Patent Publication Number: US-2020292424-A1

Title: Component concentration measuring device and component concentration measuring method

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     Priority is claimed on Japanese Patent Application No. 2019-048142, filed Mar. 15, 2019, the contents of which are incorporated herein by reference. 
     BACKGROUND 
     Field of the Invention 
     The present invention relates to a component concentration measuring device and a component concentration measuring method. 
     Background 
     There is a technology for measuring the concentration of a specific component in sweat (refer to Japanese Unexamined Patent Application, First Publication No. 2017-198577). In the related art, the concentration is measured by filling a flow path with sweat and supplying the sweat which has filled the flow path to a sensor configured to measure the concentration using the pressure of sweat vapor and the capillary phenomenon. 
     SUMMARY 
     In the related art, old sweat may remain in the vicinity of a sensor in some cases. For this reason, in the related art, only an amount of newly generated sweat may not be able to be measured and the accuracy of analysis may be poor in some cases. 
     Also, in the related art, the flow path needs to be filled with sweat. Thus, when an amount of sweating is small, an amount of object to be measured cannot be measured until a sufficient amount of sweat is collected in some cases. For this reason, in the related art, it takes a long time to collect sweat, the real-time property may be impaired, and the accuracy of analysis may be poor in some cases. 
     Such problems have an influence on a technology for measuring an amount of a specific component in sweat as well as a technology for measuring the amount of components in a liquid discharged from a discharge source such as sap discharged from a plant. 
     An object of an aspect of the present invention is to provide a technology for preventing a decrease in measurement accuracy of an amount of components in a liquid discharged from a discharge source. 
     (1) An aspect of the present invention is a component concentration measuring device including: a liquid collecting unit configured to collect a main liquid including a measurement target component to be measured and discharge a mixed liquid obtained by mixing the main liquid with an auxiliary liquid supplied from an outside; and a first sensing unit including a first flow path positioned downstream of the liquid collecting unit and an in-mixed-liquid concentration measuring unit positioned in the first flow path and configured to measure a first measurement target component concentration which is the concentration of the measurement target component in the mixed liquid. 
     (2) The component concentration measuring device may include: a second sensing unit including a second flow path positioned downstream of the liquid collecting unit and a mixed liquid amount measurement unit configured to measure a mixed liquid amount which is an amount of the mixed liquid flowing through the second flow path. 
     (3) The component concentration measuring device may further include: a component concentration calculation unit configured to calculate a second measurement target component concentration which is the concentration of the measurement target component in the main liquid based on the first measurement target component concentration, the mixed liquid amount, and an auxiliary liquid amount which is an amount of the auxiliary liquid supplied from the outside. 
     (4) The component concentration measuring device may further include: an auxiliary fluid supply unit configured to supply the auxiliary liquid to the liquid collecting unit, wherein the auxiliary fluid supply unit may be configured to supply the auxiliary liquid to the first flow path after the auxiliary liquid has been supplied to the first flow path and then an inter-process time which is a predetermined time has elapsed, and the in-mixed-liquid concentration measuring unit may be configured to measure the concentration of the measurement target component in the mixed liquid including the auxiliary liquid supplied to the first flow path by the auxiliary fluid supply unit after the inter-process time has elapsed. 
     (5) In the component concentration measuring device, the liquid collecting unit and the first sensing unit may be laminated. 
     (6) In the component concentration measuring device, at least two of the liquid collecting unit, the first sensing unit, and the second sensing unit may be laminated. 
     (7) Another aspect of the present invention is a component concentration measuring method including: collecting a main liquid including a measurement target component to be measured and discharging a mixed liquid obtained by mixing the main liquid with an auxiliary liquid supplied from an outside; and measuring a first measurement target component concentration which is the concentration of the measurement target component in the mixed liquid. 
     According to (1) to (7) described above, an increase in time required for collecting sweat is prevented and the real-time property of measurement is not impaired. For this reason, it is possible to prevent a decrease in measurement accuracy caused by a time required for collecting sweat. 
     According to (4) described above, it is possible to measure the concentration of a component which is an object to be measured by reducing an influence of old sweat. For this reason, it is possible to prevent a decrease in measurement accuracy of an amount of component which is an object to be measured. 
     According to (5) and (6) described above, it is possible to prevent an area of the device from increasing and prevent an increase in size of the device. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a diagram showing an example of a functional constitution of a sweat measuring device in an embodiment. 
         FIG. 2  is a diagram showing an example of a functional constitution of a fluid supply unit in the embodiment. 
         FIG. 3  is a diagram showing an example of a cross section of a supplied unit in the embodiment. 
         FIG. 4  is a diagram showing an example of a constitution of an in-mixed-liquid concentration measuring unit in the embodiment. 
         FIG. 5  is a diagram showing a working electrode when viewed from a direction perpendicular to that of  FIG. 4 . 
         FIG. 6  is a diagram showing a counter electrode when viewed from a direction perpendicular to that of  FIG. 4 . 
         FIG. 7  is a top view of a sweat collecting unit in the embodiment. 
         FIG. 8  is a top view of a first sensing unit in the embodiment. 
         FIG. 9  is a top view of the sweat collecting unit and the first sensing unit which have been laminated in the embodiment. 
