Current stimulation device

Abstract

The present invention provides a current stimulation device that controls the output from constant current control to constant voltage control based on information regarding the output state of an electrical signal. [Solution] An electrical stimulation device for supplying an electrical signal to the body, comprising: an electrode for supplying the electrical signal to the body; a main body; a waveform generation unit for outputting the electrical signal by constant current control or constant voltage control; and a control unit for controlling the waveform generation unit to change the characteristics of the electrical signal based on information regarding the output state of the electrical signal, wherein the control unit controls the waveform generation unit to output the electrical signal by constant voltage control based on the information regarding the output state of the electrical signal when the electrical signal is being output by constant current control. The information regarding the output state can be impedance or output voltage.

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 treatment devices, technologies related to low-frequency treatment 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, regarding a current stimulation device using microcurrent, as in Patent Document 1, by applying a weak current stimulation that does not cause muscle contraction from the skin surface of the muscle whose function recovery is desired, it is possible to immediately improve or decrease muscle output and recover motor dysfunction. In many cases, the supply of the above current stimulation signal to the living body is 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 damage heals, the positive-negative balance is restored, the impedance decreases, and the current flows smoothly. 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 pin electrodes may also be used.

[0003] In the case of stationary therapeutic devices, a predetermined voltage is generated from the commercial power supply, also known as the household power supply, for use. In this process, a known transformer or power supply IC is generally used to step up or step down the voltage to obtain the predetermined voltage. For example, Patent Document 2 proposes an electric field-operated sleep aid that generates various voltages from the commercial power supply using a transformer.

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

[0005] Regarding electrical stimulation output, a current output adjustment function is often provided from a safety standpoint. For example, as described in Patent Document 4, a muscle stimulator has been proposed that has a function to automatically adjust the current level according to the selected voltage level. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2016-202445 [Patent Document 2] Japanese Patent Application Publication No. 09-028813 [Patent Document 3] Japanese Patent Application Publication No. 10-289023 [Patent Document 4] Special table 2009-517176 publication [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] However, in devices that can use both sheet-type electrodes and stick-type electrodes, the choice between the two depends on the treatment. Regarding output control for sheet-type electrodes and stick-type electrodes, constant current control can be used for sheet-type electrodes. On the other hand, with stick-type electrodes, the part that contacts the skin is a pin-type electrode, resulting in a small contact area with the skin. In particular, at the moment the pin electrode and skin come into contact or separate, the contact area becomes extremely small, and the resistance value changes in the direction of increasing. Therefore, with constant current control, the current density at the contact site becomes high, which may cause pain to the user. For this reason, constant voltage control is preferable to constant current control. In other words, it is desirable for the device to automatically detect the electrode to be connected and switch between constant current control and constant voltage control. That is, a current stimulation device that is safe and easy to use is needed when using different electrodes. [Means for solving the problem]

[0008] To solve the above problems, the present invention employs the following means. Specifically, the present invention provides (1) an electrical stimulation device for supplying an electrical signal to the body, comprising an electrode for supplying the electrical signal to the body and a main body, wherein the main body includes a waveform generation unit that outputs the electrical signal by constant voltage control or constant current control, and a control unit that controls the waveform generation unit to change the characteristics of the electrical signal based on information regarding the output state of the electrical signal, wherein the control unit controls the waveform generation unit to output the electrical signal by constant voltage control when the electrical signal is output by constant current control, based on the information regarding the output state of the electrical signal.

[0009] Furthermore, the present invention is a current stimulation device characterized in that (2) the information relating to the output state of the electrical signal is based on impedance.

