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JP-7854842-B2 - Impedance measuring device and impedance measuring method

JP7854842B2JP 7854842 B2JP7854842 B2JP 7854842B2JP-7854842-B2

Inventors

  • 中島 駿

Assignees

  • 株式会社ＳＣＲＥＥＮホールディングス

Dates

Publication Date
20260507
Application Date
20220422

Claims (4)

  1. An impedance measuring device, Measuring container and Multiple first electrodes are arranged in an array on the bottom surface of the measuring container in which the liquid containing the object is placed , The second electrode located inside the measuring container, A voltage application circuit that applies an AC voltage between each of the first electrode and the second electrode, A current detection circuit that detects the current flowing through each of the first electrodes and outputs a voltage corresponding to the current, A voltage detection circuit for detecting the voltage between each of the first and second electrodes, A differential signal detection circuit that detects the difference between the AC voltage applied by the voltage application circuit and the voltage output by the current detection circuit, A calculation unit calculates the impedance of the object based on the difference and the voltage detected by the voltage detection circuit, An impedance measuring device equipped with the following features.
  2. An impedance measuring device according to claim 1, An impedance measuring device further comprising an electrode selection circuit that selects one first electrode from among the plurality of first electrodes to be connected to the current detection circuit.
  3. An impedance measuring device according to claim 1 or claim 2, The calculation unit is an impedance measuring device that calculates the impedance of the object based on the current detected by the current detection circuit and the voltage detected by the voltage detection circuit.
  4. An impedance measurement method, a) A step of applying an AC voltage between at least one of a plurality of first electrodes arranged in an array on the bottom surface of a measuring container in which a liquid containing the object is placed , and a second electrode located inside the measuring container, b) A step of detecting the current flowing through the first electrode while an AC voltage is applied by step a) above, and outputting a voltage corresponding to the current, c) A step of detecting the voltage between the first electrode and the second electrode while the AC voltage has been applied by step a), d) A step of detecting the difference between the voltage output in step b) and the AC voltage applied in step a), e) A step of calculating the impedance of the object based on the voltage detected by step c) and the difference detected by step d), An impedance measurement method, including the following.

Description

The subject matter disclosed herein relates to impedance measuring devices and impedance measuring methods. In the field of electrophysiology, the behavior of cellular ion channels in single cells or populations is analyzed. Examples of ion channel analyzers include intracellular action potential (IOT) detection devices using the patch-clamp method and extracellular action potential (IOT) detection devices using multi-electrode array (MEA) devices. Multi-electrode array devices are disclosed, for example, in Patent Document 1. Special Publication No. 2016-529889 This diagram schematically shows the configuration of the impedance measuring device according to the embodiment.Figure 1 is a perspective view showing the measuring container.Figure 1 is a top view showing the measuring container.This diagram shows the equivalent circuit when measuring impedance. The embodiments of the present invention will be described below with reference to the attached drawings. Note that the components described in these embodiments are merely illustrative and are not intended to limit the scope of the present invention to them alone. In the drawings, for ease of understanding, the dimensions and number of parts may be exaggerated or simplified as needed. <1. First Embodiment> Figure 1 is a schematic diagram showing the configuration of the impedance measuring device 1 according to an embodiment. Figure 2 is a perspective view showing the measuring container 10 shown in Figure 1. Figure 3 is a top view showing the measuring container 10 shown in Figure 1. As shown in Figure 1, the impedance measuring device 1 comprises a measuring container 10 and a measuring unit 20. The measurement container 10 is a container for measuring the impedance of the target object, the cell 9. A cell suspension containing the cell 9 is dropped into the measurement container 10. As shown in Figures 2 and 3, the measurement container 10 has a bottom portion 11 and side walls 13. The bottom portion 11 spreads out in a disc shape along the horizontal plane. The side walls 13 extend upward in a cylindrical shape from the periphery of the bottom portion 11. The bottom portion 11 is an example of a "measurement plate." The upper surface of the bottom portion 11 is the bottom surface inside the measurement container 10 where the cell suspension is dropped. Note that the object to be measured in the measurement container 10 is not limited to cell 9; it may also be a biological tissue slice specimen, etc. The measuring container 10 has a plurality of first electrodes 31, a second electrode 33, a plurality of first wirings 35, and a second wiring 37. The plurality of first electrodes 31, the second electrodes 33, the plurality of first wirings 35, and the second wirings 37 are located on the upper surface of the bottom 11 (the bottom surface inside the measuring container 10). Each first wiring 35 and second wiring 37 is covered with an insulator (e.g., photosensitive polyimide). Each first electrode 31, second electrode 33, each first wiring 35, and second wiring 37 are formed on the upper surface of the bottom 11, for example, by photolithography. Multiple first electrodes 31 are arranged in an array. The measuring container 10 is a multi-electrode array (or micro-electrode array) device in which multiple minute first electrodes 31 are arranged in an array. In the examples shown in Figures 1, 2, and 3, 16 first electrodes 31 are arranged in a 4x4 matrix. The number and arrangement of the first electrodes 31 can be arbitrarily set. Preferably, 10 or more first electrodes 31 are arranged. The shape of the first electrodes 31 is square when viewed from above. However, the shape of the first electrodes 31 may be a polygon or a circle other than a square. The second electrode 33 is located radially outward from the plurality of first electrodes 31. The plurality of first electrodes 31 and the second electrode 33 are insulated from each other. In the examples shown in Figures 1, 2, and 3, the second electrode 33 is substantially annular in shape with a portion open when viewed from above. The second electrode 33 is arranged to surround the plurality of first electrodes 31. Note that the shape of the second electrode 33 is not limited to substantially annular; it may also be circular or polygonal. It is not essential that the second electrode 33 is located on the upper surface of the bottom 11. For example, the second electrode 33 may be in the shape of a stick, so that it is immersed in the liquid 91 injected into the measuring container 10. Each first wire 35 is electrically connected to a corresponding first electrode 31. Each first wire 35 extends outward from the measuring container 10. Multiple first wires 35 extend outward through the open portion of the second electrode 33. The first wires 35 and the second electrode 33 are insulated from each other. The second wire 37 is electrically connected to the second electrode 33. The second wire 37 extends outwar