Electrical stimulator

Abstract

This invention provides an electrical stimulation device that enables the application of electrical stimulation to the human body to activate deep muscles. [Solution] This is an electrical stimulation device that generates a stimulating voltage between two electrodes that are electrically in contact with the human body. This electrical stimulation device comprises a regulator configured to generate an output voltage by stepping down the input voltage, a pulse voltage circuit configured to generate a pulse voltage having a magnitude corresponding to the output voltage, and a control circuit configured to control the regulator and the pulse voltage circuit. The control circuit controls the pulse voltage circuit so that a periodic pulse voltage is generated as the stimulating voltage, and controls the regulator so that the output voltage oscillates periodically.

Description

[Technical Field]

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

[0002] Electrical stimulation devices that provide electrical stimulation to a user's muscles have been known for some time (see, for example, Patent Document 1). Electrical stimulation devices can cause muscles to tense and relax by passing a weak electric current through them. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] International Publication No. 2013 / 134763 [Overview of the project] [Problems that the invention aims to solve]

[0004] However, the inventors have come to recognize the following problems. The inventors have been trying to stimulate the deep muscles of the body (hereinafter also referred to as "deep muscles") using an electrical stimulation device. The inventors have found that with electrical stimulation at a frequency of about 20 Hz, it is possible to move the superficial muscles, but it is difficult to deliver the electrical stimulation to the deep muscles, and with electrical stimulation at a frequency of 100 Hz or higher, it is possible to deliver the electrical stimulation to the deep muscles, but it is difficult to move the muscles.

[0005] This invention has been made in view of these circumstances, and one of its exemplary objectives is to provide an electrical stimulation device that enables the application of electrical stimulation to the human body to move deep muscles. [Means for solving the problem]

[0006] One aspect of the present invention is an electrical stimulation device that generates a stimulating voltage between two electrodes that are electrically in contact with the human body. This electrical stimulation device comprises a regulator configured to generate an output voltage by stepping down an input voltage, a pulse voltage circuit configured to generate a pulse voltage having a magnitude corresponding to the output voltage, and a control circuit configured to control the regulator and the pulse voltage circuit, wherein the control circuit controls the pulse voltage circuit so that a periodic pulse voltage is generated as the stimulating voltage, and controls the regulator so that the output voltage oscillates periodically.

[0007] Furthermore, any combination of the above components, as well as conversions of the expression of the present invention between methods, apparatus, systems, recording media, computer programs, etc., are also valid embodiments of the present invention. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide an electrical stimulation device that can deliver electrical stimulation to the human body to move deep muscles. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic diagram of an electrical stimulation device according to one embodiment of the present invention. [Figure 2] This is a block diagram of the controller according to the same embodiment. [Figure 3] This is a circuit diagram of a boost circuit according to the same embodiment. [Figure 4] This is a circuit diagram of a regulator according to the same embodiment. [Figure 5] This is a circuit diagram of the pulse voltage circuit according to the same embodiment. [Figure 6] This is a timing chart illustrating an example of the operation of the controller according to the same embodiment. [Figure 7] This is a block diagram of the controller related to the comparative technology. [Figure 8] This is a timing chart to explain an example of controller operation related to the comparative technology. [Figure 9] Figure 9(a) shows the waveform of the ideal stimulation current, Figure 9(b) shows the waveform of the stimulation current related to the comparative technique when the load is light, and Figure 9(c) shows the waveform of the stimulation current related to the comparative technique when the load is heavy. [Modes for carrying out the invention]

[0010] (Embodiment) Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. In the description of the drawings, the same elements will be denoted by the same reference numeral, and redundant descriptions will be omitted as appropriate. In this specification and drawings, multiple components having substantially the same functional configuration may be distinguished by adding different letters after the same reference numeral.

[0011] In this specification, "member A is connected to member B" includes not only cases where member A and member B are directly connected physically, but also cases where member A and member B are indirectly connected via other members that do not substantially affect their electrical connection or impair the functions or effects produced by their combination.

[0012] Similarly, "member C is provided between member A and member B" includes not only cases where member A and member C, or member B and member C, are directly connected, but also cases where they are indirectly connected via other members that do not substantially affect their electrical connection or impair the functions or effects produced by their combination.

[0013] In this specification, the symbols attached to electrical signals such as voltage signals and current signals, or to circuit elements such as resistors, capacitors, and inductors, shall represent the respective voltage values, current values, or circuit constants (resistance values, capacitance values, and inductance) as needed.

[0014] Figure 1 is a schematic diagram of an electrical stimulator 1 according to one embodiment of the present invention. The electrical stimulator 1 is an EMS (Electrical Muscle Stimulation) device that provides electrical stimulation to the user's muscles. The electrical stimulator 1 is configured to generate a stimulation voltage between two electrodes that are electrically in contact with the human body. The stimulation voltage is a voltage that generates an electric current (hereinafter also referred to as "stimulation current") that provides electrical stimulation to the human body.

[0015] The electrical stimulation device 1 according to this embodiment comprises a belt 2, a controller 10, a first electrode 20a, a second electrode 20b, a first coupling portion 22a, and a second coupling portion 22b. The controller 10, the first electrode 20a, the second electrode 20b, the first coupling portion 22a, and the second coupling portion 22b are each provided on the belt 2.

