Electric stimulation device

Abstract

To provide an electric stimulation device with enhanced safety.SOLUTION: In an electric stimulation device using a first switching element Q1 to a fourth switching element Q4 connected by H bridge, a control unit 30 diagnoses whether a DC power source 20 and each of the first switching element Q1 to the fourth switching element Q4 are operating normally or abnormally at the start of the electric stimulation device 1. When at least one of the them is abnormal, an electric stimulation from between a first electrode P1 and a second electrode P2 is prohibited.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an electrical stimulation device. [Background technology]

[0002] BACKGROUND ART Electrical stimulation devices that apply electrical stimulation to a user's muscles are known. Electrical stimulation devices can passively move muscles by passing a weak current through the muscles to tense and relax them.

[0003] If the electronic components used in an electrical stimulation device are damaged due to submersion in water or deterioration over time, it is necessary to consider the possibility that the user may feel uncomfortable or that it may lead to skin problems. In cases where the electrical stimulation device is built into fitness wear, there have been cases where users have washed the fitness wear without removing the controller, causing the electronic components to become submerged in water.

[0004] Patent document 1 discloses a method for performing a safety check on H-bridge circuits 2132, 2134, which are major electronic components in a medical device that applies electrical stimulation to a patient's tissue, by individually turning on each vertical leg and each horizontal leg of the H-bridge circuits 2132, 2134 and determining the current passing through sensing resistors 2112, 2122. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] WO 13 / 134763 Summary of the Invention [Problem to be solved by the invention]

[0006] The circuit configuration disclosed in Patent Document 1 does not mention diagnosing the voltage source upstream of the H-bridge circuit, and if an abnormality occurs in the upstream voltage source, the reliability of the diagnosis results of the H-bridge circuit decreases.

[0007] The present invention has been made in light of this situation, and one exemplary purpose of an embodiment thereof is to provide an electrical stimulation device with enhanced safety. [Means for solving the problem]

[0008] To achieve the above object, one embodiment of the present invention provides an electrical stimulation device comprising: a DC power supply capable of controlling the voltage of the output DC power; a first switching element and a second switching element connected in series between a high-side reference line and a low-side reference line of the DC power supply; a first electrode connected to a first connection point between the first and second switching elements and intended to contact a part of the human body; a third switching element and a fourth switching element connected in series between the high-side reference line and a low-side reference line of the DC power supply; a second electrode connected to a second connection point between the third and fourth switching elements and intended to contact another part of the human body; and a controller for controlling the DC power supply and the first to fourth switching elements. Upon startup of the electrical stimulation device, the controller diagnoses whether the DC power supply and the first to fourth switching elements are normal or abnormal, and if at least one of them is abnormal, inhibits electrical stimulation between the first and second electrodes.

[0009] Any combination of the above components, or mutual substitution of the components or expressions of the present invention between methods, devices, systems, etc., are also valid aspects of the present invention. [Effects of the Invention]

[0010] According to the present invention, an electrical stimulation device with enhanced safety can be provided. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a diagram illustrating a first example of a circuit configuration of an electrical stimulation device according to an embodiment. [Figure 2]4 is a diagram for explaining an AC voltage waveform applied between a pair of first and second electrode parts. FIG. [Figure 3] FIG. 10 is a diagram illustrating a second example of a circuit configuration of an electrical stimulation device according to an embodiment. [Figure 4] FIG. 2 is a diagram illustrating an example of a circuit configuration of a DC power supply unit. [Figure 5] FIG. 1 is a diagram illustrating an example of a circuit configuration of a switching regulator. [Figure 6] FIG. 6 is a diagram showing an example of a timing chart of the boost chopper shown in FIG. 5. [Figure 7] FIG. 1 is a diagram illustrating an example of a circuit configuration of a linear regulator. [Figure 8] FIG. 8 is a diagram illustrating an example of a timing chart of the series regulator illustrated in FIG. 7. [Figure 9] FIG. 2 is a diagram illustrating an example of the configuration of an operation unit. [Figure 10] 10 is a flowchart showing the flow of a fault diagnosis program at startup in the electrical stimulation device according to the embodiment. [Figure 11] 10 is a diagram summarizing examples of specific condition settings for a fault diagnosis program in circuit configuration example 1 of electrical stimulation device 1. FIG. [Figure 12] FIG. 10 is a diagram illustrating a third example of a circuit configuration of an electrical stimulation device according to an embodiment. [Figure 13] 10 is a diagram summarizing examples of specific condition settings for a fault diagnosis program in a third circuit configuration example of the electrical stimulation device 1. FIG. [Figure 14] 1 is a diagram schematically illustrating a mobile terminal device receiving radio waves for short-range wireless communication from an electrical stimulation device according to an embodiment. FIG. [Figure 15] FIG. 10 is a diagram showing an example of a Bluetooth (registered trademark) setting screen of the mobile terminal device. [Figure 16] 16 is a diagram for explaining the definition of a fault diagnosis log set in the device name of the electrical stimulation device shown in FIG. 15. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0012] The present invention will be described below based on preferred embodiments with reference to the drawings. The embodiments are illustrative and do not limit the invention, and all features and combinations described in the embodiments are not necessarily essential to the invention. In the embodiments and modifications, the same or equivalent components and members are designated by the same reference numerals, and redundant descriptions will be omitted where appropriate.

[0013] (Circuit configuration example 1 of electrical stimulation device 1) FIG. 1 is a diagram showing a first example circuit configuration of an electrical stimulation device 1 according to an embodiment. Electrical stimulation device 1 is an EMS (Electrical Muscle Stimulation) device that electrically stimulates the muscles of a user. Electrical stimulation device 1 includes an electrical stimulation unit 10, a DC power supply unit 20, a control unit 30, a current detection unit 40, an operation unit 50, and a first drive circuit Dr1 to a fourth drive circuit Dr4. Electrical stimulation unit 10 includes an H-bridge-connected first switching element Q1 to a fourth switching element Q4, and a pair of first and second electrodes P1 and P2.

[0014] The electrical stimulation device 1 is used with a pair of first and second electrodes P1 and P2 in contact with any part of the human body Hd. By contacting the first electrode P1 with one part of the human body Hd and the second electrode P2 with another part of the human body Hd, a current path is formed with the human body Hd as a load.

[0015] The pair of first electrode parts P1 and second electrode parts P2 are electrodes that do not require consumable gel pads, specifically, cloth electrodes. Cloth electrodes are used while soaked in water. Cloth electrodes have a long lifespan, meaning they can be used many times before their lifespan expires. Furthermore, cloth electrodes are washable. The pair of first electrode parts P1 and second electrode parts P2 may be electrodes other than cloth electrodes, such as metal. The pair of first electrode parts P1 and second electrode parts P2 may also be electrodes that require gel pads. The pair of first electrode parts P1 and second electrode parts P2 may also be rubber electrodes made of EPDM (Ethylene Propylene Diene Monomer) rubber, conductive polyurethane, or the like. Rubber electrodes can be used without soaking in water.

[0016] A first switching element Q1 and a second switching element Q2 connected in series, and a third switching element Q3 and a fourth switching element Q4 connected in series, are connected in parallel between a high-side reference line and a low-side reference line of the DC power supply unit 20. A first connection point N1 between the first switching element Q1 and the second switching element Q2 is connected to a first electrode portion P1. A second connection point N2 between the third switching element Q3 and the fourth switching element Q4 is connected to a second electrode portion P2.

[0017] The first switching element Q1 to the fourth switching element Q4 can be semiconductor switching elements such as bipolar transistors, MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors), IGBTs (Insulated Gate Bipolar Transistors), etc. In the following, we will assume an example in which PNP bipolar transistors (hereinafter simply referred to as PNP transistors) are used for the first switching element Q1 and the third switching element Q3, and NPN bipolar transistors (hereinafter simply referred to as NPN transistors) are used for the second switching element Q2 and the fourth switching element Q4.

[0018] In this case, the emitter terminal of the first switching element Q1 is connected to the high-side reference line, the emitter terminal of the second switching element Q2 is connected to the low-side reference line, and the connection point between the collector terminals of the first switching element Q1 and the second switching element Q2 is the first connection point N1. Similarly, the emitter terminal of the third switching element Q3 is connected to the high-side reference line, the emitter terminal of the fourth switching element Q4 is connected to the low-side reference line, and the connection point between the collector terminals of the third switching element Q3 and the fourth switching element Q4 is the second connection point N2.

