JP5526384B2 - Cell tissue evaluation equipment - Google Patents

Description

  The present invention relates to a cellular tissue evaluation apparatus that evaluates the structuring or intercellular communication of a cellular tissue composed of a large number of cells such as biological cells, and in particular, the evaluation is performed by detecting magnetic flux generated by the cellular tissue. The present invention relates to a cellular tissue evaluation apparatus that performs the above.

  Many living cells create a large group of tissues and perform their functions. For example, in a nerve cell tissue, a fiber is extended in a direction in which a signal is to be transmitted, and in the heart, excitement is propagated through a special conduction path to generate an integrated contraction. Therefore, if we can develop a non-invasive measurement method or device that evaluates that the cell population is structured as a tissue (cell tissue) and creates such a direction of conduction and electrical coupling of excitement, As a new evaluation method or apparatus for associating the function and structure of a cellular tissue, it can be widely applied to life science, medical care, welfare and the like.

  However, no method has been developed so far for evaluating the structuring and electrical communication paths in cell tissues in a non-contact manner. As a close technique, there is a method in which an alternating current is applied to a cultured tissue, its impedance is measured, and the number of proliferated cells is estimated. Although the number of cells can be estimated by such a method, it cannot serve as an index for communication between cells or structuring of cell tissues. In this method, an electrode is disposed in a cultured cell container, and measurement can be performed only in contact with a culture solution that is a biological fluid.

  Conventionally, in order to evaluate the electrical conductivity of living cell tissue, a plurality of electrodes are arranged on the surface of the cell tissue, and the conduction time is compared by comparing the propagation time of potential waveforms such as action potentials. The method of estimating speed has been used. FIG. 20 shows a schematic diagram of an example thereof. In FIG. 20, the surface voltages at a plurality of locations of the cell tissue 50 placed in the experimental tank 56 are measured by a plurality of voltmeters V1, V2, and V3. However, in this method, the detected action potential is only the surface potential of the cell tissue, and it is difficult to consider that the current or action potential in the entire cell tissue is reflected. That is, whether the electrical signal between adjacent electrodes is coupled by direct current propagation, indirectly coupled through excitement of another part, or even accidentally synchronized during measurement It cannot be determined whether it was recorded.

JP 2004-219109 A

  Conventionally, as a method and apparatus for detecting an action potential of a living cell tissue, for example, there are those described in the following prior art documents. For example, this is the technique described in Patent Document 1. Patent Document 1 discloses a technique in which an action potential detecting device for living cell tissue uses a SQUID magnetic sensor to measure a temporal change in a magnetic signal accompanying an action potential / current generated by the living cell tissue. . However, the SQUID magnetic sensor must be placed in liquid helium, and when the SQUID magnetic sensor at a low temperature of about minus 270 degrees is brought close to the cellular tissue to be detected, the cellular tissue is kept in a living state. Therefore, measurement can be performed stably only at a position away from the living cell tissue. Also, the SQUID is not easy to use for recording the activity of a cell tissue because the entire apparatus becomes large.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a cell tissue evaluation apparatus that non-invasively evaluates the structure of a cell tissue or cell-cell communication.

In order to achieve this object, the invention according to claim 1 is (a) a cellular tissue evaluation apparatus for evaluating the structuring of a cellular tissue composed of a large number of cells, and (b) a magnetic signal generated from the cellular tissue. A magnetic detection unit to detect, and (c) an evaluation unit that evaluates the degree of structuring of the cell tissue based on a magnetic signal detected by the magnetic detection unit, and (d) the magnetic detection unit includes: 1000μm following resolution as a magnetic sensor head has a magnetic impedance sensor capable of detecting the magnetic signal noise level below 1 nT, Ri proximity allows der within 1000μm from the cell tissue (e) magnetic impedance sensor, (F) The degree of structuring of the cellular tissue varies depending on the degree of expression of the gap channel structure in the cellular tissue. Degree Der Rukoto of the Do not contact, and said.

According to the first aspect of the present invention, a magnetic signal generated based on a current flowing through a cell tissue is detected by the magnetic detection unit, and the cell tissue is evaluated by the evaluation unit based on the detected magnetic signal. Thus, the degree of structuring of cellular tissue or intercellular communication can be evaluated non-invasively. Further, the degree of structuring of the cell tissue is a degree of electrical communication between cells in the cell tissue that changes in accordance with the degree of expression of the gap channel structure in the cell tissue. In this way, the degree of electrical communication between cells in the cellular tissue that changes according to the degree of expression of the gap channel structure in the cellular tissue is evaluated non-invasively as the degree of structuring of the cellular tissue. can do.

Preferably, (a) the magnetic detection unit is capable of detecting magnetic signals in a plurality of different directions for the cellular tissue, and (b) the evaluation unit is configured to detect the cell based on each of the magnetic signals in the plurality of directions. It evaluates the structure of the organization. In this way, when the cellular tissue generates magnetic signals based on different currents in each of the plurality of directions, the structuring of the cellular tissue is performed based on the magnetic signals in the multiple directions detected by the magnetic detection unit. Or cell-cell communication can be assessed non-invasively.

  Preferably, the evaluation unit is configured to structure the cellular tissue from a previously stored relationship based on a similarity between the magnetic signal of the sample specimen and the magnetic signal obtained from the cellular tissue to be evaluated. Is to evaluate. In this way, the structuring of both cell tissues is evaluated by comparing the magnetic signals detected by the magnetic detection unit for each of the sample specimen and the cell tissues to be evaluated.

  More preferably, the evaluation of the structuring of the cellular tissue by the evaluation unit is performed based on an analysis result in a frequency domain of a magnetic signal detected by the magnetic detection unit. In this way, the structuring of the cell tissue can be evaluated based on the characteristics of the magnetic signal in the frequency domain. Therefore, the structuring of the cellular tissue can be evaluated based on features that do not appear when the magnetic signal is analyzed in the time domain.

Preferably, (a) the magnetic impedance sensor is arranged such that a distance between the first magnetic sensor head and the cellular tissue is longer than a distance between the cellular tissue and the first magnetic sensor head. And (b) an environmental magnetic field canceling unit that reduces the influence of the environmental magnetic field based on magnetic signals detected by the first magnetic sensor head and the second magnetic sensor head, respectively. It further has these. In this way, based on the magnetic signal detected in each of the first magnetic sensor head and the second magnetic sensor head, the environmental magnetic field canceling unit can reduce the influence of the environmental magnetic field, and the cell The organization structuring is evaluated more accurately.

  Preferably, the cellular tissue evaluation apparatus includes a stimulation administration unit that administers at least one of electrical stimulation, mechanical stimulation, electromagnetic waves, heat, and a drug to the cellular tissue. In this way, a magnetic signal generated in response to a stimulus given to the cell tissue by the stimulus administration unit can be used as an evaluation index for structuring the cell tissue.

  Also preferably, the cellular tissue evaluation device supplies a physiological extracellular fluid having an ionic composition osmotic pressure to the cellular tissue in a temperature range from 0 ° C. to 42 ° C., and the survival state of the cellular tissue It has a cell tissue maintenance part which maintains the above. In this way, it is possible to non-invasively evaluate the structuring of the cell tissue or the communication between cells while the cell tissue is maintained in the living state by the cell tissue maintenance unit.

More preferably, the magnetic sensor head included in the magnetic detection unit is a magnetic impedance sensor having a columnar magnetic body, a plate-shaped magnetic body, a thin-film magnetic body, or a net-like magnetic body. In this way, the cell tissue evaluation apparatus can be provided in a small size while realizing desired accuracy.