[0016] The belt 2 may be fixed to any part of the user, but the belt 2 according to this embodiment is configured to be fixed to the user's waist or abdomen. For example, the belt 2 may be fixed to the user's waist or abdomen when wrapped around the user's waist or abdomen, by connecting a first connecting portion 22a provided at one end of the belt 2 with a second connecting portion 22b provided at the other end of the belt 2. The first connecting portion 22a and the second connecting portion 22b may be composed of, for example, a fastener and a hook-and-loop fastener.

[0017] The first electrode 20a and the second electrode 20b each make electrical contact with the human body. The first electrode 20a and the second electrode 20b may not only make direct contact with the human body, but may also make electrical contact with the human body via other conductive materials. The first electrode 20a and the second electrode 20b may each be electrodes that do not require consumable gel pads, for example, and may specifically be cloth electrodes. Cloth electrodes can be used after being moistened with water. Figure 1 shows an example of one pair of electrodes (first electrode 20a and second electrode 20b) for applying electrical stimulation, but there may be two or three such pairs of electrodes, or four or more.

[0018] In this embodiment, the first electrode 20a and the second electrode 20b are provided to apply electrical stimulation to muscles of the user's waist or abdomen (e.g., the iliopsoas muscle). Specifically, when the belt 2 is fixed to the user, the first electrode 20a and the second electrode 20b are each provided to be in electrical contact with the user's waist or abdomen.

[0019] Figure 2 is a block diagram of the controller 10 according to this embodiment. The controller 10 includes a control circuit 100, a booster circuit 120, a regulator 140, and a pulse voltage circuit 180. The controller 10 may further include an operation unit including, as necessary, a power button and a button for setting the level of electrical stimulation.

[0020] The booster circuit 120 boosts the voltage of a battery (not shown in Figure 2) to output voltage V B1 and is configured to generate said output voltage. The regulator 140 steps down the input voltage to output voltage V REG and is configured to generate said output voltage. In this embodiment, the input voltage of the regulator 140 is the output voltage V B1 of the booster circuit 120. The pulse voltage circuit 180 is configured to generate a pulse voltage having a magnitude corresponding to the output voltage V REG of the regulator 140. The pulse voltage circuit 180 according to this embodiment generates a first voltage V1 at a terminal connected to the first electrode 20a, generates a second voltage V2 at a terminal connected to the second electrode 20b, and operates such that the inter-terminal voltage V EMS1 (=V1-V2) becomes the pulse voltage.

[0021] The control circuit 100 is configured to comprehensively control the operation of the controller 10. The control circuit 100 according to this embodiment controls the booster circuit 120, the regulator 140, and the pulse voltage circuit 180. The control circuit 100 outputs, for example, a control signal S PWM1 for PWM (Pulse Width Modulation) control of the booster circuit 120, and control signals S PWM2 , S CH , S DISand control signal S for controlling the pulse voltage circuit 180 SW_A ,S SW_B It generates signals such as control signals S. PWM1 ,S PWM2 These are PWM signals, and the control circuit 100 controls the control signal S PWM1 ,S PWM2 The duty cycle can be adjusted.

[0022] The control circuit 100 receives a feedback signal V from the boost circuit 120. FB_B1 The boost circuit 120 may be controlled based on this. The control circuit 100 detects the input voltage V of the regulator 140. DIV_IN and the output voltage V of regulator 140 REG Voltage V for detection DIV_OUT The regulator 140 may be controlled based on this.

[0023] Figure 3 is a circuit diagram of the boost circuit 120 according to this embodiment. The boost circuit 120 consists of a battery 122, an output line 124, a low-side line 126, a feedback circuit 128, an inductor L1, and an output capacitor C. B It has diode D1 and transistor MN. Output line 124 is the output voltage V of the boost circuit 120. B1 The line that supplies power is the lowside line 126, which is the line that connects to the ground.

[0024] Transistor MN is composed of an N-channel MOS (Metal Oxide Semiconductor) transistor. The source of transistor MN is connected to the low-side line 126, and the drain of transistor MN is connected to the anode of diode D1. The gate of transistor MN is connected to the control signal S PWM1 It will be supplied.

[0025] One end of the inductor L1 is connected to the voltage V of the battery 122. BAT A current is supplied, and the other end of inductor L1 is connected to the anode of diode D1. The cathode of diode D1 is connected to output line 124. Output capacitor CB One end is connected to output line 124, and output capacitor C B The other end is connected to the lowside line 126.

[0026] The feedback circuit 128 outputs V B1 The corresponding feedback voltage V FB_B1 The circuit is configured to generate V. The feedback circuit 128 includes resistors R1, R2 and capacitor C1. Resistors R1 and R2 are connected in series between the output line 124 and the low-side line 126, and capacitor C1 is connected in parallel with resistor R2. Output voltage V B1 The feedback voltage V is divided by resistors R1 and R2. FB_B1 This is generated.

[0027] The boost circuit 120 converts the voltage V of the battery 122. BAT Boost the voltage to produce an output voltage V B1 Specifically, the boost circuit 120 generates the control signal S when the transistor MN is used. PWM1 By switching accordingly, the control signal S PWM1 Output voltage V according to the duty cycle B1 Generates.

