Current Stimulation Device

Abstract

To provide a current stimulation device that automatically selects constant current control and constant voltage control according to an electrode.SOLUTION: A current stimulation device for supplying an electric signal to a human body comprises: an electrode that supplies the electric signal to a human body; and a control part that includes a waveform forming part for outputting the electric signal by constant voltage control or constant current control, and controls the waveform forming part so as to change characteristics of the electric signal according to information indicating the electrode connected to the current stimulation device.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a current stimulation device used for physical therapy by percutaneous current stimulation.

Background Art

[0002] Regarding current stimulation therapy devices, technologies related to low-frequency therapy devices equipped with various operation modes or dedicated machine types that supply current stimulation signals in accordance with known current stimulation methods such as percutaneous current stimulation, interference current, high-voltage stimulation, and weak current (microcurrent) are disclosed. As current stimulation, for example, a microcurrent of 1 mA or less is passed through a living body to promote cell repair from the same effect as when a damage current flows, and for example, a weak current (microcurrent) stimulation method used for the treatment of muscle and joint damage or wounds is used. For example, as in Patent Document 1 for a current stimulation device using microcurrent, by applying a weak current stimulation that does not cause muscle contraction from the skin surface of the muscle for which functional recovery is desired, it is possible to immediately improve or decrease muscle output and thus recover motor dysfunction. The supply of the above current stimulation signal to the living body is often performed using sheet-type electrodes as in Patent Document 1. In addition, current stimulation using microcurrent is used for the recovery of damaged sites. Since damaged sites generally tend to have a negative potential, they attract positive ions in the body, causing a positive-negative bias in the body and deteriorating the current flow, that is, increasing the impedance. As the healing of the damage progresses, the impedance decreases and the current flows smoothly due to the balance of positive and negative charges. Therefore, since impedance serves as an indicator of the degree of healing, it is important to apply current stimulation to the damaged site while measuring the impedance, and for this purpose, a stick-shaped conductor with a pin electrode may also be used.

[0003] In the case of a stationary type therapeutic device, a predetermined voltage is generated from a commercial power source, i.e., a so-called household power source, and used. At this time, generally, a known transformer or power supply IC is used to step up or step down the voltage to obtain a predetermined voltage. For example, Patent Document 2 proposes an electric field-actuated sleep aid that generates various voltages from a commercial power source using a transformer.

[0004] Also, when generating the above various voltages, as in Patent Document 3, a circuit formed by connecting at least one diode-connected MOSFET in series is used to generate various voltages.

[0005] Regarding the current stimulation output, from the viewpoint of safety, an output current adjustment function is often provided. For example, as in Patent Document 4, a muscle stimulation device having a function of automatically adjusting the current level according to the selected voltage level has been proposed.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Summary of the Invention

Problems to be Solved by the Invention

[0007] However, in a device that can use both a sheet-type electrode and a rod-shaped stick-type conductor, depending on the treatment content, both the sheet-type electrode and the stick-type conductor are used separately. Regarding the control of the output to the sheet-type electrode and the stick-type conductor, in the case of the sheet-type electrode, constant current control can be used. On the other hand, in the case of the stick-type conductor, since the part in contact with the skin is a pin-type pin electrode, the contact area with the skin is small. Especially at the moment when the pin electrode contacts or separates from the skin, the contact area becomes extremely small and the resistance value changes in the direction of increasing. Therefore, in constant current control, the current density at the contact part becomes high and the user may feel pain. Therefore, constant voltage control is better than constant current. That is, it is desirable to have a control that automatically determines the connected conductor by the device and switches between constant current control and constant voltage control. That is, when using the conductors separately, a safe and easy-to-use current stimulation device is required.

Means for Solving the Problems

[0008] In order to solve the above problems, the present invention takes the following means. That is, in the present invention, (1) a current stimulation device for supplying an electric signal to the body, the electrode for supplying the electric signal to the body wherein a portion that contacts the body is a pin-type pin electrode and, an electrode that supplies the electrical signal to the body, comprising a sheet-like electrode different from the pin electrode and a main body, the main body including a connector to which the pin electrode is connected, a waveform generation unit that outputs the electric signal by constant voltage control or constant current control, and is connected to the main body and the pin the electrode is used A control unit that controls the waveform generation unit so as to change the characteristics of the electric signal according to the information indicating the electrode Based on the information indicating that the pin electrode is connected to the connector, which is the information, the waveform generation unit is controlled so that the output of the electrical signal by the constant current control is changed to the output of the electrical signal by the constant voltage control. A current stimulation device characterized by that.