[0019] The control unit 30 controls the entire electrical stimulation device 1. The control unit 30 can be configured using any one or any combination of a microcontroller, FPGA (Field Programmable Gate Array), ASIC (Application Specific Integrated Circuit), gate IC, or other LSI. The first drive circuit Dr1 to the fourth drive circuit Dr4 generate drive signals for the first switching element Q1 to the fourth switching element Q4 based on control signals for the first switching element Q1 to the fourth switching element Q4 input from the control unit 30, respectively, to drive the first switching element Q1 to the fourth switching element Q4.

[0020] In this embodiment, bipolar transistors are used for the first switching element Q1 through the fourth switching element Q4, and therefore the first driving circuit Dr1 through the fourth driving circuit Dr4 are circuits that generate base currents supplied to the base terminals of the first switching element Q1 through the fourth switching element Q4, respectively. If MOSFETs are used for the first switching element Q1 through the fourth switching element Q4, the first driving circuit Dr1 through the fourth driving circuit Dr4 are circuits that generate gate voltages supplied to the gate terminals of the first switching element Q1 through the fourth switching element Q4, respectively. If the control unit 30 includes a gate IC or the like and has sufficient driving capability, the first driving circuit Dr1 through the fourth driving circuit Dr4 can be configured solely with passive elements such as resistors.

[0021] The control unit 30 controls the first switching element Q1 and the fourth switching element Q4 to an ON state and the second switching element Q2 and the third switching element Q3 to an OFF state, thereby applying a positive voltage between the first electrode portion P1 and the second electrode portion P2. The control unit 30 controls the first switching element Q1 and the fourth switching element Q4 to an OFF state and the second switching element Q2 and the third switching element Q3 to an ON state, thereby applying a negative voltage between the first electrode portion P1 and the second electrode portion P2.

[0022] The current detection unit 40 detects the current flowing in the low-side reference line from the electrical stimulation unit 10 to the DC power supply unit 20 and outputs the detected current to the control unit 30. The current detection unit 40 includes, for example, a shunt resistor inserted in the low-side reference line, an operational amplifier that amplifies the voltage across the shunt resistor and outputs a voltage corresponding to the current flowing through the shunt resistor, and an A / D converter that converts the analog output voltage of the operational amplifier into a digital value. Note that a Hall element may be used instead of the shunt resistor. Note that the A / D converter may be one built into the microcontroller in the control unit 30.

[0023] Operation unit 50 accepts operations by the user of electrical stimulation device 1, converts the operation signal into an electrical signal, and outputs it to control unit 30. Based on the notification signal from control unit 30, operation unit 50 notifies the user visually and / or audibly of the state of electrical stimulation device 1.

[0024] Hereinafter, in this embodiment, control unit 30 controls electrostimulation unit 10 as follows. In one cycle, control unit 30 applies a positive pulse voltage and a negative pulse voltage alternately multiple times between first electrode P1 and second electrode P2, and then inserts an interval period. More specifically, in one cycle, control unit 30 applies a positive pulse voltage and a negative pulse voltage alternately an odd number of times between first electrode P1 and second electrode P2, and then inserts an interval period. In the next cycle, control unit 30 applies an odd number of pulse voltages in which the phases of the odd number of pulse voltages are inverted, and then inserts an interval period.

[0025] Fig. 2 is a diagram illustrating the AC voltage waveform applied between a pair of first electrode portion P1 and second electrode portion P2. The voltage waveform shown in Fig. 2 is composed of a combination of positive and negative basic pulses with a time width t1. A positive basic pulse causes a current to flow in a positive direction from one of the pair of first electrode portion P1 and second electrode portion P2 to the other, and a negative basic pulse causes a current to flow in a negative direction from the other to the one.

[0026] A pause period of time width t2 is provided between the positive and negative basic pulses. The applied voltage during this pause period is 0. In this waveform, a basic pulse group of time width t3 (= 5 × t1 + 5 × t2) including five basic pulses and five pause periods is formed. This basic pulse group, together with the interval period of time width t4 provided after it, forms a basic waveform of one cycle (time width) t5 (= t3 + t4).

[0027] For example, if the time width t1 is set to 100 us and the time width t2 is set to 100 us, the time width t3 will be 1 ms. In this embodiment, the user can select between Mode A (20 Hz mode) and Mode B (4 Hz mode). If Mode A is selected, the time width t5 will be 50 ms (= 20 Hz) and the time width t4 (interval period) will be 49 ms. If Mode B is selected, the time width t5 will be 250 ms (= 4 Hz) and the time width t4 (interval period) will be 249 ms.

[0028] In the example shown in FIG. 2, the voltage polarity of the basic pulse is reversed for each waveform group. That is, if a positive pulse voltage is output three times and a negative pulse voltage is output twice in a given waveform group, the next waveform group alternates between the positive pulse voltage being output two times and the negative pulse voltage being output three times. This allows the two waveform groups to be paired to suppress uneven charge distribution on the first electrode portion P1 and the second electrode portion P2 and to suppress corrosion of the first electrode portion P1 and the second electrode portion P2. Note that the pulse voltage application pattern shown in FIG. 2 is merely an example and is not limited to this application pattern. For example, a pattern in which positive and negative pulse voltages are applied consecutively multiple times rather than alternately may be used. Alternatively, a pattern in which the pulse voltage is applied an even number of times in one cycle may be used.

[0029] (Circuit configuration example 2 of electrical stimulation device 1) FIG. 3 is a diagram showing a second circuit configuration example of electrical stimulation device 1 according to an embodiment. In circuit configuration example 2 shown in FIG. 3, multiple electrical stimulation units 10 are provided. Multiple electrical stimulation units 10 may be built into a single piece of fitness wear. Below, an example is assumed in which four systems of electrical stimulation units 10a-10d are provided.

[0030] For example, first electrode unit P1a and second electrode unit P2a of first system electrical stimulation unit 10a are attached to the right arm, and first system electrical stimulation unit 10a can provide electrical stimulation to the biceps and triceps. First electrode unit P1b and second electrode unit P2b of second system electrical stimulation unit 10b are attached to the abdomen (one of them may be attached to the lower back), and second system electrical stimulation unit 10b can provide electrical stimulation to the rectus abdominis and oblique abdominal muscles.

[0031] The first electrode P1c and the second electrode P2c of the third system electrical stimulation unit 10c are attached to the right foot (one may be attached to the buttocks), and the third system electrical stimulation unit 10c can provide electrical stimulation to the quadriceps and buttocks of the right foot. The first electrode P1d and the second electrode P2d of the fourth system electrical stimulation unit 10d are attached to the left foot (one may be attached to the buttocks), and the fourth system electrical stimulation unit 10d can provide electrical stimulation to the quadriceps and buttocks of the left foot.

[0032] Control unit 30 controls DC power supply unit 20 to adjust the voltage levels output to each of multiple electrical stimulation units 10a-10d. The configuration of DC power supply unit 20 will be described later. The user can set the EMS intensity level for each system. For example, the user can set the EMS intensity level in 20 stages.

[0033] The control unit 30 controls the output voltage of the DC power supply unit 20 in accordance with the set intensity level. For example, the control unit 30 controls the output voltage of the DC power supply unit 20 in accordance with the intensity level as follows. Level 1: Around 11V, Level 2: Around 12V, Level 3: Around 14V, Level 4: Around 16V, Level 5: Around 18V, Level 6: Around 19V, Level 7: Around 21V, Level 8: Around 23V, Level 9: Around 25V, Level 10: Around 26V, Level 11: Around 28V, Level 12: Around 30V, Level 13: Around 32V, Level 14: Around 33V, Level 15: Around 35V, Level 16: Around 37V, Level 17: Around 39V, Level 18: Around 40V, Level 19: around 42V, Level 20: around 44V.

[0034] Controller 30 controls the H-bridge circuits of each of electrical stimulation units 10a-10d so that voltages of phase-shifted basic pulse groups are applied between the first electrodes P1a-P1d and the second electrodes P2a-P2d of each of the multiple systems of electrical stimulation units 10a-10d. Controller 30 shifts the drive timing of the H-bridge circuits between the multiple systems by 2 ms, for example. That is, controller 30 outputs EMS signals that are phase-shifted by 2 ms to each H-bridge circuit of the multiple systems of electrical stimulation units 10a-10d.

