Isolated constant current stimulus output circuit

Abstract

The utility model discloses an isolated constant current stimulation output circuit, constant current stimulation output circuit contains boost circuit, constant current module, stimulation output drive circuit and singlechip, boost circuit, constant current module is connected with stimulation output drive circuit electricity respectively, singlechip is connected with constant current module, stimulation output drive circuit signal respectively, boost circuit is used for output high voltage electric signal, constant current module is used for output constant current, stimulation output drive circuit receives high voltage electric signal constant current, realizes the output of adjustable stimulation signal under the control of singlechip.

Description

Technical Field

[0001] This utility model relates to the field of constant current stimulation technology, and in particular to an isolated constant current stimulation output circuit. Background Technology

[0002] Constant current source stimulation output circuits are indispensable in fields such as industrial control, scientific research experiments, and medical electrical stimulation output. Currently, common electrical stimulation output devices generally output electrical pulses in two control forms: constant voltage and constant current. Constant current stimulation output can ensure that the output current is constant and will not change with the user's own impedance.

[0003] However, current human electrical stimulation output devices on the market suffer from problems such as low precision, narrow output range, inability to adapt to changes in human body impedance, and poor stability, affecting treatment effectiveness and device lifespan. Therefore, there is an urgent need for a higher-performance constant current stimulation output circuit to meet the growing application demands in various fields. Summary of the Invention

[0004] In view of the above-mentioned prior art, the present invention provides an isolated constant current stimulation output circuit, which mainly solves the technical problems existing in the background art.

[0005] To achieve the above objectives, the technical solution of this utility model embodiment is implemented as follows: an isolated constant current stimulation output circuit, comprising a boost circuit, a constant current module, a stimulation output drive circuit, and a microcontroller. The boost circuit and the constant current module are electrically connected to the stimulation output drive circuit, and the microcontroller is signal-connected to both the constant current module and the stimulation output drive circuit.

[0006] The boost circuit is used to output a high-voltage electrical signal;

[0007] The constant current module is used to output a constant current:

[0008] The stimulation output drive circuit receives a constant current from a high-voltage electrical signal and, under the control of a microcontroller, outputs an adjustable stimulation signal.

[0009] Optionally, the boost circuit includes an active crystal oscillator module, an amplifier circuit module, a transformer module, and a half-wave rectifier module. The output terminal of the active crystal oscillator module is connected to the input terminal of the amplifier circuit module, the output terminal of the amplifier circuit module is connected to the input terminal of the transformer module, and the output terminal of the transformer module is connected to the input terminal of the half-wave rectifier module. The half-wave rectifier module is used to output a high-voltage electrical signal.

[0010] Optionally, the constant current module includes an isolation module, a digital-to-analog converter module, a voltage follower module, and a feedback adjustment module. The isolation module is connected to the digital-to-analog converter module, the voltage follower module, and the feedback adjustment module in sequence. The microcontroller is signal-connected to the isolation module. An external power supply powers the feedback adjustment module, and the feedback adjustment module outputs a constant current.

[0011] Optionally, the digital-to-analog conversion module is a DAC7311 digital-to-analog conversion chip.

[0012] Optionally, the feedback adjustment module is used to stabilize the output current at the target value through a negative feedback mechanism based on the analog voltage signal output by the voltage follower module and the sampled value of the sampling resistor.

[0013] Optionally, the stimulation output driving circuit includes a first electrode left driving circuit, a first electrode right driving circuit, a second electrode left driving circuit, a second electrode right driving circuit, and an absorption capacitor. The first electrode left driving circuit and the second electrode right driving circuit are both electrically connected to the high-voltage output terminal of the boost circuit to receive high-voltage electrical signals. The second electrode left driving circuit and the first electrode right driving circuit are both electrically connected to the output terminal of the constant current module to receive constant current.

[0014] The first electrode left drive circuit and the first electrode right drive circuit are both electrically connected to the first electrode and are used to output an adjustable stimulation signal to the first electrode.