[0009] Furthermore, in the present invention, (2) the The connector is a dedicated connector to which the pin electrode is connected A current stimulation device characterized by that.

[0010] Furthermore, in the present invention, (3) even when the output of the electric signal by the constant flow control is set by the user, based on the information indicating that the pin electrode is connected, the control unit controls the constant currentcontrol Controlling the waveform generation unit so that the output of the electrical signal is the output of the electrical signal by the constant voltage control, the current stimulation device is characterized by this.

Effect of the Invention

[0011] The present invention can improve the safety and enhance the therapeutic effect on muscle and joint damage or wounds by automatically discriminating the conductor for applying current stimulation on the device side and appropriately switching the output control in a current stimulation device. It is particularly effective for devices using a microcurrent of 1 mA or less.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Embodiments for Carrying Out the Invention

[0013] (First Embodiment) FIG. 1 shows a current stimulation device 1 according to the present invention. This device includes a main body 11 that supplies current stimulation, an output switch A121 and an output switch B122 mounted on the main body 11 that turn on the current stimulation output when pressed, a sheet-type electrode A13 that supplies current stimulation to the human body, a pin electrode B14, and an indifferent electrode C15 that is held by the user and used in pair with the pin electrode B14. The pin electrode B14 is attached to the tip of a stick-shaped conductor 16. Each electrode is connected to the main body 11 by a cable and a socket. In FIG. 1, the electrodes are connected to the branched distal ends of a Y-shaped cable via connectors, and the other end of the cable is connected to the main body 11 via a connector. Also, in this description, the sheet-type electrode A13 is configured as a pair, but it may also be configured with one of them being the indifferent electrode C15. Further, the main body 11 has a two-channel configuration that allows for the use of two pairs of connectors for connecting the sheet-type electrode A13, that is, the use of two pairs of the sheet-type electrode A13. However, the present invention is not limited to this configuration and may be one pair or a configuration of three pairs or more. Also, in this embodiment, the above-mentioned indifferent electrode C15 is used as the electrode used in pair with the pin electrode B14, but it is not limited to this and a sheet-type electrode, for example, the sheet-type electrode A13 may be used. In this case, instead of holding the indifferent electrode C15, the sheet-type electrode A13 is attached to the skin and used.

[0014] Figure 2 shows the main body 11 of the current stimulation device according to the present invention. Fig. 2(a) is a top view, Fig. 2(b) is a front view, Fig. 2(c) is a rear view, Fig. 2(d) is a right side view, Fig. 2(e) is a bottom view, and Fig. 2(f) is a left side view. On the bottom surface of the main body 11, there are provided a connector A171 for the sheet-type electrode for connecting the sheet-type electrode A13, a connector B172 for the sheet-type electrode, and a connector 18 for the stick-type conductor for connecting the stick-type conductor 16. In this configuration, since the sheet-type electrode A13 has a two-pair (two-channel) configuration, two connectors A171 for the sheet-type electrode and connectors B172 for the sheet-type electrode are provided, but a one-pair configuration or a configuration of three pairs or more may also be used. The conductor storage 19 in the front view is a storage section for temporarily placing the conductors being connected. The conductor storage 19 has a concave structure for placing the stick-type conductor 16, but any structure that can prevent the electrodes from falling or rolling down is acceptable. In the display section 20, settings necessary for treatment, including parameters of the current stimulation output and control modes, are displayed. The input of the above settings may be input by an input switch or a knob (not shown), or may be input by the display section 20 with the display section 20 being a touch panel.

[0015] FIG. 3 shows a wearing example when the current stimulation device 1 in the present invention is in use. When using the sheet electrode A13, for example, as shown in FIG. 3(A), the sheet electrode A13 is attached to the site requiring treatment and used. The sheet electrode A13 is a thin sheet having the function of an electrode. As the structure of the sheet electrode A13, it may be provided with a conductive gel on the contact surface between the sheet-like base material and the living body. As the base material, for example, it may be made of a member of a conductive metal foil such as copper, silver, aluminum, nickel, or stainless steel. Also, the member is not limited to a metal foil, and it may be a thin member with a plated surface, a thin member made of a conductive material mixed with conductive powder or conductive fibers, or a thin mesh-like or cloth-like member made of silver fibers or conductive fibers. Alternatively, as the base material, an insulating material such as cloth may be used, and a conductive gel may be arranged on the surface of the base material to ensure conductivity for contact with the living body and biocompatibility. On the other hand, when using the pin electrode B14, as shown in FIG. 3(B), the pin electrode B14 is attached to the tip of the stick-shaped conductor 16 and used while being brought into contact with and slid along the site requiring treatment. The pin electrode B14 may be made of the same metal member as the above-mentioned metal foil member, a member with a plated surface, or a member made of a conductive material, as long as it can form a pin-shaped structure. When using the pin electrode, the subject to be treated holds the indifferent electrode C15 to form an electric circuit through which current flows. The indifferent electrode C15, like the pin electrode B14, is made of a metal member, a plated member, or a conductive material member, and since it is held and used, it may be any solid that can be grasped by hand.