It is a figure explaining the outline | summary of the apparatus in an example of the cell-tissue evaluation apparatus of this invention. It is a figure explaining the structure of the experimental tank part in the cell-tissue evaluation apparatus of FIG. 1 in detail. It is a figure explaining an example of a structure of the magnetic sensor head in the cell-tissue evaluation apparatus of FIG. It is a figure explaining the positional relationship of the experimental tank, 1st magnetic sensor head, and 2nd magnetic sensor head in the cell-tissue evaluation apparatus of FIG. It is a figure explaining arrangement | positioning of the magnetic sensor head in the cell tissue evaluation apparatus of FIG. 1, Comprising: It is a figure explaining the relative positional relationship of the cell tissue which is an evaluation object, and a magnetic sensor head. It is a figure explaining the outline | summary of the function which the computer has in the cell-tissue evaluation apparatus of FIG. It is a figure explaining the relationship between the structural degree of a cell tissue, and the detected magnetic signal. It is a figure explaining the smooth muscle tissue used as a cell tissue in an Example. It is a figure explaining an example of the magnetic signal detected when the magnetic sensor head is arrange | positioned in the direction orthogonal to the major axis direction of a cell tissue. It is a figure explaining an example of the magnetic signal detected when the magnetic sensor head is arrange | positioned in the major axis direction of a cell tissue. FIG. 10 is a diagram illustrating an example of a magnetic signal detected when nifedipine is administered to a cell tissue and a magnetic sensor head is arranged in a direction orthogonal to the long axis direction of the cell tissue, corresponding to FIG. 9. FIG. FIG. 9 is a diagram illustrating an example of a magnetic signal detected when an electrical stimulus is applied to a cell tissue and a magnetic sensor head is arranged in a direction orthogonal to the long axis direction of the cell tissue. It is a corresponding figure. 3 is a flowchart for explaining an example of a control operation for evaluation of a cell tissue by the cell tissue evaluation apparatus of FIG. 1. It is a figure explaining the waveform at the time of carrying out a power spectrum analysis of the magnetic signal obtained as FIG. 9 about a part of frequency. It is a figure explaining the waveform at the time of carrying out a power spectrum analysis of the magnetic signal obtained as FIG. 11 about a part of frequency. It is another Example of the cell-tissue evaluation apparatus of this invention, Comprising: It is a figure explaining the amorphous element of a different shape which a magnetic sensor head has. It is another Example of the cell-tissue evaluation apparatus of this invention, Comprising: It is a figure explaining the amorphous element of a different shape which a magnetic sensor head has. It is a figure explaining the application example of the cellular tissue evaluation apparatus of this invention, Comprising: It is a figure which evaluates the infarction site | part in a heart. FIG. 6 is a diagram for explaining another embodiment of the present invention, that is, a mode in which a plurality of pairs of magnetic sensor heads corresponding to a plurality of directions are provided, corresponding to FIG. 5. It is a figure which shows the schematic of an example which arrange | positions several electrodes on the cell-tissue surface, and detects the action potential.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a diagram illustrating an outline of a configuration of a cell tissue evaluation apparatus 10 that is one embodiment of the present invention. As shown in FIG. 1, the cell tissue evaluation apparatus 10 includes an experimental tank section 14, two magnetic sensor heads, a first magnetic sensor head 18 and a second magnetic sensor head 20, a control circuit section 22, and the like. The The magnetic signal as a detection result output from the control circuit unit 22 is digitally converted by, for example, an A / D converter 32 as shown in FIG. 1, and is recorded by a computer 34 used for data recording or the like. The

  Among these, the experimental tank part 14 is comprised including the experimental tank 56 for arrange | positioning the cell tissue 50 used as detection object. FIG. 2 is a diagram for explaining the configuration of the experimental tank section 14 in detail. The test tank 56 is a cover having a rectangular cross section formed in a plate-like silicon (silicon plate) 55 and a cover having a thickness of about 100 μm, for example, which is installed so as to overlap the lower side of the silicon plate 55. The glass 57 is used. That is, the experimental tank 56 is a columnar container having a cover glass 57 as a bottom and a hole provided through the silicon plate 55 as a wall surface.

  The experimental tank 56 is provided with a cell tissue maintenance unit 70 for maintaining the survival state of the cell tissue 50. Specifically, the cell tissue maintenance unit 70 supplies a physiological extracellular fluid having an ionic composition osmotic pressure at a temperature set in advance in a temperature range of 0 to 42 degrees Celsius, so that the survival state of the cell tissue 50 is achieved. To maintain. More specifically, the cellular tissue maintenance unit 70 supplies this physiological extracellular fluid (perfusate) from the perfusate inflow tube 62 to the experimental tank 56. The physiological extracellular fluid in the experimental tank 56 is sucked by the circulation pump 66 through the perfusate suction tube 64 and is circulated again to the experimental tank 56 from the perfusate inflow tube 62 and supplied. In addition, a thermostatic chamber 68 is provided in the process of circulating the physiological extracellular fluid, and the physiological extracellular fluid sucked by the perfusate suction tube 64 is heated to the preset temperature by the thermostatic bath 68. Or it is cooled. In the excitable cellular tissue that is the detection target of the cellular tissue evaluation apparatus 10 of the present invention, the electrical activity is created by ionic flow due to the activation of the ion transporter. Therefore, ions do not flow below 0 degrees Celsius when the water inside and outside the cell becomes solid. In addition, at 42 degrees Celsius or higher, cells generate heat shock proteins and their functions are damaged, and irreversible changes occur. Therefore, the temperature of the physiological extracellular fluid is set to a temperature set in advance in a temperature range of 0 to 42 degrees Celsius, maintains the viable state of the cell tissue, and maintains homeostasis. These structures for circulating physiological extracellular fluid, that is, the perfusate inflow tube 62, the perfusate suction tube 64, the circulation pump 66, and the thermostatic chamber 68 correspond to the cell tissue maintenance unit 70.

  The stimulation administration unit 76 provides stimulation to the cell tissue 50 disposed in the experimental tank 56, and includes a drug supply unit 74 and a pipette 72 in this embodiment. The pipette 72 is held by a manipulator (not shown) and can be moved by moving the manipulator. Alternatively, the pipette 72 may be fixed at a predetermined position, and the experiment layer 56 may be moved by the manipulator 58 so that the drug can be dropped at an arbitrary position in the experiment tank 56. Then, by dropping the drug supplied from the drug supply unit 74 at the moved position, the drug is administered as an aspect of stimulation to any part of the cellular tissue 50 arranged in the experimental tank 56. Can do. The drug supply unit 74 stores, for example, a drug that can stimulate the excitable cell tissue that is a detection target of the cell tissue evaluation apparatus 10, and supplies a predetermined amount of drug to the pipette 72. Has been.

  The electrical stimulation unit 78 applies electrical stimulation to the cell tissue 50 disposed in the experimental tank 56. Specifically, the electrical stimulation unit 78 has electrodes 80 and 81, and one electrode 80 is disposed in a physiological extracellular fluid in the experimental tank 56. The other electrode 81 is inserted into a pipette 82 provided for electrical stimulation. Electrolyte liquid is injected into the pipette 82, and the electrode 81 and the cell tissue 50 are brought into direct contact with each other by applying the pipette 82 to an arbitrary position of the cell tissue 50. Can be done. The electrical stimulation unit 78 applies a predetermined voltage, for example, 30 volts, between the electrodes 80 and 81, or applies a predetermined current, for example, 5 mA. Thus, electrical stimulation can be applied to the cell tissue 50. The stimulation administration unit 76 and the electrical stimulation unit 78 correspond to the stimulation administration unit of the present invention.

  Returning to FIG. 1, the experimental tank section 14 is covered with, for example, a plastic container 16, and the temperature (environment temperature) around the experimental tank 56 and the cell tissue 50 arranged in the experimental tank 56 is The temperature is maintained at a desired temperature. The container 16 is made of a material that does not perform magnetic shielding. Further, the container 16 is preferably a transparent container, and can be irradiated with light from the outside, or the generation of fluorescence inside can be detected by an optical sensor or the like provided outside. Good.

  Each of the first magnetic sensor head 18 and the second magnetic sensor head 20 is a sensor for detecting a magnetic signal, and is composed of, for example, an ultra-sensitive MI (Magneto Impedance) sensor. FIG. 3 is a diagram for explaining an example of the structure of the first magnetic sensor head 18 and the second magnetic sensor head 20 (hereinafter referred to as “magnetic sensor heads 18 and 20” when they are not distinguished from each other). As shown in FIG. 3, the magnetic sensor heads 18 and 20 include an amorphous wire 84 as a columnar magnetic body and a detection coil 86 wound concentrically with the amorphous wire 84. A high-frequency alternating current of, for example, 30 kHz or more generated by a sensor driving unit 24 (see FIG. 1) described later is applied to both ends of the amorphous wire 84. A voltage generated in the detection coil 86 by the magnetic flux generated by the amorphous wire 84 is detected by the magnetic signal detection unit 28 described later. Here, when an external magnetic field having a magnetic flux density per unit area of about 0.2 nT to 1 nT is applied to the amorphous wire 84 when a high-frequency current to be applied is applied, the amorphous wire 84 has a magneto-impedance effect. Impedance changes greatly. Therefore, the change in the external magnetic field applied to the amorphous wire 84 can be detected by detecting the voltage across the detection coil 86 and detecting the change in the impedance of the amorphous wire 84 based on the detected voltage. it can.

