Patent Publication Number: US-2022212474-A1

Title: Flow path device, cartridge, and measurement system

Description:
CROSS REFERENCES TO RELATED APPLICATIONS 
     The present application claims priority to Japanese Patent Application No. 2019-084488, filed in Japan on Apr. 25, 2019. The entire disclosure of the earlier application is incorporated herein by reference. 
     TECHNICAL FIELD 
     The present disclosure relates to a flow path device, a cartridge, and a measurement system. 
     BACKGROUND ART 
     Hitherto, a known testing instrument has included a specimen supply port, a measurement chamber, and a flow path through which the specimen supply port and the measurement chamber communicate with each other (PTL 1). 
     CITATION LIST 
     Patent Literature 
     PTL 1: Japanese Unexamined Patent Application Publication No. 2002-224090 
     SUMMARY OF INVENTION 
     A flow path device according to an embodiment of the present disclosure includes a storage chamber that includes a ceiling surface and a bottom surface, and that is capable of storing a specimen; 
     an inlet through which an outside of the storage chamber and the storage chamber communicate with each other to allow the specimen to flow into the storage chamber from the outside of the storage chamber; 
     a flow path that is connected to an upper portion of the storage chamber at a location situated away from the inlet, the specimen being allowed to flow out into the flow path from the storage chamber; and 
     a projection that projects toward the bottom surface of the storage chamber from the ceiling surface of the storage chamber, and that is positioned between the inlet and the flow path, 
     wherein the projection limits a space with which a space of the storage chamber toward the inlet and a space of the storage chamber toward the flow path communicate to a height less than or equal to a predetermined height from the bottom surface of the storage chamber. 
     A cartridge according to an embodiment of the present disclosure includes 
     the flow path device; and 
     a sensor part that is connected to the flow path of the flow path device. 
     A measurement system according to an embodiment of the present disclosure includes 
     the cartridge; and 
     an air push-out unit, 
     wherein the air push-out unit includes
         a cylindrical syringe that comprises an end portion insertable into the inlet, and   a plunger that is movable in the syringe and that is capable of pushing out air in the syringe to the end portion.       

    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a schematic view of a measurement system according to an embodiment of the present disclosure. 
         FIG. 2  is a top view of a cartridge shown in  FIG. 1 . 
         FIG. 3  is a sectional view of a flow path device along line L-L shown in  FIG. 2 . 
         FIG. 4  is an exploded view of a part of the flow path device shown in  FIG. 3 . 
         FIG. 5  is a perspective view of a third base plate shown in  FIG. 4 . 
         FIG. 6  is a sectional view of a disposed state of the cartridge shown in  FIG. 1  in a measurement apparatus. 
         FIG. 7  is a sectional view of another example of a disposed state of the cartridge shown in  FIG. 1  in the measurement apparatus. 
         FIG. 8  is a sectional view of a structure when a plunger shown in  FIG. 6  has moved downward. 
         FIG. 9  is a sectional view of a structure when the plunger shown in  FIG. 8  has moved downward. 
         FIG. 10  is a sectional view of a measurement system according to a comparative example. 
         FIG. 11  is a sectional view of another example of the flow path device shown in  FIG. 3 . 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     A testing instrument is required to, for example, control a timing of supplying a specimen to a measurement chamber. 
     The present disclosure relates to providing a flow path device, a cartridge, and a measurement system that are capable of easily controlling a timing of supplying a specimen to a sensor part. 
     The flow path device, the cartridge, and the measurement system according to an embodiment of the present disclosure are capable of easily controlling a timing of supplying a specimen to the sensor part. 
     An embodiment according to the present disclosure is described below with reference to the drawings. In the drawings below, the direction of insertion of a flow path device  2  shown in  FIG. 1  into a measurement apparatus  3  is a positive direction of an X axis. The direction in which gravity acts is a position direction of a Z axis. A positive direction of a Y axis is determined to form a right-handed orthogonal coordinate system. 
     Here, in the present disclosure, “down” means the direction in which gravity acts, that is, the positive direction of the Z axis. In the present disclosure, “up” means a direction opposite to the direction in which gravity acts, that is, a negative direction of the Z axis. 
     [Structure of Measurement System] 
     As shown in  FIG. 1 , a measurement system  1  includes the measurement apparatus  3  and a cartridge  4 . The cartridge  4  includes a base plate  5 . The cartridge  4  includes the flow path device  2  and a sensor part  6  at the base plate  5 . The sensor part  6  may be constituted as a separate member from the base plate  5 . The sensor part  6  may be disposed at the measurement apparatus  3 . 
     The flow path device  2  includes a storage chamber  41  described below. The storage chamber  41  stores a specimen  7 . Examples of the specimen  7  include a person&#39;s blood, a person&#39;s cerebrospinal fluid, and a person&#39;s urine. Note that before introducing the specimen  7  into the flow path device  2 , the specimen  7  may be pre-treated as appropriate. 
     The measurement apparatus  3  includes a housing  3 A and an insertion hole  3 B. The housing  3 A may be made of, for example, a metal material or a synthetic resin material. The cartridge  4  is inserted into the measurement apparatus  3  from the insertion hole  3 B. By inserting the cartridge  4  from the insertion hole  3 B of the measurement apparatus  3 , the cartridge  4  is disposed in the measurement apparatus  3 . When the cartridge  4  is disposed in the measurement apparatus  3 , as described below, the specimen  7  is supplied to the sensor part  6 . The sensor part  6  outputs an electric signal in accordance with a component in the specimen  7 . The sensor part  6  may be constituted by, for example, a sensor using a surface acoustic wave (SAW). The measurement apparatus  3  obtains the electric signal output by the sensor part  6 . The measurement apparatus  3  measures, for example, the component in the specimen  7  based on, for example, the obtained electric signal. 
     As shown in  FIG. 2 , the sensor part  6  is disposed in a region  10 . At the base plate  5 , the region  10  is positioned toward the positive direction of the X axis than the flow path device  2 . 
