JP2020151410A - Intravital electrical conduction path evaluation apparatus - Google Patents

Abstract

To provide a conduction path evaluation apparatus capable of evaluating a conduction state of an intervention current in the body of a subject 8.SOLUTION: A conduction path evaluation apparatus 10 includes: an electrical intervention unit 32 that applies an intervention current into the living body of a subject 8; a magnetic sensor device 20 that detects, in the outside of the subject 8, a change in the magnetic field when the intervention current is applied by the electrical intervention unit 32; a magnetic sensor drive unit 32 that drives the magnetic sensor device 20; a signal detection unit 34; a magnetic field strength calculation unit 38; and a depth evaluation unit 40 that evaluates a conduction state in the subject 8 on the basis of information about the magnetic field detected by the magnetic field strength calculation unit 38.SELECTED DRAWING: Figure 1

Description

The present invention relates to an apparatus for evaluating an electrical conduction path in a living body.

The electrical excitement of the heart is measured not only on the chest surface but also on the extremities and used as an electrocardiogram. Cranial nerve activity is also measured as an electroencephalogram on the surface of the scalp. Such facts support the existence of various electrical conduction paths in the living body.

However, in electrocardiogram and electroencephalogram examination, the measurement result is actually affected not only by the change / disorder of the electric excitement source such as the heart and the brain but also by the change of the electric conduction path in the middle. It is considered. Further, it is described in Non-Patent Document 1 that the electrical resistance inside the living body fluctuates due to physiological changes, pain, psychological stress, and the like.

On the other hand, in oriental medicine and alternative medicine, there is a so-called acupuncture point as a part that gives a great therapeutic effect. This acupuncture point was found from empirical knowledge derived from Chinese medicine, but its effect is now recognized worldwide. Furthermore, according to electrophysiological experiments conducted in Japan in the 1950s and 1960s, the site called acupuncture points is a highly conductive site on the surface of the skin, and an electrical conduction path connecting multiple acupuncture points. Has been found to exist. A conduction path connecting a plurality of acupuncture points is called a "meridian" (Non-Patent Document 2).

Patent Document 1 discloses a device that measures the resistance between two points by installing electrodes at two points on the skin surface and energizing them, and estimates the position of acupuncture points. On the other hand, regarding the meridians, which are conduction paths connecting a plurality of acupuncture points, the substance such as the distribution in the living body, physiological changes, and the influence of pathological conditions cannot be grasped.

JP 2006-296809

Eiichiro Nonami: Journal of the Japanese Society of Dermatology, 68 (6), 357-379, 1958. Yoshio Nakatani: Clinical Practice of the Latest Ryodoukan, 166pp., Ryodouken Kenkyusho, Tokyo, 1960 Nakayama, S.A. , Uchiyama, T.I. Real-time measurement of biomagnetic vector fields in infunctional syncytium using amorphous mortal. Scientific Reports 5, 8837. (2015)

As described above, since the meridian is an electrical conduction path that connects a plurality of acupuncture points, it is considered that there is a portion in the body where a relatively easy current flows along the meridian. However, even if a current is applied between the two acupuncture points, it is difficult to determine which part of the living body, in other words, how deep the current flows. Therefore, even when a relatively large amount of current flows, it cannot be determined whether or not it has flowed through a conduction path corresponding to a meridian between acupuncture points.

The current circuit is closed in the living body in the electric activity generated by the living body. For example, an inward current in the cell membrane generated in a certain electrically excitable cell flows through the cell membrane and acts as a battery. When the current is conducted inside the cell and then connected to the adjacent cell by an electrical binding channel, the current flows into the cell membrane of the adjacent cell, and the cell membrane works in the same manner as the electric capacity (capacitor). In this way, a closed circuit is formed by the battery and the electric capacity, and the size of the closed circuit is considered to be at a level similar to that of a cell (in other words, on the order and scale similar to the size of a cell). Therefore, even if the cell conducts a large current inside the cell, the return current of the same magnitude flows outside the cell, so that the magnetic fields in which the two currents are generated in opposite directions cancel each other out. Therefore, in particular, when the distance from the cell that is the source increases, the magnetic field generated by the living cell itself is significantly attenuated. (Non-Patent Document 3)

The present invention has been made based on such findings, and an object of the present invention is to evaluate at which position in a living body the current flows by analyzing the current when a current is applied to the living body. The purpose is to provide a device that can be used.

The features of the first invention for achieving such an object are (a) a conduction path evaluation device for evaluating the current conduction state due to electrical intervention from the outside into the living body, and (b) the living body. An electrical intervention unit that applies the electrical intervention, and (c) a detection unit that detects a magnetic field change that occurs when an electrical intervention is applied by the electrical intervention unit outside the living body, and (d). ) It is characterized by having an evaluation unit that evaluates the conduction state in the living body based on the information about the magnetic field detected by the detection unit.

According to the first invention, the electrical intervention unit applies electrical intervention to the living body from outside the living body, and the detection unit detects a change in the magnetic field generated when the electrical intervention is applied outside the living body. Then, the conduction state in the living body is evaluated based on the information about the detected magnetic field by the evaluation unit. Therefore, the conduction state of the current evoked in the living body by electrical intervention is preferably evaluated. Can be done.

In the first invention, the electrical intervention (intervention current) is conducted unidirectionally because it energizes the living body from the outside of the living body, and the living cell itself does not generate an excitatory current under the energization condition under the threshold, or after being excited once. If it is a refractory period to electrical intervention immediately after, it returns to the inside of the living body and has no current path. Therefore, the magnetic field generated when an electric current is conducted through an electric conduction path inside a living body can be efficiently measured even by a magnetic detection device existing at a distance from the source.

Preferably, the electrical intervention performed by the electrical intervention unit is the application of a current having a rectangular waveform. In this way, it is possible to apply electrical intervention by the rectangular waveform, for example, rising and falling currents, DC components, and their repetition.