[0010] Furthermore, the present invention is a current stimulation device characterized in that (3) the information relating to the output state of the electrical signal is based on the output voltage. [Effects of the Invention]

[0011] This invention relates to an electrical stimulation device, which can enhance safety and improve the therapeutic effect on muscle and joint damage or wounds by automatically identifying the electrode that delivers electrical stimulation and appropriately switching the output control. It is particularly effective for devices that use minute currents of 1 mA or less. [Brief explanation of the drawing]

[0012] [Figure 1] This is an explanatory diagram of the current stimulation device according to the present invention. [Figure 2] This is a six-view drawing of the main body of the current stimulation device according to the present invention. [Figure 3] This is an explanatory diagram showing how to use the current stimulation device according to the present invention. [Figure 4] This is a block diagram of the current stimulation device according to the present invention. [Figure 5] This is a circuit diagram of the constant voltage adjustment unit 1111 in the present invention. [Figure 6] This is a circuit diagram of the constant voltage fine adjustment unit 1112 in the present invention. [Figure 7] This is a circuit diagram of the constant current adjustment unit 1113 in the present invention. [Figure 8] This is an explanatory diagram of impedance measurement in the present invention. [Modes for carrying out the invention]

[0013] (First Embodiment) Figure 1 shows the current stimulation device 1 according to the present invention. This device consists of a main body 11 that supplies current stimulation, output switches A121 and 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 used in pair with the pin electrode B14 and is held by the user. The pin electrode B14 is attached to the tip of a stick-type electrode 16. Each electrode is connected to the main body 11 by a cable and socket. In Figure 1, the electrodes are connected via connectors to the far end of a Y-shaped branched cable, and the other end of the cable is connected to the main body 11 via a connector. 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. Furthermore, the main body 11 has a two-channel configuration with two sets of connectors for connecting the sheet-type electrode A13, meaning that it is possible to use two pairs of sheet-type electrodes A13. However, the present invention is not limited to this configuration, and one pair or three or more pairs may be used. Also, in this embodiment, the above-mentioned indifferent electrode C15 is used as the electrode used in pair with the pin electrode B14, but the invention is not limited to this, and a sheet-type electrode, such as the sheet-type electrode A13, may be used. In this case, instead of gripping the indifferent electrode C15, the sheet-type electrode A13 is attached to the skin for use.

[0014] Figure 2 shows the main body 11 of the current stimulation device according to the present invention. Figure 2(a) is a top view, Figure 2(b) is a front view, Figure 2(c) is a rear view, Figure 2(d) is a right side view, Figure 2(e) is a bottom view, and Figure 2(f) is a left side view. On the bottom surface of the main body 11 are a sheet-type electrode connector A171 and a sheet-type electrode connector B172 for connecting a sheet-type electrode A13, and a stick-type electrode connector 18 for connecting a stick-type electrode 16. In this configuration, since the sheet-type electrode A13 is configured in two pairs (2 channels), there are two sheet-type electrode connectors A171 and B172, but it may also be configured in a one-pair configuration or a configuration of three or more pairs. The electrode holder 19 in the front view is a storage section for temporarily placing electrodes that are being connected. The electrode holder 19 has a concave structure for placing the stick-type electrode 16, but any structure that prevents electrodes from falling or rolling off is acceptable. The display unit 20 displays settings necessary for treatment, including parameters for current stimulation output and control modes. These settings may be input via input switches or knobs (not shown), or they may be input via the display unit 20 as a touch panel.

[0015] FIG. 3 shows an example of wearing the current stimulation device 1 in the present invention. When using the sheet electrode A13, for example, as shown in FIG. 3(a), the sheet electrode A13 is attached to the part that requires 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-shaped base material and the living body. As the base material, for example, it may be made of a conductive metal foil member such as copper, silver, aluminum, nickel, or stainless steel. Also, the member is not limited to a metal foil. 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-shaped or cloth-shaped 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 the ecosystem. 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 abutted against and slid on the part that requires treatment. The pin electrode B14 may be made of the same metal member as the above 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 holds the indifferent electrode C15 to form an electric circuit and allow current to flow. 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 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 can be surely maintained. Therefore, an electric circuit configured between the pin electrode B14 at the tip of the stick-shaped conductor 16, passing through the human body, and the indifferent electrode C15 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-shaped electrode, an electrode in the shape of a sphere or a roller, or a conductive cotton swab may be used. These electrodes may also 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 the ON signal from the output switch 12, the setting of the current stimulation signal output value and waveform by the user, and various settings such as the 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 setting from the user IF unit 113, and the current stimulation output is supplied to the electrodes. 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-shaped electrode A13, it is finally input to the constant current adjustment unit 1113. Here, the electrode is the sheet-shaped electrode A13, but it may also 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 enable the output of a voltage up to near 0V. The configuration is such that both constant voltage control and constant current control are possible because 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.