         FIG. 10  is a flowchart for describing a flow of a process from when a start condition is satisfied to when the sweat measuring device calculates the concentration of a component to be measured in sweat in the embodiment. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
       FIG. 1  is a diagram showing an example of a functional constitution of a sweat measuring device  1  in an embodiment. The sweat measuring device  1  measures an amount of component which is an object to be measured (hereinafter referred to as a “component to be measured”) contained in sweat. The component to be measured may be any component as long as it is a component contained in sweat. The component to be measured may be, for example, lactic acid, glucose, sodium, or potassium. 
     The sweat measuring device  1  includes a central processing unit (CPU), a memory, an auxiliary storage device, and the like connected through a bus and executes a program. The sweat measuring device  1  functions as a device which includes a fluid supply unit  10 , a supplied unit  20 , and an information processing unit  30  by executing a program. 
     The fluid supply unit  10  is connected to the supplied unit  20  using a tube and supplies an auxiliary liquid to the supplied unit  20 . 
     The auxiliary liquid may be any liquid as long as it does not contain the component to be measured and does not cause a chemical reaction with the component to be measured. For example, when the component to be measured is lactic acid in sweat, the auxiliary liquid may be pure water. 
       FIG. 2  is a diagram showing an example of a functional constitution of the fluid supply unit  10  in the embodiment. 
     The fluid supply unit  10  includes a liquid tube pump  101 , a gas tube pump  102 , and a tube  103 . 
     The liquid tube pump  101  is connected to the supplied unit  20  through the tube  103 . The liquid tube pump  101  discharges the auxiliary liquid into the tube  103 . 
     The gas tube pump  102  is connected to the supplied unit  20  through the tube  103 . The gas tube pump  102  discharges an auxiliary gas into the tube  103 . The auxiliary gas may be any gas as long as it does not contain the component to be measured and does not cause a chemical reaction with the component to be measured. For example, when the component to be measured is lactic acid in sweat, the auxiliary gas may be helium. 
     The fluid supply unit  10  sweeps a predetermined amount of the auxiliary liquid into the tube  103  using the liquid tube pump  101  and then transfers the auxiliary liquid to the supplied unit  20  using a gas pressure of the auxiliary gas discharged by the gas tube pump  102 . In this way, the auxiliary liquid flows into the supplied unit  20 . 
     A description will be provided with reference to  FIG. 1  again. 
     The supplied unit  20  includes a sweat collecting unit  21 , the first sensing unit  22 , and a second sensing unit  23  and acquires various values associated with the auxiliary liquid and the component to be measured. 
       FIG. 3  is a diagram showing an example of a cross section of the supplied unit  20  in the embodiment. 
       FIG. 3  shows the sweat collecting unit  21 , the first sensing unit  22 , and the second sensing unit  23  laminated in this order in a direction perpendicular to a surface of skin  9 . The skin  9  is an example of a discharge source of the component to be measured. The direction perpendicular to the surface of the skin  9  is, for example, a direction from an inside of the skin  9  to an outside of the skin and is a forward direction of a Z axis in  FIG. 3 . Hereinafter, a plane perpendicular to the Z axis is referred to as an XY plane. 
     The sweat collecting unit  21  includes a sheet-like first adhesive layer  211 , a sheet-like second adhesive layer  212 , and a sheet-like the first dielectric layer  213  laminated in this order in the forward direction of the Z axis. 
     The first adhesive layer  211  is in contact with the skin. The first adhesive layer  211  has an opening portion  214  formed in a surface thereof in contact with the skin. 
     The first adhesive layer  211  may be any type as long as it is the form of a sheet which adheres to the skin. The first adhesive layer  211  is, for example, a medical tape. A thickness (a length in a Z-axis direction) of the first adhesive layer  211  can be preferably 10 to 200 μm and more preferably 90 μm. 
     The opening portion  215  whose shape and size in the XY plane are substantially the same as the opening portion  214  is formed in the second adhesive layer  212 . The opening portion  215  communicates with the opening portion  214 . 
     The second adhesive layer  212  adheres the first adhesive layer  211  to the first dielectric layer  213 . The second adhesive layer  212  may be any type as long as it is in the form of a sheet which adheres the first adhesive layer  211  to the first dielectric layer  213 . The second adhesive layer  212  is, for example, a double-sided tape. 
     The thickness (a length in the Z-axis direction) of the second adhesive layer  212  can be preferably 100 to 500 μm and more preferably 200 μm. 
     The first dielectric layer  213  has two opening portions formed therein. Hereinafter, one of the opening portions is referred to as an opening portion  216 . Hereinafter, the other of the opening portions is referred to as an opening portion  217 . Sizes of the opening portion  216  and the opening portion  217  in the XY plane are smaller than sizes of the opening portion  214  and the opening portion  215  in the XY plane. The opening portion  216  communicates with the opening portion  214  and the opening portion  215 . The opening portion  217  communicates with the opening portion  214  and the opening portion  215 . 
     The first dielectric layer  213  is formed of a dielectric. The first dielectric layer  213  may be any type as long as it is a sheet-like dielectric. The first dielectric layer  213  may be, for example, a silicon sheet. A thickness (a length in the Z-axis direction) of the first dielectric layer  213  is preferably 100 to 1000 μm and more preferably 500 μm. 