[0015] The left drive circuit and the right drive circuit of the second electrode are both electrically connected to the second electrode and are used to output adjustable stimulation signals to the second electrode.

[0016] The absorption capacitor is connected between the first electrode and the second electrode and is used to absorb the peak current output by the stimulus.

[0017] Optionally, the first electrode and the second electrode are used to apply the adjustable stimulation signal output by the stimulation output drive circuit to the human body to achieve the function of electrical stimulation therapy.

[0018] The beneficial effects of this utility model are as follows: through the reasonable combination of microcontroller, boost circuit, constant current circuit and stimulation output control circuit, high-precision and high-stability isolated constant current stimulation output can be achieved, which can be widely used in fields such as bioelectric stimulation and medical treatment, and has good application prospects. Attached Figure Description

[0019] Figure 1 A schematic diagram of a constant current stimulation output structure provided by this utility model;

[0020] Figure 2 A schematic diagram of a boost circuit provided by this utility model;

[0021] Figure 3 A schematic diagram of the structure of a constant current module provided by this utility model;

[0022] Figure 4 This is a schematic diagram of the structure of a stimulation output driving module provided by this utility model.

[0023] Explanation of icon numbers:

[0024] 1. Boost circuit; 2. Constant current module; 3. Stimulation output drive circuit; 4. Microcontroller. Detailed Implementation

[0025] The technical solution of this utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this utility model belongs. The terminology used in this specification of this utility model is for the purpose of describing particular embodiments only and is not intended to limit the utility model. In the following description, the expression "some embodiments" refers to a subset of all possible embodiments; however, it should be understood that "some embodiments" can be the same subset or different subsets of all possible embodiments and can be combined with each other without conflict.

[0026] In the following description, numerous specific details are set forth in order to provide a more thorough understanding of the present invention. However, it will be apparent to those skilled in the art that the present invention can be practiced without one or more of these details. In other instances, certain technical features well-known in the art have not been described in order to avoid confusion with the present invention.

[0027] It should be understood that this invention can be embodied in various forms and should not be construed as limited to the embodiments set forth herein. Rather, providing these embodiments will make the disclosure thorough and complete, and will fully convey the scope of this invention to those skilled in the art. Furthermore, the terminology used herein is intended only to describe particular embodiments and is not intended to limit the invention. When used herein, the singular forms “a,” “an,” and “the” are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “compose” and / or “comprising,” when used in this specification, identify the presence of the stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups. When used herein, the term “and / or” includes any and all combinations of the associated listed items.

[0028] It should also be noted that when an element is referred to as being "fixed to" another element, it can be directly attached to the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "inner," "outer," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0029] To fully understand this utility model, a detailed structure will be presented in the following description to illustrate the technical solution proposed by this utility model. Optional embodiments of this utility model are described in detail below; however, in addition to these detailed descriptions, this utility model may have other embodiments.

[0030] Please refer to the attached document. Figures 1 to 4 This application provides an isolated constant current stimulation output circuit, which includes a boost circuit 1, a constant current module 2, a stimulation output drive circuit 3, and a microcontroller 4. The boost circuit 1 and the constant current module 2 are electrically connected to the stimulation output drive circuit 3, and the microcontroller 4 is signal connected to the constant current module 2 and the stimulation output drive circuit 3.

[0031] The boost circuit 1 is used to output a high-voltage electrical signal;

[0032] The constant current module 2 is used to output a constant current;

[0033] The stimulation output drive circuit 3 receives a constant current from a high-voltage electrical signal and, under the control of the microcontroller 4, realizes the output of an adjustable stimulation signal.

[0034] Specifically, the isolated constant current stimulation output circuit provided in this application uses a microcontroller 4 as the control core, which sends control signals to the constant current module 2 and the stimulation output drive circuit 3 respectively. The microcontroller sets a digital voltage for the constant current module 2 to determine the required constant current magnitude. The constant current module 2 outputs a corresponding constant current according to the set current magnitude. At the same time, the microcontroller 4 specifies the drive type to the stimulation output drive circuit 3 and regulates its working state. The boost circuit 1 operates independently and provides the required high voltage signal to the stimulation output drive circuit 3. After receiving the high voltage signal from the boost circuit 1 and the constant current from the constant current module 2, the stimulation output drive circuit 3, under the control of the drive signal from the microcontroller 4, regulates the output signal by turning on and off its internal transistors and relays, ultimately generating an adjustable stimulation signal.