Further, preferably, the evaluation unit evaluates a position in the living body where the electrical intervention is energized. By doing so, it is possible to evaluate the position where the electrical intervention is energized by detecting the magnetic field change different depending on the position where the electrical intervention is energized in the detection unit. , It is possible to evaluate at what route or depth the electrical intervention was conducted in vivo.

Further, preferably, the evaluation unit evaluates the conduction state based on the information about the magnetic field detected by the detection unit at two or more positions. In this way, the conduction state of the electrical intervention in the living body can be evaluated by detecting the change in the magnetic field, which differs depending on the conduction state of the electrical intervention, at two or more positions by the detection unit.

Also preferably, the electrical intervention propagates through the plurality of pathways in the living body, and the evaluation unit evaluates the position corresponding to the plurality of pathways. In this way, even when the electrical intervention propagates through a plurality of paths, the conduction path can be evaluated.

Further, preferably, the application of the electrical intervention by the electrical intervention unit and the detection of the magnetic field by the detection unit are executed in synchronization with each other. In this way, the change in the magnetic field outside the living body caused by the electrical intervention can be appropriately detected.

Also preferably, the stimulator applies electrical intervention to a position corresponding to the meridian of the living body. In this way, it is possible to evaluate the conduction path that transmits electrical intervention between the meridians.

Also preferably, the electrical intervention applied by the electrical intervention section flows unidirectionally through a pathway in the body and is not accompanied by a return current at the cellular level. Specifically, in order to energize the living body from outside the living body, the electrical intervention is unidirectionally conducted, and the energizing condition is below the threshold value at which the living cells themselves do not generate an excitatory current, or the applied current immediately after being excited once. If it is in the refractory period, it does not have a current path back to the inside of the living body. In this way, the magnetic field generated when electrical intervention is conducted inside the living body can be efficiently measured even by a magnetic detection device existing at a distance from the source.

It is a figure explaining the outline of the structure of the conduction path evaluation apparatus which is one Example of this invention. It is a figure explaining the structure of the sensor device in the conduction path evaluation device of FIG. 1, and the positional relationship between the sensor device and the conduction path. It is a functional block diagram explaining the outline of the control function which an electronic control unit has in the conduction path evaluation apparatus of FIG. It is a figure which showed the time change of the intervention current applied to the subject by the power supply circuit, and the output signal in one of the magnetic sensors in the conduction path evaluation apparatus of FIG. It is a figure which showed typically the conduction path in a living body. It is a figure which showed the relationship between the distance from the skin surface of the subject 8 to the magnetic sensor, and the magnetic field strength. It is a figure for demonstrating the process which the depth evaluation part evaluates the depth of a conduction path, and is the figure which expands and explains a part of the relationship between the distance from the conduction path and the magnetic field strength shown in FIG. .. It is a flowchart explaining the outline of the control operation of the conduction path evaluation apparatus of this invention.

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 conduction path evaluation device 10 which is an embodiment of the present invention. The conduction path evaluation device 10 includes electrodes 18a and 18b (hereinafter, simply referred to as “electrodes 18” when the two are not distinguished) and the pair of electrodes 18 of the subject 8 that give electrical intervention to the skin of the subject 8. Evaluation of the conduction path is performed based on the signal detected by the magnetic sensor device 20 that detects the change in the magnetic field in the vicinity of the provided portion, the power supply circuit 14 that generates a current applied to the subject 8 via the electrode 18, and the magnetic sensor 20. A display for displaying information regarding the operation of the electronic control device 12 and the conduction path evaluation device 10 which are configured to realize the functions of the evaluation unit 18 and the like and include a computer and the like for driving the power supply circuit 14. It is configured to include the device 16 and the like.

As the electrode 18, for example, a so-called gel electrode having an electrically conductive gel material on its surface is used. Due to the viscosity of the gel material, the electrode 22 is attached to the skin surface of the subject 8. In this embodiment, the two electrodes 18a and 18b are attached, for example, to two known adjacent acupuncture points, so-called pot positions.

The magnetic sensor device 20 is arranged near the skin surface of the subject 8 between the pair of electrodes 18. When an electrical intervention is applied from the power supply circuit 14 described later between the pair of electrodes 18 provided at the positions of the two acupuncture points, the electrical intervention makes the conduction path in the body of the subject 8 a unidirectional current. It will flow. The magnetic sensor device 20 detects a magnetic field change caused by a current flowing through the conduction path, and the specifications of the magnetic sensor device 20, that is, sensitivity, resolution, timing with current application, etc., detect the magnetic field change. Is selected to the extent that

Further, the magnetic sensor device 20 includes a plurality of magnetic sensors on the same surface. When the magnetic sensor device 20 is attached to the skin surface of the subject 8, these plurality of magnetic sensors have a plurality of positions in a direction substantially parallel to the skin surface and a plurality of positions having different distances from the skin surface. It is arranged so as to be (that is, a plurality of positions in a direction substantially perpendicular to the skin surface), and the magnetic field strength can be measured at the plurality of positions at the same time. In this embodiment, as shown in FIG. 2, the magnetic sensor device 20 includes nine magnetic sensors S11, S12, S13, S21, S22, S23, S31, S32, and S33 on the same surface. Has been done. Three sensors S11, S21, and S31 are located at a position where the distance from the skin surface is ds1 (mm), and three sensors S12, S22, and S32 are located at a position where the distance from the skin surface is ds2 (mm). However, three sensors S13, S23, and S33 are provided at positions where the distance from the skin surface is ds3 (mm). Further, the three sensors S11, S12, and S13, the three sensors S21, S22, and S23, and the three sensors S31, S32, and S33 each have a distance of ds1 from the skin surface on a straight line perpendicular to the skin surface. They are arranged in a grid pattern so as to be ds2 and ds3 (mm).