[0035] (Circuit configuration example of DC power supply unit 20) FIG. 4 is a diagram showing an example of the circuit configuration of the DC power supply unit 20. The DC power supply unit 20 includes a secondary battery 21, a switching regulator 22, and a linear regulator 23. In the following, an example is assumed in which a single lithium-ion cell is used as the secondary battery 21. The nominal voltage of the lithium-ion cell is 3.7 V, and varies within a range of 3.4 to 4.2 V depending on the SOC (State of Charge). The lithium-ion cell is charged with DC from a charger via a USB cable.

[0036] Switching regulator 22 is a DC / DC converter that uses a switching system to boost the voltage of the DC power supplied from secondary battery 21 to a set voltage. Linear regulator 23 is a DC / DC converter that is connected in parallel to multiple electrical stimulation units 10a-10d and that uses a linear system to reduce the voltage of the DC power supplied from switching regulator 22 to a command voltage set by control unit 30.

[0037] Generally, linear regulators can only step down, have high losses (low efficiency), generate a lot of heat, have a fast response speed, generate little noise, are simple to design, have small circuit scale, and are low cost.On the other hand, switching regulators can step up and down, have low losses (high efficiency), generate little heat, have slower response speed than linear regulators, generate more noise, are complex to design, have large circuit scale, and are high cost.

[0038] (Circuit configuration example of switching regulator 22) Fig. 5 is a diagram showing an example circuit configuration of the switching regulator 22. In the example circuit configuration shown in Fig. 5, the switching regulator 22 is configured as a boost chopper. A boost chopper is a switching-type DC / DC converter that is only capable of boosting voltage. The boost chopper includes, as its main components, an inductor L1, a diode D1, a first capacitor C1, and a first control switching element Qc1. An NPN transistor is used for the first control switching element Qc1.

[0039] An inductor L1 and a first control switching element Qc1 are connected in series across the secondary battery 21. The connection point between the inductor L1 and the first control switching element Qc1 is connected to the high-side reference line. Specifically, the collector terminal of the first control switching element Qc1 is connected to the connection point, the emitter terminal is connected to the low-side reference line, and the base terminal is connected to the controller 30 via a third resistor R3.

[0040] A diode D1 is inserted in the forward direction in the high-side reference line connected to the connection point. Specifically, the connection point side is the anode terminal and the output side of the boost chopper is the cathode terminal. A first capacitor C1 is connected between the high-side reference line and the low-side reference line on the cathode terminal side of the diode D1. The first capacitor C1 is connected at a position closer to the output side than the diode D1. The first capacitor C1 is a smoothing capacitor, and for example, an electrolytic capacitor is used.

[0041] A third discharge switching element Qd3 is connected in parallel to the first capacitor C1. An NPN transistor is used for the third discharge switching element Qd3. The base terminal of the third discharge switching element Qd3 is connected to the control unit 30 via a fourth resistor R4. The control unit 30 can reset the charge stored in the first capacitor C1 by outputting an ON signal to turn on the third discharge switching element Qd3.

[0042] A first voltage dividing circuit, in which a first resistor R1 and a second resistor R2 are connected in series, is connected across the secondary battery 21, and the voltage at the connection point between the first resistor R1 and the second resistor R2 is output to the control unit 30. The control unit 30 calculates the voltage of the secondary battery 21 (≈ the input voltage V of the boost chopper) based on the output voltage of the first voltage dividing circuit. IN Detect.

[0043] A second voltage dividing circuit, in which a fifth resistor R5 and a sixth resistor R6 are connected in series, is connected between the output terminals of the boost chopper, and the voltage at the connection point between the fifth resistor R5 and the sixth resistor R6 is output to the control unit 30. The control unit 30 calculates the output voltage V of the boost chopper based on the output voltage of the second voltage dividing circuit. out Detect.

[0044] The control unit 30 controls the output voltage V out The duty ratio of the PWM (Pulse Width Modulation) signal supplied to the base terminal of the first control switching element Qc1 is controlled so that the output voltage V matches the target voltage. out is lower than the target voltage, the control unit 30 increases the duty ratio to increase the ratio of the on-time of the first control switching element Qc1. out is higher than the target voltage, the control unit 30 reduces the duty ratio to reduce the ratio of the on time of the first control switching element Qc1.

[0045] When the first control switching element Qc1 is in the on state, a current flows through the path of the secondary battery 21, inductor L1, and first control switching element Qc1, and energy is charged in the inductor L1. Even when the first control switching element Qc1 is switched to the off state, the same current continues to flow, so the output voltage increases by the amount corresponding to the increase in impedance on the load side including the first capacitor C1.

[0046] 6 is a diagram showing an example of a timing chart of the boost chopper shown in FIG. 5. Control unit 30 sets the output target voltage of the boost chopper to a voltage obtained by adding a margin to the output voltage of electrostimulation unit 10 of the system to which the maximum intensity level is set. For example, when level 20, the maximum intensity level, is set in electrostimulation unit 10a of the first system, the voltage applied to human body Hd from electrostimulation unit 10a of the first system to which level 20 is set is 44 V. Control unit 30 adds a margin to 44 V to set the output target voltage of the boost chopper to approximately 50 V.

[0047] In the example shown in Figure 6, the input voltage V IN is the output voltage of the secondary battery 21, 3.7 V. During the ON period of the first control switching element Qc1, a collector current I E increases over time. During the OFF period of the first control switching element Qc1, the collector current I E is cut off, the diode D1 is turned on, and the current I D decreases over time.

[0048] In the example shown in FIG. 6, taking into consideration the forward voltage Vf of the diode D1, the collector voltage V between the collector and emitter during the off period of the first control switching element Qc1 is C The output voltage of the boost chopper, V out is smoothed by the first capacitor C1 and is controlled to an average of 53V.

[0049] (Circuit configuration example of linear regulator 23) Fig. 7 is a diagram showing an example circuit configuration of the linear regulator 23. In the example circuit configuration shown in Fig. 7, the linear regulator 23 is configured as a series regulator. The series regulator includes, as its main components, a second control switching element Qc2, a third control switching element Qc3, a ninth resistor R9, a tenth resistor R10, a fourth control switching element Qc4, an eleventh resistor R11, an operational amplifier OP1, a fourth voltage dividing circuit in which a twelfth resistor R12 and a thirteenth resistor R13 are connected in series, and a low-pass filter 231.

[0050] A control switching unit consisting of the second control switching element Qc2 and the third control switching element Qc3 connected in a Darlington configuration is inserted into the high-side reference line between the input and output terminals of the series regulator. An NPN transistor is used for the second control switching element Qc2, and a PNP transistor is used for the third control switching element Qc3. The collector terminal of the second control switching element Qc2 is connected to the input terminal of the series regulator, and the emitter terminal of the second control switching element Qc2 is connected to the output terminal of the series regulator. The emitter terminal of the third control switching element Qc2 is connected to the collector terminal of the second control switching element Qc2, and the collector terminal of the third control switching element Qc2 is connected to the base terminal of the second control switching element Qc2. The Darlington-connected control switching unit is equivalent to a PNP Darlington transistor with an increased current gain.

[0051] On the collector terminal side of the second control switching element Qc2, a ninth resistor R9, a tenth resistor R10, and a fourth control switching element Qc4 are connected in series between the high-side reference line and the low-side reference line. An NPN transistor is used for the fourth control switching element Qc4. The connection point between the ninth resistor R9 and the tenth resistor R10 is connected to the base terminal of a PNP Darlington transistor (third control switching element Qc3).

[0052] A fourth voltage dividing circuit, in which a twelfth resistor R12 and a thirteenth resistor R13 are connected in series, is connected between the high-side reference line and the low-side reference line on the emitter terminal side of the second control switching element Qc2.

[0053] The connection point between the twelfth resistor R12 and the thirteenth resistor R13 is connected to the inverting input terminal of the operational amplifier OP1. The non-inverting input terminal of the operational amplifier OP1 is connected to the control unit 30 via a low-pass filter 231. The output terminal of the operational amplifier OP1 is connected to the base terminal of the fourth control switching element Qc4 via an eleventh resistor R11. The emitter terminal of the fourth control switching element Qc4 is connected to the low-side reference line, and the collector terminal of the fourth control switching element Qc4 is connected to a tenth resistor R10.