  In addition, the magnetic sensor heads 18 and 20 operate in an environmental temperature range of 0 to 42 ° C. set by the above-described cell tissue maintenance unit 70 as a function of living cell tissue.

  The magnetic sensor heads 18 and 20 have a response speed of 1 ms or less with respect to magnetic fluctuations. This is based on the duration of action potential generated by various electrically excitable cells such as nerves, muscles, and endocrine cells present in the living body. That is, it is known that the action potential duration is 0.4 to 2 ms even in the nerve cell having the shortest action potential duration. Therefore, if the response speed to magnetic fluctuation, that is, the response time to respond to the magnetic change is about 1 ms or less, it is possible not only to measure and evaluate the activity of many types of nerve cells, but also to various types such as muscles and endocrine cells. This is because the activity of various electrically excitable cells can be measured and evaluated.

  FIG. 4 is a diagram for explaining the structure of the experimental tank 56, the first magnetic sensor head 18 and the second magnetic sensor head 20, and the relative positions of the first magnetic sensor head 18 and the second magnetic sensor head 20. . The first magnetic sensor head 18 and the second magnetic sensor head 20 are configured to include the columnar amorphous wire 84 and the detection coil 86 wound around the amorphous wire 84 in a cylindrical shape as described above. Specifically, in this embodiment, as shown in FIG. 4, the amorphous wire 84 included in the first magnetic sensor head 18 and the second magnetic sensor head 20 has a diameter in the cross-sectional direction of about 200 μm and the detection coil 86. The radius in the cross-sectional direction is about 500 μm. The space between the amorphous wire 84 and the detection coil may be hollow or may be filled with an insulator. Here, the length d of the amorphous wire 84 included in the magnetic sensor heads 18 and 20 is equal to or less than the distance l1 from the cell to the first magnetic sensor head 18. By doing so, when a current flows, a magnetic field having a magnitude inversely proportional to the distance is generated according to the Ampere's law, and therefore, a high spatial resolution of about d1 from the cell to the first magnetic sensor head 18, for example, a resolution of 1000 μm. Is obtained. Further, the magnetic sensor heads 18 and 20 are configured such that the shape and size of the amorphous wire 84 and the shape and size of the detection coil 86 are measured so that a magnetic signal generated by the cell tissue 50 is measured with a noise level of 1 nT or less. The number of windings is set.

  As shown in FIG. 4, the first magnetic sensor head 18 and the second magnetic sensor head 20 are, for example, a first magnetic sensor so that they are parallel to each other on the same vertical axis below the test tank 56. The amorphous wires 84 of the head 18 and the second magnetic sensor head 20 are positioned so that the axial directions thereof are parallel to each other. In the present embodiment, the first magnetic sensor head 18 so that the axial directions of the amorphous wires 84 of the first magnetic sensor head 18 and the second magnetic sensor head 20 are both parallel to the bottom surface of the experimental tank 56, that is, horizontal. The second magnetic sensor head 20 is disposed and held by a sensor head holder (not shown). The distance d1 between the first magnetic sensor head 18 and the cell tissue 50 is shorter than the distance d2 between the second magnetic sensor head 20 and the cell tissue 50, that is, in FIG. Is positioned below the first magnetic sensor head 18. The distance d1 between the first magnetic sensor head 18 and the cell tissue 50 is defined as the distance between the center of the portion that detects magnetism in the first magnetic sensor head 18 and the lower surface of the cell tissue 50. That is, as shown in FIG. 4 of this embodiment, when the first magnetic sensor head 18 has the columnar amorphous wire 84 and the axis thereof is parallel to the bottom surface of the experimental tank 56, the axis of the amorphous wire 84 and the experiment The distance from the bottom surface of the tank 56, that is, the lower surface of the cell tissue 50. The distance between the magnetic sensor head and the cell tissue is similarly defined for the second magnetic sensor head 20 or the magnetic sensor head in another embodiment.

  Here, the distance d1 between the first magnetic sensor head 18 and the cell tissue 50 is a distance at which a magnetic field generated by the cell tissue 50 can be detected, specifically, for example, 1 mm or less. On the other hand, the distance d2 between the second magnetic sensor head 20 and the cell tissue 50 is the difference between the detection signal from the first magnetic sensor head 18 and the detection signal from the second magnetic sensor head 20 calculated by the environmental magnetic field canceling unit 26 described later. The magnitude of the difference may be a distance that can exceed the noise level in the magnetic detection unit 30 described later. Specifically, for example, the magnetic field generated by the cell tissue 50 is detected only by the first magnetic sensor head 18, and the magnetic field around the experimental tank 56, that is, the environmental magnetic field is detected by the first magnetic sensor head 18 and the second magnetic sensor. It may be detected by both of the heads 20. In FIG. 4, the thickness of the cover glass 57 installed on the silicon plate 55 as the bottom of the experimental tank 56 is 100 μm, and the first magnetic sensor head 18 includes the upper end of the detection coil 86 and the lower surface of the cover glass 57. The distance is set to be 300 μm. As described above, since the radius of the cross section of the detection coil 86 is 500 μm, the distance d1 between the first magnetic sensor head 18 and the cell tissue 50 can detect the magnetic field generated by the cell tissue 50. It is set to 900 μm, which is less than 1 mm which is the distance.

  Note that the noise level tolerance of the magnetic sensor heads 18 and 20 is set based on the strength of the magnetic field generated by the cellular tissue 50 to be detected, for example, the magnetic flux density. For example, when the amplitude of the magnetic fluctuation generated with the action potential of the cell tissue 50 is about 500 to 1000 pT, the magnetic sensor heads 18 and 20 (particularly, the first sensor heads 18 and 20 that can be brought close to the cell tissue 50 within 1000 μm). If the noise level of one magnetic sensor head 18) is 1000 pT or less, it can be used for the purpose of evaluating the function of the cell tissue 50.

  The magnetic sensor heads 18 and 20 are fixed to a manipulator (not shown), and are moved in accordance with the movement of the manipulator. Specifically, by moving in the direction parallel to the experimental tank 56, for example, the first magnetic sensor head 18 is positioned at a specific position of the experimental tank 56, and the target position of magnetic detection at the specific position is determined. It is possible to change. Further, by changing the distance from the experimental tank 56, it is possible to achieve an arrangement suitable for magnetism detection by the magnetism detection unit 30.

  The magnetic sensor heads 18 and 20 are so-called vector sensors that can detect a magnetic field in a specific direction. As described above, the magnetic sensor heads 18 and 20 can detect the magnetism in a desired direction by changing the direction of the magnetic sensor heads 18 and 20 with a manipulator to which the magnetic sensor heads 18 and 20 are fixed. it can.

  FIG. 5 is a diagram for explaining the relationship between the direction of magnetism to be detected and the orientation in the arrangement of the magnetic sensor heads 18 and 20. FIG. 5 is a view of the experimental tank portion 14 in FIG. 1 as viewed from above. For the sake of explanation, as shown in FIG. 5, the experimental tank section 14 is provided with an x axis and a y axis that are orthogonal to each other in a plane parallel to the experimental tank 56. FIG. 5A is a diagram showing an example of the arrangement of the magnetic sensor heads 18 and 20 for detecting magnetism parallel to the y axis, and FIG. 5B is a diagram for detecting magnetism parallel to the x axis. 3 is a diagram illustrating an example of an arrangement of magnetic sensor heads 18 and 20. FIG. In this way, the orientation of the magnetic sensor heads 18 and 20 in the xy plane is set so that magnetism in a desired direction can be detected.

  Returning to FIG. 1, the control circuit unit 22 drives the magnetic sensor heads 18 and 20, takes out signals detected by the magnetic sensor heads 18 and 20, performs predetermined processing, and performs cell tissue 50. Extract only the signal corresponding to the magnetic field (magnetic signal) generated by. The control circuit unit 22 is configured by an analog circuit, for example, and includes a sensor driving unit 24, an environmental magnetic field canceling unit 26, and a magnetic signal detecting unit 28.