[0016] As the shape of the indifferent electrode C15, it may be a ring shape as shown in FIG. 3(B). In the case of a ring shape, the subject to be treated passes a finger through it and lightly holds it. For example, in the case of a rod shape, it may be dropped by accidentally missing the grasp or slipping, but by making it a ring shape, it can be prevented from being dropped, and the contact with the skin of the subject to be treated can be surely maintained. Therefore, an electric circuit configured between the pin electrode B14 at the tip of the stick-shaped conductor 16, through the human body, and the indifferent electrode C16 and the current stimulation device can be stably configured, and it can function more surely as an indifferent electrode.

[0017] In this embodiment, an example is given in which the pin electrode B14 with a small contact area is used at the tip of the stick-shaped conductor 16. However, depending on the treatment method, instead of the pin-type electrode, an electrode in the shape of a sphere or a roller, or a cotton swab having conductivity may be used. These electrodes may be composed of a metal member, a plated member, or a conductive material member, or may be made conductive by soaking them with water or an electrolyte solution.

[0018] FIG. 4 is a block diagram of the current stimulation device of the present invention. The main body 11 includes a waveform generation unit 111 that generates a stimulation current, a control unit 112 that controls each unit, measures signals, and generates the output waveform and timing of the waveform generation unit 111, a user IF unit 113 that receives an ON signal from the output switch 12, inputs various settings such as the set value and waveform of the current stimulation signal output by the user, and impedance setting described later, and a power supply unit 114 that supplies power to each unit. Further, the waveform generation unit 111 includes a constant voltage adjustment unit 1111, a constant voltage fine adjustment unit 1112, and a constant current adjustment unit 1113. When the output switch 12 is turned ON, a control signal from the control unit 112 is input to the waveform generation unit 111 according to the settings from the user IF unit 113, and a current stimulation output is supplied to the electrode. Here, the configuration of the waveform generation unit 111 is such that the output of the constant voltage adjustment unit 1111 is input to the constant voltage fine adjustment unit 1112 as shown in FIG. 4, and after being output from the constant voltage fine adjustment unit 1112 to the sheet-type electrode A13, it is finally input to the constant current adjustment unit 1113. Here, the electrode is the sheet-type electrode A13, but it may be the pin electrode B14 and the non-related electrode C15. The constant voltage fine adjustment unit 1112 is a circuit for finely adjusting a place where accurate voltage adjustment is difficult only with the constant voltage adjustment unit 1111, and is specifically provided to be able to output a voltage up to near 0V. Since the constant voltage adjustment unit 1111, the constant voltage fine adjustment unit 1112, and finally the constant current adjustment unit 1113 are in the output stage, a configuration enabling both constant voltage control and constant current control is achieved.

[0019] Fig. 5 shows the circuit configuration of the constant voltage adjustment unit 1111. This is a so-called flyback type DCDC conversion, in which the voltage Vcc from the power supply unit 114 is input to the primary winding side of the transformer 21. When the MOSFET 22 is ON due to its switching operation, a current flows through the primary winding side of the transformer 21, and energy is accumulated. When the MOSFET 22 turns OFF, a back electromotive force is generated in the transformer 21, and power is output to the secondary winding side. That is, the ON / OFF of the MOSFET 22 controls the output voltage. This power is half-wave rectified and converted to DC by the rectifier diode 231 and the smoothing capacitor 241. Here, the voltage obtained by resistively dividing the output voltage Vout with the resistor A 261 and the resistor B 262 is input to the reference voltage IC 232. At this time, the output voltage Vout is determined by the reference voltage of the reference voltage IC and the resistive division ratio. Then, by feeding back the output of the reference voltage IC to the switching regulator A 271 via the photocoupler 28, the switching operation of the MOSFET 22 is controlled, that is, it leads to a voltage control operation by flyback with the ON / OFF of the transformer 21, which becomes a feedback control by negative feedback to obtain a constant voltage operation. Also, the transformer 21 and the photocoupler 28 provide an insulation structure between the input side and the output side. Here, by inputting the control signal (PWM (Pulse Width Modulation) signal 1) from the control unit 112 to the reference voltage IC 232 via the resistor G 267, the capacitor 243B which is a bypass capacitor, and the resistor D 264, the output of the reference voltage IC 232 can be changed, so that the magnitude of the output voltage Vout can be controlled by the PWM signal.