     A flow path  218  is formed using the opening portion  214 , the opening portion  215 , the opening portion  216 , and the opening portion  217 . Since the flow path  218  is formed using the opening portion  214 , the opening portion  215 , the opening portion  216 , and the opening portion  217 , the opening portions are positioned in a surface in contact with the skin  9 . For this reason, sweat discharged from the skin  9  flows into the flow path  218 . 
     The auxiliary liquid flows into the sweat collecting unit  21  through the opening portion  216 . The auxiliary liquid which has flowed into the opening portion  216  flows through the flow path  218 . The auxiliary liquid flowing through the flow path  218  mixes with the sweat. Hereinafter, the auxiliary liquid which has mixed with the sweat is referred to as a mixed liquid. The mixed liquid is discharged through the opening portion  217 . 
     In this way, the sweat collecting unit  21  collects the sweat containing the component to be measured which is an object to be measured and causes the mixed liquid obtained by mixing the sweat with the auxiliary liquid supplied from the fluid supply unit  10  positioned outside of the sweat collecting unit  21  to be discharged. 
     When thicknesses of the first adhesive layer  211 , the second adhesive layer  212 , and the first dielectric layer  213  are equal to or more than preferred lower limit values, it is possible to stabilize an output of the sweat measuring device  1 . Furthermore, when thicknesses of the first adhesive layer  211 , the second adhesive layer  212 , and the first dielectric layer  213  are equal to or less than preferred upper limit values, it is easy to secure the flexibility of the supplied unit  20  and the supplied unit  20  easily follows the movement of the skin  9 . 
     A description will be provided with reference to  FIG. 3  again. The first sensing unit  22  includes a sheet-like first insulating layer  221 , a sheet-like third adhesive layer  222 , and a sheet-like second dielectric layer  223  laminated in this order in the forward direction of the Z axis. 
     The first insulating layer  221  is in contact with the first dielectric layer  213 . The first insulating layer  221  has the opening portion  224  formed in a surface thereof in contact with the first dielectric layer  213 . The opening portion  224  communicates with the opening portion  217 . 
     The first insulating layer  221  is formed of an insulator. The first insulating layer  221  may be any type as long as it is a sheet-like insulator. The first adhesive layer  211  is, for example, a Kapton tape. A thickness (a length in the Z-axis direction) of the first insulating layer  221  can be preferably 10 to 100 μm and more preferably 50 μm. 
     In the third adhesive layer  222 , the opening portion  225  having a size in the XY plane larger than that of the opening portion  224  is formed. The opening portion  225  communicates with the opening portion  224 . 
     The third adhesive layer  222  adheres the first insulating layer  221  to the second dielectric layer  223 . The third adhesive layer  222  may be any type as long as it is in the form of a sheet which adheres the first insulating layer  221  to the second dielectric layer  223 . The third adhesive layer  222  may be, for example, a double-sided tape. 
     A thickness (a length in the Z-axis direction) of the third adhesive layer  222  can be preferably 200 to 700 μm and more preferably 580 μm. 
     In the second dielectric layer  223 , the opening portion  226  having a size in the XY plane smaller than that of the opening portion  225  is formed. The opening portion  226  communicates with the opening portion  225 . A line passing through a center of the opening portion  226  in the XY plane and parallel to the Z axis does not intersect with a line passing through a center of the opening portion  224  in the XY plane and parallel to the Z axis. 
     The second dielectric layer  223  is formed of a dielectric. The second dielectric layer  223  may be any type as long as it is a sheet-like dielectric. The second dielectric layer  223  may be, for example, a silicon sheet. A thickness (a length in the Z-axis direction) of the second dielectric layer  223  can be preferably 100 to 1000 μm and more preferably 500 μm. 
     A flow path  227  is formed using the opening portion  224 , the opening portion  225 , and the opening portion  226 . The mixed liquid which has flowed through the flow path  218  flows into the first sensing unit  22  through the opening portion  224 . 
     The mixed liquid which has flowed into the opening portion  224  flows through the flow path  227 . The mixed liquid flowing through the flow path  227  is discharged through the opening portion  226 . In this way, the flow path  227  is positioned downstream of the sweat collecting unit  21 . 
     The first sensing unit  22  includes an in-mixed-liquid concentration measuring unit  24 . The in-mixed-liquid concentration measuring unit  24  measures the concentration of the component to be measured in the mixed liquid using a predetermined measuring method. For example, the in-mixed-liquid concentration measuring unit  24  measures a value of a physical quantity which changes in accordance with a change in concentration of the component to be measured in the mixed liquid and converts the measurement result into the concentration in the mixed liquid, thereby measuring the concentration in the mixed liquid. Hereinafter, the concentration of the component to be measured in the mixed liquid measured by the in-mixed-liquid concentration measuring unit  24  is referred to as a first measurement value. 
     The in-mixed-liquid concentration measuring unit  24  outputs the first measurement value of the measurement result to the information processing unit  30  in a wireless or wired manner. 
     The in-mixed-liquid concentration measuring unit  24  may be any unit as long as it can acquire the first measurement value. One example of the in-mixed-liquid concentration measuring unit  24  will be described later. 