[0019] Figure 5 shows the circuit configuration of the constant voltage adjustment unit 1111. This is a so-called flyback type DC-DC converter, where 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 switched ON, current flows to the primary winding side of the transformer 21, and energy is stored. When the MOSFET 22 is turned OFF, a back electromotive force is generated in the transformer 21, and power is output to the secondary winding side. In other words, the ON / OFF state of the MOSFET 22 controls the output voltage. This power is half-wave rectified to DC by the rectifier diode 231 and the smoothing capacitor 241. Here, the output voltage Vout is divided by resistors A261 and B262 and the resulting voltage is input to the reference voltage IC232. At this time, the output voltage Vout is determined by the reference voltage IC and the resistance division ratio. The output of the reference voltage IC is then fed back to the switching regulator A271 via the photocoupler 28, thereby controlling the switching operation of the MOSFET 22. This results in voltage control operation via flyback caused by the ON / OFF switching of the transformer 21, which is negative feedback control and provides constant voltage operation. Furthermore, the transformer 21 and photocoupler 28 provide an isolation structure between the input and output sides. Here, the control signal (PWM (Pulse Width Modulation) signal 1) from the control unit 112 is input to the reference voltage IC 232 via resistor G267, the bypass capacitor capacitor 243B, and resistor D264, allowing the output of the reference voltage IC 232 to be changed, and thus the magnitude of the output voltage Vout can be controlled by the PWM signal.

[0020] Furthermore, in this invention, a DC-DC converter is connected to the output of the constant voltage adjustment unit 1111, and a switching regulator is connected to the flyback type DC-DC output voltage to generate 3.3V. The output voltage is detected by a resistive voltage divider of resistors E265 and F266, and negative feedback control is performed on the switching regulator B272 to obtain a stable 3.3V. The output is rectified by inductance 25 and capacitor 242A. This 3.3V is used as the power supply for various elements constituting each circuit of the isolated waveform generation unit (constant voltage adjustment unit 1111, constant voltage fine adjustment unit 1112, constant current adjustment unit 1113), such as op-amps, isolators, amplifiers, etc. In other words, since a 3.3V power supply output is obtained from the therapeutic signal output, a separate power supply voltage IC or transformer is not required. Since the power supply for the various components providing 3.3V is not very high, the switching frequency of the switching regulator does not need to be very low. Generally, when the switching frequency is high, the size of the external inductor and capacitor attached to the switching regulator can be small, and when the switching frequency is low, their size needs to be large, so relatively small values ​​for the external inductor and capacitor attached to the switching regulator can be selected. Generally, the size of the components is proportional to their inductance and capacitance. Combined with the fact that a separate power supply IC or transformer is not required, this enables miniaturization of the device and low-noise electrical signal output, allowing for efficient treatment with a portable current stimulation device.