     As shown in  FIG. 3 , the flow path device  2  includes the storage chamber  41 , a flow path  48 , an inlet  50 , and a projection  51 . As shown in  FIG. 4 , the flow path device  2  includes projecting portions  49 A and  49 B (a pair of projecting portions). As shown in  FIG. 3 , the base plate  5  includes an upper base plate  20 , a small plate  30 , a sheet member  36 , and a lower base plate  40 . 
     The upper base plate  20  is positioned above the lower base plate  40 . The upper base plate  20  may be made of, for example, a synthetic resin material. The upper base plate  20  includes an accommodation portion  25 , an inner surface  23  and a wall surface  24  that form the accommodation portion  25 , an opening portion  22  that extends through an outer portion of the base plate  5  and the accommodation portion  25 , and a wall surface  21  that forms the opening portion  22 . 
     The opening portion  22  is specified as a region that is surrounded by the wall surface  21 . As shown in  FIG. 2 , in top view, the opening portion  22  may be, for example, circular. 
     The accommodation portion  25  is specified as a region that is surrounded by the inner surface  23  and the wall surface  24 . The small plate  30  is accommodated in the accommodation portion  25 . The size and the shape of the accommodation portion  25  may be adjusted as appropriate in accordance with the size of the small plate  30 . 
     The small plate  30  is positioned between the upper base plate  20  and the lower base plate  40 . The small plate  30  is accommodated in the accommodation portion  25  of the upper base plate  20 . The small plate  30  may be made of, for example, a synthetic resin material. As shown in  FIGS. 4 and 5 , the small plate  30  has an upper surface  31 , a lower surface  32 , an opening portion  33  that extends through the upper surface  31  and the lower surface  32 , and a wall surface  34  that forms the opening portion  33 . 
     As shown in  FIG. 3 , the upper surface  31  faces the inner surface  23  of the upper base plate  20 . A bonding member  35  may be disposed as appropriate between the upper surface  31  and the inner surface  23  of the upper base plate  20 . The bonding member  35  may be any adhesive selected as appropriate in accordance with the material of the small plate  30  and the material of the upper base plate  20 . The lower surface  32  faces the lower base plate  40 . As shown in  FIG. 5 , the projection  51  is disposed on the lower surface  32 . 
     The opening portion  33  is specified as a region that is surrounded by the wall surface  34 . As shown in  FIG. 4 , the opening portion  33  may be circular in top view. As shown in  FIG. 3 , the inside diameter of the opening portion  33  may be smaller than the inside diameter of the opening portion  22  of the upper base plate  20 . The inside diameter of the opening portion  33  may be adjusted as appropriate in accordance with the outside diameter of an end portion  84  of a syringe  81  of an air push-out unit  80  described below ( FIG. 6 ). 
     As shown in  FIG. 3 , the sheet member  36  is disposed to cover a gap between the wall surface  24  of the upper base plate  20  and an end portion of the small plate  30  from below the gap. The sheet member  36  may be made of, for example, synthetic resin. 
     As shown in  FIG. 3 , the lower base plate  40  is positioned below the upper base plate  20 . The lower base plate  40  may be made of, for example, a synthetic resin material. As shown in  FIG. 4 , the lower base plate  40  may have a recessed portion  40 A that opens upward. The recessed portion  40 A has a bottom surface  43 , a bottom surface  41   a , a bottom surface  46 , a wall surface  44 , a wall surface  41   b , and a wall surface  47 . 
     The storage chamber  41  shown in  FIG. 3  is specified as a region that is surrounded by the lower surface  32  of the small plate  30  and the surfaces of the recessed portion  40 A shown in  FIG. 4 . For example, the storage chamber  41  is specified as a region that is surrounded by the lower surface  32  of the small plate  30  shown in  FIG. 3 , the bottom surface  41   a , the bottom surface  43 , and the bottom surface  46  of the recessed portion  40 A shown in  FIG. 4 , and the wall surface  41   b , the wall surface  44 , and the wall surface  47  of the recessed portion  40 A. Of the lower surface  32  of the small plate  30 , a portion that specifies the storage chamber  41  may also be called a “ceiling surface” of the storage chamber  41 . 
     The storage chamber  41  is positioned in the base plate  5 . The storage chamber  41  communicates with the outside of the base plate  5  through the inlet  50  including the opening portion  22  and the opening portion  33 . In other words, the storage chamber  41  communicates with the outside of the storage chamber  41  through the inlet  50 . The storage chamber  41  is capable of storing the specimen  7 . For example, as shown in  FIG. 3 , the specimen  7  dripped toward the inlet  50  by a user is supplied to the storage chamber  41  through the inlet  50 . The storage chamber  41  stores the specimen  7  supplied through the inlet  50 . The specimen  7  can accumulate at a lower side of the storage chamber  41  due to gravity acting upon the specimen  7 . The specimen  7  is stored in the storage chamber  41  until the sensor part  6  shown in  FIG. 2  starts to measure the specimen  7 . When the sensor part  6  shown in  FIG. 2  starts to measure the specimen  7 , the specimen  7  stored in the storage chamber  41  is supplied to the sensor part  6  in the region  10  through the flow path  48  shown in  FIG. 2 . 
     As shown in  FIG. 3 , the storage chamber  41  may include a first chamber  42  and a second chamber  45 . The storage chamber  41  may have a space  41 A between the first chamber  42  and the second chamber  45 . As shown in  FIG. 4 , the space  41 A includes a portion that is specified as a region that is surrounded by the bottom surface  41   a  and the wall surface  41   b . As shown in  FIG. 4 , the first chamber  42  and the second chamber  45  communicate with each other through the space  41 A. The projection  51  is positioned in the space  41 A. By positioning the projection  51  in the space  41 A, as described below, a large amount of the specimen  7  shown in  FIG. 3  can be held back at the first chamber  42  in the storage chamber  41 . 
     As shown in  FIG. 3 , the first chamber  42  is specified as a region that is surrounded by the lower surface  32  of the small plate  30 , the bottom surface  43 , and the wall surface  44 . A part of an upper portion of the first chamber  42  communicates with the inlet  50 . As shown in  FIG. 4 , a part of the first chamber  42  toward the positive direction of the X axis communicates with the second chamber  45  through the space  41 A. As shown in  FIG. 3 , the specimen  7  that has flowed in from the inlet  50  can be stored in the first chamber  42 . 