     The second sensing unit  23  includes a sheet-like fourth adhesive layer  231  and a sheet-like third dielectric layer  232  laminated in this order in the forward direction of the Z axis. 
     In the fourth adhesive layer  231 , the opening portion  233  having a size in the XY plane larger than that of the opening portion  226  is formed. The opening portion  233  communicates with the opening portion  226 . 
     The fourth adhesive layer  231  adheres the second dielectric layer  223  to the third dielectric layer  232 . The fourth adhesive layer  231  may be any type as long as it is in the form of a sheet which adheres the second dielectric layer  223  to the third dielectric layer  232 . The fourth adhesive layer  231  is, for example, a double-sided tape. A thickness (a length in the Z-axis direction) of the fourth adhesive layer  231  can be preferably 100 to 1000 μm and more preferably 500 μm. 
     In the third dielectric layer  232 , the opening portion  234  having a size in the XY plane smaller than that of the opening portion  233  is formed. The opening portion  234  communicates with the opening portion  233 . A line passing through a center of the opening portion  226  in the XY plane and parallel to the Z axis does not intersect with a line passing through a center of the opening portion  234  in the XY plane and parallel to the Z axis. 
     The third dielectric layer  232  is formed of a dielectric. The third dielectric layer  232  may be any type as long as it is a sheet-like dielectric. The third dielectric layer  232  may be, for example, a silicon sheet. A thickness (a length in the Z-axis direction) of the third dielectric layer  232  can be preferably 100 to 1000 μm and more preferably 500 μm. 
     A flow path  235  is formed using the opening portion  233  and the opening portion  234 . The mixed liquid which has flowed through the flow path  227  flows into the second sensing unit  23  through the opening portion  226 . The mixed liquid which has flowed into the opening portion  226  flows through the flow path  235 . The mixed liquid flowing through the flow path  235  is discharged outside of the supplied unit  20  through the opening portion  234 . In this way, the flow path  235  is positioned downstream of the sweat collecting unit  21 . 
     The second sensing unit  23  includes a mixed liquid amount measurement unit  25 . The mixed liquid amount measurement unit  25  measures an amount of the mixed liquid flowing through the flow path  235  using a predetermined measuring method. Hereinafter, an amount of the mixed liquid measured by the mixed liquid amount measurement unit  25  is referred to as a second measurement value. 
     The mixed liquid amount measurement unit  25  outputs the second measurement value of the measurement result to the information processing unit  30  in a wireless or wired manner. 
     The mixed liquid amount measurement unit  25  may be any unit as long as it can acquire an amount of the mixed liquid. 
     The mixed liquid amount measurement unit  25  may be, for example, a device which includes a central processing unit (CPU), a memory, an auxiliary storage device, and a light emitting diode (LED) and executes a first sweat amount measurement program. The mixed liquid amount measurement unit  25  receives absorbed, reflected, or scattering light of light emitted by the LED by executing an sweat amount measurement program and measures a time at which the mixed liquid flowing through the flow path  235  passes through a predetermined position on the basis of the light reception result. The mixed liquid amount measurement unit  25  measures the time at which the mixed liquid passes through the predetermined position to measure the second measurement value. 
     The mixed liquid amount measurement unit  25  may be, for example, a device which includes a CPU, a memory, an auxiliary storage device, and an imaging device and executes a second sweat amount measurement program. For example, when a scale is engraved in a third flow path  230 , the mixed liquid amount measurement unit  25  may read a value of the scale in which a fluid is positioned using an imaging device by executing the second sweat amount measurement program to measure the second measurement value. 
     A description will be provided with reference to  FIG. 1  again. 
     The information processing unit  30  functions as a device which includes an input unit  301 , a control unit  302 , a component concentration calculation unit  303 , and an output unit  304 . 
     The input unit  301  is constituted to include input devices such as a touch panel and a switch. The input unit  301  may be constituted as an interface configured to connect these input devices to a subject itself. 
     The input unit  301  receives processing start information concerning the subject itself as an input. If a start instruction is input to the input unit  301 , the sweat measuring device  1  starts measuring the concentration of the component to be measured in sweat. 
     The control unit  302  controls an operation of the fluid supply unit  10 , an operation of the in-mixed-liquid concentration measuring unit  24 , and an operation of the mixed liquid amount measurement unit  25 . 
     To be specific, the control unit  302  performs a cleaning control process, a measurement fluid control process, a first measurement value measurement control process, and a second measurement value measurement control process if a start condition is satisfied. 
     The start condition may be any condition as long as it associates with an input and a time of a start instruction to the input unit  301 . The start condition may be, for example, a condition in which a start instruction is input to the input unit  301 . The start condition may be, for example, a condition in which at least one of a first condition and a second condition is satisfied. The first condition is a condition in which a start instruction is input to the input unit  301 . The second condition is a condition in which the measurement using the sweat measuring device  1  has been completed and then a predetermined time elapses. In such a case, the sweat measuring device  1  performs the measurement once at a timing at which the start instruction is input and then performs the measurement at a constant cycle. 
     The cleaning control process is a process of the control unit  302  which causes the fluid supply unit  10  to supply the auxiliary liquid to the supplied unit  20 . The fluid supply unit  10  supplies the auxiliary liquid to the supplied unit  20  by executing the cleaning control process using the control unit  302 . 