[0028] Figure 4 is a circuit diagram of the regulator 140 according to this embodiment. The regulator 140 according to this embodiment includes an input line 142, an output line 144, a power supply voltage line 146, a low-side line 148, an input voltage divider circuit 150, an output voltage divider circuit 152, a feedback circuit 154, a charging transistor 156, a discharge transistor 158, a charging control circuit 160, a discharge control circuit 162, an operational amplifier 164, a low-pass filter 166, a capacitor C3, and an output capacitor C OUT , resistance R 11 ~R 16 It also has transistors BT5 and BT6.

[0029] Input line 142 is the output voltage V of the boost circuit 120. B1 This is the line that supplies the voltage. Output line 144 is the output voltage V of regulator 140.REG This is the line that is supplied with power. Power supply voltage line 146 is supplied with power supply voltage V CC This is the line that supplies the power. Lowside line 148 is the line that connects to the ground.

[0030] Capacitor C3 controls the output voltage V of the boost circuit 120. B1 To smooth the voltage, it is provided between the input line 142 and the low-side line 148. The input voltage divider circuit 150 includes resistors R3 and R4 connected in series between the input line 142 and the low-side line 148, and the output voltage V of the boost circuit 120 B1 The voltage V obtained by dividing the voltage DIV_IN The output voltage divider circuit 152 includes resistors R5 and R6 connected in series between the output line 144 and the low-side line 148, and generates the output voltage V of the regulator 140. REG The voltage V obtained by dividing the voltage DIV_OUT Generates.

[0031] The feedback circuit 154 includes resistors R7 and R8 connected in series between the output line 144 and the low-side line 148, and a capacitor C2 connected in parallel with resistor R7. The output voltage V is across resistors R7 and R8. REG The feedback voltage V obtained by dividing the voltage FB_OP This is input to the inverting input terminal of the operational amplifier 164.

[0032] Output capacitor C OUT It is located between the output line 144 and the low-side line 148. Specifically, it is the output capacitor C OUT One end is connected to output line 144, and output capacitor C OUT The other end is connected to the low-side line 148. Output capacitor C OUT The voltage charged to it becomes the output voltage V of regulator 140. REG In other words, the output capacitor C OUT This is the output voltage V of regulator 140. REG It is charged by the output capacitor C. OUT The output voltage V is generated when the battery is charged or discharged. REGIt changes.

[0033] The charging transistor 156 connects to the input line 142 and the output capacitor C. OUT It is provided between them. The charging transistor 156 according to this embodiment is composed of a Darlington transistor formed by connecting transistors BT1 and BT2 in a Darlington configuration. Transistor BT1 is composed of a pnp type bipolar transistor, and transistor BT2 is composed of an npn type bipolar transistor. The emitter of transistor BT1 is connected to the collector of transistor BT2, the collector of transistor BT1 is connected to the base of transistor BT2, and the emitter of transistor BT2 is connected to the output line 144.

[0034] Resistance R 11 One end is connected to input line 142, and resistor R 11 The other end is connected to the emitter of charging transistor 156 (i.e., the emitter of transistor BT1). Resistor R 12 One end is connected to the emitter of the charging transistor 156, and resistor R 12 The other end is connected to the base of the charging transistor 156 (i.e., the base of transistor BT1). Resistor R 13 One end is connected to the base of the charging transistor 156.

[0035] The discharge transistor 158 is provided between the output line 144 and the low-side line 148. In this embodiment, the discharge transistor 158 is composed of an NPN bipolar transistor. The emitter of the discharge transistor 158 is connected to the low-side line 148, and the collector of the discharge transistor 158 is connected to the output line 144. Resistor R 14 It is provided between the power supply voltage line 146 and the base of the discharge transistor 158.

[0036] The charging control circuit 160 is configured to control the on / off state of the charging transistor 156. The charging control circuit 160 according to this embodiment includes a transistor BT3 and a resistor R9. The transistor BT3 is an npn bipolar transistor. The emitter of transistor BT3 is connected to the low-side line 148, and the base of transistor BT3 is connected to one end of resistor R9. The other end of resistor R9 is connected to a control signal S for controlling the on / off state of transistor BT3. CH It will be supplied.

[0037] The discharge control circuit 162 is configured to control the on / off state of the discharge transistor 158. In this embodiment, the discharge control circuit 162 includes transistor BT4 and resistor R 11 It includes. Transistor BT4 is composed of an npn type bipolar transistor. The emitter of transistor BT4 is connected to the low-side line 148, and the collector of transistor BT4 is connected to the base of discharge transistor 158. The base of transistor BT4 is connected to resistor R 11 One end of resistor R9 is connected to a control signal S for controlling the on / off state of transistor BT4. The other end of resistor R9 is connected to a control signal S for controlling the on / off state of transistor BT4. DIS It will be supplied.