When the magnetic sensor device 20 is attached to the skin surface of the subject 8, the surface on which the sensors S11 to S33 are arranged is a conduction path to be evaluated, in other words, a straight line connecting the pair of electrodes 18. It is arranged so that it is perpendicular to. As a result, the magnetic field generated by the current flowing through the conduction path based on Ampere's law can be simultaneously measured by the plurality of sensors S11 to S33, and the conduction path can be evaluated more accurately. In order to hold the measurement position, the magnetic sensor device 20 may be attached and fixed to the skin surface at the measurement site of the subject 8, or may be held by using a clamp device (not shown) or the like.

Here, among the plurality of sensors S11 to S33, the sensors S21, S22, and S23 whose measured values are used by the depth evaluation unit 40 described later are preferably true of the conduction paths 50a, 50b, and 50c as shown in FIG. Although it is positioned so as to be on the top, when the position and orientation of the magnetic sensor device 20 are determined in this way, the sensors S11 and S31 adjacent to the sensor S21, and the sensors S12 and S32 adjacent to the sensor S22 Or, it is performed based on the fact that the outputs of the pair of sensors of the sensor S13 and the sensor S33 adjacent to the sensor S23 are substantially equal. This is because the distances between the sensors S11 and S31, the sensors S12 and S32, or the sensors S13 and S33 and the conduction paths 50a, 50b, and 50c are substantially equal.

Further, the magnetic sensor device 20 includes a magnetic sensor SR for reference in addition to the plurality of magnetic sensors S11 to S33 described above. This magnetic sensor SR is for forming a differential magnetic sensor with each of the above-mentioned sensors S11 to S33. The reference magnetic sensor SR is provided at a position where an environmental magnetic field such as geomagnetism is applied in common with the above-mentioned magnetic sensors S11 to S33, but is not affected by the magnetic field caused by the current flowing through the conduction path. By differentiating the sensors S11 to S33 arranged in this way from the reference magnetic sensor SR, the influence of the environmental magnetic field can be removed from the detected values of the sensors S11 to S33, and the resolution as a sensor is improved. ..

Further, since the magnetic sensor device 20 is arranged in contact with or close to the skin surface of the subject 8, it is preferable that the magnetic sensors S11 to S33 are non-invasive to the subject 8 and operate at room temperature. .. For example, an MI sensor (magnetic impedance sensor), which is compact and capable of measuring a minute magnetic field such as a nanotesla (nT) unit, and an IPA sensor can be mentioned. These magnetic sensors utilize so-called amorphous wires and similar metal structures thereof.

Returning to FIG. 1, the power supply circuit 14 corresponds to an electrical intervention unit, is connected to the above-mentioned electrode 18 by a conducting wire, and applies an electrical intervention, that is, a current (intervention current) to the subject 8 from the outside. It is a thing. The energization of this electrical intervention is a pulsed (intermittent) direct current having a preset size and time interval, and a constant current power supply or a constant voltage power supply is appropriately used for the power supply circuit 14.

The electronic control device 14 includes a so-called microcomputer including a CPU, a ROM, a RAM, an input / output interface, and the like, and performs signal processing according to a program stored in advance in the ROM while using the temporary storage function of the RAM. By doing so, the power supply circuit 14 is controlled to generate an electrical intervention having a predetermined waveform, or an operation such as an evaluation of a conduction path described later is performed based on an output signal from the magnetic sensor device 20 is executed.

The display device 16 displays information on the operation of the conduction path evaluation device 10 based on the output from the electronic control device 14, specifically, information on the evaluation result of the conduction path in the depth evaluation unit 40, which will be described later, in characters or figures. Display by etc. As the display device 16, a known liquid crystal display or the like is used.

FIG. 3 is a functional block diagram illustrating an outline of the control function of the electronic control unit 14. The electronic control device 14 functionally includes a timer 30, an electrical intervention unit 32, a magnetic sensor drive unit 34, a signal detection unit 36, a magnetic field strength calculation unit 38, a depth evaluation unit 40, a storage unit 42, and the like.

The timer 30 supplies a time signal necessary for the electrical intervention unit 32, the magnetic sensor drive unit 34, the signal detection unit 36, and the like, which will be described later, to operate in synchronization with each other.

The electrical intervention unit 32 generates a current (hereinafter, also referred to as intervention current) which is a predetermined electrical intervention by driving the power supply circuit 14. In other words, the electrical intervention unit 32 and the power supply circuit 14 constitute the electrical intervention unit of the present invention. Specifically, for example, a pulsed current having a constant magnitude is repeatedly generated in the power supply circuit 14. This current is applied to the subject 8 through the electrode 18, and flows through the conduction path in the body of the subject 8. In this pulsed current, the magnitude of the pulse width is set so that the magnetic sensor device 20 can detect the magnetic field generated by the current flowing through the conduction path. The electrical intervention unit 32 and the power supply circuit 14 described above correspond to the electrical intervention unit of the present invention. Here, the magnitude of the pulse is determined as follows. That is, the intervention current flows through the electrode 18 through the excitatory cells located in or near the conduction path, but the magnitude of the pulse of the intervention current is such that the excitable cells do not become excited. Is set. In other words, the maximum magnitude of the intervention current that does not cause the excitatory cell to become excited by the current flowing through the excitatory cell is set as a threshold value, and the magnitude of the intervention current is set to a magnitude equal to or less than the threshold value. When an excitatory cell is in an excited state, charge is transferred to and from the excitable cell inside and outside the cell and to and from an adjacent cell. For example, in the saltatory conduction of nerve axons, ion channels open transiently at the site of excitement and play the same role as a battery. At this time, a current flows inside the cell, and a current paired with the current flows outside the cell in the opposite direction. This produces a return current at the cellular level, in other words a looped current. When a return current is generated, the intervention current does not flow unidirectionally in the living body. Therefore, an intervention current is set so that the excitable cells do not become excited. The above-mentioned threshold value is obtained in advance by an experiment or the like.