     The measurement fluid control process is a process executed by the control unit  302  after the cleaning control process ends and then a predetermined time (hereinafter referred to as an “inter-process time”) has elapsed. The measurement fluid control process is a process of the control unit  302  which causes the fluid supply unit  10  to supply a predetermined amount (hereinafter referred to as an “amount of auxiliary liquid”) of the auxiliary liquid to the supplied unit  20 . The amount of the auxiliary liquid is, for example, an amount stored in an auxiliary storage device (not shown) included in the information processing unit  30 . The fluid supply unit  10  supplies a predetermined amount of the auxiliary liquid to the supplied unit  20  by executing the measurement fluid control process using the control unit  302 . 
     The first measurement value measurement control process is a process of the control unit  302  which causes the in-mixed-liquid concentration measuring unit  24  to measure the first measurement value. The in-mixed-liquid concentration measuring unit  24  acquires the first measurement value by executing the first measurement value measurement control process using the control unit  302 . 
     The second measurement value measurement control process is a process of the control unit  302  which causes the mixed liquid amount measurement unit  25  to measure the second measurement value. The mixed liquid amount measurement unit  25  acquires the second measurement value by executing the second measurement value measurement control process using the control unit  302 . 
     The component concentration calculation unit  303  calculates the concentration of the component to be measured in sweat by performing a component concentration calculation process. 
     The component concentration calculation unit  303  calculates the concentration of the component to be measured in sweat on the basis of the first measurement value, the second measurement value, and the amount of the auxiliary liquid by performing the component concentration calculation process. 
     The output unit  304  outputs the result calculated by the component concentration calculation unit  303 . The output unit  304  may be constituted to include display devices such as a cathode ray tube (CRT) display, a liquid crystal display, and an organic electro-luminescence (EL) display. The output unit  304  may be constituted as an interface configured to connect these display devices to the subject itself. 
     (Example of in-Mixed-Liquid Concentration Measuring Unit  24 ) 
       FIG. 4  is a diagram showing an example of a constitution of the in-mixed-liquid concentration measuring unit  24  in the embodiment. 
     The in-mixed-liquid concentration measuring unit  24  includes a biological information measurement sensor  400 , a potentiostat  450 , and a current value concentration conversion unit  460 . 
     (Description of Biological Information Measurement Sensor  400 ) 
     First, the biological information measurement sensor  400  will be described. 
     The biological information measurement sensor  400  includes an insulating base member  410 , and a working electrode  420 , a counter electrode  430 , and a reference electrode  440  above the insulating base member  410 . 
     The counter electrode  430  and the reference electrode  440  are provided above the insulating base member  410  so that they are disposed on both sides of the working electrode  420 . 
     The insulating base member  410  is constituted of an insulating material so that three electrodes (that is, three electrodes, i.e., the working electrode  420 , the counter electrode  430 , and the reference electrode  440 ) are not short-circuited. 
     The insulating base member  410  can be preferably constituted of a flexible material so that the insulating base member  410  easily comes into close contact with a living body. Furthermore, the insulating base member  410  is required to have a strength in which the three electrodes can be held. 
     Examples of base materials in which these conditions are satisfied include polyimide films, polyesters, polymer films such as polytetrafluoroethylene (PTFE), paper, and ceramics such as mica. 
     The working electrode  420  is an electrode which exchanges electrons with the component to be measured. In this embodiment, as shown in  FIGS. 4 and 5 , the working electrode  420  is constituted of a working electrode main body  421 , a working electrode connection section  422  continuous with the working electrode main body  421 , and an enzyme film  423  provided above the working electrode main body  421 .  FIG. 5  is a diagram showing the working electrode  420  when viewed from a direction perpendicular to that of  FIG. 4 . 
     The working electrode main body  421  is made of a conductive solid material such as, for example, carbon, platinum, and gold. The working electrode main body  421  in this embodiment includes a straight linear section  421   a  and a circular section  421   b  integrally formed with a first end portion of the straight linear section  421   a . Furthermore, the working electrode connection section  422  is coaxially connected to a second end portion of the straight linear section  421   a . The working electrode connection section  422  is made of, for example, a metal having a low resistance value such as silver/silver chloride, silver, copper, platinum, and gold. 
     The enzyme film  423  is provided above the circular section  421   b  of the working electrode main body  421 . Examples of the enzyme film  423  include an enzyme film made of a material selected from the group consisting of lactate oxidase and glucose oxidase. 
     When the enzyme film  423  is lactate oxidase, a reaction for converting lactic acid to pyruvic acid occurs in the enzyme film  423  and hydrogen peroxide generated at the time of the reaction reacts with a dye (Prussian blue) in the electrode to generate a current. 
     The counter electrode  430  is an electrode in which a current flows between the counter electrode  430  and the working electrode  420 . In this embodiment, as shown in  FIGS. 4 and 6 , the counter electrode  430  is constituted of a counter electrode main body  431  and a counter electrode connection section  432  continuous with the counter electrode main body  431 .  FIG. 6  is a diagram showing the counter electrode  430  when viewed from a direction perpendicular to that of  FIG. 4 . 
