Flow Channel Devices

Abstract

To provide a technique capable of reducing variation in results from measuring electrical resistance due to assembly accuracy in a flow channel device.SOLUTION: A first lid member 21 blocks an opening in an upper portion of a measurement chamber 100 in an intermediate member 10. An upper-side working electrode 61 is disposed on the surface of the first lid member 21. The upper-side working electrode 61 has an upper-side first working portion 611 and an upper-side second working portion 612. A length L11 from one end portion 611E of the upper-side first working portion 611 to the other portion 612E of the upper-side second working portion 612 is greater than a lateral width W1 of the measurement chamber 100. Additionally, a gap L12 in a width direction between the upper-side first working portion 611 and the upper-side second working portion 612 is less than the lateral width W1 of the measurement chamber 100.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a flow path device that is applied to measuring the electrical resistance of cell tissue. [Background technology]

[0002] Transepithelial electrical resistance (TEER) measurement is a known method for evaluating the barrier function of cell layers that form membrane structures. In TEER measurement, a cylindrical insert with a bottom made of a porous membrane is placed in the recess of a culture plate, and cells are cultured on the porous membrane. Working electrodes for applying current and reference electrodes for measuring the potential difference are placed inside and outside the insert. Then, by applying a current between the working electrodes and measuring the potential difference generated between the reference electrodes, the electrical resistance of the cell layer is calculated.

[0003] For example, Patent Document 1 describes measuring electrical resistance by inserting electrodes (10A, 10B) into the interior and exterior of a culture insert dish (21) from one side. However, inserting the electrodes from one side requires an opening at the top of the culture insert dish (21). Therefore, this method cannot be applied to devices that do not have such an opening at the top.

[0004] On the other hand, Non-Patent Document 1 describes a flow path device in which an electrode is arranged on a lid that closes the opening at the top of a culture vessel. By arranging the electrode on the lid in this way, it is possible to measure the electrical resistance of a cell layer being cultured in a measurement chamber. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-137307 [Non-patent literature]

[0006] [Non-Patent Document 1] Booth R, Kim H. Characterization of a microfluidic in vitro model of the blood-brain barrier (mu BBB) Lab Chip. 2012 Apr. 24;12(10):1784-92. Summary of the Invention [Problem to be solved by the invention]

[0007] When assembling a flow channel device such as that described in Non-Patent Document 1, if the lid is attached out of alignment with the measurement chamber, the position of the electrode will be shifted relative to the measurement chamber. Furthermore, if the electrode is positioned near the edge of the measurement chamber, the area of ​​the electrode that comes into contact with the liquid in the measurement chamber (contact area) may change due to the lid being shifted. If the electrode is shifted in position or the contact area changes, the current density distribution in the measurement chamber changes, which may result in fluctuations in the electrical resistance measurement results.

[0008] An object of the present invention is to provide a technique capable of reducing variations in the measurement results of electrical resistance due to the assembly precision of a flow channel device. [Means for solving the problem]

[0009] In order to solve the above problem, a first aspect is a flow path device applied to measure the electrical resistance of cell tissue, the flow path device including: an intermediate member having a measurement chamber constituted by a through hole penetrating in a first direction; a first cover member located on one surface of the intermediate member in the first direction and closing an opening at one end of the measurement chamber in the first direction; a second cover member located on the other surface of the intermediate member in the first direction and closing an opening at the other end of the measurement chamber in the first direction; a porous membrane located within the measurement chamber and dividing the measurement chamber into a first chamber on one side and a second chamber on the other side in the first direction, allowing a liquid to pass through; the one-side working electrode and the one-side reference electrode overlapping with the measurement chamber, and the other-side working electrode and the other-side reference electrode located on one surface of the second cover member in the first direction and overlapping with the measurement chamber in the first direction, the one-side working electrode having a one-side first working portion and a one-side second working portion located away from the one-side first working portion on one side in a second direction intersecting with the first direction, the length from the other end of the one-side first working portion in the second direction to the one end of the one-side second working portion in the second direction being greater than the width of the measurement chamber in the second direction, and the distance between the one-side first working portion and the one-side second working portion in the second direction being smaller than the width of the measurement chamber. The measuring chamber, the one-side first acting portion, and the one-side second acting portion extend in a third direction intersecting the first direction and the second direction, and the one-side first acting portion and the one-side second acting portion extend linearly in the third direction. .

[0010] A second aspect is a flow path device of the first aspect, wherein the one-side reference electrode has a one-side first reference portion and a one-side second reference portion located away from the one-side first reference portion in one of the second directions, and the one-side first reference portion and the one-side second reference portion are located between the one-side first action portion and the one-side second action portion in the second direction.

[0011] A third aspect is a flow path device of the second aspect, wherein the one-side working electrode further has a one-side third working portion located between the one-side first reference portion and the one-side second reference portion in the second direction.

[0012] A fourth aspect is the flow path device of the third aspect, wherein the width of the one-side first action portion in the second direction is greater than the width of the one-side third action portion in the second direction.

[0013] A fifth aspect is a flow path device of the third or fourth aspect, wherein the one-side working electrode is located between the one-side first reference portion and the one-side second reference portion in the second direction, and further has a one-side fourth working portion located away from the one-side third working portion to one side in the second direction.

[0014] A sixth aspect is a flow path device of the fifth aspect, wherein the other-side working electrode has a other-side first acting portion and a other-side second acting portion located away from the other-side first acting portion in one side of the second direction, the other-side first acting portion faces the one-side first acting portion in the first direction, the other-side second acting portion faces the one-side second acting portion in the first direction, the length from the other-side end of the other-side first acting portion in the second direction to the one-side end of the other-side second acting portion in the second direction is greater than the width of the measurement chamber in the second direction, and the distance between the other-side first acting portion and the other-side second acting portion in the second direction is smaller than the width of the measurement chamber in the second direction.

[0015] A seventh aspect is a flow path device of the sixth aspect, wherein the other-side reference electrode has an other-side first reference portion and an other-side second reference portion located away from the other-side first reference portion on one side of the second direction, and the other-side first reference portion and the other-side second reference portion are located between the other-side first action portion and the other-side second action portion in the second direction.