  The sensor driving unit 24 generates a high-frequency alternating current and energizes each amorphous wire 84 of the first magnetic sensor head 18 and the second magnetic sensor head 20. The frequency and current of the high-frequency alternating current are set to values at which the amorphous wires 84 of the first magnetic sensor head 18 and the second magnetic sensor head 20 can cause a magnetic impedance phenomenon. In this embodiment, for example, the sensor driving unit 24 uses the CMOS inverter built-in IC as a timer circuit to generate pulses at intervals of 33 μs, so that the amorphous wire 84 generates a magnetic impedance phenomenon and responds to a magnetic change. The shortest time is 33μs (see Tsuyoshi Uchiyama, Shingo Tajima, pumping force, “Non-contact heart rate detection method using MI micro magnetic sensor”, Proceedings of IEEJ Magnetics Study Group, 2007, MAG-07-108, etc. ), The activity by the cell tissue 50 can be measured sufficiently.

  The environmental magnetic field canceling unit 26 reduces the influence of the environmental magnetic field based on the voltage detected by the detection coil 86 of the first magnetic sensor head 18 and the voltage detected by the detection coil 86 of the second magnetic sensor head 20. To do. In the present embodiment, as described above, the magnetic field generated by the cell tissue 50 is detected only by the first magnetic sensor head 18, and the environmental magnetic field is detected by the first magnetic sensor head 18 and the second magnetic sensor head 20. A first magnetic sensor head 18 and a second magnetic sensor head 20 are provided. Accordingly, the influence of the environmental magnetic field can be reduced by subtracting the voltage detected by the detection coil 86 of the second magnetic sensor head 18 from the voltage detected by the first magnetic sensor head 18. At this time, the distance d1 between the first magnetic sensor head 18 and the cell tissue 50 is a distance at which a magnetic field generated by the cell tissue 50 can be detected, and the distance d2 between the second magnetic sensor head 20 and the cell tissue 50. The magnitude of the difference between the detection signal from the first magnetic sensor head 18 and the detection signal from the second magnetic sensor head 20 calculated by the environmental magnetic field canceling unit 26 described later indicates the noise level in the magnetic detection unit 30 described later. The distance that can be exceeded is generated by the cell tissue 50 based on the difference between the voltage detected by the first magnetic sensor head 18 and the voltage detected by the detection coil 86 of the second magnetic sensor head 18. A voltage corresponding to the magnetic field can be detected.

  The magnetic signal detection unit 28 generates a magnetic field generated by the cellular tissue 50 based on a voltage corresponding to the magnetic field generated by the cellular tissue 50 calculated by the environmental magnetic field canceling unit 26 so that the influence of the environmental magnetic field is reduced. Is calculated by, for example, magnetic flux density.

  As described above, the first magnetic sensor head 18, the second magnetic sensor head 20, and the control circuit unit 22 can obtain the strength of the magnetic field generated by the cell tissue 50. Can do.

  The A / D conversion unit 32 is, for example, an A / D converter of 16 bits or 32 bits, and the time of the intensity of the magnetic field generated by the cellular tissue 50 generated by the magnetic signal detection unit 28 of the control circuit unit 22. The change is converted into digital data and input to a computer described later. Note that the resolution of the A / D converter 32 is not limited to the 16-bit or 32-bit described above, and can be changed as appropriate according to the resolution of the magnetic sensor heads 18 and 20.

  The computer 34 includes, for example, a so-called microcomputer having a CPU, a RAM, a ROM, an input / output interface, and the like. The CPU uses a temporary storage function of the RAM, and signals according to a program stored in the ROM or the like in advance. By performing the processing, information on the change in the magnetic field generated by the cell tissue 50 output from the control circuit unit 22 and converted into digital data by the A / D conversion unit 32 is processed.

  FIG. 6 is a functional block diagram for explaining an example of the functions of the computer 34. The electronic control unit (CPU) 36 includes a signal processing unit 38 and an evaluation unit 40. The signal processing unit 38 is a program stored in advance in the storage unit 42 with information on changes in the magnetic field generated by the cell tissue 50 output by the control circuit unit 22 and converted into digital data by the A / D conversion unit 32. Or processing according to an output from the operator via the input unit 46 such as a keyboard. In addition, the signal processing unit 38 performs identification, for example, by performing processing such as FFT (Fast Fourier Transform) or IFT (Inverse Fast Fourier Transform) on the information on the change of the magnetic field that is the input signal as necessary. Filtering such as emphasizing or removing frequencies in the range of. For example, the information about the change of the magnetic field is stored in the storage unit 42 such as a memory or a hard disk, or the information about the change of the magnetic field is displayed as a change with time in the display area of the output unit 44 such as a display device. To show.

  The evaluation unit 40 evaluates the structuring of the cell tissue 50 by comparing the information about the magnetic signal obtained by the signal processing unit 38 with respect to the cell tissue 50 to be evaluated, with the magnetic signal about the sample specimen. . This evaluation is performed based on, for example, the similarity between the two. The degree of similarity may be the magnitude of the amplitude, for example, the degree of graphical (geometric) similarity of the waveform in the obtained magnetic signal, or frequency analysis or spectrum analysis of the obtained magnetic signal As a result, the determination is also made based on the presence or absence of a specific frequency component, for example. Here, the magnetic signal for the sample specimen may be information obtained in advance as a magnetic waveform of a specific cell tissue and stored in the storage unit 42. For example, for the cell tissue 50 as an evaluation target, Before or after the detection of the magnetic signal, the sample may be a magnetic signal that has been detected once for an actual cellular tissue or that has been detected multiple times and averaged.

  The principle in this evaluation part 40 is demonstrated using FIG. FIG. 7 is a diagram for explaining an example of cell tissues 50 at a plurality of different degrees of organization and magnetic signals detected for the cell tissues 50. Of the three cell tissues 50 shown in FIG. 7, the one in (a) has the highest degree of organization (structure) (the degree of organization is high), and (b) is organized next to (a). (C) has the lowest degree of organization (low degree of organization). On the other hand, the intensity of the detected magnetic signal has the largest amplitude for (a) in each of the x and y directions shown in FIG. 7, and the magnitude of the amplitude increases in the order of (b) and (c). Is getting smaller. Thus, it can be seen that the magnetic signals detected for the cellular tissues differ depending on the degree of structuring of the cellular tissues, specifically, the magnitude of the amplitude differs in the example of FIG. This is based on the experimental findings of the inventors. Note that the x-axis and y-axis in FIG. 7 do not have to be the same as the x-axis and y-axis in FIG.

  The relationship between the degree of organization of the cellular tissue and the detected magnetic signal is based on the degree of expression of the gap channel structure that drops current in the cellular tissue. That is, in a cell tissue having a high degree of organization, cells constituting the cell tissue are densely arranged, and there are many electrical connections (cell-cell communication) between cells via gap junction channels. On the other hand, in a cell tissue with a low degree of organization, the direction of the cells constituting the cell tissue is not aligned, the cell gap is wide, the area where the cells contact each other is small, and the electrical communication through the gap junction channel is also poor. For this reason, in a cellular tissue having a low degree of organization, conduction of current generated in the cellular tissue is attenuated. Therefore, the magnetic signal generated based on the current is also reduced.

  In addition, since the magnetic signal generated based on the current is in a direction perpendicular to the current, the direction in which the current easily occurs in the cell tissue is evaluated by detecting the magnetic signal in each direction in the cell tissue. be able to. That is, the electrical communication between cells in the cell tissue, in other words, the degree of organization can be evaluated for each direction. These evaluations are information that cannot be obtained by observing the morphology (appearance) of cellular tissue.

Hereinafter, experimental examples using the cell tissue evaluation apparatus 10 of the present example will be described.
(Experimental example 1)
A cecal string smooth muscle cell tissue specimen extracted from the cecum of a guinea pig is placed in the experimental tank 56 as a cell tissue 50 (specimen), and the magnetic sensor heads 18 and 20 are positioned under the cell tissue 50 by operating a manipulator. Thus, the local magnetic fluctuation of the cell tissue 50 was measured. The cecal cord smooth muscle cell tissue specimens used consisted mostly of longitudinal muscles, and the cells are connected by gap junction channel proteins. It is known to work. In addition, the specimen also generates spontaneous electrical activity.

  FIG. 9 is a diagram schematically showing a smooth muscle tissue which is a cell tissue 50 to be evaluated in this experimental example, and FIG. 8A shows an external view thereof. In FIG. 8 (a), an x-axis, a y-axis, and a z-axis are provided for the sake of explanation. Of these, the x-axis direction is the long axis direction of smooth muscle tissue, and the y-axis and z-axis directions are Both correspond to the minor axis direction of the smooth muscle tissue. Note that these x-axis and y-axis do not have to be the same as the x-axis and y-axis in FIGS.