[0020] In the present invention, a DCDC converter is connected to the output of the constant voltage adjustment unit 1111. The flyback method DCDC output voltage is utilized, and a switching regulator is connected thereto to generate 3.3V. The output voltage is detected by the resistance voltage division of resistor E265 and resistor F266, and feedback control by negative feedback is performed on the switching regulator B272 to obtain a stable 3.3V. The output is rectified by the inductance 25 and the capacitor 242A. This 3.3V is used as the power supply for the elements constituting each circuit of the insulated waveform generation unit (constant voltage adjustment unit 1111, constant voltage fine adjustment unit 1112, constant current adjustment unit 1113), such as various elements like Op amps, isolators, and amps. That is, in order to obtain a 3.3V power supply output from the therapeutic signal output, a separate power supply voltage IC or transformer for this purpose becomes unnecessary. Since the power supply for the various elements supplying 3.3V is not very high, it is not necessary to make the switching frequency of the switching regulator very low. Generally, when the switching frequency is large, the size of the external inductor and capacitor of the switching regulator can be small. When the switching frequency is small, larger sizes of those are required. Therefore, relatively small values of the external inductor and capacitor of the switching regulator can be selected. Generally, the size of the element is proportional to the inductance and capacitance. Together with the fact that a separate power supply IC or transformer is unnecessary, it enables miniaturization of the device and low-noise electrical signal output, and enables efficient treatment with a portable current stimulation device.

[0021] Figure 6 shows the circuit configuration of the fixed voltage fine adjustment unit 1112. For fine adjustment, a circuit consisting of transistor A311, transistor B312, Op-amp A32, resistor H331, resistor I332, resistor J333, and resistor K334 is used to achieve a fixed voltage operation. The control signal (PWM (Pulse Width Modulation) signal 2) from the control unit 112 is input to Op-amp A32 via resistor L335 and capacitor C34, which is a bypass capacitor, and the output of Op-amp A32 is input to the base of transistor B312. To the non-inverting input of Op-amp A32, the control signal (PWM signal 2) is input, and to the inverting input, similar to the fixed voltage adjustment unit 1111, the voltage generated at the midpoint obtained by voltage division with resistor H331 and resistor I332 is fed back and input. That is, Op-amp A32 becomes a comparison circuit. When the base input of transistor B312 becomes equal to or higher than the base-emitter voltage (VBE), a current flows between the collector and emitter of transistor B312. Next, the base current of transistor A311 increases, and conduction between the collector and emitter causes an output to appear at Vout. That is, transistor A311 is a control circuit. By dividing Vout with resistor H331 and resistor I332 and feeding it back to the comparison circuit, a fixed voltage operation at a minute level is achieved. That is, resistor H331 and resistor I332 are detection circuits. For example, when Vout increases due to a load fluctuation, the voltage division between resistor H331 and resistor I332 increases. In that case, since it is negative feedback, the output of Op-amp A32 decreases, the base current of transistor B312 decreases, and the current between the collector and emitter of transistor B312 decreases. Then, the base current of transistor A311 decreases, and the current between the collector and emitter of transistor A311 decreases, so that Vout is adjusted in the downward direction. When Vout decreases due to a load fluctuation, the opposite action of this operation works, and Vout is adjusted in the upward direction. That is, a fixed voltage operation is achieved by control with negative feedback. Here, when the control signal (PWM signal) is increased, the output of Op-amp A32 increases. Therefore, according to the above operation description, the output of transistor A311 increases from the increase in the output of transistor B312, and Vout can be increased.On the other hand, when the control signal (PWM signal) is decreased, the opposite effect of this operation works to lower Vout. By such an operation, it becomes possible to finely adjust the Vout output to near 0V.