[0038] Transistors BT5 and BT6 are each composed of npn bipolar transistors. The emitters of transistors BT5 and BT6 are connected to the low-side line 148. The collector of transistor BT5 is connected to resistor R 13 The other end is connected, and the base of transistor BT5 is connected to the collector of transistor BT3. The collector of transistor BT6 is connected to the base of discharge transistor 158. Resistor R 15 It is placed between the base of transistor BT5 and the output terminal of op-amp 164, and resistor R 16 It is placed between the base of transistor BT6 and the output terminal of operational amplifier 164.

[0039] The low-pass filter 166 is a control signal S, which is a PWM signal. PWM2into a DC reference voltage V having a magnitude corresponding to the duty ratio of control signal S PWM2 is converted. The reference voltage V REF is input to the non-inverting input terminal of the operational amplifier 164. The operational amplifier 164 outputs an output voltage V obtained by amplifying an error between the reference voltage V REF and a feedback voltage V REF FB_OP OP .

[0040] An operation example of the regulator 140 for increasing the output voltage V REG will be described. In the present embodiment, when the charging transistor 156 is on, the output voltage V REG increases as the output capacitor C is charged by a collector current I flowing through the charging transistor 156 C_CH OUT .

[0041] Specifically, transistor BT3 of the charging control circuit 160 is turned off by control signal S CH , and transistor BT4 of the discharge control circuit 162 is turned on by control signal S DIS . Accordingly, transistor BT5 and the charging transistor 156 are each turned on, and the discharge transistor 158 is turned off. As a result, a collector current I flows through the charging transistor 156 C_CH (I C_CH > 0), and no collector current I flows through the discharge transistor 158 C_DIS (I C_DIS = 0). The collector current I C_CH is supplied to the output capacitor C OUT , whereby the output capacitor C OUT is charged and the output voltage V REG increases.

[0042] The collector current I C_CH is controlled by the operational amplifier 164. Specifically, the operational amplifier 164 outputs the output voltage V REF such that the reference voltage V FB_OP and the feedback voltage V OP are equal. The output voltage V​​​OP controls the respective base currents of the transistor BT5 and the charging transistor 156, and controls the collector current I C_CH .

[0043] An operation example of the regulator 140 for reducing the output voltage V REG will be described. In the present embodiment, the output voltage V REG decreases when the output capacitor C is discharged when the charging transistor 156 is off OUT due to the discharge of the output capacitor C. In the present embodiment, the output voltage V REG decreases when the charging transistor 156 is off and the discharging transistor 158 is on, a current flows from the output capacitor C OUT to the low-side line 148 through the discharging transistor 158, and the output capacitor C OUT is discharged.

[0044] Specifically, the control signal S CH turns on the transistor BT3 of the charge control circuit 160, and the control signal S DIS turns off the transistor BT4 of the discharge control circuit 162. Accordingly, the transistor BT5 and the charging transistor 156 are each turned off, and the discharging transistor 158 is turned on. As a result, the collector current I does not flow through the charging transistor 156 C_CH (I C_CH =0), and the collector current I flows through the discharging transistor 158 C_DIS (I C_DIS >0). The collector current I C_DIS flows from the output capacitor C OUT to the low-side line 148 through the discharging transistor 158, whereby the output capacitor C OUT is discharged and the output voltage V REG decreases.

[0045] The collector current I C_DIS is controlled by the operational amplifier 164. Specifically, the operational amplifier 164 compares the reference voltage V REF and the feedback voltage V FB_OPThe output voltage V is set to be equal to OP Outputs the output voltage V. OP This controls the base current of transistor BT6 and discharge transistor 158, respectively, and the collector current I C_DIS It is controlled.

[0046] Figure 5 is a circuit diagram of the pulse voltage circuit 180 according to this embodiment. The pulse voltage circuit 180 according to this embodiment includes a high-side line 182, a low-side line 184, a first high-side transistor MH1, a second high-side transistor MH2, a first low-side transistor ML1, a second low-side transistor ML2, a first connection point CP1, a second connection point CP2, a first connection terminal T1, and a second connection terminal T2.

[0047] High-side line 182 is connected to output line 144 of regulator 140, and the output voltage V of regulator 140 REG This is the line that supplies power. The low-side line 184 is the line connected to ground. The first connection terminal T1 is the terminal to be connected to the first electrode 20a, and the second connection terminal T2 is the terminal to be connected to the second electrode 20b. The first high-side transistor MH1, the second high-side transistor MH2, the first low-side transistor ML1, and the second low-side transistor ML2 are each composed of N-channel type MOS transistors.

[0048] The first high-side transistor MH1 and the first low-side transistor ML1 are connected in series between the high-side line 182 and the low-side line 184. Specifically, the drain of the first high-side transistor MH1 is connected to the high-side line 182, and the source of the first high-side transistor MH1 is connected to the drain of the first low-side transistor ML1. The source of the first low-side transistor ML1 is connected to the low-side line 184.

[0049] The second high-side transistor MH2 and the second low-side transistor ML2 are connected in series between the high-side line 182 and the low-side line 184. Specifically, the drain of the second high-side transistor MH2 is connected to the high-side line 182, and the source of the second high-side transistor MH2 is connected to the drain of the second low-side transistor ML2. The source of the second low-side transistor ML2 is connected to the low-side line 184.