The magnetic sensor driving unit 34 controls to drive the magnetic sensors S11 to S33 constituting the magnetic sensor device 20. For example, the supply of power for driving the magnetic sensors S11 to S33, control signals for detection start and end, and the like are generated. For example, when the MI sensor is used for the magnetic sensors S11 to S33, the drive current applied to the amorphous wire in the MI sensor is supplied. Further, the magnetic sensor driving unit 34 can be made to detect the magnetic field by the magnetic sensor device 20 as the electrical stimulation is applied by the electrical intervention unit 32.

The signal detection unit 36 receives the output signals of the magnetic sensors S11 to S33 constituting the magnetic sensor device 20 and performs appropriate processing. Specifically, a preamplifier or the like performs predetermined amplification, and a sample hold circuit is used to perform sampling processing and AD conversion at predetermined intervals. At this time, the sample hold circuit performs processing with reference to the time signal from the timer 30. At this time, the signal detection unit 36 may always process the signal, and in synchronization with the application of the electrical intervention by the electrical intervention unit 32, for example, the application is performed immediately before or after the application is completed. The signal processing may be repeated only until a predetermined time elapses when the change in the magnetic field due to the above is completed. This signal detection unit 36 corresponds to the detection unit of the present invention.

Further, when the signal detection unit 36 differentials each of the magnetic sensors S11 to S33 from the differential sensor SR, the signal detection unit 36 uses a differential amplifier or the like to display the outputs of the magnetic sensors S11 to S33 and the differential sensor SR. After generating a difference from the output, the above-mentioned amplification or AD conversion is performed on the difference.

FIG. 4 shows the time change of the intervention current applied to the subject 8 by the power supply circuit 14 and the output signal in one of the magnetic sensors S11 to S33 so as to be comparable with each other on a common time axis (horizontal axis). Is. The intervention current is applied in a rectangular pulse from time t1 to t2. The interval between the times t1 and t2, that is, the magnitude of the pulse width, the pulse duration, the pulse amplitude, and the like can be changed as appropriate. On the other hand, the output signal of the magnetic sensor rises sharply at the time t1 when the intervention current rises, and then converges to a steady value corresponding to the value of the intervention current. Further, after the intervention current suddenly becomes a negative value at the time t2 when the intervention current falls (turns off), it converges toward zero. Here, the length of the pulse width of the intervention current (duration of the current) is set to be longer than the time for the output signal of the magnetic sensor to converge.

Returning to FIG. 2, the magnetic field strength calculation unit 38 calculates the magnetic field strength at the position where the magnetic sensors S11 to S33 are arranged, based on the outputs of the magnetic sensors S11 to S33 obtained by the signal detection unit 36. calculate. The calculation of the magnetic field strength by the magnetic field strength calculation unit 38 is executed based on the relationship between the output value of the magnetic sensor and the magnetic field strength stored in the storage unit 42 or the like in advance as a map or a relational expression.

The depth evaluation unit 40 evaluates the conduction path to which the electrical intervention is applied based on the magnetic field strength at the position where the magnetic sensors S11 to S33 are arranged, which is calculated by the magnetic field strength calculation unit 38. The evaluation of this conduction path relates to the position of the conduction path, that is, the depth from the skin surface. The depth evaluation unit 40 and the like correspond to the evaluation unit of the present invention. Hereinafter, the evaluation operation of the conduction path by the depth evaluation unit 40 will be described.

FIG. 5 is a diagram schematically showing a conduction path in a living body, which was created by the inventors of the present application. As described above, it is considered that there may be an electric conduction path through which a current can flow between the pair of electrodes 18a and 18b, but the depth and electrical characteristics (for example, resistance value and resistance value) are considered. It is difficult to directly grasp the capacitor component). For example, as illustrated in FIG. 5, it is considered that at least one of the three conduction paths 50a, 50b, and 50c exists between the pair of electrodes 18a and 18b. These three conduction paths 50a, 50b, and 50c are arranged in the order of 50a, 50b, and 50c in the order closer to the skin surface, and are located at different depths. Among them, the conduction paths 50a and 50b each have R1 and R2 (Ω) as resistors and C1 and C2 (F) as capacitor components, respectively, and the conduction path 50c has only the resistance component R3. However, it does not have a capacitor component. According to the study by the present inventors, the resistance value in each electric path increases as the depth from the skin surface increases, that is, R1 <R2 <R3, and the capacitance of the capacitor component is the depth from the skin surface. The deeper the value, the smaller the value, that is, C1> C2.

FIG. 6 shows the distance ds (m) and the magnetic field strength M (T) from the skin surface of the subject 8 to the magnetic sensor when a predetermined current flows through the conduction path and the magnetic field caused by the current is measured by the magnetic sensor. ) Is shown in the figure. This relationship is obtained, for example, experimentally or by simulation in advance, and is stored in the storage unit 42, and is appropriately read out and used. The magnetic field strength M is the strength of the magnetic field generated due to the flow of a predetermined current through the conduction path 50. As shown in FIG. 6, in general, the magnetic field strength M tends to decrease as the distance ds increases.