  FIG. 8B is a plan view (for example, a plane parallel to the xy plane) when the smooth muscle tissue of FIG. In FIG. 8B, Rin represents an intracellular resistance which is an electric resistance in each cell constituting the smooth muscle tissue. Rg1 represents the electrical resistance between cells in the long axis direction (intercellular resistance) in smooth muscle tissue, and Rg2 represents the intercellular resistance in the short axis direction. This intercellular resistance corresponds to the ion permeability of the gap junction between cells. Here, since the intracellular resistance Rin is considered to be sufficiently smaller than each of the intercellular resistance Rg1 in the major axis direction and the intercellular resistance Rg2 in the minor axis direction, a current flows in the major axis direction. When an action potential is generated in smooth muscle tissue, not only current flows into and out of the cell, but also current between cells flows in the long axis direction. Therefore, it is considered that a magnetic signal (active magnetic field) is generated by the magnetic flux generated along the current between the cells and between the cells. That is, according to the magnetic signal of the smooth muscle tissue detected in this experimental example, the magnitude of the current between cells, and hence the degree of organization of the cells constituting the smooth muscle tissue can be evaluated.

  FIG. 8C is a cross-sectional view (for example, a plane parallel to the yz plane) when the smooth muscle tissue of FIG. As shown in FIG. 8C, there may be a cell gap 52 between the cells constituting the smooth muscle tissue. In such a case, when the surface of each cell constituting the smooth muscle tissue has a structure that does not allow ions or a solution to pass therethrough, such as a tight junction, the cell gap 52 is applied to the current flowing through the smooth muscle tissue. The current flowing through is included.

  At this time, the first magnetic sensor head 18 is installed approximately 1 mm directly below the cell tissue 50. The second magnetic sensor head 20 is disposed spatially parallel to the first magnetic sensor head 18 at a position 50 mm below the cell tissue 50. As described above, the first magnetic sensor head 18 mainly detects a magnetic signal generated by the cell tissue 50. On the other hand, the second magnetic sensor head 20 mainly monitors the magnetic environment in the laboratory. These magnetic sensor heads 18 and 20 are connected to the control circuit unit 22, and the environmental magnetic field canceling unit 26 of the control circuit unit 22 generates a second signal from the signal detected in the first magnetic sensor head 18 by an operational amplifier differential circuit, for example. By differentiating the signals detected in the magnetic sensor head 20, the magnetic signal generated by the specimen is detected with high sensitivity.

  The temperature of the extracellular fluid in the experimental bath 56 is adjusted to a normal body temperature of about 37 ° C. by controlling the thermostat 68 of the cell tissue maintaining unit 70 and adjusting the temperature of the extracellular fluid supplied to the experimental bath 56. Keeping the environment, when the magnetic sensor heads 18 and 20 are arranged in a direction perpendicular to the long axis direction of the cell tissue 50 as shown in FIG. 5 (a), that is, perpendicular to the fiber long axis in the smooth muscle tissue, As a temporal variation of the magnetic signal (magnetic field) generated by the cell tissue 50, the magnetic signal shown in FIG. 9 was obtained. In FIG. 9, the horizontal axis represents the number of detections (that is, corresponding to the elapsed time when the detection is repeated at regular intervals), and the vertical axis represents the magnetic flux density that is the intensity of the detected magnetic signal.

  The magnetic signal shown in FIG. 9 indicates that the electrical signal generated by the cecal cord smooth muscle cell tissue is a magnetic signal generated by conducting the tissue itself, and the amplitude and power spectrum analysis of this signal As described with reference to FIG. 7, the signal intensity obtained by the above is an indicator that the cells are structurally arranged in the cell tissue 50 and further have an electrical coupling (or conduction direction) structure. Can be used.

  Subsequently, when the magnetic sensor heads 18 and 20 are arranged in parallel with the long axis direction of the cell tissue 50 as shown in FIG. 5B, that is, in parallel with the fiber long axis in the smooth muscle tissue, the cell tissue 50 is generated. The magnetic signal shown in FIG. 10 was obtained as the temporal variation of the magnetic signal (magnetic field). When the magnetic signal shown in FIG. 9 is compared with the magnetic signal shown in FIG. 10, the magnetic signal shown in FIG. 10, that is, the magnetic signal orthogonal to the fiber long axis is the magnetic signal shown in FIG. It turns out that it is bigger than. In practice, the magnetic signal in FIG. 10 contains almost no magnetic signal emitted from the cell tissue, and is close to a state in which only noise is included. Since the direction of the current flowing through the cell tissue and the direction of the generated magnetic field are orthogonal to each other, the magnitude of the current flowing in the fiber major axis direction is larger than the magnitude of the current flowing in the direction perpendicular to the fiber major axis. I understand that. That is, when the magnetic sensor heads 18 and 20 are installed in a direction orthogonal to the current flowing through the cell tissue 50, a magnetic signal mainly generated by the current can be measured. In the present experimental example, detection of a plurality of types of magnetic signals shown in FIGS. 9 to 12 is performed for the same cell tissue 50, but the present invention is not limited to this. That is, each time a magnetic signal is detected, another specimen of the same type that is a cecal string can be used as the cell tissue 50 to be evaluated.

  In a similar experiment, Nifedipine was administered to the experimental tank 56 from the drug supply unit 74 of the stimulation administration unit 76 via the pipette 72, and the magnetic sensor heads 18 and 20 were shown as cells as shown in FIG. The magnetic signal shown in FIG. 11 was obtained as the temporal variation of the magnetic signal (magnetic field) generated by the cell tissue 50 in the direction orthogonal to the fiber long axis of the tissue 50. When the magnetic signal shown in FIG. 11 is compared with the magnetic signal shown in FIG. 9 which is a magnetic signal corresponding to the case where nifedipine is not administered, it can be seen that the intensity of the signal is weak. The magnetic signal in FIG. 11 contains almost no magnetic signal emitted from the cell tissue, and is close to a state containing only noise.

  By the way, the nifedipine is a calcium channel inhibitor that inhibits the inflow of Ca ions involved in smooth muscle contraction into cells. This calcium channel causes a current generated by the cecal cord smooth muscle, which is the cell tissue 50. However, when the nifedipine is administered, the channel between the cells of the cell tissue 50 disappears, and the current between the cells is reduced. It stops flowing. This coincides with the fact that the magnetic signal in FIG. 11 hardly includes magnetic signals emitted from the cell tissue, that is, the current flowing through the cell tissue 50 is almost eliminated.

  FIGS. 14 and 15 show the magnetic signals obtained as in FIGS. 9 and 11 in the above-described experiment, that is, the state in which no stimulation is given to the cell tissue 50 and the case where nifedipine is administered, respectively. Is a diagram in which a frequency portion of 1 Hz to 10 Hz is extracted from a diagram representing a magnetic signal obtained by positioning the magnetic sensor heads 18 and 20 in the same direction as a power spectrum. Such a power spectrum is executed in the evaluation unit 40.

  Regarding the magnetic signal for each of the sample specimen and the cellular tissue 50 to be evaluated, for example, as shown in FIG. 14 and FIG. Based on characteristics such as the presence or absence of frequency components or the identity of the characteristics of changes caused by the application of a stimulus, the structuring of the sample specimen and the cellular tissue 50 to be evaluated can be evaluated. Specifically, as the characteristics of the power spectrum of the sample specimen and the cell tissue 50 to be evaluated are more similar, it is evaluated that the structuring of both is similar.

(Experimental example 2)
In this experimental example 2, as in the above-described experimental example 1, the cecal cord smooth muscle tissue is placed in the experimental tank 56 as the cell tissue 50, and the magnetic sensor heads 18 and 20 are positioned below the cell tissue 50, The temperature of the extracellular fluid in the experimental tank 56 is maintained in a normal body temperature environment of about 37 ° C. Then, an electrical stimulation was applied to a part of the cellular tissue 50 by the electrical stimulation unit 78, and the local magnetic fluctuation of the cellular tissue 50 before and after the electrical stimulation was measured. When the magnetic sensor heads 18 and 20 were arranged in a direction orthogonal to the fiber long axis of the cell tissue 50, the magnetic signal shown in FIG. 12 was obtained. At this time, the pipette 82 is disposed at a position about 5 mm away from the first magnetic sensor head 18.

  In FIG. 12, the peak indicated by the arrow “a” indicates magnetic noise caused by the electrical stimulation provided by the electrical stimulation unit 78. A peak indicated by an arrow b indicates a change (reaction) of a magnetic waveform generated from the cell tissue 50 as a spontaneous current is transmitted through the cell tissue 50 after a given electrical stimulation. Yes.