[0021] Figure 6 shows the circuit configuration of the constant voltage fine adjustment unit 1112. For fine adjustment, constant voltage operation is achieved using a circuit consisting of transistors A311 and B312, op-amp A32, resistors H331, I332, J333, and K334. The control signal (PWM (Pulse Width Modulation) signal 2) from the control unit 112 is input to op-amp A32 via resistor L335 and the bypass capacitor C34, and the output of op-amp A32 is input to the base of transistor B312. The control signal (PWM signal 2) is input to the non-inverting input of op-amp A32, and the voltage generated at the midpoint of the voltage division by resistors H331 and I332 is fed back and input to the inverting input, similar to the constant voltage adjustment unit 1111. In other words, op-amp A32 acts as a comparator circuit. When the base input of transistor B312 exceeds the base-emitter voltage (VBE), current flows between the collector and emitter of transistor B312. Next, the base current of transistor A311 increases, causing the collector-emitter to conduct and an output appears at Vout. In other words, transistor A311 is a control circuit. Constant voltage operation at minute levels is achieved by dividing Vout using resistors H331 and I332 and feeding it back to the comparator circuit. In other words, resistors H331 and I332 are detection circuits. For example, if Vout rises due to load fluctuations, the voltage division between resistors H331 and I332 increases. In this 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, adjusting Vout in the direction of decreasing. If Vout decreases due to load fluctuations, the opposite action is taken to adjust Vout upwards. In other words, constant voltage operation is achieved through negative feedback control. If the control signal (PWM signal) is increased, the output of Op-amp A32 increases, and according to the above explanation of operation, the output of transistor B312 increases, which in turn increases the output of transistor A311, thereby raising Vout.On the other hand, if the control signal (PWM signal) is reduced, the opposite effect occurs, lowering Vout. This action makes it possible to fine-tune the Vout output to near 0V.

[0022] Figure 7 shows the circuit configuration of the constant current adjustment unit 1113. It consists of transistor C41, op-amp B42, and resistor M431. The input current I from the sheet-type electrode A13 is controlled as a constant current 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 op-amp B42 via resistor N432 and pass capacitor D44, and the output from the emitter of transistor C41 is input to the inverting input of op-amp B42. After that, the difference is amplified by op-amp B42 and input to the base of transistor C41. When the base input of transistor C41 becomes greater than or equal to the base-emitter voltage (VBE), transistor C41 turns ON, and current I begins to flow from the collector to the emitter of transistor C41. As current I flows through resistor M431 and the voltage across resistor M431 increases, the inverting input of op-amp B42 increases, and the difference with PWM signal 3 decreases, resulting in a decrease in the output of op-amp B42. In other words, the base current of transistor C41 decreases, and the current I flowing from the collector to the emitter of transistor C41 decreases. Current I, the emitter current of transistor C41, is fed back to the inverting input of op-amp B42, and the difference output with the control signal from control unit 112 (PWM signal 3) becomes the control signal of transistor C41, thereby controlling the magnitude of current I. In short, transistor C41 acts as a control circuit, resistor M431 as a detection circuit, and op-amp B42 as a comparator circuit, realizing constant current control by negative feedback.

[0023] The current stimulation device of the present invention has two operating modes: a microcurrent stimulation mode (MCR mode) for performing current stimulation by outputting an electrical signal controlled by constant current, and an impedance measurement and current stimulation mode (IM mode) for performing current stimulation and impedance measurement by outputting an electrical signal controlled by constant voltage. In other words, the current stimulation device of the present invention is capable of outputting an electrical signal controlled by constant voltage or outputting an electrical signal controlled by constant voltage. Either mode may be set as the default setting; for example, the default may be set to 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), the mode is selected by user operation via the user IF unit 113, for example, a switch button image on a touch panel constituting the display unit 20 provided on the current stimulation device, or a physical switch. A general sheet-type electrode A13 is used as the electrode. In this case, constant current control is used to control the current stimulation based on the selection made in the user IF unit 113. In other words, the control unit 112 in Figure 4 controls the waveform generation unit 111 to primarily control the constant current adjustment unit 1113. When the sheet-type electrode A13 is connected to the sheet-type electrode connector A171, turning on the output switch A121 applies current stimulation to the target site through constant current control. When the sheet-type electrode A13 is connected to the sheet-type electrode connector B172, turning on the output switch B122 applies current stimulation to the target site through constant current control. Note that in the explanation below, the output switch A121 is assumed to be the above connection configuration, and when connected to the sheet-type electrode connector B172, the output switch B122 will be turned on.