     As shown in  FIG. 4 , a side of the bottom surface  43  toward the positive direction of the X axis is continuous with the bottom surface  41   a  of the space  41 A. As shown in  FIG. 3 , a part of the bottom surface  43  toward the positive direction of the X axis may be a plane surface along an XY plane. As shown in  FIG. 3 , a part of the bottom surface  43  toward the negative direction of the X axis may be an inclined surface that inclines toward the negative direction of the Z axis as this part extends toward the negative direction of the X axis. As shown in  FIG. 4 , the wall surface  44  is connected to the wall surface  41   b  of the space  41 A. The bottom surface  43  may have a substantially rectangular shape extending along the XY plane. The wall surface  44  may extend along the negative direction of the Z axis from a part of a periphery of the bottom surface  43 . That is, the shape of the first chamber  42  may be a substantially rectangular parallelepiped shape. By forming the first chamber  42  with a substantially rectangular parallelepiped shape, the capacity of the first chamber  42  can be increased. By increasing the capacity of the first chamber  42 , even if the specimen  7  is a specimen whose amount is relatively large, such as a person&#39;s urine, the first chamber  42  is capable of storing the specimen  7 . Therefore, even if the specimen  7  is a specimen whose amount is relatively large, such as a person&#39;s urine, the probability with which the specimen  7  overflows the first chamber  42 , flows through the second chamber  45 , and flows out into the flow path  48  can be reduced. Due to such a structure, the probability with which the specimen  7  stored in the storage chamber  41  reaches the sensor part  6  shown in  FIG. 2  through the flow path  48  before the sensor part  6  shown in  FIG. 2  starts to measure the specimen  7  can be reduced. 
     As shown in  FIG. 4 , the second chamber  45  is specified as a region that is surrounded by the lower surface  32  of the small plate  30 , the bottom surface  46 , and the wall surface  47 . An upper portion of the second chamber  45  toward the positive direction of the X axis communicates with the flow path  48 . 
     As shown in  FIG. 4 , a side of the bottom surface  46  toward the negative direction of the X axis is continuous with the bottom surface  41   a  of the space  41 A. The wall surface  47  is continuous with the wall surface  41   b  of the space  41 A. The length (width) of the bottom surface  46  in the direction along the Y axis may gradually decrease toward the flow path  48 . The wall surface  47  may extend along the negative direction of the Z axis from a part of a periphery of the bottom surface  46 . That is, the width of the second chamber  45  may become gradually smaller toward the flow path  48  from a location where the projection  51  is positioned. As shown in  FIG. 3 , the bottom surface  46  may be an inclined surface that inclines toward the flow path  48  from the bottom surface  41   a  of the space  41 A. Here, the capacity of the storage chamber  41  can be set based on the quantity of air that is capable of being supplied by the air push-out unit  80  (described later) ( FIG. 6 ). That is, the sum of the capacity of the first chamber  42  and the capacity of the second chamber  45  can be set based on the quantity of air that is capable of being supplied by the air push-out unit  80  (described later) ( FIG. 6 ). In such a case, by causing the bottom surface  46  to be an inclined surface, the capacity of the second chamber  45  is reduced, as a result of which the capacity of the first chamber  42  can be increased by an amount corresponding to the decrease in the capacity of the second chamber  45 . By increasing the capacity of the first chamber  42 , the probability with which the specimen  7  overflows the first chamber  42 , flows through the second chamber  45 , and flows out into the flow path  48  can be reduced. 
     As shown in  FIG. 3 , the flow path  48  is positioned in the base plate  5 . The flow path  48  is specified as a region that is surrounded by a groove in the lower base plate  40  and a lower surface of the upper base plate  20  or the sheet member  36 . The flow path  48  is connected to the storage chamber  41  at a location situated away from the inlet  50 . For example, in a structure in which the inlet  50  shown in  FIG. 3  is connected to the first chamber  42  of the storage chamber  41 , the flow path  48  is connected to the second chamber  45  of the storage chamber  41 . As shown in  FIG. 2 , the flow path  48  extends from the storage chamber  41  to the region  10  where the sensor part  6  is disposed. In other words, the sensor part  6  is connected to the flow path  48 . The specimen  7  can flow out into the flow path  48  from the storage chamber  41 . For example, when the sensor part  6  shown in  FIG. 2  starts to measure the specimen  7 , air is sent out into the storage chamber  41  by the air push-out unit  80  described below ( FIG. 7 ). As described below, the specimen  7  flows out into the flow path  48  from the storage chamber  41  by the air sent out into the storage chamber  41 . The specimen  7  that has flowed out into the flow path  48  reaches the sensor part  6  shown in  FIG. 2  through the flow path  48 . 
     The flow path  48  is connected to an upper portion of the storage chamber  41 . For example, as shown in  FIG. 3 , the flow path  48  is connected to the upper portion of the second chamber  45  of the storage chamber  41 . Here, the specimen  7  can accumulate at the lower side of the storage chamber  41  due to gravity acting upon the specimen  7 . Since the specimen  7  accumulates at the lower side of the storage chamber  41 , by connecting the flow path  48  to the upper portion of the storage chamber  41 , the probability with which the specimen  7  flows into the flow path  48  before the sensor part  6  shown in  FIG. 2  starts to measure the specimen  7  can be reduced. Due to such a structure, the probability with which the specimen  7  reaches the sensor part  6  shown in  FIG. 2  through the flow path  48  before the sensor part  6  starts to measure the specimen  7  can be reduced. 
     As shown in  FIG. 4 , the projecting portions  49 A and  49 B are positioned at a portion of the first chamber  42  toward the second chamber  45 . The projecting portions  49 A and  49 B may each be formed as a part of the lower base plate  40 . The projecting portions  49 A and  49 B face each other. The projecting portion  49 A projects toward the negative direction of the Y axis. The projecting portion  449  projects toward the positive direction of the Y axis. By disposing the projecting portions  49 A and  49 B, it is possible to easily position the projection  51  in the space  41 A of the storage chamber  41  in an assembly step of the base plate  5 . 