  As described above, when an electrical stimulus is applied to the cellular tissue 50, a magnetic signal is generated in response to the electrical stimulation. The generated magnetic signal varies depending on the degree of organization of the cellular tissue. Therefore, for example, the time from when an electrical stimulus is applied until the response of the corresponding magnetic signal occurs, the amplitude in the response of the magnetic signal generated with respect to the electrical stimulus of a predetermined voltage, the time when the response occurs In addition to these lengths, or in addition to these, a relationship such as a distance between a part to which an electrical stimulus is applied and a part for detecting a magnetic signal can be used as an index for evaluating the degree of organization of the cell tissue 50.

  FIG. 13 is a flowchart for explaining an example of the control operation of the cell tissue evaluation apparatus 10 in the present embodiment. First, in a step (hereinafter, “step” is omitted) S1 corresponding to the magnetic detection unit 30, the control circuit unit 22, and the like, the magnetic signal of the cell tissue 50 to be evaluated is detected. In this detection, electrical stimulation, stimulation by drug administration, or the like may be performed as necessary.

  In S2 corresponding to the signal analysis unit 38 and the like, the magnetic signal of the cell tissue 50 detected in S1 is analyzed. The analysis of the magnetic signal in this step is an analysis necessary for calculating the similarity performed in S4 described later. Specifically, for example, the calculation of the magnitude of the amplitude, the power spectrum analysis, the magnitude of the amplitude in the reaction based on the stimulus application, and the elapsed time from the stimulus application to the occurrence of the response are performed.

  Subsequent S3 to S5 correspond to the evaluation unit 40. Among these, in S3, the information of the magnetic signal about the sample specimen previously stored in the storage unit 42 or the like is read out. In S4, the magnetic signal of the cell tissue 50 analyzed in S2 is compared with the magnetic signal of the sample specimen read out in S3, and the similarity between the two is calculated. As described above, this similarity may be in various forms such as the geometric similarity of waveforms.

  In subsequent S5, the structuring of the cell tissue 50 is evaluated based on the similarity calculated in S4. In this evaluation, for example, the structural similarity with the sample sample read out in S3 is evaluated numerically.

  Further, after repeatedly performing S3 and S4 for a plurality of sample samples, in S5, by presenting which sample sample has the highest similarity among the plurality of calculated similarities, A mode of evaluating the structuring of the cell tissue 50 is also possible.

  According to the above-described embodiment, the magnetic signal generated from the cell tissue 50 is detected by the magnetic detection unit 30, and the degree of organization of the cell tissue 50 is evaluated by the evaluation unit 38 based on the detected magnetic signal. Cellular tissue structuring or intercellular communication can be assessed non-invasively.

Further, according to the above-described embodiment, the magnetic detection unit 30 is a magnetic impedance sensor that can detect the magnetic signal with a resolution of 1000 μm or less, a noise level of 1 nT or less, and a response speed of 1 ms or less as a magnetic sensor head. Since the sensor heads 18 and 20 are included and the magnetic sensor heads 18 and 20 are close to the cell tissue 50 within 1000 μm, a magnetic signal generated based on the current flowing through the cell tissue 50 can be suitably detected. The structuring of cell tissue 50, or cell-cell communication can be assessed non-invasively. In addition, since equipment for cooling such as a liquid nitrogen container is unnecessary as compared with an apparatus using SQUID, the entire cell tissue evaluation apparatus 10 can be supplied at a low cost and can be made small. .

  Further, according to the above-described embodiment, the magnetic detection unit 30 can detect magnetic signals in different directions with respect to the cell tissue 50, and the evaluation unit 38 can detect the cell tissue 50 based on each of the magnetic signals in the multiple directions. Structuring can be evaluated.

  Further, according to the above-described embodiment, the evaluation unit 38 stores in advance, for example, as shown in FIG. 7 based on the similarity between the magnetic signal for the sample specimen and the magnetic signal obtained from the cell tissue 50 to be evaluated. Since the structuring of the cell tissue 50 is evaluated based on the relationship, the degree of structuring of the two cell tissues can be relatively evaluated.

  Further, according to the above-described embodiment, the evaluation of the structuring of the cell tissue 50 by the evaluation unit 38 is performed based on the power spectrum of the magnetic signal detected by the magnetic detection unit 30. For example, FIG. Based on the characteristics of the magnetic signal in the frequency domain as shown, the structuring of the cellular tissue 50 can be evaluated. Therefore, the structuring of the cell tissue 50 can be evaluated based on features that do not appear when the magnetic signal is analyzed in the time domain.

Further, according to the above-described embodiment, the magnetic detection unit 30 is the magnetic impedance sensor , and the distance d2 between the first magnetic sensor head 18 and the cell tissue 50 rather than the distance d1 between the cell tissue 50 and the first magnetic sensor head 18. The second magnetic sensor head 20 is disposed so as to be longer, and the influence of the environmental magnetic field is determined based on the magnetic signal detected by each of the first magnetic sensor head 18 and the second magnetic sensor head 20. Since the environmental magnetic field canceling unit 26 is further reduced, the environmental magnetic field canceling unit 26 reduces the influence of the environmental magnetic field based on the magnetic signals detected in the first magnetic sensor head 18 and the second magnetic sensor head 20. Therefore, the structuring evaluation of the cell tissue 50 can be performed with higher accuracy.

  Further, according to the above-described embodiment, the cellular tissue evaluation device 10 administers at least one of electrical stimulation, mechanical stimulation, electromagnetic waves, heat, and drugs to the cellular tissue 50. Therefore, a magnetic signal generated in response to a stimulus applied to the cell tissue 50 can be used as an evaluation index for structuring the cell tissue 50.

  Further, according to the above-described embodiment, the cellular tissue evaluation apparatus 10 supplies the cellular tissue 50 with a physiological extracellular fluid having an ionic composition osmotic pressure in a temperature range of 0 to 42 degrees Celsius, Since the cell tissue maintaining unit 70 that maintains the viable state of the tissue 50 is provided, the structuring of the cell tissue 50 or the intercellular communication can be evaluated non-invasively while the cell tissue 50 is maintained in the viable state.

  Subsequently, another embodiment of the present invention will be described. In the following description, portions common to the embodiments are denoted by the same reference numerals and description thereof is omitted.

  The present embodiment relates to the structure of the magnetic sensor heads 18 and 20. In the above-described embodiment, the magnetic sensor heads 18 and 20 have the structure shown in FIG. 3, that is, the columnar amorphous wire 84 and the cylindrical detection coil wound so as to be coaxial with the amorphous wire 84. 86. Then, a predetermined high-frequency alternating current was passed through the amorphous wire 84 and the voltage across the detection coil 86 was detected. However, the magnetic impedance phenomenon is a phenomenon in which the impedance of the amorphous wire 84 itself changes according to the change in the magnetic field around the amorphous wire 84 when a high-frequency alternating current is passed through the amorphous wire 84. That is, if the impedance of the amorphous wire 84 or a value having a one-to-one relationship with the impedance of the amorphous wire 84 can be detected, the intensity of the magnetic field around the amorphous wire 84 can be detected.

  Therefore, in this embodiment, the magnetic sensor heads 18 and 20 have a structure without the detection coil 86. A high-frequency alternating current generated by the sensor driving unit 24 is supplied to the amorphous wire 84, and the voltage across the amorphous wire 84 is detected by the control circuit unit 22. In this way, the signal processing unit 22 can calculate the impedance of the amorphous wire 84 based on the voltage across the detected amorphous wire and the magnitude of the high-frequency alternating current generated by the sensor driving unit 24. it can.

  According to the above-described embodiment, since the magnetic sensor heads 18 and 20 are configured without the detection coil, it is possible to bring the amorphous wire 84 closer to the cell tissue 50 to be detected. In general, since the strength of the magnetic field decreases in proportion to the square of the distance, the detection accuracy of the cell tissue evaluation apparatus 10 can be improved by bringing the magnetic sensor heads 18 and 20 close to the cell tissue 50.

  This embodiment also relates to the structure of the magnetic sensor heads 18 and 20. As shown in the above-described embodiment, the magnetic sensor heads 18 and 20 do not need to have the detection coil 86 if the impedance of the amorphous wire 84 or a value having a one-to-one relationship with the impedance of the amorphous wire 84 can be detected. The intensity of the magnetic field around the amorphous wire 84 can be detected.