[0054] The operational amplifier OP1 outputs the feedback voltage V FB and the reference voltage V supplied from the control unit 30 via the low-pass filter 231. REF The third control switching element Qc3 has a base terminal to which a base current according to the output voltage of the operational amplifier OP1 and the resistance value of the eleventh resistor R11 is supplied.

[0055] A second capacitor C2 is connected between the input terminals of the series regulator. A third capacitor C3 is connected between the output terminals of the series regulator. The second capacitor C2 is connected to the input voltage V IN The third capacitor C3 is a capacitor for smoothing the output voltage V of the series regulator. out The second capacitor C2 and the third capacitor C3 are capacitors for smoothing the voltage. For example, electrolytic capacitors are used as the second capacitor C2 and the third capacitor C3.

[0056] A fourth discharge switching element Qd4 is connected in parallel to the third capacitor C3. The base terminal of the fourth discharge switching element Qd4 is connected to the control unit 30 via a fourteenth resistor R14. The control unit 30 can reset the charge stored in the third capacitor C3 by outputting an ON signal to turn on the fourth discharge switching element Qd4.

[0057] A third voltage dividing circuit, in which a seventh resistor R7 and an eighth resistor R8 are connected in series, is connected between the input terminals of the series regulator, and the voltage at the connection point between the seventh resistor R7 and the eighth resistor R8 is output to the control unit 30. The control unit 30 calculates the input voltage V of the series regulator based on the output voltage of the third voltage dividing circuit. IN Detect.

[0058] A fifth voltage dividing circuit, in which a fifteenth resistor R15 and a sixteenth resistor R16 are connected in series, is connected between the output terminals of the series regulator, and the voltage at the connection point between the fifteenth resistor R15 and the sixteenth resistor R16 is output to the control unit 30. The control unit 30 calculates the output voltage V of the series regulator based on the output voltage of the fifth voltage dividing circuit. out Detect.

[0059] The control unit 30 generates a reference voltage V according to the command voltage. REF is input to the non-inverting input terminal of the operational amplifier OP1. The command voltage is a voltage that is set according to the intensity level set by the user. In the example above, if the intensity level set by the user is level 1, the command voltage is set to 11V.

[0060] When the output current of the series regulator increases due to a load fluctuation, the output voltage V out The feedback voltage V FB The feedback voltage V FB is the reference voltage V REFWhen the voltage drops below 1 V, the output voltage of the operational amplifier OP1 rises, the base current of the fourth control switching element Qc4 increases, and the collector current of the fourth control switching element Qc4 increases. This increases the base current of the control switching element (PNP Darlington transistor), and the collector voltage between the collector and emitter of the control switching element (PNP Darlington transistor) decreases, resulting in the output voltage V of the series regulator. out rises.

[0061] Conversely, when the output current of the series regulator decreases due to a load fluctuation, the output voltage V out rises, and the feedback voltage V FB The feedback voltage V FB is the reference voltage V REF When the voltage becomes higher, the output voltage of the operational amplifier OP1 drops, the base current of the fourth control switching element Qc4 decreases, and the collector current of the fourth control switching element Qc4 decreases. This causes the base current of the control switching unit (PNP Darlington transistor) to decrease, and the collector voltage between the collector and emitter of the control switching unit (PNP Darlington transistor) increases, resulting in the output voltage V of the series regulator. out decreases.

[0062] 8 is a diagram showing an example of a timing chart of the series regulator shown in FIG. 7. In the example shown in FIG. 8, the twelfth resistor R12 is set to 190 kΩ, the thirteenth resistor R13 is set to 10 kΩ, and the feedback voltage V FB is the output voltage of the series regulator, V out In this case, the control unit 30 sets the reference voltage V to 1 / 20 of the command voltage. REF is input to the non-inverting input terminal of the operational amplifier OP1. The series regulator receives an input voltage V of about 50V from the boost chopper in the previous stage. IN is assumed to be supplied.

[0063] The example shown in Figure 8 shows an example in which the first system electrical stimulation unit 10a and the second system electrical stimulation unit 10b are operating, and the intensity level of the first system electrical stimulation unit 10a is set to level 20, and the intensity level of the second system electrical stimulation unit 10b is set to level 1.

[0064] The control unit 30 applies a reference voltage V of 2.2 V to the non-inverting input terminal of the operational amplifier OP1 during the period when the EMS signal is output to the H-bridge circuit of the first system electrical stimulation unit 10a. REF This supplies the output voltage V out However, it is controlled to 44V corresponding to level 20.

[0065] The control unit 30 applies a reference voltage V of 0.55 V to the non-inverting input terminal of the operational amplifier OP1 during the period when the EMS signal is output to the H-bridge circuit of the second system electrical stimulation unit 10b. REF This supplies the output voltage V out However, it is controlled to 11V according to level 1.

[0066] The control unit 30 maintains a constant voltage output during the time width t3 during which the basic pulse group is applied, and changes the voltage level during the interval period of time width t4. Note that since the series regulator needs to ensure a voltage difference of at least 2V between the input and output, the control unit 30 adjusts the voltage level to V IN ≧V out Control to maintain the +5 state.

[0067] In this way, control unit 30 controls the command voltage set in the series regulator, and can adjust the voltage levels output to multiple systems of electrical stimulation units 10a-10d. REF is input to the non-inverting input terminal of the operational amplifier OP1. The operational amplifier OP1 outputs the output voltage V out The control circuit outputs a voltage for controlling the second controlling switching element Qc2 so that the output voltage of the second controlling switching element Qc2 coincides with the command voltage.

[0068] (Configuration example of operation unit 50) Fig. 9 is a diagram showing an example of the configuration of the operation unit 50. The operation unit 50 shown in Fig. 9 is provided with a power button 51, a PART button 52, an UP button 53, a DOWN button 54, and four lamps for status notification. The first lamp 55 includes a red LED and a green LED, and the red LED lights up during charging and the green LED lights up during 20 Hz mode operation. The second lamp 56 includes a green LED, and the green LED lights up during 4 Hz mode operation.

[0069] The third lamp 57 includes a green LED, which lights up when the first system (SIDE BACK system) is operating. The fourth lamp 58 includes a green LED, which lights up when the second system (FRONT system) is operating.

[0070] The user can turn the power of electrical stimulation device 1 on / off by pressing and holding power button 51. The user can switch between 20 Hz mode and 4 Hz mode by pressing power button 51 while the power is on. The user can select all systems, SIDE BACK system, or FRONT system by pressing PART button 52. The user can increase the intensity level by pressing up button 53, and can decrease the intensity level by pressing down button 54.

[0071] Although not shown, the operation unit 50 is assumed to have a built-in speaker for outputting warning sounds and audio guidance.

[0072] As mentioned above, the DC power supply unit 20 and the electrical stimulation unit 10 are equipped with a large number of electronic components, and if a malfunction occurs due to submersion in water or deterioration, it is necessary to consider the possibility that this could lead to health damage depending on the location and type of malfunction.

[0073] Therefore, when starting up electrical stimulation device 1, control unit 30 diagnoses whether DC power supply unit 20 and first switching element Q1 through fourth switching element Q4 are normal or abnormal. If at least one of them is abnormal, control unit 30 prohibits electrical stimulation from between first electrode unit P1 and second electrode unit P2. When starting up electrical stimulation device 1, control unit 30 first diagnoses whether DC power supply unit 20 is normal or abnormal, and if DC power supply unit 20 is normal, it diagnoses whether each of first switching element Q1 through fourth switching element Q4 is normal or abnormal.

[0074] Fig. 10 is a flowchart showing the flow of a fault diagnosis program at startup in electrical stimulation device 1 according to an embodiment. Fig. 11 is a diagram summarizing an example of specific condition settings for the fault diagnosis program in circuit configuration example 1 of electrical stimulation device 1.

[0075] 10, when power button 51 of operation unit 50 is pressed and held (Y in S10), electrostimulation device 1 starts up and enters an idling state. Controller 30 executes a fault diagnosis of DC power supply unit 20 (S11). In the fault diagnosis mode for DC power supply unit 20, controller 30 sets the output setting voltage (output target voltage) of switching regulator 22 to a voltage equivalent to intensity level 1 (e.g., 12 V).