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

[0025] In the impedance measurement and current stimulation mode (IM mode), which applies current stimulation while measuring impedance using the pin electrode B14 of the stick-type electrode 16, the stick-type electrode 16 is connected to the stick-type electrode connector 18 of the main unit 11, and the pin electrode B14 is further connected to the distal end of the stick-type electrode 16. If the device is in microcurrent stimulation mode (MCR mode) instead of impedance measurement and current stimulation mode (IM mode), the user selects the impedance measurement and current stimulation mode (IM mode) through the user IF unit 113. For example, when the user selects the impedance measurement and current stimulation mode (IM mode) using a switch button image on the touch panel that constitutes the display unit 20 on the current stimulation device, or a physical switch, the control unit 112 measures the impedance of the human body. The impedance measurement results are displayed on the main unit 11 using its display function. For example, the results may be displayed visually in an easy-to-understand format such as a graph, meter, or gauge on the display that constitutes the display unit 20. Furthermore, the main unit 11 may be equipped with a sound-producing function to intermittently emit beeps. For example, when the impedance is low, it may emit a rapid beeping sound, and when the impedance is high, it may emit a slower beeping sound to provide auditory notification. The output of the electrical signal that provides current stimulation is controlled by constant voltage control by controlling the constant voltage adjustment unit 1111 and the constant voltage fine adjustment unit 1112 in the control unit 112 to perform constant voltage operation, and is output by turning on the output switch 122B. In other words, the control unit 112 controls the waveform generation unit 111 to output current stimulation by constant voltage control, thereby applying current stimulation to the target area. In this case, the output switch B122 is used in common with the sheet-type electrode connector B172 and the stick-type electrode connector 18.

[0026] Here, the switch to constant voltage control was performed based on the user selecting the impedance measurement and current stimulation mode (IM mode), but is not limited to this. It may also be automatically switched based on information indicating that the stick-type electrode 16 or pin electrode B14 or these have been used, i.e., information indicating the electrodes being used.

[0027] Furthermore, the stick-type electrode 16 can also be used in microcurrent stimulation mode (MCR mode). In this case, the user selects the microcurrent stimulation mode (MCR mode) through the user IF unit 113. For example, when the user selects the impedance measurement and current stimulation mode (MCR mode) using a switch button image on the touch panel constituting the display unit 20 on the current stimulator, or a physical switch, the control unit 112 controls the constant current adjustment unit 1113 to perform constant current operation, thereby controlling the device with constant current control, and by turning on the output switch 122B, current stimulation is applied to the target area.

[0028] Alternatively, instead of the above operation, the system may be implemented to automatically select a mode 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 with the stick-type electrode 16, as described above, it is used by sliding it across the skin surface, so the measured impedance tends to fluctuate significantly. Therefore, if the fluctuation of the measured impedance exceeds a predetermined value, it can be determined that the pin electrode B14 is being used. In other words, the measured impedance is information indicating the electrode to be used, for example, information indicating the pin electrode, and the electrode to be used is determined based on this. In addition, although the pin electrode B14 is intended to be used by sliding it across the skin, the pin electrode B14 often temporarily or instantaneously separates from the skin, and the measured impedance becomes very large. Thus, it can also be determined that the pin electrode B14 is being used when the impedance exceeds a predetermined value. In this case, both the measured impedance and the information that the measured impedance exceeds a predetermined value are information indicating that the pin electrode B14 is being used. This information can be used as a criterion for control to automatically select the impedance measurement and current stimulation mode (IM mode), which is a constant voltage operation. If, for example, a sheet-type electrode A13 is used instead of the stick-type electrode 16 or pin electrode B14, the electrode is attached to the human body, and therefore the impedance fluctuation is not very large. In this case, the mode selection may be automatically switched to the microcurrent stimulation mode (MCR mode) based on the criterion that the impedance value is below a preset value, or that the measured impedance does not exceed that value. In this case, both the measured impedance and the information that the measured impedance does not exceed a preset value constitute information indicating that the sheet-type electrode A13 is being used, that is, information indicating the electrode being used.

