of the present invention may be configured so that the first flow path has a first inlet-side flow path connected to the first inlet, the second flow path has a second outlet-side flow path connected to the second outlet, and the first inlet-side flow path and the second outlet-side flow path are arranged on opposite sides of each other in the extension direction of the second inlet-side flow path.

[0023] 1(a) and 1(b) are a plan view (FIG. 1(a)) and a front view (FIG. 1(b)) of a secretion component measuring device 1 according to an embodiment of the present invention. A cross-sectional view of a first substrate 120 taken along II-II. A cross-sectional view of a second substrate 140 taken along III-III. A plan view of a measuring device 16. A plan view of a second substrate 140 when the measuring device 16 is attached to the secretion component measuring device 1. A plan view showing a first flow path 12 in a secretion component measuring device 1 according to a first modified example. A plan view showing a second flow path 14 in a secretion component measuring device 1 according to a second modified example. A plan view showing a first flow path 12 and a second flow path 14 in a secretion component measuring device 1 according to a third modified example.

[0024] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0025] FIG. 1 is a plan view (FIG. 1(a)) and a front view (FIG. 1(b)) of a secretion component measuring device 1 according to an embodiment of the present invention. FIG. 2 is a cross-sectional view of the first substrate 120 taken along line II-II. FIG. 3 is a cross-sectional view of the second substrate 140 taken along line III-III. However, for convenience of illustration, the measuring device 16 (see FIGS. 4 and 5) is omitted from FIGS. 1 and 3.

[0026] The secretion component measuring device 1 according to the embodiment of the present invention includes a first substrate 120, a second substrate 140, a first tube mounting port 11, a second tube mounting port 15, a PBS supply unit 10, a pump 17, a waste liquid storage unit 18, and tubes T1, T2, and T3. Note that while the tubes T1, T2, and T3 are shown as straight lines for convenience of illustration, in reality they are curved and have slack.

[0027] The PBS supply unit 10 stores PBS (phosphate-buffered saline) and supplies PBS to the first flow path 12 and the second flow path 14. The PBS supply unit 10 is attached to the first tube attachment port 11 via a tube T1.

[0028] The first tube attachment port 11 is attached directly above the first inlet 12a.

[0029] The first substrate 120 has a first flow path 12. The first flow path 12 has a first inlet 12a, a first outlet 12b, a first outlet-side flow path 12c, and a first inlet-side flow path 12d.

[0030] First flow path 12 is disposed on skin 2. First flow path 12 is open to the bottom surface of first substrate 120. Liquid (PBS) flows in from first inlet 12a. The liquid (PBS) flows toward first outlet 12b together with secretions (e.g., sweat) from skin 2. First inlet 12a is a circular hole that penetrates first substrate 120 and second substrate 140. First outlet 12b is a circular hole that penetrates first substrate 120.

[0031] The first outlet-side flow path 12c is a straight flow path connected to the first outlet 12b. The first inlet-side flow path 12d is a straight flow path connected to the first inlet 12a.

[0032] The second tube attachment port 15 is attached directly above the second outlet port 14b.

[0033] The second substrate 140 has a second flow path 14. The second flow path 14 has a second inlet 14a, a second outlet 14b, a second inlet-side flow path 14c, and a second outlet-side flow path 14d. The second substrate 140 is attached directly above the first substrate 120.

[0034] The second inlet 14a is connected to the first outlet 12b. The liquid (PBS) flows together with secretions (sweat) from the second inlet 14a toward the second outlet 14b. The second inlet 14a is a circular hole provided in the second substrate 140 and opening downward from the second substrate 140. The second outlet 14b is a circular hole provided in the second substrate 140 and opening upward from the second substrate 140.

[0035] The second inlet 14a is disposed directly above the first outlet 12b and is directly connected to the first outlet 12b.

[0036] The second inlet-side flow path 14c is a linear flow path connected to the second inlet 14a. The second outlet-side flow path 14d is a linear flow path connected to the second outlet 14b. The second inlet-side flow path 14c and the second outlet-side flow path 14d are disposed inside the second substrate 140.

[0037] The second inlet-side flow passage 14c is disposed directly above the first outlet-side flow passage 12c.

[0038] The first inlet-side flow path 12d and the second outlet-side flow path 14d are disposed on opposite sides of the second inlet-side flow path 14c in the extending direction of the second inlet-side flow path 14c. For example, in Fig. 1(a) , the first inlet-side flow path 12d is disposed above the second inlet-side flow path 14c, and the second outlet-side flow path 14d is disposed below the second inlet-side flow path 14c.

[0039] In FIG. 1(a), the first inlet-side flow path 12d, the second outlet-side flow path 14d, and the second inlet-side flow path 14c appear to form a Y-shape.

[0040] The second tube attachment port 15 is attached directly above the second outlet port 14b.