[0076] The control unit 30 sets a voltage (e.g., 3.7 V) equivalent to the output voltage of the secondary battery 21 as the output command voltage (output target voltage) of the linear regulator 23. The control unit 30 controls the first switching element Q1 and the fourth switching element Q4, or the second switching element Q2 and the third switching element Q3, to an ON state, thereby establishing electrical continuity between the first electrode P1 and the second electrode P2 via the human body Hd.

[0077] The control unit 30 controls the output voltage V of the switching regulator 22. outIf the difference between the detected value and the set voltage is within a predetermined range (the difference is less than ±10% in the example of FIG. 11), the switching regulator 22 is diagnosed as normal, and if the difference is not within the predetermined range (the difference is more than ±10% in the example of FIG. 11), the switching regulator 22 is diagnosed as abnormal (diagnosis No. 1 in FIG. 11).

[0078] The control unit 30 controls the output voltage V out If the difference between the detected value and the command voltage is within a predetermined range (the difference is less than ±10% in the example of FIG. 11), the linear regulator 23 is diagnosed as normal, and if it is not within the predetermined range (the difference is more than ±10% in the example of FIG. 11), the linear regulator 23 is diagnosed as abnormal (diagnosis No. 2 in FIG. 11).

[0079] If both the switching regulator 22 and the linear regulator 23 are normal (Y in S12), the process proceeds to step S13, and if at least one of the switching regulator 22 and the linear regulator 23 is abnormal (N in S12), the process proceeds to step S18.

[0080] In step S13, control unit 30 performs a fault diagnosis of electrical stimulation unit 10 (S13). Control unit 30 controls first switching element Q1 through fourth switching element Q4 to an all-off state, and acquires a current detection value from current detection unit 40 in this state. If control unit 30 does not detect a significant current, it determines that the current detection system including current detection unit 40 is normal, and if a significant current is detected, it determines that there is an abnormality in the current detection system (diagnosis No. 3 in FIG. 11 ).

[0081] Under ideal conditions, when first switching element Q1 through fourth switching element Q4 are all off, no current flows through electrical stimulation unit 10, and the voltage corresponding to the current flowing through the shunt resistor of current detection unit 40 is 0 V. However, under actual conditions, a voltage higher than 0 V may be detected due to variations in the shunt resistor and operational amplifier, quantization error of the A / D converter, environmental conditions such as temperature, and the influence of noise.

[0082] Taking these conditions into consideration, the designer sets the reference value for determining that no current is flowing through electrical stimulation unit 10 to (0 + α) V. Control unit 30 determines that the current detection system is normal if the voltage corresponding to the current detected by current detection unit 40 (hereinafter referred to as the detected current) is less than the reference value, and determines that there is an abnormality in the current detection system if the voltage corresponding to the detected current is equal to or greater than the reference value (diagnosis No. 3 in FIG. 11).

[0083] Abnormalities in the current detection system include failures or deterioration of shunt resistors, operational amplifiers, A / D converters, wiring connecting these elements, and passive elements, as well as abnormalities in the source code of the fault diagnosis program implemented in the control unit 30.

[0084] When the current detection system is normal, the control unit 30 controls the second switching element Q2 to be on and the first switching element Q1, the third switching element Q3, and the fourth switching element Q4 to be off, and acquires the detected current value from the current detection unit 40 in this state. When no significant current is detected (when the voltage corresponding to the detected current is less than the reference value), the control unit 30 determines that the first switching element Q1 is normal, and when a significant current is detected (when the voltage corresponding to the detected current is equal to or greater than the reference value), the control unit 30 determines that there is an abnormality in the first switching element Q1 (specifically, a short circuit failure) (diagnosis No. 4 in FIG. 11).

[0085] Even if second switching element Q2 is on, when first switching element Q1, third switching element Q3, and fourth switching element Q4 are off, no current should flow through electrical stimulation unit 10. If current detection unit 40 detects a significant current, it is considered that first switching element Q1 has a short circuit failure.

[0086] Short circuit faults include full shorts, half shorts, and layer shorts. If the first switching element Q1 is half shorted or layer shorted when the electrical stimulation device 1 operates, the positive basic pulse does not drop to 0 V, resulting in a decrease in the sensation of sensation due to a positive / negative voltage imbalance. This can also cause unwanted pseudo-DC current to be generated in the human body Hd.

[0087] When the first switching element Q1 is normal, the control unit 30 controls the fourth switching element Q4 to be in the on state and the first switching element Q1, the second switching element Q2, and the third switching element Q3 to be in the off state, and acquires a current detection value from the current detection unit 40 in this state. When no significant current is detected (when the voltage corresponding to the detected current is less than the reference value), the control unit 30 determines that the third switching element Q3 is normal, and when a significant current is detected (when the voltage corresponding to the detected current is equal to or greater than the reference value), the control unit 30 determines that there is an abnormality in the third switching element Q3 (specifically, a short circuit failure) (diagnosis No. 5 in FIG. 11).

[0088] If the third switching element Q3 is normal, the control unit 30 controls the third switching element Q3 to the on state and the first switching element Q1, the second switching element Q2, and the fourth switching element Q4 to the off state, and acquires a current detection value from the current detection unit 40 in this state. If the control unit 30 does not detect a significant current (if the voltage corresponding to the detected current is less than the reference value), it determines that the fourth switching element Q4 is normal, and if it detects a significant current (if the voltage corresponding to the detected current is equal to or greater than the reference value), it determines that there is an abnormality in the fourth switching element Q4 (specifically, a short circuit failure) (diagnosis No. 6 in FIG. 11).

[0089] When the fourth switching element Q4 is normal, the control unit 30 controls the first switching element Q1 to be on and the second switching element Q2, the third switching element Q3, and the fourth switching element Q4 to be off, and acquires a current detection value from the current detection unit 40 in this state. When no significant current is detected (when the voltage corresponding to the detected current is less than the reference value), the control unit 30 determines that the second switching element Q2 is normal, and when a significant current is detected (when the voltage corresponding to the detected current is equal to or greater than the reference value), the control unit 30 determines that there is an abnormality in the second switching element Q2 (specifically, a short circuit failure) (diagnosis No. 7 in FIG. 11).

[0090] In circuit configuration example 2 of electrical stimulation device 1, control unit 30 executes diagnosis No. 3 to diagnosis No. 7 in order for each system. In the case of four systems, control unit 30 executes diagnosis No. 3 to diagnosis No. 7 for electrical stimulation unit 10a of the first system, diagnosis No. 3 to diagnosis No. 7 for electrical stimulation unit 10b of the second system, diagnosis No. 3 to diagnosis No. 7 for electrical stimulation unit 10c of the third system, and diagnosis No. 3 to diagnosis No. 7 for electrical stimulation unit 10d of the fourth system, in that order.

[0091] If the first switching element Q1 to the fourth switching element Q4 of the current detection system and all systems of the electrical stimulation unit 10 are normal (Y in S14), the process transitions to step S15, and if at least one of the first switching element Q1 to the fourth switching element Q4 of the current detection system and all systems of the electrical stimulation unit 10 is abnormal (N in S14), the process transitions to step S18.

[0092] In step S15, the control unit 30 executes a skin detection diagnosis (S15). The skin detection diagnosis is to diagnose the contact state of the pair of first electrode unit P1 and second electrode unit P2 with the skin of the human body Hd. The control unit 30 transmits a test pulse at a fixed cycle (e.g., 500 ms) to repeatedly detect the skin contact state. The voltage of the test pulse is set to a low voltage that does not cause any bodily sensation, for example, a voltage equivalent to the output voltage of the secondary battery 21 (e.g., 3.7 V).

[0093] If the pair of first electrode P1 and second electrode P2 is in good contact with the skin, the detected current will be equal to or greater than the reference value. Note that different values may be used for the reference value used in the skin detection diagnosis and the reference value used in the fault diagnosis of electrical stimulation unit 10. In circuit configuration example 2 of electrical stimulation device 1, control unit 30 executes skin detection diagnosis for each system in turn.

[0094] If the skin detection diagnosis of all systems is successful (Y in S16), control unit 30 starts the electrical stimulation program (S17). If the skin detection diagnosis of at least one system is unsuccessful (N in S16), the process proceeds to step S18.

[0095] It is desirable that the fault diagnosis in steps S11 to S16 be completed within a time that is not noticeable to the user so as not to impede normal use by the user. For example, it is desirable that the fault diagnosis at startup be completed within one second after power-on.