[0016] An eighth aspect is a flow path device of the seventh aspect, wherein the other-side working electrode further has an other-side third working portion located between the other-side first reference portion and the other-side second reference portion in the second direction.

[0017] A ninth aspect is a flow path device of the eighth aspect, wherein the other-side working electrode is located between the other-side first reference portion and the other-side second reference portion in the second direction, and further has an other-side fourth working portion located away from the other-side third working portion to one side in the second direction.

[0018] A tenth aspect is a flow path device of any one of the first to ninth aspects, wherein the intermediate member has a first intermediate member and a second intermediate member located on one side of the first intermediate member in the first direction, the first intermediate member has the first chamber, the second intermediate member has the second chamber, and the porous membrane is located between the first intermediate member and the second intermediate member in the first direction.

[0019] An eleventh aspect is a flow path device according to any one of the first to tenth aspects, wherein the intermediate member has a first flow path communicating with the first chamber and a second flow path communicating with the second chamber.

[0020] A twelfth aspect is the flow path device of the eleventh aspect, in which the first cover member has a first through-hole communicating with the first flow path and a second through-hole communicating with the second flow path.

[0022] No. 13 The aspect is 1 Aspects From the 12th aspect A flow path device, wherein the one-side first action portion and the one-side second action portion extend from a position away from the measurement chamber in one of the third directions to a position away from the measurement chamber in the other of the third directions. [Effects of the Invention]

[0023] First to second aspects 13According to this embodiment of the flow path device, even if the first cover member is displaced in the second direction relative to the measurement chamber, the one-side first working portion and the one-side second working portion can be disposed at both ends of the measurement chamber in the second direction. Therefore, even if the first cover member is displaced, voltage can be applied to both ends of the measurement chamber. Furthermore, even if the first cover member is displaced, fluctuations in the contact area of ​​the one-side working electrode with the liquid in the measurement chamber can be suppressed. Therefore, variations in the electrical resistance measurement results due to the assembly accuracy of the first cover member can be reduced.

[0024] According to the flow channel device of the third aspect, by providing the one-side third acting portion, it is possible to effectively apply a voltage near the center of the measurement chamber in the second direction.

[0025] According to the flow path device of the fourth aspect, the one-side first acting portion can be made larger, and therefore the tolerance for displacement of the first cover member with respect to the measurement chamber can be increased.

[0026] According to the flow channel device of the fifth aspect, by providing the one-side fourth acting portion, it is possible to effectively apply a voltage near the center of the measurement chamber in the second direction.

[0027] According to the flow channel device of the sixth aspect, by making the other electrode face the one electrode, a voltage can be applied uniformly to the cellular tissue between the electrodes.

[0028] According to the flow channel device of the eighth aspect, by providing the other-side third acting portion, it is possible to effectively apply a voltage near the center of the measurement chamber in the second direction.

[0029] According to the flow path device of the ninth aspect, by providing the other-side fourth acting portion, it is possible to effectively apply a voltage near the center of the measurement chamber in the second direction.

[0030] According to the flow path device of the eleventh aspect, the liquids in the first chamber and the second chamber can be exchanged.

[0031] According to the flow path device of the twelfth aspect, the liquid can be supplied into the measurement chamber through the first through-hole of the first cover member, and the liquid in the measurement chamber can be discharged through the second through-hole.

[0032] No. 13 According to the flow path device of the embodiment, since the one-side first acting portion and the one-side second acting portion traverse the measurement chamber in the third direction, even if the first cover member is displaced in the third direction relative to the measurement chamber, a voltage can be applied to the measurement chamber over the entire third direction, thereby reducing variations in the electrical resistance measurement results due to assembly precision of the flow path device. [Brief explanation of the drawings]

[0033] [Figure 1] FIG. 2 is a cross-sectional view of a flow path device according to an embodiment. [Figure 2] FIG. 2 is an exploded cross-sectional view of the flow channel device according to the embodiment. [Figure 3] FIG. 2 is a plan view of the upper working electrode and the upper reference electrode as viewed from above. [Figure 4] FIG. 2 is a cross-sectional view of a flow path device according to an embodiment. [Figure 5] FIG. 1 shows a circuit for measuring the electrical resistance of tissue. [Figure 6] FIG. 2 is a diagram showing a cross-sectional structure of a flow channel device used in a simulation. [Figure 7] FIG. 10 is a diagram showing a simulation result of a current density distribution. [Figure 8] 10 is a diagram showing frequency characteristics of a flow channel device according to an embodiment and a flow channel device according to a comparative example. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0034] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. Note that the components described in the embodiment are merely examples and are not intended to limit the scope of the present invention. In the drawings, the dimensions and numbers of each part may be exaggerated or simplified as necessary to facilitate understanding.

[0035] <1. Embodiment> Fig. 1 is a cross-sectional view of a flow channel device 1 according to an embodiment. Fig. 2 is an exploded cross-sectional view of the flow channel device 1 according to the embodiment. The flow channel device 1 is a so-called micro flow channel device in which a measurement chamber 100, which is an internal space, is a closed space except for a fine first flow channel 51 and a fine second flow channel 53. The flow channel device 1 is applicable to an apparatus that measures the electrical resistance (resistance, instance, or impedance) of a cell tissue 9 cultured in the measurement chamber 100 by a four-terminal measurement method.

[0036] 1 and 2, the flow path device 1 has an intermediate member 10, a first cover member 21, and a second cover member 22. The intermediate member 10, the first cover member 21, and the second cover member 22 are flat plate-shaped. In the flow path device 1, the intermediate member 10 is disposed on an upper surface 220 of the second cover member 22. The first cover member 21 is disposed on an upper surface of the intermediate member 10.

[0037] As shown in FIG. 1, the intermediate member 10 has a measurement chamber 100 therein. The measurement chamber 100 forms a space capable of containing a liquid such as a culture medium. As shown in FIGS. 1 and 2, the intermediate member 10 has a first intermediate member 11 and a second intermediate member 12. The second intermediate member 12 has an upper member 121 and a lower member 122. The upper member 121 is disposed on the upper surface of the lower member 122. The first intermediate member 11 is disposed above the second intermediate member 12.