[0035] In one or more embodiments of this application, the boost circuit 1 includes an active crystal oscillator module, an amplifier circuit module, a transformer module, and a half-wave rectifier module. The output terminal of the active crystal oscillator module is connected to the input terminal of the amplifier circuit module, the output terminal of the amplifier circuit module is connected to the input terminal of the transformer module, and the output terminal of the transformer module is connected to the input terminal of the half-wave rectifier module. The half-wave rectifier module is used to output a high-voltage electrical signal.

[0036] Specifically, the active crystal oscillator module generates a square wave signal, which is amplified by the amplifier circuit module and then sent to the transformer module for voltage boosting. The signal is then converted into a high-voltage DC signal by the half-wave rectifier module, providing the required high-voltage electrical signal for the stimulation output drive circuit 3.

[0037] The active crystal oscillator module includes a 12MHz active crystal oscillator X1, a ferrite bead FB1, and resistive and capacitive components. The power supply pin of the active crystal oscillator is connected to a capacitor through the ferrite bead FB1 to reduce the influence of power supply noise. One end of the decoupling capacitors C27, C28, and C29 is connected to the power supply pin, and the other end is grounded. The output OUT pin of the active crystal oscillator will output a square wave signal. The output terminal is connected in series with a resistor R30 and grounded through a capacitor C26 to form an RC circuit to shape the square wave.

[0038] The amplifier circuit module mainly consists of transistors Q22 and Q23. The active crystal oscillator module is connected to the base of transistors Q22 and Q23. The emitter of transistor Q23 is connected to a 5V power supply, and the emitter of transistor Q22 is connected to ground. The collectors of the two transistors are connected together, which can generate a square wave signal from the active crystal oscillator module and output it as a 5V square wave signal.

[0039] The transformer module mainly consists of a transformer and a capacitor C30. The capacitor C30 is connected in parallel to the primary winding of the transformer. The number of turns of the transformer is N2:N1=16. This transformer will boost the 5V square wave signal to 80V AC output.

[0040] The half-wave rectifier circuit mainly consists of diode D3 and capacitor C31. An 80V AC signal is input on the left side, and the AC power is converted into pulsed DC power through this circuit, outputting an 80V voltage HV+.

[0041] In one or more embodiments of this application, the constant current module 2 includes an isolation module, a digital-to-analog converter module, a voltage follower module, and a feedback adjustment module. The isolation module is connected in sequence to the digital-to-analog converter module, the voltage follower module, and the feedback adjustment module. The microcontroller 4 is signal-connected to the isolation module. An external power supply powers the feedback adjustment module, and the feedback adjustment module outputs a constant current.

[0042] Specifically, after receiving the SPI signal from the microcontroller 4, the constant current module 2 converts the digital signal into a precise analog voltage through the digital-to-analog converter module. This voltage is then processed by the voltage follower module and fed into the feedback regulation module. Through the negative feedback loop formed by the operational amplifier and the sampling resistor in the feedback regulation module, the output current is stabilized at the target value based on the analog voltage signal output by the voltage follower module and the sampling value of the sampling resistor, thereby controlling the transistor to output a stable constant current.

[0043] The isolation module mainly includes the ADUM1401 digital isolation chip U4 and filter capacitors C24 and C25. The SPI signal transmitted by the microcontroller 4 is isolated by this chip and outputs the isolated SPI signal.

[0044] The digital-to-analog converter module mainly includes a DAC7311 digital-to-analog converter chip U1, a pull-up resistor R1, and a filter capacitor C2, which generates an accurate analog signal based on the isolated SPI signal.