     The counter electrode main body  431  is made of a conductive solid material such as, for example, carbon, platinum, and gold. The counter electrode main body  431  in this embodiment includes a straight linear section  431   a  and a circular arc section  431   b  integrally formed with a first end portion of the straight linear section  431   a . The circular arc section  431   b  is formed in a circular arc shape to surround the circular section  421   b  of the working electrode main body  421  at substantially the same distance from the circular section  421   b . Furthermore, the counter electrode connection section  432  is coaxially connected to a second end portion of the straight linear section  431   a . The counter electrode connection section  432  is made of, for example, a metal having a low resistance value such as silver/silver chloride, silver, copper, platinum, and gold. 
     The reference electrode  440  is an electrode serving as a reference for a potential of the working electrode  420 . The reference electrode  440  is made of silver/silver chloride. As shown in  FIGS. 4 and 6 , the reference electrode  440  in this embodiment includes a straight linear section  440   a  and a circular arc section  440   b  integrally formed with a first end portion of the straight linear section  440   a . The circular arc section  440   b  is formed in a circular arc shape to surround the circular section  421   b  of the working electrode main body  421  at substantially the same distance from the circular section  421   b  together with the circular arc section  431   b  of the counter electrode  430 .  FIG. 6  is a diagram showing the reference electrode  440  when viewed from a direction perpendicular to that of  FIG. 4 . 
     Thicknesses of the working electrode main body  421 , the counter electrode main body  431 , and the reference electrode  440  can be preferably 10 to 100 μm. 
     When the thicknesses of these members are equal to or more than preferred lower limit values, it is possible to stabilize an output of the biological information measurement sensor  400 . Furthermore, the thicknesses of these members are equal to or less than preferred upper limit values, it is easy to secure the flexibility of the biological information measurement sensor  400  and the biological information measurement sensor  400  easily follows the movement of a living body. 
     Also, widths of the straight linear section  421   a  of the working electrode main body  421 , the counter electrode main body  431 , and the reference electrode  440  can be preferably 0.05 to 3 mm and more preferably 0.3 to 1.5 mm. 
     When the widths of these members are equal to or more than preferred lower limit values, it is easy to stabilize an output of the biological information measurement sensor  400 . Furthermore, when the widths of these members are equal to or less than preferred upper limit values, it is possible to form the entire biological information measurement sensor  400  to have a smaller size. 
     An amount of enzyme used for forming the enzyme film  423  can be preferably 3.2 to 25.6 units and more preferably 12.8 units. 
     If the amount of enzyme used for forming the enzyme film  423  is equal to or more than a preferred lower limit value, a sufficient sensitivity can be obtained. If the amount of enzyme used for forming the enzyme film  423  is equal to or less than a preferred upper limit value, the costs can be reduced. 
     An area of the circular section  421   b  in the working electrode main body  421  can be preferably 1 to 30 mm 2  and more preferably 1.5 to 20 mm 2 . If the area of the circular section  421   b  is equal to or more than a preferred lower limit value, it is easy to form the enzyme film  423  with a sufficient amount of enzyme. If the area of the circular section  421   b  is equal to or less than a preferred upper limit value, it is possible to form the entire biological information measurement sensor  400  to have a smaller size. 
     A separation distance between the working electrode  420  and the counter electrode  430  and a separation distance between the working electrode  420  and the reference electrode  440  can be preferably 0.5 to 3 mm and more preferably 1 to 2 mm. 
     When the separation distances are equal to or more than preferred lower limit values, an excellent production efficiency is provided at the time of producing electrodes. When the separation distances are equal to or less than preferred upper limit values, it is possible to accurately perform the measurement even if an amount of specimen is reduced at the time of performing the measurement. 
     (Description of Potentiostat  450 ) 
     The potentiostat  450  will be described below. 
     The potentiostat  450  is connected to the biological information measurement sensor  400  using a working electrode lead wire  462 , a counter electrode lead wire  463 , and a reference electrode lead wire  464 . 
     The working electrode lead wire  462  is a lead wire configured to connect the working electrode  420  to the potentiostat  450 . The counter electrode lead wire  463  is a lead wire configured to connect the counter electrode  430  to the potentiostat  450 . The reference electrode lead wire  464  is a lead wire configured to connect the reference electrode  440  to the potentiostat  450 . 
     The potentiostat  450  applies a constant potential with respect to the reference electrode  440  to the working electrode  420  and measures a current between the working electrode  420  and the counter electrode  430 . 
     (Description of Current Value Concentration Conversion Unit  460 ) 
     The current value concentration conversion unit  460  acquires the concentration of the component to be measured in the mixed liquid on the basis of a current value of a current measured by the potentiostat  450 . 
     (Description of Operations of Biological Information Measurement Sensor  400 , Potentiostat  450 , and Current Value Concentration Conversion Unit  460 ) 
     The potentiostat  450  applies a predetermined constant potential with respect to the reference electrode  440  to the working electrode  420  of the biological information measurement sensor  400 . Furthermore, a current (a current flowing between the working electrode  420  and the counter electrode  430 ) obtained from the biological information measurement sensor  400  at this time is detected using the potentiostat  450 . 