[0038] The intermediate member 10 is formed of, for example, PET (polyethylene terephthalate). The first intermediate member 11 is preferably translucent, and more preferably colorless and transparent. As shown in FIG. 1, the intermediate member 10 has a through-hole 10H that passes through the intermediate member 10 from top to bottom. The inner surface of the through-hole 10H forms the inner surface of the measurement chamber 100.

[0039] The first cover member 21 and the second cover member 22 are transparent substrates made of, for example, quartz glass. As shown in Fig. 1, the first cover member 21 closes the upper opening of the measurement chamber 100. That is, the upper part of the measurement chamber 100 is closed by the first cover member 21. The second cover member 22 closes the lower opening of the measurement chamber 100. That is, the lower part of the measurement chamber 100 is closed by the second cover member 22.

[0040] As shown in FIGS. 1 and 2, the flow path device 1 has a porous membrane 30. The porous membrane 30 is a sheet-like permeable membrane that allows liquid to pass through. The porous membrane 30 is formed of, for example, PC (polycarbonate), PTFE (polytetrafluoroethylene), or PET. The porous membrane 30 is preferably translucent. The porous membrane 30 is disposed between the first intermediate member 11 and the second intermediate member 12 in the vertical direction.

[0041] The porous membrane 30 divides the measurement chamber 100 (through-hole 10H) into an upper first chamber 101 and a lower second chamber 102. As shown in FIG. 1, the cell tissue 9 is supported on the upper surface of the porous membrane 30 in the measurement chamber 100, and is thereby placed in the first chamber 101 of the measurement chamber 100. The upper surface of the portion of the porous membrane 30 placed in the measurement chamber 100 (through-hole 10H) may be coated with a cell adhesion factor (such as collagen).

[0042] 1, the first chamber 101 of the measurement chamber 100 is made up of the inner surface of the first through-hole 11H that passes through the first intermediate member 11 in the vertical direction, the upper surface of the porous membrane 30, and the lower surface 210 of the first cover member 21. The second chamber 102 of the measurement chamber 100 is made up of the inner surface of the second through-hole 12H that passes through the second intermediate member 12 in the vertical direction, the lower surface of the porous membrane 30, and the upper surface 220 of the second cover member 22.

[0043] As shown in FIGS. 1 and 2, the flow path device 1 has a flat top member 40. The top member 40 is disposed on the upper surface of the first cover member 21. The top member 40 is formed of, for example, PET. The top member 40 has an observation opening 41. The observation opening 41 is a through-hole that passes through the top member 40 from top to bottom. The observation opening 41 is disposed directly above the measurement chamber 100. That is, the observation opening 41 overlaps with the measurement chamber 100 from top to bottom.

[0044] As shown in FIG. 1 , the intermediate member 10 has a first flow path 51. The first flow path 51 is in communication with the first chamber 101 of the measurement chamber 100. "In communication" refers to a state in which a fluid is connected to allow it to flow. The first flow path 51 is a flow path for supplying a liquid such as a culture medium to the first chamber 101 of the measurement chamber 100. The first flow path 51 is tubular, penetrating the first intermediate member 11 from top to bottom and surrounded by the inner surface of a through-hole extending in the width direction (second direction), the upper surface of the upper member 121 of the second intermediate member 12, and the lower surface 210 of the first cover member 21. The width direction is a direction intersecting the up-down direction, and preferably is a direction perpendicular to the up-down direction.

[0045] 1, the intermediate member 10 has a second flow path 53. The second flow path 53 is connected to the second chamber 102 of the measurement chamber 100. The second flow path 53 is a flow path for discharging liquid from the second chamber 102 of the measurement chamber 100. The second flow path 53 is tubular and surrounded by the inner surface of a through-hole that vertically penetrates the upper member 121 of the second intermediate member 12 and extends in the width direction, the lower surface of the first intermediate member 11, and the upper surface of the lower member 122 of the second intermediate member 12.

[0046] 1, a portion of the upper end of the first flow path 51 communicates with a first through-hole 43 that vertically penetrates the top member 40 and the first cover member 21. In addition, a portion of the upper end of the second flow path 53 communicates with a second through-hole 45 that vertically penetrates the top member 40 and the first cover member 21. Liquid can be supplied into the measurement chamber 100 from the first through-hole 43. In addition, liquid in the measurement chamber 100 can be discharged from the second through-hole 45.

[0047] <Electrode> 1 and 2, the flow path device 1 includes an upper working electrode 61, a lower working electrode 63, an upper reference electrode 71, and a lower reference electrode 73. The upper working electrode 61 and the upper reference electrode 71 are disposed on the lower surface 210 of the first cover member 21. The lower working electrode 63 and the lower reference electrode 73 are disposed on the upper surface 220 of the second cover member 22. Each electrode is formed by vacuum deposition or the like. A portion of each electrode (for example, a portion facing the inside of the measurement chamber 100) may be covered with an insulating film such as a silicon oxide film.

[0048] The upper working electrode 61, the lower working electrode 63, the upper reference electrode 71, and the lower reference electrode 73 have portions that overlap with the measurement chamber 100 in the vertical direction. That is, the upper working electrode 61, the lower working electrode 63, the upper reference electrode 71, and the lower reference electrode 73 have portions that overlap with the measurement chamber 100 in the vertical direction.

[0049] <Upper working electrode 61> 3 is a plan view seen from above of the upper working electrode 61 and the upper reference electrode 71. As shown in FIG. 3, the upper working electrode 61 has an upper first working portion 611, an upper second working portion 612, an upper third working portion 613, and an upper fourth working portion 614.

[0050] 3, the measurement chamber 100 extends in the vertical direction (third direction). The vertical direction is a direction intersecting the up-down direction and the width direction, and preferably is a direction perpendicular to the up-down direction and the width direction. In addition, the upper first acting portion 611, the upper second acting portion 612, the upper third acting portion 613, and the upper fourth acting portion 614 also extend linearly in the vertical direction.