     As shown in  FIG. 3 , the inlet  50  has the opening portion  22  of the upper base plate  20  and the opening portion  33  of the small plate  30 . That is, the inlet  50  includes a portion that is specified as a region that is surrounded by the wall surface  21  of the upper base plate  20  and a portion that is specified as a region that is surrounded by the wall surface  34  of the small plate  30 . The inlet  50  is positioned in the base plate  5 . The inlet  50  causes the outside of the base plate  5  and the storage chamber  41  to communicate with each other to allow the specimen  7  to flow into the storage chamber  41  from the outside of the base plate  5 . In other words, the inlet  50  causes the outside of the storage chamber  41  and the storage chamber  41  to communicate with each other to allow the specimen  7  to flow into the storage chamber  41  from the outside of the storage chamber  41 . For example, a user drips the specimen  7  toward the inlet  50  from a side of the negative direction of the Z axis. The specimen  7  dripped toward the inlet  50  can flow into the storage chamber  41  from the inlet  50 . 
     As shown in  FIG. 3 , the projection  51  is positioned in the base plate  5 . For example, as shown in  FIG. 5 , the projection  51  is positioned on the lower surface  32  of the small plate  30 . The projection  51  may be integrated with the small plate  30 . 
     As shown in  FIG. 3 , the projection  51  projects toward the bottom surface  41   a  of the space  41 A of the storage chamber  41  from the lower surface  32  of the small plate  30 , which is the ceiling surface of the storage chamber  41 . In sectional view along the direction toward the flow path  48  from the inlet  50 , the projection  51  may have a substantially inverted triangular shape whose apex is positioned toward the bottom surface  41   a  of the storage chamber  41 . 
     The projection  51  limits a space with which a space of the storage chamber  41  toward the inlet  50  and a space of the storage chamber  41  toward the flow path  48  communicate to a height less than or equal to a predetermined height from a bottom surface of the storage chamber  41 . For example, the projection  51  limits the space  41 A with which the first chamber  42  as a space of the storage chamber  41  toward the inlet  50  and the second chamber  45  as a space of the storage chamber  41  toward the flow path  48  communicate to a height less than or equal to the predetermined height from the bottom surface  41   a  of the storage chamber  41 . 
     Due to the projection  51  limiting the space  41 A to a height less than or equal to the predetermined height from the bottom surface  41   a  of the storage chamber  41 , the surface tension of the specimen  7  makes it difficult for the specimen  7  to leak and spread toward the flow path  48  at a location between the projection  51  and the bottom surface  46 . By making it difficult for the specimen  7  to leak and spread toward the flow path  48 , a large amount of the specimen  7  can be held back at the first chamber  42  in the storage chamber  41 . By holding back a large amount of the specimen  7  at the first chamber  42  in the storage chamber  41 , the probability with which the specimen  7  flows into the second chamber  45  of the storage chamber  41  before the sensor part  6  shown in  FIG. 2  starts to measure the specimen  7  can be reduced. By reducing the probability with which the specimen  7  flows into the second chamber  45  of the storage chamber  41 , the probability with which the specimen  7  reaches the sensor part  6  shown in  FIG. 2  through the flow path  48  before the sensor part  6  shown in  FIG. 2  starts to measure the specimen  7  can be reduced. By holding back a large amount of the specimen  7  at the first chamber  42 , a liquid surface of the specimen  7  at the first chamber  42  can be positioned above a lower portion of the projection  51 . Due to the liquid surface of the specimen  7  at the first chamber  42  being positioned above the lower portion of the projection  51 , as described below, the specimen  7  can be efficiently supplied to the sensor part  6  when the sensor part  6  shown in  FIG. 2  starts to measure the specimen  7 . 
     The predetermined height above may be set as appropriate by considering how easily the specimen  7  at the storage chamber  41  leaks and spreads. For example, the predetermined height may be set as appropriate based on the material of the lower base plate  40  and the surface tension of the specimen  7 . 
       FIG. 6  is a sectional view of a disposed state of the cartridge  4  shown in  FIG. 1  in the measurement apparatus  3 .  FIG. 7  is a sectional view of another example of a disposed state of the cartridge  4  shown in  FIG. 1  in the measurement apparatus  3 . The measurement apparatus  3  shown in  FIG. 1  includes a case  60  shown in  FIG. 6  and the air push-out unit  80  shown in  FIG. 6 . The measurement apparatus  3  may include, for example, a heater or a cooler for controlling the temperature of the specimen  7  or the like, and a controller. The controller of the measurement apparatus  3  may be constituted by, for example, a processor or a microcomputer capable of executing application software. The controller of the measurement apparatus  3  may measure, for example, a component in the specimen  7  based on an electric signal output by the sensor part  6 . 
     The case  60  shown in  FIG. 6  is disposed in the housing  3 A of the measurement apparatus  3  shown in  FIG. 1 . The case  60  may be made of, for example, a metal material or a synthetic resin material. When the cartridge  4  is inserted from the insertion hole  3 B of the measurement apparatus  3  shown in  FIG. 1 , the flow path device  2  is disposed in the case  60  shown in  FIG. 6 . The case  60  includes an accommodation portion  70 . The accommodation portion  70  is specified as a region that is surrounded by a wall surface  61 , a wall surface  62 , and a bottom surface  63 . The wall surface  61  and the wall surface  62  face each other. One end of the wall surface  61  toward the positive direction of the Z axis and one end of the wall surface  62  toward the positive direction of the Z axis are each continuous with the bottom surface  63 . The accommodation portion  70  accommodates a first spring  86  described below. 
     As shown in  FIG. 6 , the air push-out unit  80  includes the syringe  81  having an upper surface  81 A and a plunger  87  having a contact surface  88 . When the flow path device  2  is disposed in the case  60 , first, the upper surface  81 A of the syringe  81  is pushed downward by the measurement apparatus  3 . By pushing the upper surface  81 A of the syringe  81  downward, the syringe  81  is pushed downward. Then, the contact surface  88  of the plunger  87  is pushed downward by the measurement apparatus  3 . By pushing the contact surface  88  of the plunger  87  downward, the plunger  87  is pushed downward. The structure shown in  FIG. 6  is a structure when only the syringe  81  is pushed downward by the measurement apparatus  3 . The structure shown in  FIG. 7  is a structure when, in addition to the syringe  81 , the plunger  87  is pushed downward by the measurement apparatus  3 . Note that, when the measurement on the specimen  7  shown in  FIG. 1  ends, the measurement apparatus  3  shown in  FIG. 1  stops pushing the upper surface  81 A of the syringe  81  downward and stops pushing the contact surface  88  of the plunger  87  downward. 