[0096] If any of the diagnostic targets is determined to be abnormal in steps S12 and S14, the control unit 30 repeats the diagnosis of the target determined to be abnormal a set number of times (e.g., 10 times), and if it is determined to be abnormal the set number of times in a row, it confirms the abnormal diagnosis of that target. The control unit 30 saves error log information on the target for which the abnormal diagnosis was confirmed and the number of abnormality determinations in an internal non-volatile storage area (S18). When the control unit 30 confirms the abnormal diagnosis, it notifies the user of the error with at least one of an alarm sound and a lamp (S19). This will be explained in more detail below.

[0097] If it is determined in steps S11 and S12 that the switching regulator 22 is abnormal, the control unit 30 repeats a set number of times the boost state (control of the first controlling switching element Qc1 is enabled) and the stopped state (control of the first controlling switching element Qc1 is disabled) of the switching regulator 22. If the detected value of the output voltage Vout of the switching regulator 22 deviates from the set voltage by ±10% or more for a set number of consecutive times, the control unit 30 confirms the abnormality diagnosis of the switching regulator 22.

[0098] Controller 30 stores switching regulator 22 in error and the number of times the error has been detected in a non-volatile storage area (S18). Controller 30 cumulatively counts up the number of times the error has been detected for each error. Controller 30 notifies the user of the error by outputting a warning sound (e.g., a buzzer sound) from the speaker of operation unit 50 (S19). Controller 30 may also flash all lamps 55-58 of operation unit 50. After notifying the user of the error, controller 30 transitions electrical stimulation device 1 to a sleep state or shuts it down.

[0099] During the retry, the output voltage V outIf the detected value falls within ±10% of the set voltage once or several times in succession, the control unit 30 determines that the switching regulator 22 is normal.

[0100] In steps S11 and S12, if it is determined that the linear regulator 23 is abnormal, the control unit 30 sets the linear regulator 23 to a step-down state (reference voltage REF output is enabled) and stopped (reference voltage REF The output voltage V of the linear regulator 23 is repeatedly out If the detected value deviates from the set voltage by ±10% or more for a set number of consecutive times, the control unit 30 determines that the linear regulator 23 is abnormal.

[0101] Controller 30 stores linear regulator 23 in error and the number of times the error has been detected in a non-volatile memory area (S18). Controller 30 notifies the user of the error by outputting an alarm sound from the speaker of operation unit 50 (S19). Controller 30 may also flash all lamps 55-58 of operation unit 50. After notifying the user of the error, controller 30 transitions electrical stimulation device 1 to a sleep state or shuts it down.

[0102] During the retry, the output voltage V out If the detected value falls within ±10% of the set voltage once or several times in succession, the control unit 30 determines that the linear regulator 23 is normal.

[0103] If it is determined in steps S13 and S14 that there is an abnormality in the current detection system, the control unit 30 repeats the cycle of turning off all of the first switching element Q1 through the fourth switching element Q4 and turning on all of the first switching element Q1 through the fourth switching element Q4 a set number of times. If the voltage corresponding to the detected current is equal to or greater than the reference value for a set number of consecutive times, the control unit 30 confirms the diagnosis of an abnormality in the current detection system.

[0104] In addition, in circuit configuration example 2 of the electrical stimulation device 1, if the current detection unit 40 is shared by all systems and the voltage corresponding to the detected current when the first switching element Q1 to the fourth switching element Q4 are all off in all systems becomes equal to or exceeds a reference value, the control unit 30 may confirm the abnormality diagnosis of the current detection system without retrying.

[0105] Controller 30 stores the current detection system in error and the number of times the error has occurred in a non-volatile memory area (S18). Controller 30 notifies the user of the error by outputting an alarm sound from the speaker of operation unit 50 (S19). Controller 30 may also flash all lamps 55-58 of operation unit 50. After notifying the user of the error, controller 30 transitions electrical stimulation device 1 to a sleep state or shuts it down.

[0106] During the retry, if the voltage corresponding to the detected current becomes equal to or exceeds the reference value once or several times in succession, the control unit 30 determines that the current detection system is normal.

[0107] If it is determined in steps S13 and S14 that the first switching element Q1 is abnormal, the control unit 30 repeatedly turns the first switching element Q1 on and off a set number of times. If the voltage corresponding to the detected current is equal to or greater than the reference value for the set number of consecutive times, the control unit 30 confirms the abnormality diagnosis of the first switching element Q1.

[0108] Controller 30 stores the first switching element Q1 that has the error and the number of times the error has been detected in a non-volatile storage area (S18). Controller 30 notifies the user of the error by outputting an alarm sound from the speaker of operation unit 50 (S19). Controller 30 then blinks only the lamp of operation unit 50 for the system in which first switching element Q1 has been detected as abnormal. For example, if first switching element Q1 included in the H-bridge circuit of the first system (SIDE BACK system) is detected as abnormal, controller 30 blinks only third lamp 57. After notifying the user of the error, controller 30 transitions electrical stimulation device 1 to a sleep state or shuts it down.

[0109] During the retry, if the voltage corresponding to the detected current becomes equal to or exceeds the reference value once or several times in succession, the control unit 30 determines that the first switching element Q1 is normal.

[0110] If it is determined in steps S13 and S14 that the third switching element Q3, the fourth switching element Q4, or the second switching element Q2 has an abnormality, the control unit 30 performs the same process as when it is determined that the first switching element Q1 has an abnormality. In this case, the first switching element Q1 may be read as the third switching element Q3, the fourth switching element Q4, or the second switching element Q2, as appropriate.

[0111] If the skin detection diagnosis fails for any system in steps S15 and S16, control unit 30 stores the system for which the skin detection diagnosis failed in a non-volatile memory area (S18). Control unit 30 outputs an alarm sound from the speaker of operation unit 50 to notify the user of the error (S19). Furthermore, control unit 30 flashes only the lamp of operation unit 50 for the system for which the skin detection diagnosis failed. Note that control unit 30 may flash the lamp of operation unit 50 for the system for which the skin detection diagnosis succeeded, and turn off the lamp of the system for which the skin detection diagnosis failed.

[0112] If the user reattaches the first electrode P1 and the second electrode P2 of the system in question based on the error notification and the skin detection abnormality is resolved, control unit 30 starts the electrical stimulation program (S17). If the skin detection abnormality is not resolved after a certain period of time has passed, control unit 30 transitions electrical stimulation device 1 to a sleep state or shuts it down.

[0113] (Circuit configuration example 3 of electrical stimulation device 1) Fig. 12 is a diagram showing a third example circuit configuration of an electrical stimulation device 1 according to an embodiment. In the third example circuit configuration of an electrical stimulation device 1 shown in Fig. 12, a first coupling capacitor Cc1, a second coupling capacitor Cc2, and first and second discharge switching elements Qd1 and Qd2 as discharge circuits are added to the first example circuit configuration of an electrical stimulation device 1 shown in Fig. 1.

[0114] The first coupling capacitor Cc1 is inserted between the first connection point N1 and the first electrode P1 of the H-bridge circuit to provide DC insulation between the first connection point N1 and the first electrode P1. The second coupling capacitor Cc2 is inserted between the second connection point N2 and the second electrode P2 of the H-bridge circuit to provide DC insulation between the second connection point N2 and the second electrode P2.

[0115] By adding a first coupling capacitor Cc1 in series between the H-bridge circuit and the first electrode P1, and a second coupling capacitor Cc2 in series between the H-bridge circuit and the second electrode P2, it is possible to cut off the DC current flowing into the human body Hd from the electrical stimulation device 1. As described above, the EMS current supplied to the human body Hd from the electrical stimulation device 1 is an AC pulse, and therefore passes through the first coupling capacitor Cc1 and the second coupling capacitor Cc2 and does not affect steady-state operation.

[0116] The first discharge switching element Qd1 is connected between the wiring connecting the first coupling capacitor Cc1 and the first electrode portion P1 and the low-side reference line. The second discharge switching element Qd2 is connected between the wiring connecting the second coupling capacitor Cc2 and the second electrode portion P2 and the low-side reference line. NPN transistors are used for the first discharge switching element Qd1 and the second discharge switching element Qd2. When NPN transistors are used, base current flows, so there is no need to connect discharge resistors in series with the first discharge switching element Qd1 and the second discharge switching element Qd2. Furthermore, when MOSFETs are used instead of bipolar transistors, discharge resistors should be connected in series with each as necessary.