[0022] FIG. 7 shows the circuit configuration of the constant current adjustment unit 1113. It is composed of a transistor C41, an Op amp B42, and a resistor M431. The input current I from the sheet-type electrode A13 is subjected to constant current control by the constant current adjustment unit 1113. The control signal (PWM signal 3) from the control unit 112 is input to the non-inverting input of the Op amp B42 via a resistor N432 and a capacitor D44 which is a bypass capacitor, and the output from the emitter of the transistor C41 is input to the inverting input of the Op amp B42. After that, the difference is amplified by the Op amp B42 and input to the base of the transistor C41. When the base input of the transistor C41 becomes equal to or higher than the base-emitter voltage (VBE), the transistor C41 turns ON, and a current I starts to flow from the collector to the emitter direction of the transistor C41. When the current I flows through the resistor M431 and the voltage of the resistor M431 increases, the inverting input of the Op amp B42 increases, and the difference from the PWM signal 3 becomes smaller, so the output of the Op amp B42 becomes smaller. That is, the base current of the transistor C41 becomes smaller, and the current I flowing from the collector to the emitter direction of the transistor C41 decreases. The emitter current I of the transistor C41 is fed back to the inverting input of the Op amp B42, and the differential output with the control signal (PWM signal 2) from the control unit 112 becomes the control signal of the transistor C41, and the magnitude of the current I is controlled. That is, the transistor C41 serves as a control circuit, the resistor M431 serves as a detection circuit, and the Op amp B42 serves as a comparison circuit, and realizes constant current control by negative feedback.

[0023] The current stimulation device of the present invention has two modes: a microcurrent stimulation mode (MCR mode) for performing current stimulation by outputting an electrical signal under constant current control as an operation mode, and an impedance measurement and current stimulation mode (IM mode) for performing current stimulation and impedance measurement by outputting an electrical signal under constant voltage control. That is, the current stimulation device of the present invention can output an electrical signal under constant voltage control or output an electrical signal under constant current control. In the default setting, either mode may be selected. For example, the default may be the impedance measurement and current stimulation mode (IM mode) or the microcurrent stimulation mode (MCR mode). Here, the default is set to the impedance measurement and current stimulation mode (IM mode). When using the microcurrent stimulation mode (MCR mode), it is selected by user operation using the user IF unit 113, for example, a switch button image on the touch panel constituting the display unit 20 provided on the current stimulation device, or a physical switch. As the electrode, a general sheet-type electrode A13 is used. At this time, in response to the selection by the user IF unit 113, constant current control is used for the control of current stimulation. That is, the control unit 112 in FIG. 4 controls the waveform generation unit 111 mainly to control the constant current adjustment unit 1113. When the sheet-type electrode A13 is connected to the sheet-type electrode connector A171, by turning on the output switch A121, current stimulation under constant current control is applied to the target site. When the sheet-type electrode A13 is connected to the sheet-type electrode connector B172, by turning on the output switch B122, current stimulation under constant current control is applied to the target site. In the following description, the output switch A121 is based on the above connection configuration. When connected to the sheet-type electrode connector B172, the output switch B122 will be turned on.

[0024] When the sheet-type electrode A13 is connected, it may automatically switch to the micro-power stimulation mode (MCR mode) upon determining that it is not the stick-type conductor 16. For example, based on the determination result that the stick-type conductor is not connected and impedance measurement is impossible, or the detection result of the electrodes and conductors by a physical switch that detects insertion in the sheet-type electrode connector 17 or the stick-type conductor connector 18 of the main body 11, or the detection result by electrical connection, the type of the connected electrodes and conductors may be determined.

[0025] When performing current stimulation while measuring impedance using the pin electrode B14 of the stick-shaped conductor 16 in the impedance measurement and current stimulation mode (IM mode), connect the stick-shaped conductor 16 to the stick-shaped conductor connector 18 of the main body 11, and further connect the pin electrode B14 to the distal end of the stick-shaped conductor 16. Here, when it is in the micro current stimulation mode (MCR mode) instead of the impedance measurement and current stimulation mode (IM mode), the mode is selected to the impedance measurement and current stimulation mode (IM mode) through the user IF unit 113 by user operation. For example, when a mode selection to the impedance measurement and current stimulation mode (IM mode) is made on a switch button image on a touch panel constituting the display unit 20 provided on the current stimulation device, or a physical switch, the control unit 112 measures the impedance of the human body. The impedance measurement result is displayed by giving the main body 11 a display function. For example, it may be visually and clearly displayed on a display constituting the display unit 20 in the form of a graph, meter, gauge, etc. Further, the main body 11 may be provided with a sounding function and emit beep sounds intermittently. For example, when the impedance is low, it may be made to sound at a fast tempo like pipipi, and when the impedance is high, it may be made to sound at a slow tempo like pi - piiipi to notify audibly. The output of the electrical signal for giving current stimulation is controlled by constant voltage control by controlling the constant voltage adjustment unit 1111 and the constant voltage fine adjustment unit 1112 so as to perform constant voltage operation in the control unit 112, and is output by turning on the output switch 122B. That is, the control unit 112 controls the waveform generation unit 111 so as to output current stimulation by constant voltage control, and thus the current stimulation is applied to the target site. In this case, the output switch B122 is shared and used by the sheet-type electrode connector B172 and the stick-shaped conductor connector 18.