     As shown in  FIG. 6 , the syringe  81  has a cylindrical shape. The syringe  81  may be made of, for example, a synthetic resin material or a glass material. The syringe  81  has the upper surface  81 A as described above. The syringe  81  further includes a body portion  82 , an intermediate portion  83 , the end portion  84 , a first seal member  85 , and the first spring  86 . The plunger  87  is movable in the syringe  81 , and is capable of pushing out air in the syringe  81  to the end portion  84 . The plunger  87  may be made of a synthetic resin material or a glass material. The plunger  87  has the contact surface  88  as described above. The plunger  87  further includes a shaft portion  89 , a second seal member  90 , a flange portion  91 , a rod-like portion  92 , and a second spring  93 . 
     The upper surface  81 A faces upward. The upper surface  81 A can be pushed downward by the measurement apparatus  3  shown in  FIG. 1  as described above. By pushing the upper surface  81 A downward by the measurement apparatus  3 , the syringe  81  can be pushed downward. The upper surface  81 A may be the upper surface of the body portion  82 . 
     The body portion  82  may have a cylindrical shape. The body portion  82  may have an inner peripheral surface  82 A, a fixing surface  82 B, and a lower surface  82 C. The inner peripheral surface  82 A faces the plunger  87 . The fixing surface  82 B faces upward. An outer peripheral end of the fixing surface  82 B is continuous with a lower portion of the inner peripheral surface  82 A. As shown in  FIG. 7 , when the plunger  87  is pushed downward, the fixing surface  82 B abuts upon a lower surface of the flange portion  91  of the plunger  87 . Due to the fixing surface  82 B abutting upon the lower surface of the flange portion  91  of the plunger  87 , the plunger  87  is fixed. As shown in  FIG. 6 , the lower surface  82 C is continuous with an outer peripheral surface of the body portion  82  and an outer peripheral surface of the intermediate portion  83 . The lower surface  82 C faces downward. 
     The intermediate portion  83  shown in  FIG. 6  may have a cylindrical shape. In a direction along the Z axis, the intermediate portion  83  is positioned between the body portion  82  and the end portion  84 . The inside diameter of the intermediate portion  83  is smaller than the inside diameter of the body portion  82 . The inside diameter of the intermediate portion  83  is larger than the inside diameter of the end portion  84 . The first spring  86  may be disposed around the intermediate portion  83 . The intermediate portion  83  has an inner peripheral surface  83 A and a fixing surface  83 B. The inner peripheral surface  83 A faces the plunger  87 . An upper portion of the inner peripheral surface  83 A is continuous with an inner peripheral end of the fixing surface  82 B of the body portion  82 . The fixing surface  83 B faces upward. An outer peripheral end of the fixing surface  83 B is continuous with a lower portion of the inner peripheral surface  83 A. 
     The end portion  84  may have a cylindrical shape. The end portion  84  can be inserted into the inlet  50 . For example, when the syringe  81  is pushed downward by the measurement apparatus  3  shown in  FIG. 1 , as shown in  FIG. 6 , the end portion  84  is inserted into the inlet  50 . 
     The first seal member  85  is disposed on the end portion  84 . The first seal member  85  may be an O ring made of a flexible material, such as rubber. The first seal member  85  may be disposed along an entire lower surface of the end portion  84 . The first seal member  85  is capable of hermetically sealing a location between the end portion  84  and the storage chamber  41 . For example, when the syringe  81  is pushed downward, as shown in  FIG. 6 , the first seal member  85  can abut upon a portion of the upper surface  31  of the small plate  30  surrounding the wall surface  34  of the small plate  30 . Due to the first seal member  85  abutting upon the portion of the upper surface  31  of the small plate  30  surrounding the wall surface  34  of the small plate  30 , the location between the end portion  84  and the storage chamber  41  is hermetically sealed. 
     The first spring  86  is disposed around the intermediate portion  83 . The first spring  86  may be, for example, a coil spring. The first spring  86  may be wound around the outer peripheral surface of the intermediate portion  83 . As shown in  FIG. 6 , when the syringe  81  is pushed downward, the first spring  86  is accommodated in the accommodation portion  70  of the case  60 . One end of the first spring  86  is fixed to the lower surface  82 C of the body portion  82 . The other end of the first spring  86  is a free end. As shown in  FIG. 6 , when the syringe  81  is pushed downward, the other end of the first spring  86  is pushed against the bottom surface  63  of the accommodation portion  70 . By pushing the other end of the first spring  86  against the bottom surface  63  of the accommodation portion  70 , the first spring  86  is compressed. When the measurement apparatus  3  stops pushing the upper surface  81 A of the syringe  81  downward as a result of ending the measurement on the specimen  7  shown in  FIG. 1 , the first spring  86  expands. By expanding the first spring  86 , an elastic force that moves the syringe  81  upward is applied to the syringe  81 . By applying the elastic force to the syringe  81  by the first spring  86 , after the measurement apparatus  3  shown in  FIG. 1  stops pushing the upper surface  81 A of the syringe  81  downward, the syringe  81  moves upward and returns to its original position. 
     The contact surface  88  is positioned above the shaft portion  89 . As described above, the contact surface  88  can be pushed downward by the measurement apparatus  3  shown in  FIG. 1 . When the contact surface  88  is pushed downward by the measurement apparatus  3  shown in  FIG. 1 , as shown in  FIG. 7 , the plunger  87  is pushed downward. When the plunger  87  is pushed downward, as shown in  FIG. 7 , air in the syringe  81  is sent out into the storage chamber  41 . For example, when the plunger  87  is pushed downward, air in a portion of a region surrounded by the inner peripheral surface  82 A of the body portion  82  shown in  FIG. 6  is sent out into the storage chamber  41 , the portion being situated between the fixing surface  82 B of the body portion  82  and the lower surface of the flange portion  91 . By the air sent out into the storage chamber  41 , as described below, the specimen  7  flows into the flow path  48  and is supplied to the sensor part  6  shown in  FIG. 2 . 