Further, in FIG. 6, three curves are shown as the relations La to Lc. The relationships La to Lc correspond to conduction paths 50a to 50c at three different depths. In FIG. 6, the horizontal axis is the distance ds from the skin surface to the magnetic sensor. Since the magnetic field generated by the current flowing through the conduction path propagates in the living body of the subject 8 and then propagates in the atmosphere from the skin surface and is detected by the magnetic sensor, the actual propagation distance D of the magnetic field is different. It is the sum of the depths d1 to d3 of the conduction paths 50a to 50c from the skin surface and the distance ds from the skin surface of the magnetic sensor for measuring the magnetic field strength. Specifically, showing using the example of FIG. 2, when the magnetic field strength due to the current flowing through the conduction path 50a is measured by the sensor s23, the distance D is the depth d1 from the skin surface of the conduction path 50a and the magnetic sensor s23. It is the sum of the distance from the skin surface ds3 (that is, D = d1 + ds3). It should be noted that the inside of the living body 8 and the atmosphere in which the sensor devices 20 (sensors 11 to s33) are provided can usually be regarded as having substantially the same magnetic permeability. Further, as shown in FIG. 5, the conduction paths 50a and 50b contain capacitor components C1 and C2, respectively, and when a direct current is applied to the conduction paths 50a and 50b, they are contained in the capacitor components C1 and C2. It is conceivable that no more current will flow when the electrification is accumulated up to the capacitance of, but the relationship shown in FIG. 6 is that each conduction path 50a and before being affected by the charging state of the capacitor components C1 and C2. It is about the current flowing through 50b.

Specifically, the depth evaluation unit 40 uses the magnetic field strengths of a plurality of sensors having different distances from the conduction path 50x among the magnetic field strengths at the points S11 to S33 calculated by the magnetic field strength calculation unit 38. , Evaluate the depth of the conduction path 50x. In the following, the conduction path 50x refers to at least one conduction path in which the applied intervention current actually flows among the above-mentioned conduction paths 50a to 50c.

In this embodiment, as shown in FIG. 2, the position and orientation of the magnetic sensor 20 are determined so that the conduction path 50x is perpendicular to the sensor surface 21 provided with the sensors S11 to S33 of the magnetic sensor device 20. Will be done. This is magnetic, assuming that the conduction paths 50a to 50c are on a straight line connecting the pair of meridians when the pair of electrodes 18a and 18b are attached at positions corresponding to the adjacent meridians of the subject 8. The sensor surface 21 of the sensor device 20 is arranged so as to be perpendicular to a pair of meridians, that is, a straight line (line segment) connecting the pair of electrodes 18a and 18b, and also perpendicular to the skin surface.

When arranged in this way, as shown in FIG. 2, the sensors S21, S22, and S23 in the magnetic sensor device 20 are located directly above the conduction paths 50a to 50c. When the magnetic field strengths of the sensors S21, S22, and S23 measured by the magnetic field strength calculation unit 38 are obtained, the depth evaluation unit 40 determines the measured magnetic field strength values and the distance from the conduction path stored in advance. The depth of the conduction path is evaluated based on the relationship between D and the magnetic field strength M.

FIG. 7 is a diagram for explaining a process in which the depth evaluation unit 40 evaluates the depth of the conduction path, and a part of the relationship between the distance ds from the conduction path and the magnetic field strength M shown in FIG. 6 is enlarged. It is a figure to explain. In FIG. 7, as an example, two relations La corresponding to the conduction path 50a and the relation Lb corresponding to the conduction path 50b are described. When the magnetic field strengths of the sensors S21, S22, and S23 measured by the magnetic field strength calculation unit 38 are obtained as M1, M2, and M3 (T), respectively, the depth evaluation unit 40 determines the conduction path 50x through which the current actually flows. The distance between each sensor and the conduction path 50x is calculated from the relationships La and Lb shown in FIG. 7 for each of the conduction paths 50a and 50b.

When the magnetic field strengths detected by the sensors S21, S22, and S23 are M1, M2, and M3 (T), respectively, the distance between the conduction path 50a and each of the sensors S21, S22, and S23 according to the relationship La in FIG. However, according to the relationship Lb, the distances between the conduction path 50a and the sensors S21, S22, and S23 are D1b, D2b, and D3b, respectively. Here, when the sensor device 20 is arranged so that the sensors S21, S22, and S23 are on the same straight line as the conduction path 50x through which the current actually flows as shown in FIG. 2, from the conduction path 50x to the sensor S21. The difference D2-D1 between the distance D1 and the distance D2 from the conduction path 50x to the sensor S22 is the distance between the sensor S21 and the sensor S22, and the distance D2 from the conduction path 50x to the sensor S22 and the conduction path 50x to the sensor S23. The difference D3-D2 from the distance D3 is the distance between the sensor S22 and the sensor S23.

The depth evaluation unit 40 includes the difference D2-D1 between the distance D1 from the conduction path 50x to the sensor S21 and the distance D2 from the conduction path 50x to the sensor S22, and the distance D2 from the conduction path 50x to the sensor S22 and the conduction path 50x. The difference D3-D2 from the distance D3 to the sensor S23 is calculated based on the relations La and Lb, respectively. That is, the difference D2-D1 between the distance D1 from the conduction path 50x to the sensor S21 and the distance D2 from the conduction path 50x to the sensor S22 is D2a-D1a based on the relation La, and D2b- based on the relation Lb. It is D1b. Similarly, the difference D3-D2 between the distance D2 from the conduction path 50x to the sensor S22 and the distance D3 from the conduction path 50x to the sensor S23 is D3a-D2a based on the relation Lb, and D3b based on the relation Lb. -D2b.

Here, the mutual positional relationship between the sensors S21, S22, and S23 is known by design, and as shown in FIG. 2, the distance between the sensors S21 and S22 is ds2-ds1, and the distance between the sensors S22 and S23 is ds3. −Ds2. With respect to the difference D2-D1, the depth evaluation unit 40 determines which of D2a-D1a obtained based on the relation La and D2b-D1b obtained based on the relation Lb is the actual value ds2-ds1. And whether or not it is within a predetermined error range. Similarly, for the difference D3-D2, the depth evaluation unit 40 has an actual value of D3a-D2a obtained based on the relation La and D3b-D2b obtained based on the relation Lb. It is determined whether or not it is within a predetermined error range with ds3-ds2.