[0026] Here, the switching to constant voltage control was performed based on the selection of the impedance measurement and current stimulation mode (IM mode) by the user, but it is not limited to this, and it may be automatically switched based on information indicating that the stick-shaped conductor 16, the pin electrode B14, or these have been used, that is, information indicating the electrodes to be used.

[0027] In addition, it is also possible to use the stick-shaped electrode 16 in the microcurrent stimulation mode (MCR mode). In that case, the mode is selected to the microcurrent stimulation mode (MCR mode) through the user IF unit 113 by user operation. For example, when the mode is selected to the impedance measurement and current stimulation mode (MCR mode) by a switch button image on the touch panel constituting the display unit 20 provided on the current stimulation device or a physical switch, the constant current adjustment unit 1113 is controlled to perform a constant current operation in the control unit 112, so as to be controlled by constant current control. By turning on the output switch 122B, current stimulation is applied to the target site.

[0028] Instead of the above operation, it may also be implemented to automatically perform mode selection by comparing the impedance measurement result of the human body with a predetermined value set in advance. For example, when using the pin electrode B14 for the stick-shaped conductor 16, since the skin surface is slid as described above, the measured impedance tends to vary greatly. Therefore, when the variation of the measured impedance is equal to or greater than a predetermined value, it can be determined that it is the pin electrode B14. That is, the information indicating the electrode to be used, for example, the measured impedance as the information indicating the pin electrode, is used to determine the electrode to be used. In addition, although the pin electrode B14 is assumed to be used by sliding on the skin, the pin electrode B14 often temporarily or instantaneously leaves the skin, and the measured impedance becomes very large. In this way, it can also be determined that the pin electrode B14 is being used when the impedance exceeds the preset value. In this case, both the measured impedance and the information that the measured impedance exceeds the preset value are information indicating that the pin electrode B14 is being used. Based on this information as a criterion, control may be performed to automatically select the impedance measurement and current stimulation mode (IM mode), which is a constant voltage operation. Instead of the stick-shaped conductor 16 or the pin electrode B14, for example, when using the sheet-shaped electrode A13, since the electrode is attached to the human body, the impedance variation is not so large. Therefore, based on the criterion that the impedance value is equal to or less than the preset value or the measured impedance does not exceed the value, the mode selection may be automatically switched to the microcurrent stimulation mode (MCR mode). In this case, both the measured impedance and the information that the measured impedance does not exceed the preset value correspond to the information indicating that the sheet-shaped electrode is being used, that is, the information indicating the electrode to be used.

[0029] Furthermore, after the mode is selected, the type of the above-described conductor and electrode may be determined. If the combination of the mode selection and the conductor and electrode is inappropriate, it may be automatically switched to an appropriate mode. For example, when the pin electrode B14 is used for the stick-shaped conductor 16 after the micro current stimulation mode (MCR mode) is selected, it is automatically switched to the impedance measurement and current stimulation mode (IM mode). Conversely, when the sheet-type electrode A13 is used after the impedance measurement and current stimulation mode (IM mode) is selected, it is automatically switched to the micro current stimulation mode (MCR mode). Whether the pin electrode B14 is used or not may be configured such that a dedicated connector portion for using the pin electrode B14 is provided in the main body 11, and when a cable is connected to the connector, the current stimulation is output in a constant voltage operation. That is, based on the information indicating that the pin electrode B14 is used, the control unit 112 may be configured to switch to perform current stimulation by constant voltage control. Examples of the information indicating the electrode to be used include, but are not limited to, the operation mode, the measured impedance, the connector to be used, and the like. In the present invention, not only the switching to the output by a constant voltage is limited, but also the switching to a constant current may be performed, and the control may be such that the switching to the constant current control is performed based on the information indicating the electrode to be used. For example, the switching to the constant current control can also be performed according to the information indicating that the sheet-type electrode A13 is used.

[0030] Furthermore, an implementation may be such that when the mode is manually selected and the connected conductor and electrode are inappropriate, a warning message is displayed to the user to connect a conductor suitable for the mode selection. In this case, it is desirable that the output is not performed until it is determined that an appropriate conductor and electrode are connected.