[0050] The first connection point CP1 is a node located between the first high-side transistor MH1 and the first low-side transistor ML1, and is to be connected to the first electrode 20a. In this embodiment, the first connection point CP1 is connected to the first electrode 20a via the first connection terminal T1. The second connection point CP2 is a node located between the second high-side transistor MH2 and the second low-side transistor ML2, and is to be connected to the second electrode 20b. In this embodiment, the second connection point CP2 is connected to the second electrode 20b via the second connection terminal T2.

[0051] With the first electrode 20a connected to the first connection terminal T1 and the second electrode 20b connected to the second connection terminal T2, a first voltage V1 is generated at the first connection point CP1 and a second voltage V2 is generated at the second connection point CP2, resulting in a terminal voltage V EMS1 Stimulating current I corresponding to the current I EMS1 It is given to the human body.

[0052] Control signal S SW_A The signal level is high, and the control signal S SW_B When the voltage is low, the first high-side transistor MH1 and the second low-side transistor ML2 are turned on, and the second high-side transistor MH2 and the first low-side transistor ML1 are turned off. As a result, the output voltage V REG A positive terminal voltage V with a corresponding magnitude EMS1 (>0) is generated, and a positive stimulating current I EMS1 (>0) flows into the human body.

[0053] Control signal S SW_A The signal is at a low level, and the control signal S SW_B When the voltage is high, the first high-side transistor MH1 and the second low-side transistor ML2 are turned off, and the second high-side transistor MH2 and the first low-side transistor ML1 are turned on. As a result, the output voltage V REG A negative terminal voltage V of a corresponding magnitude EMS1 (<0) is generated, and a negative stimulation current I EMS1 (<0) flows into the human body.

[0054] In this embodiment, the pulse stimulation current I EMS1 A control signal S is generated. SW_B When it is off, the control signal S of a positive pulse SW_A When supplied, the terminal voltage V EMS1 This results in a positive pulse voltage and a positive pulse stimulation current I EMS1 This is generated. Alternatively, the control signal S SW_A When it is off, the control signal S of a positive pulse SW_B When supplied, the terminal voltage V EMS1 This results in a negative pulse voltage and a negative pulse stimulation current I EMS1 This is generated.

[0055] Figure 6 is a timing chart illustrating an example of the operation of the controller 10 according to this embodiment. Figure 6 shows the output voltage V of the boost circuit 120. B1 , the output voltage of regulator 140 V REG , the stimulation current I generated by the pulse voltage circuit 180 EMS1 and the control signal S of regulator 140 CH ,S DIS This indicates the control signal S. CH When the signal is at a low level (L), the charging transistor 156 turns on, and the control signal S CH When the signal is at a high level (H), the charging transistor 156 turns off. Also, the control signal S DIS When the signal is at a low level (L), the discharge transistor 158 turns on, and the control signal S DISWhen the voltage is at a high level (H), the discharge transistor 158 turns off.

[0056] The control circuit 100 controls the pulse voltage circuit 180 so that a periodic pulse voltage is generated as a stimulus voltage. Specifically, the control circuit 100 controls the on / off states of the first high-side transistor MH1, the first low-side transistor ML1, the second high-side transistor MH2, and the second low-side transistor ML2 so that a periodic pulse voltage is generated between the first connection point CP1 and the second connection point CP2. The control circuit 100 also controls the output voltage V REG The regulator 140 is controlled so that it oscillates periodically.

[0057] The control circuit 100 according to this embodiment has a frequency f EMS (1 / T EMS ) generates a periodic pulse voltage in the pulse voltage circuit 180. Frequency f EMS and period T EMS These are, respectively, terminal voltage V EMS1 and stimulating current I EMS1 This is common in the following respects. The control circuit 100 has a period T EMS During this time, for example, the pulse voltage circuit 180 may generate one positive pulse voltage and one negative pulse voltage. At this time, the control circuit 100 controls the terminal voltage V between each pulse voltage. EMS1 The pulse voltage circuit 180 is controlled so that there is a period when the value is 0. This completes one period T. EMS During this time, a positive pulse current I P+ and negative pulse current I P+ This is generated.

[0058] The control circuit 100 according to this embodiment has a frequency f REG (1 / T REG ) and output voltage V REG The regulator 140 is controlled so that it oscillates periodically. Period T REG The output voltage V REG The period is the output voltage V REG The period T during which it should rise CH and output voltage VREG The period T over which it should decrease DIS It is the sum of (V REG =T CH +T DIS Output voltage V REG frequency f REG The terminal voltage V EMS1 frequency f EMS Lower than (f REG <f EMS ). That is, output voltage V REG Period T REG The terminal voltage V EMS1 Period T EMS Longer than (T REG >T EMS ). frequency f EMS is, frequency f REG It can be n times (where n is an integer greater than or equal to 2), for example, frequency f EMS The frequency is 100Hz, and the frequency is f REG It can be 10Hz.