Of the values obtained based on the relation La and the values obtained based on the relation Lb, both the value of the difference D2-D1 and the value of the difference D3-D2 are the actual value and the predetermined value. If it is determined that it is within the error range, the depth evaluation unit 40 evaluates that the relationship used to obtain the value is the conduction path 50x in which the current actually flows. For example, the value of the difference D2-D1 obtained based on the relationship La is within the predetermined error of ds2-ds1 for the distance between the actual sensors S21 and S22, and the value of the difference D3-D2 is the actual sensor S22 and. When the distance between S23 is within a predetermined error of ds3-ds2, it is evaluated that the conduction path 50a corresponding to the relation La is the conduction path 50x in which the current actually flows. In other words, the position of the conduction path 50a is evaluated as the depth of the conduction path. Further, the depth evaluation unit 40 causes the display unit 16 to display information about the evaluation result as needed.

Further, the intervention current is applied by the electrical intervention unit 32, the magnetic field strength of each magnetic sensor is measured by the magnetic sensor drive unit 34, the signal detection unit 36, and the magnetic field strength calculation unit 38, and the conduction path is measured by the depth evaluation unit 40. The series of evaluation operations is performed only once in the above description, but the present invention is not limited to this, and the above series of operations may be repeated a plurality of times. In that case, the evaluation of the conduction path through which the current actually flows is evaluated. May be confirmed when the above is performed more than a predetermined number of times.

FIG. 8 is an example of a flowchart for explaining the outline of the control operation of the conduction path evaluation device 10 of the present invention. In step ST (hereinafter, the term “step” is appropriately omitted) 10 corresponding to the electrical intervention unit 32, an intervention current having a predetermined current magnitude is generated by the power supply circuit 14, and the skin of the subject 8 is subjected to. The intervention current is applied through the pair of electrodes 18 attached to the.

In ST20 corresponding to the magnetic sensor driving unit 34, the signal detecting unit 36, the magnetic field strength calculating unit 38, etc., the magnetic sensor device 20 is driven, and the magnetic field strength M is measured by the sensors S11 to S33 in the magnetic sensor device 20. It is done.

In ST30 corresponding to the depth evaluation unit 40, the value of the magnetic field strength in each sensor obtained in ST20, the relationship between the distance ds from the skin surface to the sensor and the magnetic field strength M stored in advance in the storage unit 42, Is used to evaluate the conduction path through which the intervention current actually flows.

In ST40 corresponding to the depth evaluation unit 40, it is determined whether or not a series of operations of ST10 to ST30 are repeated a predetermined number of times. This is to prevent erroneous evaluation based on the fact that the same evaluation is repeatedly obtained a predetermined number of times in ST30.

According to the above-described embodiment, the conduction path evaluation device 10 determines the change in the magnetic field when the intervention current is applied by the electrical intervention unit 32 that applies the intervention current to the living body of the subject 8 and the electrical intervention unit 32. It was detected by the magnetic sensor device 20 detected outside the subject 8, the magnetic sensor driving unit 34 that drives the magnetic sensor device 20, the signal detecting unit 36, the magnetic field strength calculating unit 38, and the magnetic field strength calculating unit 38. Since the depth evaluation unit 40 that evaluates the conduction state in the subject 8 based on the information about the magnetic field, the conduction state of the intervention current in the body of the subject 8 can be evaluated.

Further, according to the above-described embodiment, the intervention current applied by the electrical intervention unit 32 is a current having a rectangular waveform. In this way, it is possible to apply electrical intervention by the rectangular waveform, for example, rising and falling currents, DC components, and their repetition.

Further, according to the above-described embodiment, the depth evaluation unit 40 evaluates based on the magnetic field strength in the steady state detected by the magnetic field strength calculation unit 38. In this way, it is possible to evaluate the conduction state of the intervention current in the body of the subject 8 based on the position of the conduction path 50x through which the intervention current flows, particularly the magnetic field strength M that differs depending on the depth from the skin surface. Further, by being based on the magnetic field strength M in the steady state, the influence of the element that causes the frequency component can be reduced.

Further, according to the above-described embodiment, the evaluation of the conduction state in the body of the subject 8 is an evaluation of the position in the body of the subject 8 of the conduction path 50x through which the intervention current flows, particularly the depth from the skin surface. In this way, it is possible to evaluate at what route or depth the intervention current is conducted in the body of the subject 8.

Further, preferably, the application of the intervention current by the electrical intervention unit 32 and the detection of the magnetic field by the magnetic sensor driving unit 34, the signal detection unit 36, and the magnetic field strength calculation unit 38 are executed in synchronization with each other. is there. In this way, the change in the magnetic field outside the body of the subject 8 caused by the intervention current can be appropriately detected.

Further, preferably, the electrical intervention unit 32 applies an intervention current via electrodes 18a and 18b provided at positions corresponding to the meridians of the living body of the subject 8. In this way, it is possible to evaluate the conduction path for transmitting the intervention current between the meridians.

Further, preferably, the electrical intervention IE applied by the electrical intervention unit 32 flows in one direction in a pathway in the living body and is not accompanied by a return current at the cellular level. In other words, the conduction path conducts electrical intervention IE in one direction to energize the living body from outside the living body, and the energizing condition is below the threshold in which the living cells themselves do not generate an excitatory current, or the refractory period immediately after being excited once. If this is the case, the living cell itself does not get excited without responding to the applied current again, and does not have a current path back to the inside of the living body. In this way, the magnetic field generated when the electrical intervention IE conducts inside the living body can be efficiently measured by the magnetic sensor device 20 existing at a distance from the conduction path which is the source of the magnetic field. ..

Further, preferably, the application of the electrical intervention IE by the electrical intervention unit 32 and the detection of the magnetic field by the detection unit 36 are executed in synchronization with each other. In this way, the change in the magnetic field outside the living body caused by the electrical intervention IE can be efficiently and appropriately detected by the detection unit 36.

Although the examples of the present invention have been described in detail with reference to the drawings, the present invention also applies to other aspects.