     The contact surface  88  may be an inclined surface that inclines toward the positive direction of the Z axis with respect to the XY plane. The contact surface  88  can be gradually pushed downward by the measurement apparatus  3  shown in  FIG. 1 . By gradually pushing the contact surface  88  downward, the plunger  87  is capable of gradually moving downward. By gradually moving the plunger  87  downward, air in the syringe  81  can be gradually sent out into the storage chamber  41 . 
     The shaft portion  89  may have a columnar shape. The contact surface  88  is positioned above the shaft portion  89 . The flange portion  91  and the rod-like portion  92  are positioned below the shaft portion  89 . 
     The second seal member  90  is disposed around the shaft portion  89 . The second seal member  90  may be an O ring made of a flexible material, such as rubber. The second seal member  90  is capable of hermetically sealing a location between the shaft portion  89  and the inner peripheral surface  82 A of the body portion  82 . By hermetically sealing the location between the shaft portion  89  and the inner peripheral surface  82 A of the body portion  82  by the second seal member  90 , the syringe  81  can contain a larger amount of air in the region surrounded by the inner peripheral surface  82 A of the body portion  82 . 
     The flange portion  91  is disposed at a lower portion of the shaft portion  89 . The flange portion  91  projects toward the inner peripheral surface  82 A of the body portion  82  from the shaft portion  89 . As shown in  FIG. 7 , when the plunger  87  is pushed downward, the lower surface of the flange portion  91  abuts upon the fixing surface  82 B of the body portion  82 . 
     As shown in  FIG. 6 , the rod-like portion  92  is positioned at a lower portion of the flange portion  91 . The second spring  93  is disposed around the rod-like portion  92 . The second spring  93  may be, for example, a coil spring. The second spring  93  may be wound around an outer peripheral surface of the rod-like portion  92 . One end of the second spring  93  is fixed to the lower portion of the flange portion  91 . The other end of the second spring  93  is fixed to the fixing surface  83 B of the intermediate portion  83 . As shown in  FIG. 7 , when the plunger  87  is pushed downward, the distance between the lower surface of the flange portion  91  and the fixing surface  83 B of the intermediate portion  83  becomes smaller than the distance between the lower surface of the flange portion  91  and the fixing surface  83 B of the intermediate portion  83  shown in  FIG. 6 . Due to the distance between the lower surface of the flange portion  91  and the fixing surface  83 B of the intermediate portion  83  being reduced as a result of the plunger  87  being pushed downward, the second spring  93  is compressed. When the measurement apparatus  3  shown in  FIG. 1  stops pushing the contact surface  88  downward as a result of ending the measurement on the specimen  7  shown in  FIG. 1 , the second spring  93  expands. By expanding the second spring  93 , an elastic force that moves the plunger  87  upward is applied to the plunger  87 . By applying the elastic force to the plunger  87  by the second spring  93 , after the measurement apparatus  3  shown in  FIG. 1  stops pushing the contact surface  88  downward, the plunger  87  is pushed upward. 
     [Operation of Measurement System] 
     As shown in  FIG. 3 , a user drips the specimen  7  toward the inlet  50  of the flow path device  2 . The specimen  7  dripped toward the inlet  50  is stored in the storage chamber  41 . As described above with reference to  FIG. 3 , a large amount of the specimen  7  can be held back at the first chamber  42  in the storage chamber  41  by the projection  51 . By holding back a large amount of the specimen  7  at the first chamber  42  in the storage chamber  41 , the probability with which the specimen  7  flows into the second chamber  45  of the storage chamber  41  can be reduced. In addition, as described above with reference to  FIG. 3 , by connecting the flow path  48  to the upper portion of the storage chamber  41 , the probability with which the specimen  7  accumulated at the lower side of the storage chamber  41  flows into the flow path  48  can be reduced. 
     After the user has dripped the specimen  7  toward the inlet  50  of the flow path device  2 , as shown in  FIG. 1 , the cartridge  4  including the flow path device  2  is inserted into the insertion hole  3 B of the measurement apparatus  3 . The cartridge  4  that has been inserted from the insertion hole  3 B of the measurement apparatus  3  shown in  FIG. 1  is disposed in the case  60  shown in  FIG. 6 . 
     When the cartridge  4  is disposed in the case  60  shown in  FIG. 6 , the sensor part  6  shown in  FIG. 2  starts to measure the specimen  7 . First, the upper surface  81 A of the syringe  81  shown in  FIG. 6  is pushed downward by the measurement apparatus  3  shown in  FIG. 1 . When the upper surface  81 A of the syringe  81  shown in  FIG. 6  is pushed downward, the syringe  81  moves downward. By moving the syringe  81  downward, the end portion  84  of the syringe  81  is inserted into the inlet  50  of the flow path device  2  as shown in  FIG. 6 . 
     When the syringe  81  is pushed downward, the contact surface  88  of the plunger  87  of the air push-out unit  80  shown in  FIG. 6  is gradually pushed downward by the measurement apparatus  3  shown in  FIG. 1 . When the contact surface  88  of the plunger  87  is gradually pushed downward, the plunger  87  gradually moves downward. 
     As shown in  FIG. 8 , when the plunger  87  starts to move downward, as the plunger  87  moves downward, a part of air in the syringe  81  is sent out toward the first chamber  42  of the storage chamber  41 . A liquid surface of the specimen  7  stored in the first chamber  42  is pushed downward by the air. When the liquid surface of the specimen  7  in the first chamber  42  is pushed downward, the specimen  7  passes below the projection  51  and flows into the second chamber  42 . Due to continued flowing of the specimen  7  into the second chamber  42 , the liquid surface of the specimen  7  in the second chamber  45  rises. Due to continued downward movement of the plunger  87 , the air continues to push downward the liquid surface of the specimen  7  in the first chamber  42  of the storage chamber  41 . Due to the continued downward pushing on the liquid surface of the specimen  7  in the first chamber  42 , the liquid surface of the specimen  7  in the second chamber  45  continues to rise. Due to the continued rising of the liquid surface of the specimen  7  in the second chamber  45 , the liquid surface reaches the position of the flow path  48 . 