[0059] The control circuit 100 according to this embodiment periodically switches the charging transistor 156 of the regulator 140 on and off, thereby controlling the output voltage V REG The output voltage V is oscillated periodically. For example, the control circuit 100 controls the output voltage V REG The period T during which it should rise CH When the charging transistor 156 is turned on, the output voltage V REG The period T over which it should decrease DIS In this case, the charging transistor 156 is turned off by the control signal S DIS This generates a result for a period T. CH In this case, the output capacitor C of the regulator 140 OUT When charged, the output voltage V REG It rose, during period T DIS In this case, the output capacitor C OUT When discharged, the output voltage V REG It decreases. Period T DIS Output capacitor C OUT The discharge is caused by the stimulating current I EMS1 This may include discharge due to the flow of current and discharge using the discharge transistor 158.

[0060] The control circuit 100 controls the output voltage V of the regulator 140. REG Furthermore, the discharge transistor 158 is periodically switched on and off so that it oscillates periodically. For example, the control circuit 100 controls the output voltage V REG The period T during which it should rise CH In this state, the discharge transistor 158 is off, and the output voltage V REG The period T over which it should decrease DIS The control signal S is used so that the discharge transistor 158 is turned on in at least part of the signal. DIS This generates a result for a period T. DIS When the discharge transistor 158 turns on, the output capacitor V of the regulator 140 OUT This is discharged via the discharge transistor 158. As a result, the load is small (stimulation current I EMS1 Even when (it is small), the output voltage V is reliably maintained. REG It becomes possible to reduce this.

[0061] Output capacitor V of regulator 140 OUT When it is charged, the output capacitor V OUT The current used to charge the boost circuit 120's output capacitor C B It is supplied from there. Therefore, the output voltage V of regulator 140 REG Period T during which the value increases CH In this case, the output voltage V of the boost circuit 120 B1 It decreases. On the other hand, the output capacitor V of regulator 140 OUT When the battery is discharged, the charging transistor 156 is off, so the output capacitor C of the boost circuit 120 is off. B The discharge is suppressed, and the boost circuit 120 operates, resulting in the output voltage V B1 The voltage increases. As a result, as shown in Figure 6, the output voltage V of regulator 140 increases. REG The phase is the output voltage V of the boost circuit 120. B1 This results in the opposite phase.

[0062] For regulator 140 to operate properly, the output voltage V of regulator 140 must be REGHowever, the output voltage V of the boost circuit 120 B1 Rather than the threshold voltage V th Therefore, it needs to be larger. Thus, the output voltage of regulator 140 V REG and the output voltage V of the boost circuit 120 B1 Minimum voltage difference V d V d >V th The following conditions must be met. If these conditions are not met, the stimulation current I EMS1 The waveform may be distorted. Minimum voltage difference V d The voltage can range from 5V to 20V, depending on the load.

[0063] The control circuit 100 according to this embodiment can be controlled in synchronization with the regulator 140 and the pulse voltage circuit 180. Specifically, the control circuit 100 controls the output voltage V of the regulator 140. REG The period T over which it should decrease DIS In this configuration, when a pulse voltage is generated, the discharge transistor 158 is turned off, and when the generation of the pulse voltage stops, the discharge transistor 158 is turned on. For example, the control circuit 100 operates during period T DIS In this case, the stimulating current I EMS1 is pulse current I P1 ~I P7 The period in which this occurs (for example, t0~t1, t2~t3, t4~t5, t6~t7, t8~t9, t 10 ~t 11 ,t 12 ~t 13 ), the discharge transistor 158 may be turned off. The control circuit 100 controls the stimulation current I EMS1 is pulse current I P1 ~I P7 The period between the following periods (for example, t1~t2, t3~t4, t5~t6, t7~t8, t9~t 10 ,t 11 ~t 12 In this case, the discharge transistor 158 may be turned on.

[0064] Period T DIS So, pulse current I P1 ~I P7As a result of the current flowing, the output capacitor V of regulator 140 OUT Because it is discharged, the output voltage V of regulator 140 REG The value decreases. In this case, if the load is large, the pulse current I P1 ~I P7 As it flows, period T DIS Output voltage V REG The voltage can drop to the desired voltage (e.g., 0V). However, when the load is small, the pulse current I P1 ~I P7 Output capacitor V OUT Discharge alone will not occur during period T. DIS Output voltage V REG The voltage may not drop to the desired level. Pulse current I P1 ~I P7 During periods when no discharge occurs, the output capacitor V of the regulator 140 is controlled using the discharge transistor 158. OUT By discharging the battery, the output voltage V can be reliably maintained even under light load conditions. REG This makes it possible to reduce the voltage to the desired level.

[0065] The configuration and operation examples (mainly the operation examples of the controller 10) of the electrical stimulation device 1 according to this embodiment have been described above. The electrical stimulation device 1 according to this embodiment provides a stimulation voltage (terminal voltage V) between two electrodes (first electrode 20a and second electrode 20b) that are electrically in contact with the human body. EMS1 This electrical stimulation device 1 is configured to generate an input voltage (output voltage V of the boost circuit 120). B1 The output voltage V obtained by stepping down the voltage from the above. REG A regulator 140 configured to generate the output voltage V REG The system comprises a pulse voltage circuit 180 configured to generate a pulse voltage having a magnitude corresponding to the voltage, and a control circuit 100 configured to control the regulator 140 and the pulse voltage circuit 180. The control circuit 100 controls the pulse voltage circuit 180 so that a periodic pulse voltage is generated as the stimulus voltage, and the output voltage V REG The regulator 140 is controlled so that it oscillates periodically.