In the conduction path evaluation device 10 of the present embodiment, the depth evaluation unit 40 uses the outputs of the three sensors S21, S22, and S23 to allow an intervention current to flow through any of the conduction paths 50a and 50b corresponding to the related La and Lb. However, it is not limited to such a mode. For example, the same evaluation may be performed using only two of the above three sensors.

The conduction path evaluation device 10 of this embodiment is configured to include a display device 16 that displays the operation thereof, but is not limited to such a mode. For example, in place of or in addition to the display device 16, one or more display lamps and a buzzer that emits a buzzer sound may be provided. Here, the indicator lamp and the buzzer indicate information regarding the operation of the conduction path evaluation device 10 by a light emitting state or an operation sound. Specifically, for example, the intensity of the light emitted from the lamp, the blinking interval, the number of lamps emitting light, or the loudness and frequency of the buzzer sound are different according to the depth from the skin surface of the subject 8 to the conduction path. Can be used instead of the display on the display device 16.

As the electrode 18 of this embodiment, a gel electrode is used, but the electrode 18 is not limited to such an embodiment. For example, a needle-shaped electrode may be used and electrical intervention may be applied by pointing the subject 8 at its tip.

In the above-described embodiment, the magnetic sensor device 20 is provided with a magnetic sensor SR for reference, and is differentiated from each of the magnetic sensors S11 to S33, but the present invention is not limited to this. That is, the reference magnetic sensor SR is not always essential, the reference magnetic sensor SR is not provided, and the measured values of the magnetic sensors S11 to S33 may be used as they are.

Further, the intervention current is applied by the electrical intervention unit 32, the magnetic field strength of each magnetic sensor is measured by the magnetic sensor drive unit 34, the signal detection unit 36, and the magnetic field strength calculation unit 38, and the conduction path is measured by the depth evaluation unit 40. A series of evaluation operations may be repeated a plurality of times, but the present invention is not limited to this mode. For example, the application of the intervention current by the electrical intervention unit 32, the operation of measuring the magnetic field strength in each magnetic sensor by the magnetic sensor driving unit 34, the signal detection unit 36, and the magnetic field strength calculation unit 38 are repeatedly performed, and the magnetic field of each sensor is operated. After obtaining the average value of the measured values of the intensity, the depth evaluation unit 40 may evaluate the conduction path only once.

Further, in the above-described embodiment, as shown in FIG. 2, the sensor device 20 has three locations in the vertical direction, that is, in the direction away from the conduction path, and three locations in the horizontal direction, which is a direction perpendicular to the vertical direction. Nine magnetic sensors S11 to S33 have been provided, but the present invention is not limited to this mode. For example, when the intervention current is repeatedly applied, one sensor S changes its position instead of the three magnetic sensors S21, S22, and S23 used by the depth evaluation unit 40 in the above-described embodiment. , The measurement may be repeated at the positions of the three magnetic sensors S21, S22, and S23. In this case, the magnetic sensor device 20 may be attached to a manipulator or a robot arm so that the position of the magnetic sensor device 20 can be moved to the plurality of measurement positions and temporarily held at each measurement position. Alternatively, the sensor device 20 may be composed of only the three magnetic sensors S21, S22, and S23 used by the depth evaluation unit 40.

Further, in the above-described embodiment, the sensor device 20 is provided with nine magnetic sensors S11 to S33 on one plane, but the present invention is not limited to this mode. For example, in addition to these nine magnetic sensors, a pair of sensors S41 and S42 may be provided on a straight line orthogonal to the one plane so that the distances from the one plane are equal. In this way, by arranging the sensor device 20 so that the outputs of the pair of sensors S41 and S42 are equal, the pair of sensors S41 and S42 are parallel to the conduction path 50x, in other words. The sensor device 20 can be arranged so that one plane orthogonal to the straight line connecting the pair of sensors S41 and S42 is orthogonal to the conduction path 50x.

Further, in the above-described embodiment, the relationship between the distance ds from the skin surface of the subject 8 to the sensor and the measured magnetic field strength M is, for example, the relationships La, Lb, and Lc exemplified in FIGS. 6 and 7. However, it is not limited to such an aspect. For example, instead of the relations La, Lb, and Lc, for example, a relational expression (mathematical expression) in which the distance ds and the magnetic field strength M are variables and the depth D is a parameter may be used. In this case, the depth evaluation unit 40 evaluates the depth by specifying a relational expression satisfying the magnetic field strength M measured by each sensor S21, S22, S23, specifically, a parameter in the expression. You may. In particular, when the conduction paths 50x in which the intervention current actually flows are a plurality of the conduction paths 50a, 50b, and 50c, a magnetic field is generated according to the magnitude of the current flowing through the plurality of conduction paths. Therefore, each of the relational expression corresponding to one conduction path (for example, 50a) and the relational expression corresponding to another conduction path (for example, 50b) are weighted according to the magnitude of the flowing current. A plurality of conduction paths 50x can be specified by solving them in a row with. In this case, it is desirable that the number of sensors S in the magnetic sensor device 20 is equal to or greater than the number of conduction paths 50x through which current flows.

Further, in the above-described embodiment, a pulsed current is applied as the intervention current IE, but the present invention is not limited to this. That is, the intervention current may be not only a continuous step pulse having the same amplitude but also a combined current of pulses having a plurality of different frequencies. Further, as the pulse having a plurality of different frequencies, a pulse having a plurality of frequencies in a predetermined frequency band may be used.

Further, in the above-described embodiment, a pulsed current, that is, an intermittent direct current is used as the intervention current, and the power supply circuit 14 is used as the electrical intervention unit 32 for generating the intervention current. The mode is not limited to the above. That is, since various modes of current can be used as the intervention current as described above, various electrical intervention units 32 that realize such currents are appropriately used. That is, a configuration of a programmable electric waveform creating device or the like driven by a current amplifier and a timer can be considered. In this way, the electrical excitatory cell group existing in the conduction path inside the living body to which the intervention current is applied does not generate the active current by itself and form another current closing circuit inside the living body. Since the current can be applied again when it is in the refractory period after being excited by the lower energization or once applying the current, it is easy to estimate the unidirectional in-vivo current conduction path. Furthermore, if the response magnetic field to the required frequency current can be measured in a short time and the response waveform itself is recorded in the storage unit, the response of a complicated biomagnetic field change can be evaluated offline.