[0117] In circuit configuration example 3 of electrical stimulation device 1, a fifth drive circuit Dr5 is added. The fifth drive circuit Dr5 generates drive signals for the first discharge switching element Qd1 and the second discharge switching element Qd2 based on control signals for the first discharge switching element Qd1 and the second discharge switching element Qd2 input from control unit 30, thereby driving the first discharge switching element Qd1 and the second discharge switching element Qd2. The fifth drive circuit Dr5 generates base currents to be supplied to base terminals of the first discharge switching element Qd1 and the second discharge switching element Qd2.

[0118] The control unit 30 controls the on / off of the first discharge switching element Qd1 and the second discharge switching element Qd2 in synchronization. Therefore, the first discharge switching element Qd1 and the second discharge switching element Qd2 can share a drive circuit, as shown in Fig. 12. However, separate drive circuits may be provided for the first discharge switching element Qd1 and the second discharge switching element Qd2.

[0119] The control unit 30 applies a positive pulse voltage and a negative pulse voltage alternately multiple times between the first electrode P1 and the second electrode P2 in one cycle, and inserts a discharge period (a period during which the first discharge switching element Qd1 and the second discharge switching element Qd2 are on) in the interval period thereafter. By simultaneously turning on the first discharge switching element Qd1 and the second discharge switching element Qd2 during the interval period, the first electrode P1 and the second electrode P2 become at the same potential via the ground potential of the low-side reference line, and any charge remaining in the human body Hd can be discharged.

[0120] 13 is a diagram summarizing an example of specific condition settings for a fault diagnosis program in circuit configuration example 3 of electrical stimulation device 1. In circuit configuration example 3 of electrical stimulation device 1, in diagnosis No. 3, control unit 30 controls first switching element Q1 through fourth switching element Q4 and first discharging switching element Qd1 through second discharging switching element Qd2 to an all-off state, and acquires a detected current value from current detection unit 40 in this state. If a significant current is detected, control unit 30 determines that the current detection system, including current detection unit 40, is abnormal.

[0121] If no significant current is detected, the control unit 30 controls the first discharge switching element Qd1 to the second discharge switching element Qd2 to be on, and controls the high-side first switching element Q1 and third switching element Q3 to be on. Note that the control unit 30 preferably turns on the first switching element Q1 and the third switching element Q3 with a time lag.

[0122] In this state, the control unit 30 acquires the detected current value from the current detection unit 40. If the control unit 30 detects a current equal to or greater than the set value, it determines that the current detection system including the current detection unit 40 is normal, and if the control unit 30 does not detect a current equal to or greater than the set value, it determines that there is an abnormality in the current detection system. The set value may be set to the upper limit of the detection range of the current detection unit 40, or may be set to a value lower than the upper limit by a predetermined value.

[0123] In circuit configuration example 3 of the electrical stimulation device 1, because the first coupling capacitor Cc1 is interposed between the first switching element Q1 and the first discharging switching element Qd1, even when both are controlled to the ON state, no DC current flows between the high-side reference line and the low-side reference line. Similarly, because the second coupling capacitor Cc2 is interposed between the third switching element Q3 and the second discharging switching element Qd2, even when both are controlled to the ON state, no DC current flows between the high-side reference line and the low-side reference line. Furthermore, the DC current to the human body Hd is also cut off. Therefore, it is possible to safely diagnose whether the current detection unit 40 can detect a conduction current in a short-circuit state.

[0124] In tests No. 4 to No. 7, the first discharge switching element Qd1 to the second discharge switching element Qd2 are maintained in the off state. The diagnostic method is the same as in circuit configuration example 1 of the electrical stimulation device 1.

[0125] As described above, according to this embodiment, when starting up electrical stimulation device 1, a fault diagnosis program is executed before starting the electrical stimulation program, and if an abnormality is detected, the start of the electrical stimulation program is prohibited, thereby enhancing safety. This can prevent the user from feeling uncomfortable or from experiencing health problems.

[0126] Furthermore, by identifying the location of the failure and storing it in the control unit 30, failure analysis can be facilitated. Conventionally, when a failure is discovered by a user after shipment, the controller (control unit 30 and operation unit 50) is returned and then analyzed using measuring instruments such as a tester or oscilloscope. This method requires a great deal of man-hours and effort to identify the location of the failure. In contrast, according to the present embodiment, the location of the failure and the number of errors are stored as an error log in the control unit 30, and by reading the error log, failure analysis can be performed easily and in detail.

[0127] Furthermore, when a malfunction is detected, the user is notified of the malfunction by at least one of an alarm sound and a lamp, allowing the user to instantly grasp the occurrence of the error and the malfunctioning system. This allows the user to promptly request repair or replacement from customer support. Furthermore, when the user consults customer support by phone, the user can easily convey the details of the malfunction to the support staff by telling them the status of the lamp.

[0128] Furthermore, by diagnosing whether the output voltage of DC power supply unit 20 is appropriate at startup, it is possible to prevent deviations in the perceived intensity level due to deviations in the output voltage of DC power supply unit 20. It is also possible to ensure that electronic components used in electrical stimulation unit 10 are used within their rated voltage ranges. Furthermore, in fault diagnosis of first switching element Q1 to fourth switching element Q4, it is possible to prevent deviations in the voltage corresponding to the detected current due to deviations in the output voltage of upstream DC power supply unit 20, thereby ensuring the reliability of fault diagnosis of first switching element Q1 to fourth switching element Q4.

[0129] Furthermore, because the output voltage of DC power supply unit 20 is first diagnosed as being appropriate, fault diagnosis of first switching element Q1 to fourth switching element Q4 can be performed while ensuring the reliability of the power supply voltage input to electrical stimulation unit 10. Furthermore, if there is an abnormality in DC power supply unit 20, the process does not proceed to fault diagnosis of electrical stimulation unit 10, so in that case, unnecessary fault diagnosis processing can be avoided.

[0130] Furthermore, by using the switching regulator 22 and the linear regulator 23 in the DC power supply unit 20, the switching regulators 22 can be consolidated into one system, thereby reducing the size and cost of the DC power supply unit 20. The inductor L1 and the first capacitor C1 used in the switching regulator 22 are large in size, which hinders miniaturization. If a switching regulator 22 is provided for each system, the DC power supply unit 20 will become larger and more expensive.

[0131] By providing a linear regulator 23 after the switching regulator 22, it is possible to change the voltage instantaneously. The response time of the linear regulator 23 is approximately equal to the response time of the control switching unit (PNP Darlington transistor), and it has a fast transient response speed. In contrast, the switching regulator 22 must take into account the charge speed of the first capacitor C1 in addition to the response time of the first control switching element Qc1, and therefore its transient response speed is slower than that of the linear regulator 23.

[0132] When the above-described control of shifting the drive timing of the H-bridge circuit among the multiple systems is adopted, even if one linear regulator 23 is shared by multiple systems of electrical stimulation units 10a-10d, the intensity level of each system can be adjusted individually. Furthermore, the use of linear regulator 23 allows the output voltage of DC power supply unit 20 to be changed rapidly, making it possible to apply AC voltages of various shapes other than pulse waves (e.g., shapes similar to sine waves) from electrical stimulation unit 10 to human body Hd. This allows various flavors to be added to the bodily stimulation experienced by the user.

[0133] Furthermore, by providing linear regulator 23 downstream of switching regulator 22, a fault diagnosis program at startup can diagnose faults in switching regulator 22 without causing the user to feel any electrical stimulation. That is, even if the boost rate of switching regulator 22 is increased, downstream linear regulator 23 can reduce the voltage to a level at which the user does not feel any electrical stimulation, so fault diagnosis of switching regulator 22 can be performed without causing the user to feel any electrical stimulation.

[0134] The fault diagnosis program described above diagnoses short-circuit faults between the first switching element Q1 and the fourth switching element Q4, but if an open fault occurs, no current flows, so no safety issue arises. Furthermore, the user can immediately notice the abnormality because electrical stimulation device 1 does not operate.

[0135] The present invention has been described above based on an embodiment. This embodiment is merely an example, and it will be understood by those skilled in the art that various modifications are possible in the combination of each component and each treatment process, and that such modifications are also within the scope of the present disclosure. Such modifications will be described below.