[0051] The upper first acting portion 611, the upper second acting portion 612, the upper third acting portion 613, and the upper fourth acting portion 614 overlap with the measurement chamber 100. As shown in Fig. 3, the length of each of the upper first acting portion 611, the upper second acting portion 612, the upper third acting portion 613, and the upper fourth acting portion 614 in the vertical direction is greater than the length of the measurement chamber 100 in the vertical direction. The upper first acting portion 611, the upper second acting portion 612, the upper third acting portion 613, and the upper fourth acting portion 614 extend from a position spaced apart from the measurement chamber 100 in one vertical direction to a position spaced apart from the measurement chamber 100 in the other vertical direction. That is, the upper first action portion 611, the upper second action portion 612, the upper third action portion 613, and the upper fourth action portion 614 cross the measurement chamber 100 in the vertical direction.

[0052] As shown in FIGS. 1 and 3 , the upper working electrode 61 has a wiring portion 615 and a pad portion 616. The wiring portion 615 is disposed away from the measurement chamber 100 in the other vertical direction. The wiring portion 615 extends in the width direction and is connected to the pad portion 616. The other ends of the upper first working portion 611, the upper second working portion 612, the upper third working portion 613, and the upper fourth working portion 614 in the vertical direction are connected to the wiring portion 615. That is, the upper first working portion 611, the upper second working portion 612, the upper third working portion 613, and the upper fourth working portion 614 are electrically connected to the pad portion 616 via the wiring portion 615.

[0053] 1 and 3, the upper second acting portion 612 is disposed apart from the upper first acting portion 611 on one side in the width direction. The upper third acting portion 613 is disposed apart from the upper first acting portion 611 on one side in the width direction. The upper fourth acting portion 614 is disposed apart from the upper second acting portion 612 on the other side in the width direction. The upper fourth acting portion 614 is disposed apart from the upper third acting portion 613 on one side in the width direction.

[0054] <Upper reference electrode 71> The upper reference electrode 71 has an upper first reference portion 711 and an upper second reference portion 712. The upper first reference portion 711 and the upper second reference portion 712 extend linearly along the vertical direction.

[0055] 3, the upper first reference portion 711 and the upper second reference portion 712 extend from a position spaced apart in one vertical direction from the measurement chamber 100 to a position spaced apart in the other vertical direction from the measurement chamber 100. In other words, the upper first reference portion 711 and the upper second reference portion 712 traverse the measurement chamber 100 in the vertical direction.

[0056] 1 and 3, the upper second reference portion 712 is disposed apart from the upper first reference portion 711 on one side in the width direction. The upper first reference portion 711 is disposed apart from the upper first acting portion 611 on one side in the width direction. The upper second reference portion 712 is disposed apart from the upper second acting portion 612 on the other side in the width direction.

[0057] The upper first reference portion 711 is disposed between the upper first acting portion 611 and the upper third acting portion 613 in the width direction. The upper second reference portion 712 is disposed between the upper second acting portion 612 and the upper fourth acting portion 614 in the width direction.

[0058] The upper third action portion 613 and the upper fourth action portion 614 are disposed between the upper first reference portion 711 and the upper second reference portion 712 in the width direction.

[0059] As shown in FIG. 3, the upper reference electrode 71 has a wiring portion 715 and a pad portion 716. The wiring portion 715 is disposed away from the measurement chamber 100 in one vertical direction. The wiring portion 715 extends in the width direction and is connected to the pad portion 716. As shown in FIG. 3, one end of each of the upper first reference portion 711 and the upper second reference portion 712 in the vertical direction is connected to the wiring portion 715. One end of each of the upper first reference portion 711 and the upper second reference portion 712 in the vertical direction is connected to the wiring portion 715. In other words, the upper first reference portion 711 and the upper second reference portion 712 are electrically connected to the pad portion 716 via the wiring portion 715.

[0060] <Lower working electrode 63> As shown in FIG. 1, the lower working electrode 63 has a lower first working portion 631, a lower second working portion 632, a lower third working portion 633, and a lower fourth working portion 634.

[0061] The lower first acting portion 631, the lower second acting portion 632, the lower third acting portion 633 and the lower fourth acting portion 634 have the same size and shape as the upper first acting portion 611, the upper second acting portion 612, the upper third acting portion 613 and the upper fourth acting portion 614, respectively.

[0062] The upper first acting portion 611, the upper second acting portion 612, the upper third acting portion 613, and the upper fourth acting portion 614 of the upper working electrode 61 and the lower first acting portion 631, the lower second acting portion 632, the lower third acting portion 633, and the lower fourth acting portion 634 of the lower working electrode 63 are plane-symmetrical with respect to a predetermined plane, a plane perpendicular to the up-down direction.

[0063] In the vertical direction, the lower first working portion 631, the lower second working portion 632, the lower third working portion 633, and the lower fourth working portion 634 face the upper first working portion 611, the upper second working portion 612, the upper third working portion 613, and the upper fourth working portion 614, respectively. By facing the upper working electrode 61 and the lower working electrode 63 in this way, a voltage can be applied uniformly to the cellular tissue 9 between the electrodes.

[0064] Although detailed illustration is omitted, the lower first acting portion 631, the lower second acting portion 632, the lower third acting portion 633, and the lower fourth acting portion 634 cross the measurement chamber 100 in the vertical direction.

[0065] The lower second acting portion 632 is disposed away from the lower first acting portion 631 on one side in the width direction. The lower third acting portion 633 is disposed away from the lower first acting portion 631 on one side in the width direction. The lower fourth acting portion 634 is disposed away from the lower second acting portion 632 on the other side in the width direction. The lower fourth acting portion 634 is disposed away from the lower third acting portion 633 on one side in the width direction.