[0029] Furthermore, after selecting a mode, the type of electrode may be determined, and if the combination of the selected mode and electrode is inappropriate, the system may automatically switch to an appropriate mode. For example, if the microcurrent stimulation mode (MCR mode) is selected and a pin electrode B14 is used with the stick-type electrode 16, the system will automatically switch to the impedance measurement and current stimulation mode (IM mode). Conversely, if the impedance measurement and current stimulation mode (IM mode) is selected and a sheet-type electrode A13 is used, the system will automatically switch to the microcurrent stimulation mode (MCR mode). In addition to the above, the system may also be configured to have a dedicated connector section on the main unit 11 for the use of the pin electrode B14, and when a cable is connected to this connector, the current stimulation is output in constant voltage mode. That is, the control unit 112 may be configured to switch to perform current stimulation by constant voltage control based on information indicating that the pin electrode B14 is being used. Examples of information indicating the electrode to be used include, but are not limited to, the operating mode, the measured impedance, and the connector used. In this invention, the switch to output is not limited to constant voltage; it may also be a switch to constant current, and the control may switch to constant current control based on information indicating the electrode being used. For example, it is possible to switch to constant current control according to information indicating that sheet-type electrode A13 is being used.

[0030] Furthermore, the system may be implemented to allow manual mode selection and to display a warning message to the user if the connected electrodes are inappropriate, prompting them to connect electrodes that match the selected mode. In this case, it is desirable that the system be implemented so that the message is not output until it is determined that the appropriate electrodes have been connected.

[0031] Regarding the control of the current stimulation output, in microcurrent stimulation mode (MCR mode), constant current operation is performed, and the constant current adjustment unit 1113 functions to apply a maximum current limit (1mA according to specifications), which is the maximum current that can be output with constant current control. In order to reduce the risk of burns during treatment, constant voltage operation is performed in impedance measurement and treatment mode (IM mode), but a maximum limit is set on 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 during constant current control operation (1mA according to specifications), i.e., it can be set to 500μA or 800μA. Constant voltage operation is performed when using the pin electrode B14 as described above, so the contact area between the pin electrode B14 and the skin is small and the current density tends to be large, and therefore pain and burns are likely to occur. Therefore, even when the contact area between the pin electrode B14 and the skin is small and the current density is large due to the use of the pin electrode B14, it is also acceptable to set the maximum limit to a current value that does not cause pain or burns, or makes them less likely to occur. The maximum limit at constant voltage may vary depending on the output voltage.

[0032] Specifically, to further reduce the risk of burns, the control unit 112 is configured to impose a maximum current limit according to the set voltage. For example, the current limit is increased by several tens of μA for every 0.5V increment, providing stepwise output limit control up to the maximum voltage value in impedance measurement and treatment mode (IM mode). This also has the effect of mitigating the sensation of irritation at low voltage output. Furthermore, when the min value is set to 0.5V, a certain amount of offset current is applied, and the maximum limit is controlled as follows: When the output voltage is 0.5V, the maximum limit = offset current + 20 = (offset current + 20) μA; when the output voltage is 1.0V, the maximum limit = offset current + 20 × 2 = (offset current + 40) μA; when the output voltage is 1.5V, the maximum limit = offset current + 20 × 3 = (offset current + 60) μA, ... Here, the current limit is controlled to not exceed a maximum of 1 mA. In particular, outputs of around 20V are sometimes used for roller-type electrodes with a large contact area, and in this case, a relatively large output current is required to prevent the current density from dropping too low. Thus, in constant voltage operation, the control unit 112 can set the maximum output current to an initial value plus a fluctuation value that varies based on the output voltage. Although an offset current is added as the initial value above, it is not limited to this, and there may be no offset current. Also, although the fluctuation value is set to change every 0.5V, which is the output voltage step, it is not limited to this, and the fluctuation value may change in steps of 0.5V or less, or above 0.5V, and the fluctuation rate, which is the value that changes, may be 20μA or less, or above. For example, it may change linearly with respect to the output voltage, or it may change nonlinearly. For example, when the output voltage is low, it may fluctuate by 20μA every 0.5V, but when the output voltage is high, the fluctuation rate may be changed to, for example, 10μA every 0.5V. In other words, a configuration in which the fluctuation rate changes depending on the output voltage is also possible. Furthermore, although the maximum limit is controlled to increase with the output voltage as described above, its maximum value may be controlled so that it does not exceed a certain value. For example, it could be used as a maximum current limit during constant current control.In other words, in the above embodiment, the current limit may be 1000 μA, or a different value 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 a current lower than the maximum current limit during constant current control, such as 500 μA or 800 μA.