[0031] Regarding the control of current stimulation output, in the microcurrent stimulation mode (MCR mode), it is a constant current operation, and the maximum current limit (1 mA in specifications), which is the maximum current that can be output by the constant current adjustment unit 1113 functioning for constant current control, is applied. To reduce the risk of burns during treatment, in the impedance measurement and treatment mode (IM mode), it is a constant voltage operation, but a maximum limit is provided for the output current to reduce the risk of burns during treatment. Here, the maximum limit during constant voltage operation can be set to be smaller than the maximum current limit (1 mA in specifications) during constant current operation, that is, it can be set to 500 μA, 800 μA, etc. Since the constant voltage operation is when using the pin electrode B14 as described above, the contact area between the pin electrode B14 and the skin is small and the current density is likely to increase, so pain and burns are likely to occur. Therefore, even when the contact area between the pin electrode B14 and the skin becomes small and the current density increases due to the use of the pin electrode B14, control may be such that the maximum limit is set to a current value at which pain or burns do not occur or are less likely to occur. Note that the maximum limit at constant voltage may vary according to the output voltage.

[0032] Specifically, in order to further reduce the risk of burns, in the control unit 112, a setting is made to apply a maximum limit to the current according to the set voltage. For example, for every 0.5 V, the upper limit of the current limit is increased by several tens of μA, and stepwise output upper limit control is performed up to the maximum voltage value in the impedance measurement and treatment mode (IM mode). This also has the effect of alleviating the sense of stimulation during low-voltage output. Also, when the min value is set to 0.5 V, a certain amount of offset current is applied, and the maximum limit is controlled as follows, for example. When the output voltage is 0.5 V, the maximum limit = offset current + 20 = (offset current + 20) μA; when the output voltage is 1.0 V, the maximum limit = offset current + 20×2 = (offset current + 40) μA; when the output voltage is 1.5 V, the maximum limit = offset current + 20×3 = (offset current + 60) μA. Here, the current limit is controlled so as not to exceed 1 mA at maximum. In particular, an output of about 20 V may be used for a roller-type electrode with a large contact area, and in this case, a relatively large output current is required so that the current density does not decrease too much. Thus, in the constant voltage operation, the control unit 112 can make the maximum value of the output current be the sum of an initial value and a variable value that varies based on the output voltage. Although the offset current is added as the initial value above, it is not limited to this, and the offset current may not be present. Also, although the variable value is set to change every 0.5 V, which is the step of the output voltage, it is not limited to this. The step may be less than 0.5 V or more than 0.5 V, and the variable ratio, which is the value that varies, may be less than or more than 20 μA. For example, it may change linearly or non-linearly with respect to the output voltage. For example, when the output voltage is low, it may change by 20 μA for every 0.5 V, but when the output voltage becomes high, the variable ratio may be changed so as to change by 10 μA for every 0.5 V, for example. That is, a configuration in which the variable ratio changes according to the output voltage may also be used. Furthermore, although the maximum limit is controlled to increase with the output voltage as described above, its maximum value may be controlled so as not to become larger than a certain value. For example, it may be used as the maximum current limit during constant current control.That is, in the above embodiment, it may be 1000 μA, or a value different from the maximum current limit may be set. For example, it may be controlled to a specific value that does not exceed the maximum current limit during constant current control. The specific value may be, for example, 500 μA, 800 μA, etc., which are currents lower than the maximum current limit during constant current control.

[0033] In the above-described embodiment, it is described that the output for applying electrical stimulation is performed under constant voltage control based on the information that the pin electrode B14 is being used. However, the switching to constant voltage control may be performed in the following cases. For example, when using the sheet-type electrode A13, when the output is by constant current control, by measuring the impedance of the sheet-type electrode A13, for example, when the impedance exceeds a threshold value which is a pre-set value, the control may be switched to constant voltage control. When using a conductive sheet such as the sheet-type electrode A13 as a therapeutic electrode, the sheet needs to be in complete contact with the skin. However, if this contact is insufficient, the contact area between the electrode and the skin becomes small. In the case of constant current control, the output current concentrates on this small contact area, resulting in current concentration, and pain and burns due to the current concentration are likely to occur. Also, when the conductive sheet deteriorates, a part of the sheet becomes high resistance or the current flows only through a part, and again current concentration occurs, making pain and burns due to the current concentration likely to occur. Even in such a case where the area through which the current flows decreases, in the case of constant voltage control, the output current can be maintained so that pain and burns do not occur. Therefore, even when the output is by constant current control, a configuration may be adopted in which the impedance is measured and when the impedance exceeds a pre-set value, the control is switched to constant voltage control. Instead of measuring the impedance in this case, a configuration may be adopted in which the output voltage is monitored and when the output voltage exceeds a pre-set value, the control is switched to constant voltage control. Further, when such a switch to constant voltage control occurs, information indicating that the control has switched to constant voltage, the possibility of current concentration, insufficient contact of the electrode with the skin, or deterioration of the conductive sheet, etc. may be notified to the user, or information prompting the confirmation of the electrode or prompting the replacement of the electrode may be notified. As the notification, these may be displayed on the display unit 20, the LED may be lit, or a beep sound may be emitted, etc.