[0066] As shown in FIG. 1, the lower working electrode 63 has a wiring portion 635 and a first pad portion 636. The lower first working portion 631, the lower second working portion 632, the lower third working portion 633, and the lower fourth working portion 634 are connected to the wiring portion 635. The wiring portion 635 is connected to the first pad portion 636. The second pad portion 637 is a conductive film provided on the lower surface 210 of the first cover member 21. As shown in FIG. 1, the first pad portion 636 and the second pad portion 637 are electrically connected via a conductive member 638. The conductive member 638 is inserted into a through-hole that penetrates the first intermediate member 11, the second intermediate member 12, and the porous membrane 30.

[0067] <Lower reference electrode 73> The lower reference electrode 73 has a lower first reference portion 731 and a lower second reference portion 732. The lower first reference portion 731 and the lower second reference portion 732 extend linearly in the vertical direction. Although not shown in detail, the lower first reference portion 731 and the lower second reference portion 732 traverse the measurement chamber 100 in the vertical direction.

[0068] The lower first reference portion 731 and the lower second reference portion 732 have the same size and shape as the upper first reference portion 711 and the lower second reference portion 732. The upper first reference portion 711 and the upper second reference portion 712 and the lower first reference portion 731 and the lower second reference portion 732 are symmetrical with respect to a plane perpendicular to the up-down direction.

[0069] In the vertical direction, the lower first reference portion 731 and the lower second reference portion 732 face the upper first reference portion 711 and the upper second reference portion 712 of the upper reference electrode 71, respectively.

[0070] The lower second reference portion 732 is disposed apart in one width direction from the lower first reference portion 731. The lower first reference portion 731 and the lower second reference portion 732 are disposed between the lower first acting portion 631 and the lower third acting portion 633 of the lower working electrode 63 in the width direction.

[0071] The lower third action portion 633 and the lower fourth action portion 634 are disposed between the lower first reference portion 731 and the lower second reference portion 732 in the width direction.

[0072] The lower reference electrode 73 has a wiring portion and a pad portion, similar to the upper reference electrode 71. The lower first reference portion 731 and the lower second reference portion 732 can be electrically connected to a measuring device outside the measurement chamber 100 via the wiring portion and the pad portion.

[0073] As shown in FIG. 1, the flow path device 1 has introducing holes 81 and 82. The introducing holes 81 and 82 are constituted by the inner surface of a through hole that passes through the intermediate member 10, the porous membrane 30, and the second cover member 22 in the vertical direction, and the lower surface 210 of the first cover member 21 that closes the upper part of the through hole. The introducing hole 81 is disposed away from the measurement chamber 100 on the other side in the width direction. The introducing hole 82 is disposed away from the measurement chamber 100 on one side in the width direction. As shown in FIG. 1, conductive probe pins 90 (external electrodes) can be inserted into the introducing holes 81 and 82.

[0074] 1 , a pad portion 616 of the upper working electrode 61 is disposed in the conduction hole 81. A second pad portion 637 is disposed in the conduction hole 82. The upper working electrode 61 is electrically connected to the probe pin 90 via the pad portion 616 in the conduction hole 81. The lower working electrode 63 is electrically connected to the probe pin 90 via the second pad portion 637 in the conduction hole 82. Although not shown, the flow path device 1 is provided with conduction holes for electrically connecting the upper reference electrode 71 and the lower reference electrode 73 to external electrodes.

[0075] 4 is a cross-sectional view of the flow path device 1 according to the embodiment. As shown in FIGS. 3 and 4, the length L11 from the other end 611E of the upper first action part 611 in the width direction to one end 612E of the upper second action part 612 in the width direction is greater than the width W1 of the measurement chamber 100 in the width direction (L11>W1). In addition, the distance L12 between the upper first action part 611 and the upper second action part 612 in the width direction is smaller than the width W1 of the measurement chamber 100 (L12 <W1)。

[0076] By satisfying L11>W1>L12, the upper first acting portion 611 and the upper second acting portion 612 are arranged at each end of the measurement chamber 100 in the width direction, straddling the inside and outside of the measurement chamber 100. Therefore, even if the first cover member 21 is shifted in the width direction relative to the measurement chamber 100, it is possible to suppress fluctuations in the total area of ​​the portions of the upper first acting portion 611 and the upper second acting portion 612 arranged in the measurement chamber 100. In other words, it is possible to suppress fluctuations in the contact area of ​​the upper first acting portion 611 and the upper second acting portion 612 with the liquid in the measurement chamber 100. This makes it possible to reduce variations in the measurement results of electrical resistance due to the assembly accuracy of the flow path device 1 (the attachment accuracy of the first cover member 21).

[0077] Furthermore, even if the first cover member 21 is shifted in the width direction relative to the measurement chamber 100, the upper first acting portion 611 and the upper second acting portion 612 can be disposed at both ends in the width direction in the first chamber 101 of the measurement chamber 100. Therefore, even if the first cover member 21 is shifted, a voltage can be applied effectively near both ends in the width direction in the measurement chamber 100. Therefore, it is possible to reduce variations in the electrical resistance measurement results due to the assembly precision of the flow path device 1.

[0078] Because the upper first acting portion 611 and the upper second acting portion 612 of the upper working electrode 61 traverse the measurement chamber 100 in the vertical direction, a voltage can be applied to the entire vertical portion of the measurement chamber 100 even if the first cover member 21 is displaced in the vertical direction. This makes it possible to suppress variations in measurement performance among a plurality of flow path devices 1. Furthermore, because the lower first acting portion 631 and the lower second acting portion 632 of the lower working electrode 63 traverse the measurement chamber 100 in the vertical direction, a voltage can be applied to the entire vertical portion of the measurement chamber 100 even if the second cover member 22 is displaced in the vertical direction. This makes it possible to reduce variations in the electrical resistance measurement results due to the assembly precision of the flow path device 1.

