Electrical stimulation circuit capable of detecting skin impedance

Abstract

The utility model discloses an electrical stimulation circuit capable of detecting skin impedance, which relates to the field of medical instruments and comprises a control module, a first switch, an electrode and an impedance detection component. Two first switches are connected in series to form a bridge arm, a plurality of bridge arms are connected in parallel to form a switching circuit, one end of the switching circuit is connected with a power supply, and the other end is grounded. And each bridge arm is connected with an electrode. The control module is provided with a first output interface, a second output interface and a first input interface which control the first switches to be turned on and turned off, and each first switch corresponds to one first output interface. The impedance detection assembly comprises a first resistor and a diode, the second output interface is connected with the anode of the diode through the first resistor, and the cathode of the diode is connected between the two first switches of one bridge arm. The first input interface is connected between the first resistor and the diode. Three functions of skin depolarization, skin impedance measurement and electrical stimulation can be realized by adjusting the on-off states of different first switches through the control module.

Description

Technical Field

[0001] This utility model relates to the field of medical devices, and more specifically, it relates to an electrical stimulation circuit that also detects skin impedance. Background Technology

[0002] Electrical stimulation promotes drug penetration by means of an electric current stimulating the skin, which alters the cell membrane potential and intermolecular structure, increases cell membrane permeability, and promotes drug absorption in the body.

[0003] The magnitude of skin impedance affects drug permeability under electrical stimulation. Lower skin impedance usually means that electrical stimulation significantly increases drug permeability, in which case a lower concentration of drug solution can be considered. When skin impedance is high, electrical stimulation is less effective in improving drug permeability; to ensure sufficient drug absorption, a higher drug concentration is typically required.

[0004] During electrical stimulation, skin impedance changes with variations in factors such as humidity and temperature on the skin surface. When skin impedance decreases, the current intensity passing through the skin at the same voltage increases. Therefore, if skin impedance decreases due to humidity, temperature, or other factors, the current intensity may need to be adjusted accordingly to avoid overstimulating the skin or causing discomfort.

[0005] In other words, during electrical stimulation, both drug concentration and current intensity should be adjusted accordingly to dynamically changing skin impedance in order to achieve the best therapeutic effect. Therefore, it is necessary to develop an electrical stimulation circuit that also detects skin impedance, so as to monitor the patient's skin impedance in real time while performing electrical stimulation, providing a basis for the dynamic adjustment of drug concentration and current intensity. Utility Model Content

[0006] To address the problem that existing electrical stimulation circuits cannot simultaneously monitor skin impedance in real time, the purpose of this invention is to provide an electrical stimulation circuit that can detect skin impedance, comprising a control module, a first switch, electrodes, and an impedance detection component.

[0007] Two first switches connected in series form a bridge arm, and multiple bridge arms connected in parallel form a switching circuit. One end of the switching circuit is connected to a power source, and the other end is grounded. Each bridge arm corresponds to an electrode, and each electrode is connected between its two corresponding first switches.

[0008] The control module has a first output interface, with each first switch corresponding to one first output interface, and each first switch is signal-connected to its corresponding first output interface. The signal emitted by the first output interface is used to control the opening and closing of its corresponding first switch.

[0009] The control module further has a second output interface and a first input interface. The second output interface is used for sending a step voltage signal, the impedance detection component comprises a first resistor and a diode, the second output interface is connected with the anode of the diode through the first resistor, and the cathode of the diode is connected between the two first switches of any one bridge arm.

[0010] The utility model further sets up: still include current -limiting component, the current -limiting component includes operation module, second switch and second resistance. The control module further has a third output interface. The operation module has a same-phase signal input end, an opposite-phase signal input end and a signal output end. One end of the switching circuit not connected with the power supply is connected with the second switch and the second resistance in sequence, and the second resistance is grounded. The third output interface is connected with the same-phase signal input end, the opposite-phase signal input end is connected between the second resistance and the second switch, and the third output interface is used for outputting a voltage signal. When the voltage of the same-phase signal input end is greater than the voltage of the opposite-phase signal input end, the signal output end outputs a signal to control the second switch to reduce the resistance, and when the voltage of the same-phase signal input end is less than the voltage of the opposite-phase signal input end, the signal output end outputs a signal to control the second switch to increase the resistance.

[0011] The utility model further sets up: still include drive circuit, the control module is singlechip, and the first output interface is used for outputting PWM signal, and every first output interface is connected with the first switch corresponding thereof through drive circuit, and drive circuit is used for amplifying PWM signal.

[0012] The utility model further sets up: the control module includes analog-digital converter, and the first input interface is located on analog-digital converter.

[0013] The utility model further sets up: the control module still includes digital-analog converter, and the third output interface is located on digital-analog converter.

[0014] The utility model further sets up: the operation module is operational amplifier.

[0015] The utility model further sets up: the first switch is any one in triode, MOS tube, relay.

[0016] The utility model further sets up: the second switch is any one in triode, MOS tube, relay.

[0017] The utility model further sets up: the voltage signal of the third output interface output is 0-2.5V.