[0066] In this configuration, the output voltage V oscillates periodically due to the regulator 140. OUT This is generated. The pulse voltage circuit 180 controls the output voltage V of the regulator 140. OUT A periodic pulse voltage with a magnitude corresponding to the is generated as a stimulus voltage. At this time, the output voltage V OUT The vibration of this device makes it possible to deliver electrical stimulation to the human body that moves muscles, even when the pulse voltage frequency is high (for example, 100Hz or higher). As a result, it becomes possible to deliver electrical stimulation to the human body that moves deep muscles.

[0067] Figure 7 is a block diagram of the controller 90 relating to the comparative technology. The advantages of the controller 10 according to this embodiment become even clearer when compared with the controller 90 relating to the comparative technology. The controller 90 relating to the comparative technology differs from the controller 10 according to this embodiment mainly in that it does not have a regulator 140.

[0068] The control circuit 900 related to the comparative technology receives a feedback voltage V from the boost circuit 120. FB_B9 Accordingly, the control signal S, which is a PWM signal supplied to the boost circuit 190, is used. PWM9 The boost circuit 120 generates the output voltage V in response to the PWM control by the control circuit 900. B9 The pulse voltage circuit 180 generates the output voltage V of the boost circuit 190. B9 Using this, the first voltage V supplied to the first electrode 20a 91 and the second voltage V supplied to the second electrode 20b 92 Generates the stimulation voltage V. EMS9 The first voltage V 91 and the second voltage V 92 This is the difference from (V EMS9 =V 91 -V 92 ).

[0069] Figure 8 is a timing chart illustrating an example of the operation of the controller 90 related to the comparative technology. Figure 8 shows the stimulation voltage V EMS9 Stimulating current I applied to the human body in response to this.EMS9 , the output voltage V of the boost circuit 120 B9 , the feedback voltage V of the boost circuit 120 FB_B9 and the control signal S of the boost circuit 120 PWM9 This is shown. Referring to Figure 8, in the controller 90 relating to the comparative technology, the output voltage V of the boost circuit 120 B9 This explains the process by which it rises.

[0070] The control circuit 900 related to the comparative technology has a feedback voltage V FB_B9 The upper threshold voltage V th_H When it is lower than, the feedback voltage V FB_B9 The threshold voltage V th_H The boost circuit 120 is PWM controlled until it reaches (t 91 ~t 92 ). The control circuit 900 controls the feedback voltage V FB_B9 The threshold voltage V th_H When it reaches this point, the output voltage V B9 Maintain (t 92 ~t 93 ).

[0071] Pulse current I P9 When this occurs, the output voltage V B9 and feedback voltage V FB_B9 The feedback voltage V begins to decrease. FB_B9 The lower threshold voltage V th_L It decreases to (t 93 ~t 94 ). The control circuit 900 controls the feedback voltage V FB_B9 In response to the decrease in the upper threshold voltage V, the boost circuit 120 is controlled by PWM. The control circuit 900 controls the upper threshold voltage V th_H By gradually increasing the voltage, the output voltage V of the boost circuit 120 B9 Increase the pulse current I. P9 The output voltage V B9 It increases in proportion to the rise in [the value].

[0072] Figure 9(a) shows the waveform of an ideal stimulation current, and Figure 9(b) shows the stimulation current I related to the comparative technique when the load is light. EMS9The waveform is shown, and Figure 9(c) shows the stimulation current I related to the comparison technique when the load is heavy. EMS9 The waveform is shown. As shown in Figure 9(a), an ideal stimulation current has a sinusoidal waveform with symmetrical amplitude for both positive and negative values. The frequency of this stimulation current is assumed to be approximately 10 Hz.

[0073] As shown in Figure 9(b), the stimulation current I related to the comparative technique when the load is light EMS9 This is the period T during which the pulse current should be small. 91 In this case, the pulse current does not become sufficiently small. Period T 91 Now, let's look at the output capacitor C of the boost circuit 120. B The pulse current decreases as the capacitor discharges. However, when the load is light, the output capacitor C B Because the charge is not sufficiently dissipated, the pulse current does not become sufficiently small.

[0074] As shown in Figure 9(c), the stimulation current I related to the comparison technique when the load is heavy EMS9 So, what is the period T over which it rises from 0 to its maximum? 92 However, this becomes longer than the ideal stimulation current shown in Figure 9(a). This is because, under heavy load, the boost in the boost circuit 120 is longer than the output capacitor C B This is because the charge consumption cannot keep up. In the controller 90 of the comparative technology, if it is possible to take about 3 seconds to increase the stimulation current and about 3 seconds to decrease the stimulation current, it may be possible to create a waveform that is close to a sinusoidal wave. However, it is difficult to create a sinusoidal wave of about 10 Hz with the controller 90 of the comparative technology.

[0075] According to the controller 10 of this embodiment, the regulator 140 supplies the output voltage V to the pulse voltage circuit 180. B1 This allows for active vibration. Therefore, regardless of the load weight, and without using low-frequency interference from the power supply, a stimulating current I can be generated at a frequency of approximately 10 Hz, for example. EMS1 This makes it possible to make the waveform sinusoidal.