[0041] The pump 17 sucks the liquid (PBS) from the second outlet 14b. The pump 17 is attached to the second tube attachment port 15 via a tube T2. The waste liquid storage section 18 is attached to the pump 17 via a tube T3. The liquid (including secretions (sweat)) sucked by the pump 17 is stored in the waste liquid storage section 18 as waste liquid.

[0042] Fig. 4 is a plan view of the measuring device 16. Fig. 5 is a plan view of the second substrate 140 when the measuring device 16 is attached to the secretion component measuring device 1.

[0043] The measuring device 16 measures components in the secretions (sweat). The measuring device 16 may be, for example, an electrochemical sensor, a calorimetric sensor, or a quartz crystal microbalance sensor. In this embodiment, the measuring device 16 is a well-known electrochemical sensor.

[0044] The components measured by the measuring device 16 may be, for example, lactic acid, sugar, uric acid, mineral components (e.g., sodium), or active oxygen. In this embodiment, the component measured by the measuring device 16 is lactic acid.

[0045] The measuring device 16 has electrodes CE, WE, and RE, wirings 162C, 164C, 162W, 164W, 162R, and 164R, and a substrate 166.

[0046] Electrode CE is a counter electrode, electrode WE is a working electrode, and electrode RE is a reference electrode (e.g., a silver-silver chloride electrode). A thin wire 162C is connected to electrode CE, and a thick wire 164C is connected to wire 162C. A thin wire 162R is connected to electrode RE, and a thick wire 164R is connected to wire 162R. A thin wire 162W is connected to electrode WE, and a thick wire 164W is connected to wire 162W. Wires 164C, 164R, and 164W are arranged on a substrate 166. Wires 164C, 164R, and 164W are connected to a potentiostat (not shown), and an output corresponding to the concentration of lactic acid in the secretion (sweat) is obtained from the potentiostat.

[0047] Electrode WE has a layer of Prussian blue formed on a layer of carbon graphite, and a layer of lactate oxidase formed on the Prussian blue layer. Electrode CE has a layer of carbon graphite. Electrode RE has a layer of silver-silver chloride formed on a layer of carbon graphite.

[0048] Although the measuring device 16 is not shown in Figures 1 and 3, it is actually attached to the secretion component measuring device 1 as shown in Figure 5. Electrodes CE, WE, and RE, which are part of the measuring device 16, are partially disposed inside the second inlet-side flow path 14c of the second flow path 14.

[0049] Although the measuring device 16 has been described as having one working electrode (electrode WE), it is also possible to provide multiple working electrodes (electrodes WE), each with a different enzyme layer disposed thereon, so that each electrode measures a different component.

[0050] Next, the operation of the embodiment of the present invention will be described.

[0051] The lower portions of the first inlet-side flow path 12d and the first outlet-side flow path 12c are open toward the skin 2, and sweat secreted from the skin 2 enters the first inlet-side flow path 12d and the first outlet-side flow path 12c.

[0052] Here, PBS is sucked out from PBS supply unit 10 by pump 17, and is provided to first inlet 12a via tube T1 and first tube attachment port 11. The PBS further flows through first inlet-side flow path 12d and first outlet-side flow path 12c, washing away sweat secreted from skin 2 from skin 2, and then flows toward first outlet 12b together with the washed-out sweat.

[0053] The PBS (containing sweat) heading toward the first outlet 12b moves to the second inlet 14a connected directly above the first outlet 12b, and flows through the second inlet-side flow path 14c.

[0054] The electrodes CE, WE, and RE arranged in the second inlet-side flow path 14c cause the measuring device 16 to generate a current corresponding to the lactic acid in the sweat, thereby enabling the concentration of lactic acid to be measured.

[0055] At the electrode WE, lactic acid is decomposed by the enzyme to generate hydrogen peroxide, which then undergoes a redox reaction to generate electrons. These electrons are injected into the carbon graphite layer, with the Prussian blue layer of the electrode WE acting as an electron mediator. These injected electrons then move to the electrode CE, causing a current to flow between the electrodes CE and WE. However, electron injection by the Prussian blue layer requires a potential, and this potential (0 V) is provided by the electrode RE.

[0056] The PBS (with sweat) that has flowed through the second inlet-side flow path 14c flows through the second outlet-side flow path 14d, and is sucked out by the pump 17 via the second outlet 14b, the second tube attachment port 15, and the tube T2.

[0057] The sucked-out PBS (containing sweat) is given to the waste liquid reservoir 18 via the tube T3 and is stored as waste liquid.

[0058] According to the embodiment of the present invention, second inlet 14a is disposed directly above first outlet 12b, which shortens the time required for PBS (containing sweat) to move from first substrate 120 to second substrate 140. This shortens the time required to guide secretions (e.g., sweat) from the living body to measuring device 16.

[0059] Furthermore, according to an embodiment of the present invention, when placing the secretion component measuring device 1 on the skin 2, there is no need to connect the second inlet 14a and the first outlet 12b with a tube, thereby reducing the effort required when placing the secretion component measuring device 1 on the skin 2.