  In this embodiment, the magnetic sensor heads 18 and 20 do not have the detection coil 86 as in the second embodiment. On the other hand, in Example 2 described above, the amorphous element included in the magnetic sensor heads 18 and 20 was the columnar amorphous wire 84. However, in this example, a flat or thin film amorphous element 88 is used. It is done. The amorphous element 88 has, for example, a rectangular shape as shown in FIG. 16, and a high frequency alternating current generated by the sensor driving unit 24 is passed through the electrodes provided at the diagonal apexes thereof. The voltage across the amorphous element 88 is detected by the control circuit unit 22. In this way, in the signal processing unit 22, the impedance of the amorphous element 88 can be calculated based on the voltage across the detected amorphous wire and the magnitude of the high-frequency alternating current generated by the sensor driving unit 24. it can. The thin film amorphous element 88 in this embodiment is, for example, a sputtered thin film.

  According to the above-described embodiment, the magnetic sensor heads 18 and 20 have the amorphous element 88 made of a plate-like magnetic body or a thin-film magnetic body, so that the surface area is larger than the amorphous wire 84 of the above-described embodiment, The skin effect when an alternating current is applied can be strengthened. Therefore, it is possible to provide the magnetic sensor heads 18 and 20 having the performance necessary for detecting the magnetic signal. Moreover, it can be made to adjoin to the cell tissue 50 used as a measuring object so that it may become a distance required in order to implement | achieve desired spatial resolution.

  The present embodiment relates to the structure of the magnetic sensor heads 18 and 20 and relates to the structure of the magnetic sensor heads 18 and 20 having higher spatial resolution.

  FIG. 17 is a diagram illustrating the structure of the magnetic sensor heads 18 and 20 in the present embodiment. As shown in FIG. 17, the magnetic sensor heads 18, 20 are fixed to an amorphous wire set 90 </ b> A composed of a plurality of amorphous wires 90 arranged in parallel at equal intervals and the amorphous wire 90 constituting the amorphous wire set 90 </ b> A. A magnetic material having a network structure (lattice structure; matrix structure) is formed by an amorphous wire set 90B including a plurality of amorphous wires 90 arranged in parallel at equal intervals so as to have an angle. In this embodiment, as shown in FIG. 17, the amorphous wires 90 constituting the amorphous wire set 90A and the amorphous wires 90 constituting the amorphous wire set 90B are arranged so as to be orthogonal to each other.

  In the sensor driving unit 24, a high-frequency alternating current is applied to each of the amorphous wire 90A and the amorphous wire 90 constituting the amorphous wire set 90B, and the voltage at both ends of the amorphous wire 90 is detected by the control circuit unit 22. Is done. In this way, the signal processing unit 22 can calculate the impedance of the amorphous wire 84 based on the voltage across the detected amorphous wire and the magnitude of the high-frequency alternating current generated by the sensor driving unit 24. it can. In FIG. 17, only an example of connection between each of the amorphous wires 90 constituting the amorphous wire set 90A and the control circuit unit 22 is shown, and each of the amorphous wires 90 constituting the amorphous wire set 90B and the control circuit are illustrated. A connection example with the unit 22 is omitted.

  In this way, a combination of any one of the amorphous wires 90 constituting the amorphous wire set 90A and any one of the amorphous wires 90 constituting the amorphous wire set 90B allows the above-described magnetic sensor of the network structure to be detected by the intersection of the amorphous wires. Since the positions of the heads 18 and 20 can be specified, the magnetic sensor heads 18 and 20 of the present embodiment have higher spatial resolution. Specifically, for example, when 20 μm amorphous wires are arranged at intervals of 80 μm as shown in FIG. 17, a spatial resolution of 100 μm can be obtained.

  According to the above-described embodiment, the magnetic sensor heads 18 and 20 have a net-like magnetic body, specifically, a magnetic body configured in a matrix by a plurality of amorphous wires 90, and therefore are necessary for detecting a magnetic signal. The magnetic sensor heads 18 and 20 having excellent performance can be provided, and the magnetic sensor heads 18 and 20 can be brought close to the cell tissue to be measured so as to have a distance necessary for realizing a desired spatial resolution.

  As mentioned above, although the Example of this invention was described in detail based on drawing, this invention is applied also in another aspect. For example, it can be implemented by being incorporated in the following application examples.

(Application 1)
FIG. 18 is a diagram for explaining one application example using the cellular tissue evaluation apparatus 10 of the present invention, in which the destruction of the functional structure due to the infarct lesion of the heart is detected. Vector magnetic sensors MVX, MVY, and MVZ installed on the chest surface via the chest wall 110 detect magnetic signals generated by the heart in, for example, three directions orthogonal in three dimensions. In a normal heart, a current flows in the tissue from the bottom to the top of the ventricular myocyte tissue on the surface of the heart, so that a normal magnetic signal corresponding to the current flows. Such normal magnetic signals are acquired in advance and stored in the storage unit 42 of the computer 34 or the like. Then, the signal analysis unit 38 of the computer 34 detects the magnetic signal of the subject's heart to be evaluated, and the evaluation unit 40 compares it with the normal magnetic signal stored in advance. When an infarct site 150 that has become infarcted due to ischemia exists in the subject's heart, in the infarct site 150, intracellular energy is depleted, and the gap junction channel that conducts current between cells closes. For this reason, the current in the tissue at the site does not flow. Therefore, the detected magnetic signal is different from the normal magnetic signal. Thus, it can be evaluated based on the magnetic signal that there is an infarct region 150 having a difference in the degree of structuring of the cellular tissue as compared with a similar region of a normal heart. In this way, an abnormal part of the heart can be detected using the cellular tissue evaluation apparatus 10 of the present invention.

  In the above-described embodiment, each of the magnetic sensor heads 18 and 20 is a sensor capable of detecting a magnetic signal in one direction. When detecting a magnetic signal in a plurality of directions, first, detection in the first direction is performed. After this, the direction of the magnetic sensor heads 18 and 20 was changed using a manipulator (not shown) and the like, and detection in the second direction was performed (see FIGS. 5A and 5B). Not limited to. For example, by using a plurality of magnetic sensor heads as the first magnetic sensor head 18 and the second magnetic sensor head 20, respectively, for example, as shown in FIG. 19, detection of magnetic signals in a plurality of directions may be performed simultaneously. . In FIG. 19, two first magnetic sensor heads 18A and 18B and two second magnetic sensor heads 20A and 20B are provided. In FIG. 19, the first magnetic sensor head 18A and the second magnetic sensor head 20A are both parallel to the x-axis in FIG. 19, and can detect a magnetic signal in the x-axis direction. The first magnetic sensor head 18B and the second magnetic sensor head 20B are both parallel to the y-axis in FIG. 19, and an example is shown in which a magnetic signal in the y-axis direction can be detected.

  In the above-described embodiment, the drug supply unit 74 supplies the drug to the experimental tank 56 via the pipette 72, but the present invention is not limited to such a mode. For example, the drug may be mixed into the physiological extracellular fluid supplied by the cell tissue maintenance unit 70. In this case, the cell tissue maintenance unit 70 also functions as the stimulation administration unit 76.

  In the above-described embodiment, the stimulation administration unit 76 includes the drug supply unit 74 that supplies a drug for acting on the cell tissue 50 and the pipette 72 that drops the drug supplied by the drug supply unit 74 onto the experimental tank 56. It was done. That is, the stimulus given to the cell tissue 50 by the stimulus administration unit 76 is a drug, but is not limited thereto. Specifically, the stimulation given to the cell tissue 50 by the stimulation administration unit 76 may be mechanical stimulation, electromagnetic waves, heat, or the like. In this case, the stimulation administration unit 76 is configured by a device corresponding to each stimulation. Is done. For example, when the stimulus given to the cell tissue 50 by the stimulus administration unit 76 is a mechanical stimulus, the stimulus administration unit 76 may be a vibration device or the like, and when the stimulus given to the cell tissue 50 is an electromagnetic wave. The stimulation administration unit 76 may be an electrode or a magnetic pole. Moreover, when the stimulus given to the cell tissue 50 is heat, the stimulus administration unit 76 may be a cooling device or a heating device capable of locally cooling or heating. Furthermore, instead of the stimulation administration by the stimulation administration unit 76, gene introduction may be performed on the cells constituting the cell tissue 50 to be detected. For this purpose, the strength of the magnetic field generated by the cell tissue 50 by introducing into the cell a gene of a protein that generates an electric current, such as an ion channel, or a gene that has an action of controlling such a protein. By detecting the change, the effect of the gene introduction can be detected.