[0079] 4, the length L31 from the other end 631E of the lower first action part 631 in the width direction to one end 632E of the lower second action part 632 in the width direction is greater than the width W1 of the measurement chamber 100 (L31>W1). Also, the distance L32 between the lower first action part 631 and the lower second action part 632 in the width direction is smaller than the width W1 of the measurement chamber 100 (L32 <W1)。

[0080] By satisfying L31>W1>L32, even if the first cover member 21 is shifted in the width direction relative to the measurement chamber 100 (through-hole 10H), it is possible to suppress fluctuations in the total area of ​​the portions of the lower first acting portion 631 and the lower second acting portion 632 that are arranged in the measurement chamber 100. That is, it is possible to reduce fluctuations in the contact area of ​​the lower first acting portion 631 and the lower second acting portion 632 that come into contact with the liquid in the measurement chamber 100. This makes it possible to suppress fluctuations in the conditions for applying voltage to the liquid in the measurement chamber 100. Therefore, it is possible to reduce variations in the measurement results of electrical resistance that are caused by the assembly accuracy of the flow path device 1 (the attachment accuracy of the second cover member 22).

[0081] Furthermore, even if the second cover member 22 is shifted in the width direction relative to the measurement chamber 100, the lower first acting portion 631 and the lower second acting portion 632 can be disposed at both ends in the width direction in the second chamber 102 of the measurement chamber 100. This allows voltage to be applied effectively near both ends in the width direction in the measurement chamber 100. This reduces variations in the electrical resistance measurement results due to assembly precision of the flow path device 1.

[0082] 4, the width W11 of the upper first acting portion 611 in the width direction is preferably larger than the width W12 of the upper third acting portion 613 in the width direction. The widths W11 and W12 are preferably larger than the width W13 of the upper first reference portion 711 in the width direction (W11>W12>W13). In this way, by increasing the width W11 of the upper first acting portion 611, the tolerance for misalignment of the first cover member 21 with respect to the measurement chamber 100 can be increased.

[0083] The width W21 of the upper second action portion 612 is preferably the same as the width W11 of the upper first action portion 611. The width W22 of the upper fourth action portion 614 is preferably the same as the width W12 of the upper third action portion 613. The width W23 of the upper second reference portion 712 is preferably the same as the width W13 of the upper first reference portion 711.

[0084] The width W31 of the lower first acting portion 631 in the width direction is larger than the width W32 of the lower third acting portion 633 in the width direction. Furthermore, the widths W31 and W32 are preferably larger than the width W33 of the lower first reference portion 731 in the width direction (W31>W32>W33). In this way, by increasing the width W31 of the lower first acting portion 631, the tolerance for misalignment of the second cover member 22 can be increased.

[0085] The width W41 of the lower second action portion 632 is preferably the same as the width W31 of the lower first action portion 631. The width W42 of the lower fourth action portion 634 is preferably the same as the width W32 of the lower third action portion 633. The width W43 of the lower second reference portion 732 is preferably the same as the width W33 of the lower first reference portion 731.

[0086] Since the upper working electrode 61 has the upper third working portion 613 and the upper fourth working portion 614, a voltage can be applied effectively to the vicinity of the widthwise center of the first chamber 101 in the measurement chamber 100. Furthermore, since the lower working electrode 63 has the lower third working portion 633 and the lower fourth working portion 634, a voltage can be applied effectively to the vicinity of the widthwise center of the second chamber 102 in the measurement chamber 100.

[0087] <Electrical resistance measurement> 5 is a diagram showing a circuit for measuring the electrical resistance of the cellular tissue 9. When measuring the electrical resistance of the cellular tissue 9, a power supply 91 and a voltmeter 92 are connected to the flow path device 1. That is, the output terminal of the power supply 91 is electrically connected to the upper working electrode 61 and the lower working electrode 63 via conductors 94a. The input terminal of the voltmeter 92 is electrically connected to the upper reference electrode 71 and the lower reference electrode 73 via conductors 94b. The conductors 94a and 94b are connected to the respective electrodes via probe pins 90.

[0088] A cell tissue 9 is held on the upper surface of the porous membrane 30 in the measurement chamber 100. A supply tube is connected to the first through-hole 43 of the top member 40 to supply a liquid (such as a culture medium) into the measurement chamber 100. The liquid is supplied to the first flow path 51 and the measurement chamber 100 via the supply tube. A discharge tube is connected to the second through-hole 45 of the top member 40. The liquid is discharged from the measurement chamber 100 and the second flow path 53 via the discharge tube. This allows the exchange (or circulation) of the liquid between the first chamber 101 and the second chamber 102 of the measurement chamber 100 to be performed appropriately.

[0089] 5, resistance Rm corresponds to the electrical resistance of the porous membrane 30 in the measurement chamber 100 and the cell tissue 9 supported by the porous membrane 30 (hereinafter, these are referred to as the "cellular portion"). Resistance Rw1 corresponds to the electrical resistance of the liquid between the upper working electrode 61 and the cellular portion (specifically, the liquid in the first chamber 101 of the measurement chamber 100). Resistance Rw2 corresponds to the electrical resistance of the liquid between the lower working electrode 63 and the cellular portion (specifically, the liquid in the second chamber 102).

[0090] 5, resistance Rr1 corresponds to the electrical resistance of the liquid between the upper reference electrode 71 and the cell portion (specifically, the liquid in the first chamber 101 of the measurement chamber 100). Resistance Rr2 corresponds to the electrical resistance of the liquid between the lower reference electrode 73 and the cell portion (specifically, the liquid in the second chamber 102 of the measurement chamber 100).

[0091] A power supply 91 applies a voltage between the upper working electrode 61 and the lower working electrode 63, and a voltmeter 92 measures the voltage between the upper reference electrode 71 and the lower reference electrode 73. Then, a computer (not shown) calculates the accurate voltage value between the upper working electrode 61 and the lower working electrode 63 from the measured voltage value. The resistance Rm of the cell part is also calculated from the calculated voltage value. The electrical resistance of the cell tissue 9 is determined by subtracting the resistance value of the porous membrane 30 from the resistance Rm of the cell part. The resistance value of the porous membrane 30 is determined by measuring the electrical resistance in the absence of the cell tissue 9.