[0136] In Figure 1, the current detection unit 40 is configured to detect the current flowing in the low-side reference line from the electrical stimulation unit 10 to the DC power supply unit 20 and output it to the control unit 30, but it may also be configured to detect the current flowing in the high-side reference line from the DC power supply unit 20 to the electrical stimulation unit 10 and output it to the control unit 30.

[0137] Hereinafter, we consider a method for a maintenance technician to check the fault diagnosis log (error log) stored in a nonvolatile memory area in control unit 30 when electrical stimulation device 1 is returned due to a malfunction. A typical method involves a maintenance technician opening the housing of the malfunctioning controller, connecting the microcontroller inside to a maintenance PC with a serial communications cable, and loading the fault diagnosis log stored in the microcontroller into the PC. This method requires cumbersome tasks such as removing screws from the housing of the controller and connecting a cable to the serial communications port of the microcontroller.

[0138] A method for easily checking the fault diagnosis log stored in the non-volatile memory area in the control unit 30 using short-range wireless communication will be described below. In this embodiment, it is assumed that BLE (Bluetooth Low Energy) is used as the short-range wireless communication. BLE is an extended standard of Bluetooth and is a low-power short-range wireless communication standard that uses the 2.4 GHz band. BLE is suitable for battery operation due to its ultra-low power consumption. Wi-Fi (registered trademark) may also be used instead of BLE. The maintenance person checks the fault diagnosis log using a mobile information terminal equipped with short-range wireless communication functionality.

[0139] 14 is a schematic diagram of a mobile terminal device 2 receiving radio waves via short-range wireless communication from an electrical stimulation device 1 according to an embodiment. In the example shown in FIG. 14, a smartphone is used as the mobile terminal device 2. Note that a tablet terminal or a laptop computer may be used instead of a smartphone. A control unit 30 of the electrical stimulation device 1 includes a short-range wireless communication unit.

[0140] The short-range wireless communication unit of electrical stimulation device 1 transmits advertising packets as beacon packets at regular time intervals to notify external devices that support short-range wireless communication of the presence of electrical stimulation device 1. The short-range wireless communication unit of electrical stimulation device 1 sets a fault diagnosis log for the device name included in the advertising packet.

[0141] 15 is a diagram showing an example of a Bluetooth setting screen 2a of mobile terminal device 2. When mobile terminal device 2 is within the reach of BLE radio waves transmitted from electrical stimulation device 1, the device name of electrical stimulation device 1 is displayed on Bluetooth setting screen 2a of mobile terminal device 2.

[0142] 16 is a diagram illustrating the definition of the fault diagnosis log set in the device name of the electrical stimulation device 1. The first and second bytes from the highest order of 0x "0150000001" define the status of the electrical stimulation device 1, with "01" indicating a fault detection state.

[0143] Bytes 3-10 define the fault detection count value indicating the diagnosis history of the fault diagnosis process described above. From the least significant byte, the cumulative count value determined to be abnormal in test No. 1 shown in Fig. 13, the cumulative count value determined to be abnormal in test No. 2, the cumulative count value determined to be abnormal in test No. 3-1, the cumulative count value determined to be abnormal in test No. 3-2, the cumulative count value determined to be abnormal in test No. 4, the cumulative count value determined to be abnormal in test No. 5, the cumulative count value determined to be abnormal in test No. 6, and the cumulative count value determined to be abnormal in test No. 7 are defined.

[0144] The example shown in Fig. 16 indicates that the cumulative number of times that diagnosis No. 1 was judged to be abnormal is 1, and the cumulative number of times that diagnosis No. 7 was judged to be abnormal is 5. Since the maximum value of 1 byte is F(15), the fault diagnosis log shown in Fig. 16 can display the number of times that each diagnosis item was judged to be abnormal up to 15 times. Note that the fault diagnosis log shown in Fig. 16 is just an example, and if there are a large number of systems or if the number of diagnosis items is increased, the number of bytes of the fault detection count value will increase.

[0145] When an error is detected during the fault diagnosis and an alarm sound is emitted, many users restart electrostimulation device 1. Restarting often resolves the error. In such cases, the user does not return electrostimulation device 1 to the service center. Regardless of whether the device is returned or not, control unit 30 counts up the number of errors for the diagnosis number determined to be abnormal, which is stored in an internal nonvolatile memory area.

[0146] With the method described above, a maintenance technician can check the fault diagnosis log of electrical stimulation device 1 simply by displaying Bluetooth setting screen 2a on mobile terminal device 2. This significantly reduces the amount of work compared to when electrical stimulation device 1 and mobile terminal device 2 are connected via a wire. Furthermore, since there is no need to pair electrical stimulation device 1 and mobile terminal device 2, the cumbersome pairing connection operation is also eliminated. [Explanation of symbols]

[0147] 1 Electrical stimulation device, 2 Portable terminal device, 10 Electrical stimulation section, 20 DC power supply section, 21 Secondary battery, 22 Switching regulator, 23 Linear regulator, 231 Low-pass filter, 30 Control section, Q1-Q4 Switching element, P1 First electrode section, P2 Second electrode section, Dr1-Dr5 Drive circuit, Qd1-Qd4 Discharge switching element, Qc1-Qc4 Control switching element, Cc1 First coupling capacitor, Cc2 Second coupling capacitor, Hd Human body, L1 Inductor, C1-C3 Capacitor, D1 Diode, OP1 Operational amplifier, R1-R16 Resistor.

Claims

1. a DC power supply unit capable of controlling the voltage of DC power to be output; a first switching element and a second switching element connected in series between a high-side reference line and a low-side reference line of the DC power supply unit; a first electrode portion connected to a first connection point between the first switching element and the second switching element, the first electrode portion being to be brought into contact with a part of a human body; a third switching element and a fourth switching element connected in series between a high-side reference line and a low-side reference line of the DC power supply unit; a second electrode portion connected to a second connection point between the third switching element and the fourth switching element, the second electrode portion being to be in contact with another part of the human body; a control unit that controls the DC power supply unit and the first switching element to the fourth switching element, The control unit diagnoses whether the DC power supply unit and the first switching element to the fourth switching element are normal or abnormal at the time of startup of the electrical stimulation device, and if at least one of them is abnormal, prohibits electrical stimulation from between the first electrode unit and the second electrode unit. Electrical stimulation device.

2. The control unit diagnoses whether the DC power supply unit is normal or abnormal at the time of startup of the electrical stimulation device, and if the DC power supply unit is normal, diagnoses whether each of the first switching element to the fourth switching element is normal or abnormal. The electrical stimulation device according to claim 1 .

3. The DC power supply unit is a first DC / DC converter that boosts the voltage of DC power supplied from the battery to a set voltage using a switching system; a second DC / DC converter that linearly reduces the voltage of the DC power supplied from the first DC / DC converter to a command voltage; When the electrical stimulation device is started, the control unit compares the detected value of the output voltage of the first DC / DC converter with the set voltage, and compares the detected value of the output voltage of the second DC / DC converter with the command voltage, and if the deviations between the detected value and the command voltage are within a predetermined range, diagnoses the DC power supply unit as normal, and if at least one of the deviations is not within the predetermined range, diagnoses the DC power supply unit as abnormal. The electrical stimulation device according to claim 1 or 2.

4. a current detection unit that detects a current flowing through the low-side reference line or the high-side reference line and outputs the detected current to the control unit; The control unit, when starting the electrical stimulation device, When a significant current is detected with the first switching element-the fourth switching element all in an off state, it is determined that an abnormality exists in a detection system including the current detection unit; When a significant current is detected while the second switching element is in an on state and the first switching element, the third switching element, and the fourth switching element are in an off state, it is determined that an abnormality exists in the first switching element; When a significant current is detected while the fourth switching element is in an ON state and the first switching element, the second switching element, and the third switching element are in an OFF state, it is determined that an abnormality exists in the third switching element; When a significant current is detected while the third switching element is in an ON state and the first switching element, the second switching element, and the fourth switching element are in an OFF state, it is determined that an abnormality exists in the fourth switching element; When a significant current is detected while the first switching element is in an on state and the second, third, and fourth switching elements are in an off state, it is determined that an abnormality exists in the second switching element. The electrical stimulation device according to claim 1 or 2.

5. The control unit The diagnosis of the object determined to be abnormal is repeated a set number of times, and if the object is determined to be abnormal for the set number of consecutive times, the abnormal diagnosis of the object is confirmed. The electrical stimulation device according to claim 1 or 2.

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