[0018] The utility model further sets up: the second resistance is greater than or equal to 20Ω.

[0019] In summary, the present invention has the following advantages over the prior art: The present invention provides an electrical stimulation circuit that takes into account real-time monitoring of skin impedance. In this embodiment, the power supply is connected to multiple parallel grounding bridge arms. Each bridge arm is composed of two first switches connected in series. By adjusting the opening and closing states of different first switches through the control module, the three functions of skin depolarization, skin impedance measurement and electrical stimulation can be realized. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of an embodiment.

[0021] In the diagram: 1. Control module; 2. Switching circuit; 3. Current limiting component; 4. Drive circuit; 5. Impedance detection component;

[0022] P1-P4 are electrodes; Q1-Q8 are the first switch; Q9 is the second switch; R1 is the first resistor; D is a diode; GPIO1-4 and GPIO6-9 are the first output interfaces; GPIO5 is the second output interface; ADC is an analog-to-digital converter; DAC is a digital-to-analog converter; R2 is the second resistor; AMP is an operational amplifier. Detailed Implementation

[0023] The technical solution of this utility model will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are not all embodiments of this utility model. All other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0024] It should be noted that the terms "center", "upper", "lower", "horizontal", "left", "right", "front", "back", "lateral", "longitudinal", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0025] Terminology explanation: In the diagram, MCU refers to the microcontroller, VCC refers to the power supply, and GND refers to ground.

[0026] Example

[0027] like Figure 1 As shown, this is a preferred embodiment of the present invention. This embodiment provides an electrical stimulation circuit that also detects skin impedance, which includes a control module 1, a first switch, electrodes, and an impedance detection component 5.

[0028] Two first switches are connected in series to form a bridge arm, and multiple bridge arms are connected in parallel to form the switching circuit 2, one end of which is connected to a power supply and the other end is grounded. Each bridge arm corresponds to an electrode, and each electrode is connected between the two first switches corresponding to the electrode.

[0029] The control module 1 has a first output interface, and each first switch corresponds to a first output interface, and each first switch is connected to the corresponding first output interface. The signal emitted by the first output interface is used to control the opening and closing of the corresponding first switch.

[0030] The control module 1 also has a second output interface and a first input interface. The second output interface is used to emit a step voltage signal, and the impedance detection component 5 includes a first resistor and a diode, the second output interface is connected to the anode of the diode through the first resistor, and the cathode of the diode is connected between the two first switches of any bridge arm. The first input interface is connected between the first resistor and the diode.

[0031] The system includes skin depolarization, skin impedance measurement, and electrical stimulation when in operation.

[0032] Skin depolarization: all first switches are turned off, the electrode corresponding to the bridge arm where the cathode of the diode is located and the electrode corresponding to any other bridge arm are in contact with the skin, the first switch far from the power supply in the two bridge arms is turned on by the control module 1, and the skin between the electrodes corresponding to the two bridge arms is short-circuited by the control module 1 emitting a step voltage signal, thereby completing the skin depolarization.

[0033] Skin impedance measurement: all first switches are turned off, and the first switch far from the power supply in any bridge arm except the bridge arm where the cathode of the diode is located is turned on by the control module 1, so that the bridge arm is grounded. The voltage at the second output interface and the first input interface is measured by the control module 1 emitting a step voltage signal, the voltage at the second output interface is V1, the voltage at the first input interface is V2, the resistance of the first resistor is R1, and the skin impedance is RX. The exact value of the skin impedance RX can be obtained by V2 / RX=V1 / (R1+RX).

[0034] Electrical stimulation. At most one first switch in each bridge arm is turned on, and at least one first switch in the upper bridge arm and at least one first switch in the lower bridge arm are turned on. The upper bridge arm first switch is the first switch close to the power supply in a single bridge arm, and the lower bridge arm first switch is the first switch far from the power supply in a single bridge arm. At least two electrodes are in contact with the skin at this time, and the skin is electrically stimulated.

[0035] In this embodiment, four bridge arms are provided, and eight first switches are provided.

[0036] The embodiment further comprises a current limiting component 3, which comprises an operation module, a second switch and a second resistor. The control module 1 further has a third output interface. The operation module has a non-inverted signal input end, an inverted signal input end and a signal output end. One end of the switching circuit 2 not connected with the power supply is connected with the second switch and the second resistor in sequence, and the second resistor is connected with the ground. The third output interface is connected with the non-inverted signal input end, and the inverted signal input end is connected between the second resistor and the second switch. The third output interface is used for outputting a voltage signal. When the voltage of the non-inverted signal input end is greater than the voltage of the inverted signal input end, the signal output end outputs a signal to control the second switch to conduct a resistor to reduce, so as to increase the current of the first resistor, and then increase the voltage of the inverted signal input end. When the voltage of the non-inverted signal input end is less than the voltage of the inverted signal input end, the signal output end outputs a signal to control the second switch to conduct a resistor to increase, so as to reduce the current of the first resistor, and then reduce the voltage of the inverted signal input end. Through the feedback adjustment mechanism, the voltage on the first resistor and the output voltage of the third output interface can always tend to be equal. Through the operation module, the current flowing through the skin of the loop can be controlled to be a set value I, I=V3 / R2, V3 is the voltage of the third output interface, and R2 is the resistance value of the second resistor.