[0092] When a voltage is applied between the upper working electrode 61 and the lower working electrode 63, oxidation and reduction reactions of the liquid may occur on the surfaces of the upper working electrode 61 and the lower working electrode 63, forming an electric double layer. If an electric double layer is formed, the voltage applied between the upper working electrode 61 and the lower working electrode 63 may differ from the output voltage of the power supply 91. To address this issue, an upper reference electrode 71 and a lower reference electrode 73 are disposed in the measurement chamber 100 near the upper working electrode 61 and the lower working electrode 63. Therefore, the voltage between the upper working electrode 61 and the lower working electrode 63 can be approximately obtained from the measured value of the voltage between the upper reference electrode 71 and the lower reference electrode 73. This allows the resistance Rm of the cell portion to be measured accurately.

[0093] <Current density distribution> Next, the results of a current density simulation will be described. Fig. 6 shows the cross-sectional structure of the flow path devices 1 and 1a used in the simulation. Fig. 6(a) is a cross-sectional view of the flow path device 1 according to the embodiment, and Fig. 6(b) is a cross-sectional view of the flow path device 1a according to the comparative example. Fig. 6 illustrates the size of each electrode portion, the spacing between the electrode portions, and the like.

[0094] 6(b), in the flow path device 1a according to the comparative example, the first upper working portion 611 and the second upper working portion 612 of the upper working electrode 61 and the first lower working portion 631 and the second lower working portion 632 of the lower working electrode 63 are respectively disposed away from the ends of the measurement chamber 100 in the width direction toward the inside of the measurement chamber 100. In addition, in the flow path device 1a, the third upper working portion 613 and the fourth upper working portion 614 of the upper working electrode 61 and the third lower working portion 633 and the fourth lower working portion 634 of the lower working electrode 63 are respectively omitted.

[0095] Fig. 7 is a diagram showing the simulation results of the current density distribution. In Fig. 7, the horizontal axis represents the position in the width direction of the measurement chamber 100, and the vertical axis represents the current density distribution. In Fig. 7, graphs G11 to G13 represent the simulation results of the flow path device 1 according to the embodiment, and graphs G21 to G23 represent the simulation results of the flow path device 1 according to the comparative example.

[0096] Graphs G11 and G21 show simulation results when the first cover member 21 and the second cover member 22 are attached without misalignment with respect to the measurement chamber 100. Graphs G12 and G22 show simulation results when the first cover member 21 and the second cover member 22 are attached with a widthwise offset relative to the measurement chamber 100. Graphs G13 and G23 show simulation results when the first cover member 21 is attached with a widthwise offset relative to the measurement chamber 100, and the second cover member 22 is attached with a widthwise offset relative to the measurement chamber 100, respectively.

[0097] In the case of the flow path device 1a according to the comparative example, as shown in graphs G21 to G23, the current density distribution fluctuates significantly when the first cover member 21 and the second cover member 22 are shifted in the width direction. In particular, as shown in graph G22, when the first cover member 21 and the second cover member 22 are shifted in the same direction, the difference between the current density at the other end in the width direction of the measurement chamber 100 (the part where the position is "0") and the current density at one end in the width direction (the part where the position is "2.0") becomes relatively large. In contrast, in the case of the flow path device 1, as shown in graphs G11 to G13, the fluctuation in the current density distribution when the first cover member 21 and the second cover member 22 are shifted in the width direction is sufficiently smaller than that of the flow path device 1a.

[0098] If the current density distribution becomes non-uniform, the electrical characteristics of the part of the cell layer where the current density is high may have a strong effect on the measurement results. With the flow channel device 1, even if the position of the first cover member 21 or the second cover member 22 is shifted, the fluctuation in the current density distribution is small. Therefore, it is possible to suppress variations in the performance of the flow channel device 1 due to assembly precision.

[0099] Furthermore, since the flow channel device 1 has the upper third acting portion 613, the upper fourth acting portion 614, the lower third acting portion 633, and the lower fourth acting portion 634, it is possible to apply a voltage uniformly across the width direction of the measurement chamber 100. Therefore, the current density of the flow channel device 1 (graphs G11 to G13) is more uniform than the current density of the flow channel device 1a (graphs G21 to G23). In this way, the flow channel device 1 of this embodiment can make the current density uniform, thereby preventing the measurement results from being strongly influenced by only a portion of the cell portion.

[0100] <Frequency characteristics> FIG. 8 is a diagram showing the frequency characteristics of the flow path device 1 according to the embodiment and the flow path device 1a according to the comparative example. In FIG. 8, the horizontal axis represents frequency (Hz), and the vertical axis represents resistance (Ω). FIG. 8 shows the results of measuring the resistance by introducing a liquid (culture medium) into each measurement chamber 100 of the flow path device 1 or the flow path device 1a and sweeping the frequency of the applied voltage. FIG. 8 also shows measurement results R11 to R14 for four flow path devices 1 and measurement results R21 to R24 for four flow path devices 1a.

[0101] 8, the measurement results R11 to R14 of the flow path device 1 have smaller variations in the measurement values ​​between devices in each frequency range than the measurement results R21 to R24 of the flow path device 1a according to the comparative example. In particular, in the low frequency range (around 10 Hz) used in TEER measurement, the variations in the measurement values ​​between the four flow path devices 1 are smaller than the variations in the measurement values ​​between the four flow path devices 1a.

[0102] Furthermore, in impedance measurement, the resistance and capacitance components of the cellular tissue 9 are estimated from the measurement results over a wide frequency range. In the case of the flow channel device 1, the variability in measurement values ​​between devices can be reduced across the entire frequency range. Therefore, by employing the flow channel device 1, the measurement accuracy of the impedance measurement can be improved.

[0103] <2. Variations> Although the embodiments have been described above, the present invention is not limited to the above and various modifications are possible.

[0104] For example, it is not essential that the upper working electrode 61 , the lower working electrode 63 , the upper reference electrode 71 and the lower reference electrode 73 extend across the measuring chamber 100 .

[0105] It is not essential that the upper working electrode 61 has the upper third working portion 613 or the upper fourth working portion 614. In addition, it is not essential that the lower working electrode 63 has the lower third working portion 633 and the lower fourth working portion 634.