  In the above-described embodiment, when an electrical stimulus is applied to the cellular tissue 50, the degree of organization of the cellular tissue 50 is evaluated based on a change in a magnetic signal generated due to the electrical stimulation. However, the present invention is not limited to this. That is, when the magnetic signal changes (reacts) from the cell tissue 50 based on the stimulus given from the stimulus administration unit 76, the change of the magnetic signal differs depending on the degree of organization of the cell tissue 50. In some cases, it can be the basis for evaluation as well. For example, the stimulation given by the drug administered by the stimulation administration unit 76 may be combined, or a coil (not shown) is provided as the stimulation administration unit 76, and local magnetic stimulation is applied to the cell tissue 50 by the coil. You may do it.

  In the above-described embodiment, the electrode 81 of the electrical stimulation unit 78 is inserted into the pipette 82 provided for electrical stimulation, and the electrode 81 is brought into contact with an arbitrary position of the cell tissue 50. However, the present invention is not limited to such a mode. That is, electrical stimulation may be applied to the cell tissue 50 by directly contacting the electrode 81 with the cell tissue 50.

  In the above-described embodiment, the experimental tank 56 in the cell tissue evaluation apparatus 10 is configured such that a cell tissue is installed. However, the present invention is not limited to this, and for example, a cell tissue culture container can be used as it is. Is also possible. In this way, it is possible to detect a magnetic signal using a cell tissue in the middle of culture as a detection target.

  Moreover, in the above-mentioned Example, although the container 16 was used for heat retention, the use of the container 16 is not restricted to this. Specifically, for example, an environment control unit for controlling the environment in the container can be provided, and not only the temperature in the container 16 but also the air configuration such as humidity and carbon dioxide concentration can be changed. In this manner, when the cell tissue culture vessel is used as the experimental tank 56 as described above, when the cell tissue culture conditions are varied, the local magnetic field of the cell tissue is maintained in the long-term culture process. Variations can be detected.

  Moreover, in the above-mentioned Example, although the magnetic sensor heads 18 and 20 were installed through the cover glass 57 under the experimental tank 56, it is not restricted to such an aspect. For example, it is also possible to cover the magnetic sensor heads 18 and 20 with a thin film having a thickness of 100 μm or less and bring the magnetic sensor head 18 and 20 close to the cell tissue 50 from above the experimental tank 56 to measure the local magnetic change of the cell tissue 50.

  In the above-described embodiment, the ultrasensitive MI magnetic sensor is used as the magnetic sensor heads 18 and 20, but is not limited thereto. That is, when approaching the cellular tissue 50 to be detected within 1000 μm, based on the output signal from the magnetic sensor head, the magnetic field with a resolution of 1000 μm or less, a noise level of 1 nT or less, and a response speed of 1 ms or less. The magnetic sensor head is not limited to the MI sensor as long as it can detect a signal.

  In the above-described embodiment, the environmental magnetic field canceling unit 26 and the magnetic signal detecting unit 28 for processing signals detected by the magnetic sensor heads 18 and 20 are provided in the control circuit unit 22 configured by an analog circuit. The signal processed in the control circuit unit 22 is converted into digital data by the A / D conversion unit 32 and taken into the computer 34. However, the present invention is not limited to this mode. For example, after the signals detected by the magnetic sensor heads 18 and 20 are converted into digital data by the A / D converter 32, the same processing may be performed. In this case, the environmental magnetic field canceling unit 26 and the magnetic signal detecting unit 28 are realized as digital circuits realized by, for example, a computer.

  Moreover, in the above-mentioned Example, although the experiment tank 56 was made into the rectangular parallelepiped thing, it is not restricted to this, For example, a cylindrical thing may be sufficient and another shape may be sufficient.

  In the above-described embodiment, the distance d1 between the first magnetic sensor head 18 and the cell tissue 50 is set to be about 1000 μm (see FIG. 4), but is not limited to such a mode. That is, it is desirable that the first magnetic sensor head 18 and the cell tissue 50 be placed closer to each other in order to detect magnetic signals in a systematic manner. For example, the detection coil of the first magnetic sensor head 18 in FIG. The first magnetic sensor head 18 may be installed such that the upper end of 86 and the lower surface of the cover glass 57 are closer to each other.

  Moreover, in the above-mentioned Example, the cell tissue 50 evaluated by the cell tissue evaluation apparatus 10 of this invention does not prevent that it is a cell tissue in culture. That is, this is because the cellular tissue evaluation apparatus 10 of the present invention performs noninvasive evaluation while maintaining the survival state of the cellular tissue 50. In this way, it becomes possible to evaluate the cell tissue in the middle of the culture, and it is possible to appropriately induce the cell tissue based on the evaluation result in the transfer culture.

  In the above-described embodiment, the power spectrum analysis is used as the analysis result in the frequency domain of the magnetic signal detected by the magnetic detection unit 30. However, the present invention is not limited to this. For example, analysis using a linear spectrum, autocorrelation spectrum, cross-correlation spectrum, spectrum of real and imaginary parts in Fourier transform, bispectrum, or the like, or spectrum analysis using the maximum entropy method may be used. That is, the method is not limited as long as the method can analyze temporal fluctuations of the magnetic signal in the frequency domain.

  In addition, although not listed one by one, the present invention can be implemented in a mode with various changes, modifications, improvements, and the like based on the knowledge of those skilled in the art. It goes without saying that all are included in the scope of the present invention without departing from the spirit of the present invention.

10: Cell tissue evaluation device 18: First magnetic sensor head ( magnetic impedance sensor )
20: Second magnetic sensor head ( magnetic impedance sensor )
26: Environmental magnetic field canceling unit 30: Magnetic detection unit 38: Evaluation unit 50: Cell tissue 70: Cell tissue maintenance unit 76: Stimulation administration unit 78: Electrical stimulation unit (stimulation administration unit)

Claims (7)

A cell tissue evaluation apparatus for evaluating the structure of a cell tissue composed of a large number of cells,
A magnetic detection unit for detecting a magnetic signal generated from the cellular tissue;
An evaluation unit that evaluates the degree of structuring of the cellular tissue based on a magnetic signal detected by the magnetic detection unit;
The magnetic detection unit has a magnetic impedance sensor capable of detecting the magnetic signal with a resolution of 1000 μm or less and a noise level of 1 nT or less as a magnetic sensor head,
Said magnetic impedance sensor Ri proximity allows der within 1000μm from the tissue,
The degree of structuring of the cellular tissue is a degree of electrical communication between cells in the cellular tissue that changes according to the degree of expression of the gap channel structure in the cellular tissue;
An apparatus for evaluating cellular tissue. The magnetic detection unit is capable of detecting magnetic signals in different directions for the cellular tissue,
The evaluation unit evaluates the structuring of the cellular tissue based on each of the magnetic signals in the plurality of directions;
The cellular tissue evaluation apparatus according to claim 1 . The evaluation unit evaluates the structuring of the cellular tissue based on the similarity between the magnetic signal about the sample specimen and the magnetic signal obtained from the cellular tissue to be evaluated, from a previously stored relationship;
The cell tissue evaluation apparatus according to claim 1 or 2 . The evaluation unit evaluates the structuring of the cellular tissue based on an analysis result in a frequency domain of a magnetic signal detected by the magnetic detection unit;
The cell tissue evaluation apparatus according to claim 1 or 2 . As the magnetic impedance sensor, a first magnetic sensor head, a second magnetic sensor head disposed so that a distance between the cellular tissue and the first magnetic sensor head is longer than a distance between the cellular tissue and the first magnetic sensor head; Have
An environmental magnetic field canceling unit that reduces the influence of the environmental magnetic field based on magnetic signals detected by each of the first magnetic sensor head and the second magnetic sensor head;
The cellular tissue evaluation apparatus according to any one of claims 1 to 3 . Having a stimulation administration unit for administering at least one of electrical stimulation, mechanical stimulation, electromagnetic waves, heat, and drugs to the cellular tissue;
The cellular tissue evaluation apparatus according to any one of claims 1 to 4 , wherein: Having a cell tissue maintenance unit for supplying a physiological extracellular fluid having an ionic composition osmotic pressure to the cell tissue in a temperature range of 0 ° C. to 42 ° C. and maintaining the viability of the cell tissue;
The cellular tissue evaluation apparatus according to any one of claims 1 to 5 .

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