[0033] In the above embodiment, the output that provides electrical stimulation based on the information that pin electrode B14 is being used is controlled by constant voltage. However, switching to constant voltage control may be done in the following cases. For example, when using sheet-type electrode A13, if the output is provided by constant current control, the impedance of sheet-type electrode A13 can be measured, and if, for example, the impedance exceeds a threshold value set in advance, the control may be switched to constant voltage control. When a conductive sheet such as sheet-type electrode A13 is used as a therapeutic electrode, the sheet needs to be in complete contact with the skin. If this contact is insufficient, the contact area between the electrode and the skin becomes small, and in the case of constant current control, the output current concentrates on this small contact area, causing current concentration and making it easier for pain and burns to occur due to current concentration. Also, if the conductive sheet deteriorates, part of the sheet becomes highly resistant or the current flows only through part of it, again causing current concentration and making it easier for pain and burns to occur due to current concentration. Even if the area over which the current flows decreases in this way, constant voltage control can maintain the output current so as not to cause pain or burns. Therefore, even when outputting by constant current control, the impedance may be measured, and if the impedance exceeds a preset value, the system may switch to constant voltage control. Alternatively, instead of measuring the impedance in this case, the output voltage may be monitored, and if the output voltage exceeds a preset value, the system may switch to constant voltage control. Furthermore, when the system switches to constant voltage control, the user may be notified of information indicating that the system has switched to constant voltage, that there is a possibility of current concentration, that the electrodes are not making sufficient contact with the skin, or that the conductive sheet is deteriorating. The user may also be notified of information prompting them to check the electrodes or to replace them. This notification may be displayed on the display unit 20, an LED may be lit, or a beep sound may be emitted.