     As shown in  FIG. 9 , when the liquid surface of the specimen  7  in the second chamber  45  reaches the position of the flow path  48 , the specimen  7  in the second chamber  45  flows out into the flow path  48 . The specimen  7  that has flowed out into the flow path  48  reaches the sensor part  6  shown in  FIG. 2  through the flow path  48 . The sensor part  6  outputs an electric signal that is in accordance with the component in the specimen  7  to the controller of the measurement apparatus  3  shown in  FIG. 1 . 
     Here, as described above, the bottom surface  46  may be an inclined surface that inclines toward the flow path  48  from the bottom surface  41   a  of the space  41 A. Due to the bottom surface  46  being an inclined surface that inclines towards the flow path  48 , the specimen  7  can smoothly flow toward the flow path  48  from the second chamber  45 . 
     As shown in  FIG. 7 , the plunger  87  moves downward until the lower surface of the flange portion  91  of the plunger  87  abuts upon the fixing surface  82 B of the syringe  81 . In the structure shown in  FIG. 7 , air from the air push-out unit  80  passes below the projection  51 . The air that has passed below the projection  51  pushes out the specimen  7  in the second chamber  45  toward the positive direction of the X axis. Here, as described above, the projection  51  may have in sectional view a substantially inverted triangular shape whose apex is positioned toward the bottom surface  41   a  of the storage chamber  41 . Due to the projection  51  having a substantially inverted triangular shape, air that flows in the upper portion of the first chamber  42  of the storage chamber  41  can be smoothly guided to a location below the projection  51  by an oblique surface of the projection  51 . Due to the air being smoothly guided to a location below the projection  51  by the oblique surface of the projection  51 , the air is capable of efficiently pushing out the specimen  7  in the second chamber  45  toward the positive direction of the X axis. 
     When the measurement apparatus  3  shown in  FIG. 1  ends the measurement on the specimen  7 , the measurement apparatus  3  shown in  FIG. 1  stops pushing the upper surface  81 A of the syringe  81  shown in  FIG. 7  downward and stops pushing the contact surface  88  of the plunger  87  shown in  FIG. 7  downward. By stopping the downward pushing on the upper surface  81 A of the syringe  81  shown in  FIG. 7 , as described above, the syringe  81  can be returned to its original position by the first spring  86  shown in  FIG. 7 . In addition, by stopping the downward pushing on the contact surface  88  of the plunger  87  shown in  FIG. 7 , the plunger  87  can be returned to its original position by the second spring  93  shown in  FIG. 7 . 
     As described above, since the flow path device  2  according to the present embodiment includes the projection  51 , as described below, it is possible to easily control a timing of supplying the specimen  7  to the sensor part  6 . 
     COMPARATIVE EXAMPLE 
       FIG. 10  is a sectional view of a measurement system  1 X according to a comparative example. The measurement system  1 X includes a flow path device  2 X. Unlike the flow path device  2  shown in  FIG. 6 , the flow path device  2 X does not include a projection  51 . In such a comparative example, a specimen  7  can spread over the entire bottom surface of a storage chamber  41 . Even in the comparative example, similarly to the present embodiment, in order to reduce the probability with which the specimen  7  accumulated at a lower side of the storage chamber  41  flows into a flow path  48 , the flow path  48  is connected to an upper portion of the storage chamber  41 . In such a measurement system  1 X, when air is sent out into the storage chamber  41  by an air push-out unit  80 , the air passes the upper portion of the storage chamber  41  and flows into the flow path  48 . That is, in the measurement system  1 X according to the comparative example, the air from the air push-out unit  80  cannot cause the specimen  7  stored in the storage chamber  41  to flow out into the flow path  48  from the storage chamber  41 . 
     In contrast, in the flow path device  2  shown in  FIG. 6 , a large amount of the specimen  7  can be held back at the first chamber  42  in the storage chamber  41  by the projection  51 . By holding back a large amount of the specimen  7  at the first chamber  42 , a liquid surface of the specimen  7  in the first chamber  42  can be positioned above the lower portion of the projection  51 . By positioning the liquid surface of the specimen  7  in the first chamber  42  above the lower portion of the projection  51 , a space portion of the first chamber  42  above the liquid surface of the specimen  7 , excluding the inlet  50 , can become a closed space. Due to such a structure, as shown in  FIG. 8 , air that has flowed in from the inlet  50  can reliably push the liquid surface of the specimen  7  in the first chamber  42  downward. By pushing the liquid surface of the specimen  7  in the first chamber  42  downward, as described above with reference to  FIG. 9 , the specimen  7  can reach the sensor part  6  shown in  FIG. 2  through the flow path  48 . 
     Therefore, according to the present embodiment, it is possible to provide the flow path device  2  and the measurement system  1  that are capable of easily controlling a timing of supplying the specimen  7  to the sensor part  6 . 
     Further, in the measurement system  1  according to the present embodiment, as shown in  FIG. 7 , it is possible to send out air to the storage chamber  41  by the air push-out unit  80  from above the flow path device  2 . Due to such a structure, in the present embodiment, a mechanism for sending out air to the storage chamber  41  does not need to be disposed at the flow path device  2  at a location differing from the location of the storage chamber  41 . In the present embodiment, since a mechanism for sending out air to the storage chamber  41  does not need to be disposed at the flow path device  2 , it is possible to reduce the size of the flow path device  2  in the XY plane. By reducing the size of the flow path device  2  in the XY plane, it is possible to accommodate a large portion of the flow path device  2  in the measurement apparatus  3  shown in  FIG. 1 . By accommodating a large portion of the flow path device  2  in the measurement apparatus  3 , it is possible to more efficiently increase the temperature of the specimen  7  disposed in the flow path device  2 . By more efficiently increasing the temperature of the specimen  7 , the measurement system  1  is capable of more precisely measuring, for example, a component of the specimen  7 . 