[0106] The upper working electrode 61 may further have an electrode portion other than the upper third working portion 613 and the upper fourth working portion 614 between the upper first working portion 611 and the upper second working portion 612 in the width direction. The lower working electrode 63 may also have an electrode portion between the lower first working portion 631 and the lower second working portion 632 in the width direction.

[0107] Although the present invention has been described in detail, the above description is merely illustrative in all respects and does not limit the present invention. It is understood that countless variations not illustrated can be envisioned without departing from the scope of the present invention. The configurations described in the above embodiments and variations can be combined or omitted as appropriate as long as they are not mutually inconsistent. [Explanation of symbols]

[0108] 1. Flow path device 10 Intermediate parts 100 measurement room 101 Room 1 102 Room 2 10H through hole 11 First intermediate member 11H 1st through hole 12 Second intermediate member 12H 2nd through hole 1a Flow path device 21 First cover member 22 Second cover member 30 Porous membrane 43 First through hole 45 Second through hole 51 First Channel 53 Second Channel 61 Upper working electrode (one side working electrode) 611 Upper first action part (one side first action part) 612 Upper second action part (one side second action part) 613 Upper third action part (one side third action part) 614 Upper fourth action part (one side fourth action part) 63 Lower working electrode (other side working electrode) 631 Lower side first action part (other side first action part) 632 Lower side second action part (other side second action part) 633 Lower third action part (other side third action part) 634 Lower side 4th action part (other side 4th action part) 71 Upper reference electrode (one side reference electrode) 711 Upper first reference portion (first reference portion on one side) 712 Upper second reference portion (second reference portion on one side) 73 Lower reference electrode (other side reference electrode) 731 Lower first reference point (other side first reference point) 732 Lower second reference portion (other side second reference portion) 9 Cell tissue

Claims

1. A flow path device applied to measure electrical resistance of cell tissue, an intermediate member having a measurement chamber formed by a through hole penetrating in a first direction; a first cover member located on one surface of the intermediate member in the first direction and covering an opening at one end of the measurement chamber in the first direction; a second cover member located on the other surface of the intermediate member in the first direction and covering an opening at the other end of the measurement chamber in the first direction; a porous membrane located within the measurement chamber, dividing the measurement chamber into a first chamber on one side and a second chamber on the other side in the first direction, and allowing a liquid to pass through; a first working electrode and a first reference electrode located on the surface of the other side of the first cover member in the first direction and overlapping with the measurement chamber in the first direction; a second working electrode and a second reference electrode located on a surface of one side of the second cover member in the first direction and overlapping with the measurement chamber in the first direction; Equipped with The one-side working electrode is a first action portion on one side; a one-side second acting portion located away from the one-side first acting portion in one side of a second direction intersecting with the first direction; and a length from an end portion on the other side of the one-side first action portion in the second direction to an end portion on one side of the one-side second action portion in the second direction is greater than a width of the measurement chamber in the second direction; a distance between the one-side first action portion and the one-side second action portion in the second direction is smaller than a width of the measurement chamber; the measuring chamber, the one-side first action portion, and the one-side second action portion extend in a third direction intersecting the first direction and the second direction, The one-side first action portion and the one-side second action portion extend linearly in the third direction.

2. The flow path device according to claim 1 , The one-side reference electrode is a first reference portion on one side; a one-side second reference portion located away from the one-side first reference portion in one of the second directions; and a flow path device in which the one-side first reference portion and the one-side second reference portion are located between the one-side first action portion and the one-side second action portion in the second direction.

3. The flow path device according to claim 2, a one-side working electrode further including a one-side third working portion located between the one-side first reference portion and the one-side second reference portion in the second direction;

4. The flow path device according to claim 3 , A flow path device, wherein the width of the one-side first action portion in the second direction is greater than the width of the one-side third action portion in the second direction.

5. The flow path device according to claim 3 or 4, the one-side working electrode is located between the one-side first reference portion and the one-side second reference portion in the second direction, and further has a one-side fourth working portion located away from the one-side third working portion to one side in the second direction.

6. The flow path device according to claim 5 , The other working electrode is the other-side first action portion; an other-side second acting portion located away from the other-side first acting portion in one side of the second direction; and In the first direction, the other-side first acting portion faces the one-side first acting portion, In the first direction, the other-side second action portion faces the one-side second action portion, a length from an end portion of the other-side first action portion in the second direction to an end portion of the other-side second action portion in the second direction is greater than a width of the measurement chamber in the second direction; a distance between the other-side first action portion and the other-side second action portion in the second direction is smaller than a width of the measurement chamber in the second direction;

7. The flow path device according to claim 6, The other reference electrode is the other-side first reference portion; an other-side second reference portion located away from the other-side first reference portion in one direction in the second direction; and a flow path device in which the other-side first reference portion and the other-side second reference portion are located between the other-side first action portion and the other-side second action portion in the second direction.

8. The flow path device according to claim 7 , The other working electrode is The flow path device further includes an other-side third action portion located between the other-side first reference portion and the other-side second reference portion in the second direction.

9. The flow path device according to claim 8 , The other working electrode is A flow path device further having an other-side fourth action portion located between the other-side first reference portion and the other-side second reference portion in the second direction and located away from the other-side third action portion to one side in the second direction.

10. The flow path device according to any one of claims 1 to 9, The intermediate member is a first intermediate member; a second intermediate member located on one side of the first intermediate member in the first direction; and the first intermediate member has the first chamber, the second intermediate member has the second chamber, A flow path device, wherein the porous membrane is located between the first intermediate member and the second intermediate member in the first direction.

11. The flow path device according to any one of claims 1 to 10, The intermediate member is a first flow path communicating with the first chamber; a second flow path communicating with the second chamber; A flow path device comprising:

12. The flow path device according to claim 11, The first cover member is a first through hole communicating with the first flow path; a second through hole communicating with the second flow path; A flow path device comprising:

13. The flow path device according to any one of claims 1 to 12, A flow path device, wherein the one-side first action portion and the one-side second action portion extend from a position away from the measurement chamber in one of the third directions to a position away from the measurement chamber in the other of the third directions.

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