Further, when a current having a plurality of different frequencies is sequentially output as an intervention current, an oscillator capable of dynamically changing the frequency of the current may be used. When currents having a plurality of different frequencies are sequentially applied as intervention currents, when the intervention currents flow through the plurality of conduction paths (for example, 50a and 50b) shown in FIG. 5, the high-pass frequency characteristics of both conduction paths are utilized. Since the amount of current flowing through each conduction path can be changed by sweeping the frequency of the oscillator, the position of the conduction path 50 can be evaluated even if the number of sensors S included in the magnetic sensor device 20 is reduced. it can.

In addition, although not listed one by one, the present invention can be implemented in a mode in which various changes, modifications, improvements, etc. are added based on the knowledge of those skilled in the art, and such an embodiment is the present invention. Needless to say, all of them are included in the scope of the present invention as long as they do not deviate from the gist.

For example, in the above-described embodiment, the magnetic impedance sensor (MI sensor) is used as the magnetic sensor 20, but the present invention is not limited to this. That is, when the intervention current IE is applied to the subject 8, another type of magnetic sensor can be used as long as it is a sensor having accuracy and resolution capable of detecting the magnetic field fluctuation caused by the intervention current IE. Specifically, for example, a fluxgate sensor or the like can be used. Further, the magnetic sensor 20 in the present invention may have a relatively low sensitivity. That is, in such an embodiment, even when the above-mentioned magnetic impedance sensor or iPA sensor is used as the magnetic sensor 20, the sensor element made of an amorphous similar metal does not have to have a sufficiently high sensitivity. Here, sufficiently high sensitivity means, for example, high sensitivity to the extent that the resolution of a superconducting quantum interferometer or an optical pumping atomic magnetic measuring instrument has.

Further, as the electrical intervention unit 32, a so-called programmable electric waveform generator can also be used. This programmable electric waveform generator has, for example, a current amplifier and a timer, and can generate a current of an arbitrary waveform by driving the current amplifier based on a time signal generated by the timer. Is. In this way, the electrical excitatory cell group existing in the conduction path inside the living body to which the intervention current is applied does not generate the active current by itself and form another current closing circuit inside the living body. Since the intervention current can be applied again when it is in the refractory period after being excited by the lower energization or once applying the current, it is easy to estimate the unidirectional in-vivo current conduction path. Preferably, the programmable electric waveform generator continuously measures the magnetic field response by the signal detection unit 36 while synthesizing electric waveforms including direct current and various AC frequencies for a certain period of time, and immediately calculates the result. Instead, it may be stored in the storage unit 42. By doing so, the response of complex biomagnetic field changes can be evaluated offline.

Further, in the above-described embodiment, the size of the intervention current set by the electrical intervention unit 32 is set so that the excitable cells through which the current flows do not become excited, but the present invention is not limited to this mode. For example, it is conceivable to apply a current having a magnitude exceeding the above-mentioned threshold value prior to the application of the intervention current to intentionally bring the excitable cells into an excited state and apply the intervention current within the predetermined time immediately after that. In this way, when the excitatory cell becomes excited, the intervention current is utilized by utilizing the property that the excitable cell does not become further excited within a predetermined time and does not generate a return current. Can flow in one direction. The above-mentioned predetermined time is obtained in advance by an experiment or the like.

8: Subject, 10: Conduction path evaluation device, 12: Electronic control device, 14: Power supply circuit (electrical intervention unit), 16: Display device, 18a, 18b: Electrodes, 20: Magnetic sensor device (detection unit), 30 : Timer, 32: Electrical intervention unit, 34: Magnetic sensor drive unit, 36: Signal detection unit, 38: Magnetic field strength calculation unit, 40: Depth evaluation unit, 42: Storage unit, 50a to 50c, 50x: Conduction path

Claims (8)

It is a conduction path evaluation device that evaluates the current conduction state due to electrical intervention from the outside into the living body.
An electrical intervention unit that applies the electrical intervention to the living body,
A detection unit that detects a change in the magnetic field that occurs when an electrical intervention is applied by the electrical intervention outside the living body.
Having an evaluation unit that evaluates the conduction state in the living body based on the information about the magnetic field detected by the detection unit.
A conduction path evaluation device characterized by. The electrical intervention performed by the electrical intervention unit is the application of a current having a rectangular waveform.
The conduction path evaluation device according to claim 1. The evaluation unit evaluates the position in the living body where the electrical intervention is energized.
The conduction path evaluation apparatus according to claim 1 or 2. The evaluation unit evaluates the conduction state based on the information about the magnetic field detected by the detection unit at two or more positions.
The conduction path evaluation apparatus according to claim 3. The electrical intervention propagates through the plurality of pathways in the living body.
The evaluation unit evaluates the positions corresponding to the plurality of routes.
The conduction path evaluation device according to claim 3 or 4. The application of electrical intervention by the electrical intervention unit and the detection of the magnetic field by the detection unit shall be executed in synchronization.
The conduction path evaluation device according to any one of claims 1 to 5, wherein the conduction path evaluation device is characterized. The electrical intervention unit shall apply electrical intervention to a position corresponding to the meridian of the living body.
The conduction path evaluation device according to any one of claims 1 to 6, wherein the conduction path evaluation device is characterized. The electrical intervention applied by the electrical intervention unit flows in one direction in the in vivo pathway and is not accompanied by a return current at the cellular level.
The conduction path evaluation device according to any one of claims 1 to 7, wherein the conduction path evaluation device is characterized.

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