[0037] The embodiment further comprises a driving circuit 4. The control module 1 is a single-chip microcomputer. The first output interface is used for outputting a PWM signal. Each first output interface is connected with the corresponding first switch through the driving circuit 4, and the driving circuit 4 is used for amplifying the PWM signal. In the embodiment, the driving circuit 4 is provided with two driving circuits.

[0038] Specifically, the control module 1 comprises an analog-to-digital converter. The first input interface is located on the analog-to-digital converter, so as to convert the analog signal received by the single-chip microcomputer from the external power supply into a digital signal input into the driving circuit 4.

[0039] Specifically, the control module 1 further comprises a digital-to-analog converter. The third output interface is located on the digital-to-analog converter, so as to convert the digital signal output by the single-chip microcomputer into an analog signal.

[0040] Specifically, the operation module is an operational amplifier.

[0041] Specifically, the first switch is any one of a triode, a MOS tube and a relay.

[0042] Specifically, the second switch is any one of a triode, a MOS tube and a relay.

[0043] In the embodiment, the first switch and the second switch are both MOS tubes.

[0044] Specifically, the voltage signal output by the third output interface is 0-2.5V. In the embodiment, the voltage signal is 2.5V.

[0045] In particular, the second resistance is greater than or equal to 20Ω. In the embodiment, the second resistance is equal to 20Ω.

[0046] In summary, the embodiment provides an electric stimulation circuit which takes into account real-time monitoring of skin impedance. In the embodiment, the power supply is connected to a plurality of parallel ground bridge arms, each of which is composed of two series-connected first switches. By adjusting the opening and closing states of different first switches through the control module 1, the three functions of skin depolarization, skin impedance measurement and electric stimulation can be realized.

[0047] The above merely describes preferred embodiments of the present application and is not intended to limit the present application. For those skilled in the art, the present application can be variously changed and modified. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. An electrical stimulation circuit that incorporates detection of skin impedance, characterized by: The control module (1), the first switch, the electrode and the impedance detection component (5) are included. Two first switches are connected in series to form a bridge arm, and multiple bridge arms are connected in parallel to form a switching circuit (2), one end of the switching circuit (2) is connected to a power supply, and the other end is grounded; each bridge arm corresponds to an electrode, and each electrode is connected between the two first switches corresponding to the electrode; The control module (1) has a first output interface, each first switch corresponds to a first output interface, and each first switch is connected to the corresponding first output interface; the signal emitted by the first output interface is used to control the opening and closing of the corresponding first switch. The control module (1) also has a second output interface and a first input interface; the second output interface is used to emit a step voltage signal, the impedance detection component (5) includes a first resistor and a diode, the second output interface is connected to the anode of the diode through the first resistor, and the cathode of the diode is connected between the two first switches of any bridge arm; the first input interface is connected between the first resistor and the diode.

2. The electric stimulation circuit with skin impedance detection according to claim 1, characterized in that: It also includes a current limiting component (3), the current limiting component (3) includes an operation module, a second switch and a second resistor; the control module (1) also has a third output interface; the operation module has a same signal input end, an opposite signal input end and a signal output end; one end of the switching circuit (2) not connected to the power supply is connected to the second switch and the second resistor in turn, and the second resistor is grounded; the third output interface is connected to the same signal input end, the opposite signal input end is connected between the second resistor and the second switch, and the third output interface is used to output a voltage signal; when the voltage of the same signal input end is greater than the voltage of the opposite signal input end, the signal output end outputs a signal to control the second switch to reduce the resistance, and when the voltage of the same signal input end is less than the voltage of the opposite signal input end, the signal output end outputs a signal to control the second switch to increase the resistance.

3. The circuit according to claim 2, wherein: The operation module is an operational amplifier.

4. The circuit according to claim 2, characterized in that: The voltage signal output by the third output interface is 0-2.5V.

5. The circuit according to claim 4, wherein: The second resistor is greater than or equal to 20Ω.

6. The circuit according to claim 2, wherein: The second switch is any one of a triode, a MOS tube and a relay.

7. The circuit according to any one of claims 2-6, characterized in that: It also includes a driving circuit (4), the control module (1) is a single-chip microcomputer, the first output interface is used to output a PWM signal, each first output interface is connected to the corresponding first switch through the driving circuit (4), and the driving circuit (4) is used to amplify the PWM signal.

8. The circuit according to claim 7, characterized in that: The control module (1) includes an analog-to-digital converter, and the first input interface is located on the analog-to-digital converter.

9. The circuit according to claim 7, wherein the circuit is capable of detecting the impedance of the skin. The control module (1) also includes a digital-to-analog converter, and the third output interface is located on the digital-to-analog converter.

10. The circuit according to any one of claims 1-6, wherein the circuit is capable of detecting skin impedance. The first switch is any one of a triode, a MOS tube and a relay.

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