[0034] Regarding the impedance measurement of this embodiment, it is measured by the mechanism shown in FIG. 8. The state where the electrode is in contact with the human body is regarded as the load 55, and for the current I, the current flowing through the shunt resistor 54 inserted in the supply circuit is measured by the current measurement IC 52. For the voltage V, the voltage applied to the load 55 is measured by the voltage measurement IC 53. The impedance is calculated from the above V and I. Here, by controlling the switching circuit 51 by the control unit 112 to alternately and quickly measure the voltage V and the current I, the impedance is obtained. With this configuration, it is possible to make the circuit configuration smaller than when measuring simultaneously, and it is possible to realize a current stimulation device with better portability. However, the voltage V and the current I may be measured simultaneously without using the switching circuit 51. Furthermore, the present invention is a current stimulation device for supplying an electrical signal to the body, comprising: an electrode for supplying the electrical signal to the body; and a waveform generation unit that outputs the electrical signal by constant voltage control or constant current control, and controls the waveform generation unit to change the characteristics of the electrical signal according to information indicating the electrode connected to the current stimulation device. Furthermore, the present invention is a current stimulation device characterized in that (2) the information indicating the electrode is information indicating a pin electrode. Furthermore, the present invention is a current stimulation device characterized in that (3) the control unit controls the waveform generation unit to output the electrical signal by the constant voltage control according to the information indicating the pin electrode. Furthermore, in the present invention, even when the output of the electrical signal by the constant voltage control is set by the user, based on the information indicating that the pin electrode is connected, the control unit controls the waveform generation unit so that the output of the electrical signal by the constant current is the same as the output of the electrical signal by the constant voltage control. The current stimulation device is characterized by this.

Explanation of Signs

[0035] 1 Current stimulation device 11 Main body 13 Sheet-type electrode A 14 Pin electrode B 15 Indifferent electrode 16 Stick-type conductor 18 Connector for stick-type conductor 19 Conductor storage 20 Display unit 21 Transformer 22 MOSFET 25 Inductance 28 Photo Coupler 32 Op Amp A 34 Capacitor C 41 Transistor C 42 Op Amp B 44 Capacitor D 51 Switching Circuit 52 Current Measurement IC 53 Voltage Measurement IC 54 Shunt Resistor 55 Load 111 Waveform Generation Unit 112 Control Unit 113 User IF Unit 114 Power Supply Unit 121 Output Switch A 122 Output Switch B 171 Connector A for Sheet-Type Electrode 172 Connector B for Sheet-Type Electrode 231 Rectifier Diode 232 Reference Voltage IC 241 Smoothing Capacitor 242 Capacitor A 243 Capacitor B 261 Resistor A 262 Resistor B 263 Resistor C 264 Resistor D 265 Resistor E 266 Resistor F 267 Resistor G 271 Switching Regulator A 272 Switching Regulator B 311 Transistor A 312 Transistor B 331 Resistor H 332 Resistor I 333 Resistor J 334 Resistor K 335 Resistor L 431 Resistor M 432 Resistor N 1111 Constant Voltage Adjustment Unit 1112 Constant voltage fine adjustment unit 1113 Constant current adjustment unit

Claims

1. A current stimulation device for supplying an electrical signal to the body, comprising: an electrode for supplying the electrical signal to the body, wherein a portion that contacts the body is a pin-type pin electrode; an electrode for supplying the electrical signal to the body, which is a sheet-shaped electrode different from the pin electrode; a main body; the main body includes a connector to which the pin electrode is connected; a waveform generation unit that outputs the electrical signal by constant voltage control or constant current control and is connected to the main body, and a control unit that controls the waveform generation unit to change the characteristics of the electrical signal according to information indicating that the pin electrode is used; The current stimulation device is characterized in that, based on the information indicating that the pin electrode is connected to the connector, which is the information, the waveform generation unit is controlled so that the output of the electrical signal by the constant current control is the output of the electrical signal by the constant voltage control.

2. The current stimulation device according to claim 1, wherein the connector is a dedicated connector to which the pin electrode is connected.

3. Even when the output of the electrical signal by the constant current control is set by the user, based on the information indicating that the pin electrode is connected, the control unit controls the waveform generation unit so that the output of the electrical signal by the constant current control is the output of the electrical signal by the constant voltage control. The current stimulation device according to claim 1 or claim 2.

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