     When the biological information measurement sensor  400  is positioned in the mixed liquid, a current flowing between the working electrode  420  and the counter electrode  430  is a current of a current value according to the concentration of the component to be measured in the mixed liquid. For this reason, when the biological information measurement sensor  400  is positioned in the mixed liquid, a current value of a current measured by the potentiostat  450  is a value of a physical quantity which changes in accordance with a change in concentration of the component to be measured in the mixed liquid. 
     The current value concentration conversion unit  460  acquires the first measurement value which is the concentration of the component to be measured in the mixed liquid on the basis of the current value of the current measured by the potentiostat  450 . 
     (Top View of Sweat Collecting Unit  21  and First Sensing Unit  22 ) 
       FIG. 7  is a top view of the sweat collecting unit  21  in the embodiment.  FIG. 7  shows the sweat collecting unit  21  having a size of 30 mm×48 mm  FIG. 7  shows the flow path  218  formed in a bellows shape.  FIG. 7  shows the flow path  218  having a size and a shape in which the flow path  218  is positioned in a rectangular shape of 23 mm×35 mm  FIG. 7  shows the flow path  218  having a width of a flow path thereof being 1 mm  FIG. 7  shows the flow path  218  having a distance between flow paths thereof being 1 mm. 
       FIG. 8  is a top view of the first sensing unit  22  in the embodiment.  FIG. 8  shows the flow path  227  having a straight linear shape with a length of 25 mm and a width being 1 mm  FIG. 8  is a top view of the in-mixed-liquid concentration measuring unit  24 .  FIG. 8  shows a part of the in-mixed-liquid concentration measuring unit  24  positioned in a region with a length of 4 mm in a center of the flow path  227 . 
       FIG. 9  is a top view of the sweat collecting unit  21  and the first sensing unit  22  which have been laminated in the embodiment.  FIG. 9  shows the first sensing unit  22  laminated on the sweat collecting unit  21  and one end portion of the flow path  218  and one end portion of the flow path  227  overlapping. In  FIG. 9 , one end portion of the flow path  218  overlapping one end portion of the flow path  227  is an example of the opening portion  217 . In  FIG. 9 , one end portion of the flow path  227  overlapping one end portion of the flow path  218  is an example of the opening portion  224 . 
     (Flowchart) 
       FIG. 10  is a flowchart for describing a flow of a process from when a start condition is satisfied to when the sweat measuring device  1  calculates the concentration of a component to be measured in sweat in the embodiment. 
     The control unit  302  executes the cleaning control process and the fluid supply unit  10  supplies the auxiliary liquid to the supplied unit  20  (Step S 101 ). To be specific, the fluid supply unit  10  supplies the auxiliary liquid to the supplied unit  20  by being controlled through the cleaning control process executed by the control unit  302 . The auxiliary liquid supplied to the supplied unit  20  mixes with old sweat accumulated in the supplied unit  20  and is discharged to the outside of the supplied unit  20  through the opening portion  234 . For this reason, the supplied unit  20  can remove old sweat accumulated in the supplied unit  20  through the process of Step S 101 . 
     After the cleaning control process is completed and then the inter-process time elapses, the control unit  302  executes the measurement fluid control process. When the control unit  302  executes the measurement fluid control process, the fluid supply unit  10  supplies the auxiliary liquid of the amount of the auxiliary liquid to the supplied unit  20  (Step S 102 ). To be specific, the fluid supply unit  10  supplies the auxiliary liquid of the amount of the auxiliary liquid to the supplied unit  20  by being controlled through the measurement fluid control process executed by the control unit  302 . 
     In the sweat collecting unit  21 , the auxiliary liquid flowing through the flow path  218  in the sweat collecting unit  21  mixes with sweat discharged into the sweat collecting unit  21  (Step S 103 ). In Step S 103 , the sweat mixing with the auxiliary liquid is sweat which has flowed from the skin  9  into the supplied unit  20  during the inter-process time. 
     The mixed liquid which is a liquid obtained by mixing the auxiliary liquid with the sweat is supplied from the sweat collecting unit  21  to the first sensing unit  22  (Step S 104 ). To be specific, when the mixed liquid flows from the flow path  218  to the flow path  227 , the mixed liquid is supplied from the sweat collecting unit  21  to the first sensing unit  22 . 
     In the first sensing unit  22 , the first measurement value is acquired (Step S 105 ). To be specific, the control unit  302  executes the first measurement value measurement control process and the in-mixed-liquid concentration measuring unit  24  measures the concentration of the component to be measured in the mixed liquid flowing through the flow path  227 . An operation of the in-mixed-liquid concentration measuring unit  24  in Step S 105  is controlled through the first measurement value measurement control process executed by the control unit  302 . 
     The mixed liquid is supplied from the first sensing unit  22  to the second sensing unit  23  (Step S 106 ). To be specific, when the mixed liquid flows from the flow path  227  to the flow path  235 , the mixed liquid is supplied from the first sensing unit  22  to the second sensing unit  23 . 
     In the second sensing unit  23 , the second measurement value is acquired (Step S 107 ). To be specific, the control unit  302  executes the second measurement value measurement control process and the mixed liquid amount measurement unit  25  measures an amount of the mixed liquid. An operation of the mixed liquid amount measurement unit  25  in Step S 107  is controlled through the second measurement value measurement control process executed by the control unit  302 . 