[0076] The present invention has been described above based on embodiments. These embodiments are illustrative, and it will be understood by those skilled in the art that various modifications are possible in combinations of these components and processing processes, and that such modifications also fall within the scope of the present invention.

[0077] (modified version) In the above embodiment, the stimulation current I EMS1 1 period T EMS In this example, we explained the generation of one positive pulse current and one negative pulse current. However, this is not limited to this example, and the stimulation current I EMS1 1 period T EMS In this case, multiple positive pulse currents or multiple negative pulse currents may occur, and pulse currents with different pulse widths may occur.

[0078] In the above embodiment, the output voltage V of the regulator 140 is the main component. REG frequency f REG However, the stimulating current I EMS1 frequency f EMS I explained an example of a lower value. This is not limited to this; for example, the stimulation current I EMS1 1 period T EMS In this case, if multiple positive pulse currents or multiple negative pulse currents occur, the frequency f REG ≥f EMS That's fine.

[0079] In the above embodiment, the output capacitor C using the charging transistor 156 OUT Output capacitor C using the charging and discharging transistor 158 OUT Due to the discharge, the output voltage V of regulator 140 REG An example of causing vibration was explained. This is not limited to this example; the output voltage V can be generated by switching the charging transistor 156 on and off while the discharge transistor 158 is off. REG It may be vibrated. When both the charging transistor 156 and the discharging transistor 158 are off, the output capacitor C OUT is the stimulating current I EMS Discharge occurs as a current flows. Depending on the weight of the load, the output voltage VREG The period T over which it should decrease DIS In this case, the stimulating current I EMS Output voltage V is generated solely by discharge. REG It is possible to significantly reduce it. [Explanation of Symbols]

[0080] 1 Electrical stimulator, 2 Belt, 10 Controller, 20a First electrode, 20b Second electrode, 22a First coupling, 22b Second coupling, 100 Control circuit, 120 Boost circuit, 122 Battery, 124 Output line, 126 Low-side line, 128 Feedback circuit, 140 Regulator, 142 Input line, 144 Output line, 146 Power supply voltage line, 148 Low-side line, 150 Input voltage divider circuit, 152 Output voltage divider circuit, 154 Feedback circuit, 156 Charging transistor, 158 Discharging transistor, 160 Charging control circuit, 162 Discharging control circuit, 164 Operational amplifier, 166 Low-pass filter, 180 Pulse voltage circuit, 182 High-side line, 184 Low-side line, R1~R 16 Resistor, L1 inductor, C1-C3 capacitors, C B ,C OUT Output capacitor, D1 diode, BT1~BT6 transistors, MH1 first high-side transistor, MH2 second high-side transistor, ML1 first low-side transistor, ML2 second low-side transistor, CP1 first connection point, CP2 second connection point, T1 first connection terminal, T2 second connection terminal.

Claims

1. An electrical stimulator that generates a stimulating voltage between two electrodes that are electrically in contact with the human body, A regulator configured to generate an output voltage obtained by stepping down the input voltage, A pulse voltage circuit configured to generate a pulse voltage having a magnitude corresponding to the output voltage, The system comprises a control circuit configured to control the regulator and the pulse voltage circuit, The control circuit controls the pulse voltage circuit so that the periodic pulse voltage is generated as the stimulus voltage, and controls the regulator so that the output voltage oscillates periodically. Electrical stimulation device.

2. The regulator comprises an input line to which the input voltage is supplied, an output line to which the output voltage is supplied, an output capacitor charged by the output voltage, and a charging transistor provided between the input line and the output capacitor. The output voltage increases when the charging transistor is on, as the output capacitor is charged by the current flowing through the charging transistor, and decreases when the charging transistor is off, as the output capacitor is discharged. The control circuit periodically oscillates the output voltage by periodically switching the charging transistor on and off. The electrical stimulation device according to claim 1.

3. The regulator further includes a discharge transistor provided between the output line and a low-side line connected to ground. The output voltage decreases when the charging transistor is off and the discharging transistor is on, as current flows from the output capacitor through the discharging transistor to the low-side line, causing the output capacitor to discharge. The control circuit further periodically switches the discharge transistor on and off so that the output voltage oscillates periodically. The electrical stimulation device according to claim 2.

4. The pulse voltage circuit includes a high-side line connected to the output line, a low-side line connected to ground, a first high-side transistor and a first low-side transistor connected in series between the high-side line and the low-side line, a second high-side transistor and a second low-side transistor connected in series between the high-side line and the low-side line, a first connection point between the first high-side transistor and the first low-side transistor to be connected to one of the two electrodes, and a second connection point between the second high-side transistor and the second low-side transistor to be connected to the other of the two electrodes. The control circuit controls the on / off states of the first high-side transistor, the first low-side transistor, the second high-side transistor, and the second low-side transistor, respectively, so that the periodic pulse voltage is generated between the first connection point and the second connection point. The electrical stimulation device according to claim 3.

5. The control circuit turns off the discharge transistor when the pulse voltage is generated during the period in which the output voltage should decrease, and turns on the discharge transistor when the generation of the pulse voltage stops. The electrical stimulation device according to claim 4.

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