[0060] Furthermore, according to an embodiment of the present invention, the second inlet-side flow path 14c is positioned directly above the first outlet-side flow path 12c, so that the first flow path 12 and the second flow path 14 can be stored in a smaller space.

[0061] Furthermore, according to an embodiment of the present invention, the first inlet-side flow path 12d and the second outlet-side flow path 14d are arranged on opposite sides of each other in the extension direction of the second inlet-side flow path 14c, so that the first inlet-side flow path 12d and the second outlet-side flow path 14d can be stored in a smaller space.

[0062] The following modifications of the embodiment of the present invention are possible.

[0063] <Modification 1> Fig. 6 is a plan view showing the first flow path 12 in the secretion component measuring device 1 according to Modification 1. However, the first substrate 120 is not shown in Fig. 6. Also, in Fig. 6, the first flow path 12 is shown in a simplified manner using thick lines.

[0064] The first flow path 12 according to the first modification is a broken line. That is, the first flow path 12 has three or more linear flow paths 12e, and the extension directions of adjacent linear flow paths 12e are different from each other. For example, the extension direction of the second linear flow path 12e from the left is different from the extension direction of the leftmost linear flow path 12e and the extension direction of the third linear flow path 12e from the left.

[0065] In this way, by forming first flow path 12 in a bent line shape, it is possible to widen the area of ​​skin 2 that acquires sweat without making first flow path 12 thicker.

[0066] <Modification 2> Fig. 7 is a plan view showing the second flow path 14 in the secretion component measuring device 1 according to Modification 2. However, the second substrate 140 is not shown in Fig. 7. Also, in Fig. 7, the second flow path 14 is simplified and shown by a thick line.

[0067] The second flow path 14 according to the second modification is branched into flow paths 14e and 14f.

[0068] By branching the second flow path 14 in this way, a measuring device 16 can be installed for each of the flow paths 14e and 14f, so that a plurality of measuring devices 16 can be installed.

[0069] <Modification 3> Fig. 8 is a plan view showing the first flow path 12 and the second flow path 14 in the secretion component measuring device 1 according to Modification 3. However, the first substrate 120 and the second substrate 140 are omitted from Fig. 8. Also, in Fig. 8, the first flow path 12 and the second flow path 14 are simplified and shown by thick lines.

[0070] The second flow path 14 is disposed at a location different from that directly above the first flow path 12 according to Modification 3. In this case, the space for accommodating the first flow path 12 and the second flow path 14 becomes larger, but this is preferable when the first inlet 12 a and the second outlet 14 b need to be disposed far apart.

[0071] REFERENCE SIGNS LIST 1 Secretion component measuring device 2 Skin 120 First substrate 12 First flow path 12a First inlet 12b First outlet 12c First outlet-side flow path 12d First inlet-side flow path 12e Straight flow path 140 Second substrate 14 Second flow path 14a Second inlet 14b Second outlet 14c Second inlet-side flow path 14d Second outlet-side flow path 14e, 14f Flow path 10 PBS supply unit 11 First tube attachment port 15 Second tube attachment port 16 Measuring device 17 Pump 18 Waste liquid storage unit CE, WE, RE Electrodes T1, T2, T3 Tube

Claims

1. A secretion component measuring device comprising: a first flow path that is placed on the skin, through which liquid flowing in from a first inlet flows toward a first outlet together with secretions from the skin; a measuring device that measures components in the secretions; and a second flow path through which the liquid flows from a second inlet connected to the first outlet toward a second outlet, wherein a part of the measuring device is placed inside the second flow path, and the second inlet is placed directly above the first outlet.

2. A secretion component measuring device according to claim 1, wherein the second inlet is directly connected to the first outlet.

3. A secretion component measuring device according to claim 1, wherein the secretion is sweat.

4. The secretion component measuring device according to claim 1, wherein the component is lactic acid, sugar, uric acid, a mineral component or active oxygen.

5. The secretion component measuring device according to claim 1, wherein the measuring device is an electrochemical sensor, a calorimetric sensor or a quartz crystal microbalance sensor.

6. A secretion component measuring device according to claim 1, wherein the first flow path has three or more straight flow paths, and the extension directions of adjacent straight flow paths are different from each other.

7. A secretion component measuring device according to claim 1, wherein the second flow path is branched.

8. A secretion component measuring device according to claim 1, wherein the second flow path is disposed at a position different from that directly above the first flow path.

9. A secretion component measuring device as described in claim 1, wherein the first flow path has a linear first outlet-side flow path connected to the first outlet, the second flow path has a linear second inlet-side flow path connected to the second inlet, and the second inlet-side flow path is disposed directly above the first outlet-side flow path.

10. A secretion component measuring device as described in claim 9, wherein the first flow path has a first inlet-side flow path connected to the first inlet, the second flow path has a second outlet-side flow path connected to the second outlet, and the first inlet-side flow path and the second outlet-side flow path are arranged on opposite sides to each other in the extension direction of the second inlet-side flow path.

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