[0034] In this embodiment, impedance is measured using the mechanism shown in Figure 8. The state in which the electrodes are in contact with the human body is considered as the load 55. The current I is measured by the current flowing through the shunt resistor 54 inserted in the supply circuit using the current measurement IC 52. The voltage V is measured by the voltage applied to the load 55 using the voltage measurement IC 53. The impedance is calculated from the above V and I, but here the voltage V and current I are measured alternately and quickly by controlling the switching circuit 51 with the control unit 112 to obtain the impedance. This configuration makes it possible to reduce the circuit configuration compared to simultaneous measurement, and enables the realization of a more portable current stimulation device. However, the voltage V and 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 a body, characterized in that it comprises (1) 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 a control unit that 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 electrodes is information indicating pin electrodes. 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 constant voltage control according to information indicating the pin electrode. Furthermore, the present invention is a current stimulation device characterized in that, even when the output of the electrical signal by constant voltage control is set by the user, the control unit controls the waveform generation unit to change the output of the electrical signal by constant current to the output of the electrical signal by constant voltage control, based on information indicating that the pin electrodes are connected. Furthermore, the present invention provides a current stimulation device for supplying an electrical signal to a body, comprising: (1) an electrode for supplying the electrical signal to the body, wherein the portion in contact with the body is a pin-type pin electrode; an electrode for supplying the electrical signal to the body, wherein the portion in contact with the body is a sheet-type electrode; and a main body, wherein the main body comprises a connector to which the pin electrode is connected, a waveform generation unit for outputting the electrical signal by constant voltage control or constant current control, and a control unit connected to the main body for controlling the waveform generation unit to change the characteristics of the electrical signal according to information indicating that the pin electrode is being used, wherein the waveform generation unit is controlled to change the output of the electrical signal by constant current control to the output of the electrical signal by constant voltage control based on the information, which is information indicating that the pin electrode is connected to the connector. Furthermore, the present invention is a current stimulation device characterized in that (2) the connector is a dedicated connector to which the pin electrodes are connected. Furthermore, the present invention is a current stimulation device characterized in that (3) even when the output of the electrical signal by constant current control is set by the user, the control unit controls the waveform generation unit to change the output of the electrical signal by constant current control to the output of the electrical signal by constant voltage control based on information indicating that the pin electrodes are connected. Furthermore, the present invention provides a current stimulation device for supplying an electrical signal to a body, comprising: (1) an electrode for supplying the electrical signal to the body, wherein the portion of which contacts the body is a pin-type pin electrode; an electrode for supplying the electrical signal to the body, wherein the portion of which contacts the body is a pin-type pin electrode; a sheet-shaped electrode for supplying the electrical signal to the body, which is different from the pin electrode; and a main body, wherein the main body comprises 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 a control unit connected to the main body that controls the waveform generation unit to change the characteristics of the electrical signal according to information indicating that the pin electrode is being used, wherein the waveform generation unit is controlled based on the information, which is information indicating that the pin electrode is connected to the connector, to change the output of the electrical signal by constant current control to the output of the electrical signal by constant voltage control, and to make the upper limit of the output of the electrical signal by constant voltage control smaller than the upper limit of the output of the electrical signal by constant current control. Furthermore, the present invention is a current stimulation device characterized in that (2) the upper limit of the output value of the electrical signal controlled by constant voltage changes according to the output voltage of the electrical signal. Furthermore, the present invention is a current stimulation device characterized in that (3) the upper limit of the output value of the electrical signal by constant voltage control is controlled in steps according to the output voltage of the electrical signal. [Explanation of Symbols]

[0035] 1 Current stimulator 11 Main unit 13 Sheet-type electrode A 14 Pin electrode B 15 Indifferent electrode C 16 Stick-type electrodes 18. Connector for stick-type electrodes 19 Electrode placement 20 Display section 21 Transformers 22 MOSFET 25 Inductance 28 Photocoupler 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 generator 112 Control Unit 113 User Interface Section 114 Power supply section 121 Output switch A 122 Output switch B 171 Connector A for sheet-type electrodes 172 Sheet-type electrode connector B 231 Rectifier diode 232 Reference Voltage IC 241 Smoothing Capacitor 242 Capacitor A 243 Capacitor B 261 Resistance A 262 Resistance B 263 Resistance C 264 Resistance D 265 Resistance E 266 Resistance F 267 Resistance G 271 Switching Regulator A 272 Switching Regulator B 311 Transistor A 312 Transistor B 331 Resistance H 332 Resistance I 333 Resistance J 334 Resistance K 335 Resistance L 431 Resistance M 432 Resistance N 1111 Constant Voltage Adjustment Section 1112 Constant voltage fine adjustment section 1113 Constant current adjustment section

Claims

1. An electrical stimulation device for supplying electrical signals to the body, An electrode that supplies the aforementioned electrical signal to the body, Having the main body, The aforementioned main body is The system includes a waveform generation unit that outputs the aforementioned electrical signal by constant voltage control or constant current control, The system includes a control unit that controls the waveform generation unit to change the characteristics of the electrical signal based on information regarding the output state of the electrical signal, The current stimulation device is characterized in that, when the electrical signal is output by constant current control, the control unit controls the waveform generation unit to make the electrical signal an output by constant voltage control based on the information regarding the output state of the electrical signal.

2. The current stimulation device according to claim 1, characterized in that the information relating to the output state of the electrical signal is based on impedance.

3. The current stimulation device according to claim 1, characterized in that the information relating to the output state of the electrical signal is based on the output voltage.

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