     The sweat measuring device  1  in the embodiment constituted as described above includes the fluid supply unit  10  and the supplied unit  20  and the cleaning control process is executed before the measurement fluid control process. Thus, it is possible to measure the concentration of the component to be measured by reducing an influence of old sweat. For this reason, the sweat measuring device  1  can prevent a decrease in measurement accuracy of an amount of component in a liquid (sweat) discharged from sweat which is a discharge source. 
     Also, the sweat measuring device  1  in the embodiment constituted as described above measures the concentration of the component to be measured using not only the sweat but also the auxiliary liquid. For this reason, the sweat measuring device  1  prevents an increase in time required for collecting the sweat and the measurement using the sweat measuring device  1  does not impair the real-time property. For this reason, the sweat measuring device  1  can prevent a decrease in measurement accuracy due to the time required for collecting the sweat. 
     Also, the sweat measuring device  1  in the embodiment constituted as described above includes the sweat collecting unit  21 , the first sensing unit  22 , and the second sensing unit  23  laminated in the direction perpendicular to the surface of the skin  9 . For this reason, the sweat measuring device  1  can prevent an increase in area of a device and prevent an increase in size of a device. 
     Furthermore, the sweat measuring device  1  in the embodiment constituted as described above measures the concentration of the component to be measured using not only the sweat but also the auxiliary liquid. For this reason, the sweat measuring device  1  can measure the concentration of the component to be measured using sweat less than that of a case in which the measurement is performed without using the auxiliary liquid. For this reason, an area of the sweat collecting unit  21  in contact with the skin  9  is smaller than that a case in which the measurement is performed without using the auxiliary liquid. For this reason, the sweat measuring device  1  can prevent an increase in area of a device and prevent an increase in size of a device. 
     (Modification) 
     The working electrode  420  is not limited to the electrode having the enzyme film. For example, the working electrode  420  may be an electrode obtained by adhering an oxygen permeable film to a surface of a conductive solid material. 
     Also, the working electrode lead wire  462  may be directly connected to a main body of the working electrode  420  made of carbon or the like without passing through the working electrode connection section. Similarly, the counter electrode lead wire  463  may be directly connected to a main body of the counter electrode  430  made of carbon or the like without passing through the counter electrode connection section. 
     There is no particular limitation on a shape of each of the three electrodes and a mutual positional relationship among these three electrodes. It is also possible to appropriately change a shape of the insulating base member to correspond to the shape of each of the three electrodes the mutual positional relationship among these three electrodes. 
     Also, the potentiostat  450  and the biological information measurement sensor  400  may be connected wirelessly without using a lead wire. In the case of wireless connection, for example, it is possible to utilize short-range wireless communication such as Bluetooth (registered trademark). 
     The sweat collecting unit  21 , the first sensing unit  22 , and the second sensing unit  23  do not necessarily need to be all laminated. Only the sweat collecting unit  21  and the first sensing unit  22  may be laminated and only the sweat collecting unit  21  and the second sensing unit  23  may be laminated. Only the first sensing unit  22  and the second sensing unit  23  may be laminated. In this way, the sweat collecting unit  21 , the first sensing unit  22 , and the second sensing unit  23  do not all need to be laminated and at least two thereof may be laminated. 
     It is not always necessary that the sweat collecting unit  21  is connected to the first sensing unit  22  and the first sensing unit  22  is connected to the second sensing unit  23 . In the sweat collecting unit  21 , the first sensing unit  22 , and the second sensing unit  23 , if the sweat collecting unit  21  is in contact with the skin  9 , the sweat collecting unit  21  may be connected to the second sensing unit  23  and the second sensing unit  23  may be connected to the first sensing unit  22 . 
     Sweat is an example of a main liquid and the skin  9  is an example of a discharge source. The main liquid may be a sap. In this case, the discharge source may be the bark of a tree. The flow path  227  is an example of a first flow path. The flow path  235  is an example of a second flow path. The sweat collecting unit  21  is an example of a liquid collecting unit. The sweat measuring device  1  is an example of a component concentration measuring device. The first measurement value is an example of a first measurement target component concentration. The second measurement value is an example of an amount of mixed liquid. The concentration of the component to be measured in sweat is an example of a second measurement target component concentration. The fluid supply unit  10  is an example of an auxiliary fluid supply unit. 
     All or some of functions of the sweat measuring device  1  may be realized using hardware such as an application specific integrated circuit (ASIC), a programmable logic device (PLD), and a field programmable gate array (FPGA). The program may be recorded on a computer-readable recording medium. The computer-readable recording medium is, for example, a portable medium such as a flexible disk, a magneto-optical disk, a read only memory (ROM), a compact disk (CD)-ROM, or a storage device such as a hard disk built in a computer system. The program may be transmitted via a telecommunication line. 
     The sweat measuring device  1  may be implemented using multiple information processing devices communicably connected over a network. In this case, functional units included in the sweat measuring device  1  may be separately implemented in the multiple information processing devices. For example, the information processing unit  30  and the other functional units may be implemented in different information processing devices. 
     Although the embodiments of the present invention have been described in detail above with reference to the drawings, the specific constitution is not limited to the embodiments and includes a design and the like without departing from the scope of the present invention.