     In the flow path device  2  according to the present embodiment, as shown in  FIG. 3 , the lower surface  32  of the small plate  30  can be used as the ceiling surface of the storage chamber  41 . The small plate  30  is a component that differs from the lower base plate  40  having the bottom surfaces  43  and  46  and the wall surfaces  44  and  45  of the storage chamber  41 . By using the small plate  30  as a component that differs from the lower base plate  40 , the storage chamber  41  is less likely to be influenced by surface accuracy. Due to the storage chamber  41  being less likely to be influenced by surface accuracy, it is possible to increase the ability with which the storage chamber  41  is sealed. 
     The figures for describing the embodiment according to the present disclosure are schematic figures. For example, the dimensional proportions in the figures do not necessarily match the actual dimensional proportions. 
     Although the embodiment according to the present disclosure has been described based on various figures and examples, it is to be noted that various modifications or corrections can be easily made based on the present disclosure by any person skilled in the art. Therefore, it is to be noted that these modifications or corrections are included within the scope of the present disclosure. For example, the functions or the like of the corresponding structural portions can be rearranged in a noncontradictory manner, a plurality of structural portions or the like can be combined into one or can be separated in a noncontradictory manner. 
     For example, in the present embodiment above, one end of the first spring  86  shown in  FIG. 6  has been described as being fixed to the lower surface  82 C of the body portion  82  of the syringe  81 . However, the one end of the first spring  86  may not be fixed to the lower surface  82 C. The first spring  86  only needs to be disposed around the syringe  81 . 
     For example, in the embodiment above, one end of the second spring  93  shown in  FIG. 6  has been described as being fixed to the lower portion of the flange portion  91 . The other end of the second spring  93  has been described as being fixed to the fixing surface  83 B of the intermediate portion  83 . However, the one end of the second spring  93  may not be fixed to the lower portion of the flange portion  91 . The other end of the second spring  93  may not be fixed to the fixing surface  83 B of the intermediate portion  83 . The second spring  93  only needs to be disposed around the rod-like portion  92  of the plunger  87 . 
     For example, in the present embodiment above, the projection  51  shown in  FIG. 3  has been described as limiting the space  41 A to a height less than or equal to the predetermined height from the bottom surface  41   a  of the storage chamber  41 . In the description, it has been described that the predetermined height above may be set as appropriate by considering how easily the specimen  7  in the storage chamber  41  leaks and spreads. However, the setting of the predetermined height is not limited thereto. For example, the predetermined height may be set to position the liquid surface of the specimen  7  in the first chamber  42  above the lower portion of the projection  51 . A flow path device  102  shown in  FIG. 11  includes a projection  151 . Similarly to the projection  51  shown in  FIG. 3 , the projection  151  limits a space  41 A to a height less than or equal to a predetermined height from a bottom surface  41   a  of a storage chamber  41 . However, in the structure shown in  FIG. 11 , the predetermined height is set to position a liquid surface of a specimen  7  in a first chamber  42  above a lower portion of the projection  151 . In the structure shown in  FIG. 11 , the predetermined height may be calculated based on the area of the bottom surface of the entire storage chamber  41  and an assumed amount of the specimen  7 . In the structure shown in  FIG. 11 , the predetermined height is set to position the liquid surface of the specimen  7  in the first chamber  42  above the lower portion of the projection  151 . Due to such a structure, in the structure shown in  FIG. 11 , similarly to the structure shown in  FIG. 3 , a space portion of the first chamber  42  above the liquid surface of the specimen  7 , excluding an inlet  50 , can become a closed space. Due to the space portion of the first chamber  42  above the liquid surface of the specimen  7 , excluding the inlet  50 , becoming a closed space, as described above with reference to  FIG. 8 , in the flow path device  102 , air that has flowed in from the inlet  50  can reliably push the liquid surface of the specimen  7  in the first chamber  42  downward. As described above with reference to  FIG. 8 , in the flow path device  102 , by pushing the liquid surface of the specimen  7  in the first chamber  42  downward, the specimen  7  can reach the sensor part  6  shown in  FIG. 2  through the flow path  48 . 
     For example, “first” and “second” in the present disclosure are identifiers for distinguishing between corresponding structures. The structures that are distinguished by, for example, “first” and “second” in the present disclosure can have their numbers exchanged. For example, “the first” in the first chamber, which distinguishes the first chamber from the second chamber, can be replaced by “the second”. The identifiers are exchanged at the same time. After the replacement of the identifiers, the structures are distinguished from each other. The identifiers may be deleted. The structures whose identifiers have been deleted are distinguished by their reference signs. Identifiers, such as “first” and “second”, in the present disclosure alone should not be used to interpret the order of the corresponding structures or used as a basis for the existence of identifiers containing small numbers. 
     REFERENCE SIGNS LIST 
     
         
         
           
               1  measurement system 
               2 ,  102  flow path device 
               3  measurement apparatus 
               3 A housing 
               3 B insertion hole 
               4  cartridge 
               5  base plate 
               6  sensor part 
               7  fluid 
               10  region 
               20  upper base plate 
               21  wall surface 
               22  opening portion 
               23  inner surface 
               24  wall surface 
               25  accommodation portion 
               30  small plate 
               31  upper surface 
               32  lower surface 
               33  opening portion 
               34  wall surface 
               35  bonding member 
               40  lower base plate 
               41  storage chamber 
               42  first chamber 
               41   a ,  43 ,  46  bottom surface 
               41   b ,  44 ,  47  wall surface 
               45  second chamber 
               45 A space 
               49 A,  49 B projecting portion 
               50  inlet 
               51 ,  151  projection 
               60  case 
               61 ,  62  wall surface 
               63  bottom surface 
               70  accommodation portion 
               80  air push-out unit 
               81  syringe 
               81 A upper surface 
               82  body portion 
               82 A inner peripheral surface 
               82 B fixing surface 
               82 C lower surface 
               83  intermediate portion 
               83 A inner peripheral surface 
               83 B fixing surface 
               84  end portion 
               85  first seal member 
               86  first spring 
               87  plunger 
               88  contact surface 
               89  shaft portion 
               90  second seal member 
               91  flange portion 
               92  rod-like portion 
               93  second spring