[0045] The voltage follower module mainly includes operational amplifier U2 and filter capacitor C4. The precise analog voltage signal provided by DAC7311 is connected to the non-inverting input terminal of operational amplifier U2, and the output terminal of operational amplifier U2 is connected to its inverting input terminal, forming a voltage follower circuit 22, which provides a clean and stable voltage for the feedback adjustment module.

[0046] The feedback adjustment module includes an operational amplifier U3, a transistor Q1, a current-limiting resistor R2, an accelerating capacitor C1, and a sampling resistor R3. One end of the non-inverting input of operational amplifier U3 is connected to the output of operational amplifier U2, and the other end is connected to the current-limiting resistor R2 and the accelerating capacitor C1. The base of transistor Q1 is connected to the current-limiting resistor R2 and the accelerating capacitor C1, the emitter is connected to the inverting input of operational amplifier U3 and the sampling resistor R3, and the collector is connected to the stimulation output drive circuit 3. The other end of the sampling resistor R3 is grounded. Together, they form a constant current module 2 composed of the operational amplifier and the transistor. Operational amplifier U3 precisely processes the input analog voltage signal, and transistor Q1 operates in a suitable current amplification state under the control of the output signal of operational amplifier U3. Resistor R3 samples the output current in real time and feeds back the sampled voltage signal to the input of operational amplifier U3, forming a negative feedback control loop. Through this negative feedback mechanism, operational amplifier U3 can adjust the output signal in real time to ensure that the collector current of transistor Q1 remains constant, achieving constant current stimulation control. When the DAC input value changes, the voltage at the op-amp input changes synchronously. The feedback mechanism forces the current to stabilize at the new target value, achieving corresponding constant current control. C1, at 4.7nF, acts as an accelerating capacitor, speeding up the switching of the transistor and preventing output spikes. The sampling resistor, at 51Ω, achieves a constant current range of 0mA-60mA according to I=V / R.

[0047] In one or more embodiments of this application, the stimulation output driving circuit 3 includes a first electrode left driving circuit, a first electrode right driving circuit, a second electrode left driving circuit, a second electrode right driving circuit, and an absorption capacitor. The first electrode left driving circuit and the second electrode right driving circuit are both electrically connected to the high-voltage output terminal of the boost circuit 1 to receive high-voltage electrical signals. The second electrode left driving circuit and the first electrode right driving circuit are both electrically connected to the output terminal of the constant current module 2 to receive constant current.

[0048] The first electrode left drive circuit and the first electrode right drive circuit are both electrically connected to the first electrode and are used to output an adjustable stimulation signal to the first electrode.

[0049] The left drive circuit and the right drive circuit of the second electrode are both electrically connected to the second electrode and are used to output adjustable stimulation signals to the second electrode.

[0050] The absorption capacitor is connected between the first electrode and the second electrode and is used to absorb the peak current output by the stimulus.

[0051] Specifically, when the microcontroller 4 sends a drive signal, the left drive circuit of the first electrode, the right drive circuit of the first electrode, the left drive circuit of the second electrode, and the right drive circuit of the second electrode operate according to the signal command. The left drive circuit of the first electrode and the right drive circuit of the second electrode receive the high-voltage signal from the boost circuit 1, and the left drive circuit of the second electrode and the right drive circuit of the first electrode receive the constant current from the constant current module 2. By controlling the conduction and cutoff of the transistors and the switching state of the relays in each drive circuit, the high-voltage signal and the constant current are transmitted to the first electrode and the second electrode respectively through the corresponding drive circuits. A loop is formed between the first electrode and the second electrode. The current passes through the human tissue and produces a stimulating effect. The absorption capacitor connected between the two electrodes absorbs the peak current that may occur during the stimulation output process in real time, avoiding the interference of the peak current on the stimulation effect.

[0052] In the first electrode left drive circuit and the second electrode left drive circuit, the base of NPN transistor Q4 is connected to resistor R7, and the emitter is grounded. Pin 1 of relay Q2 is connected to resistor R4, pin 2 is connected to the collector of transistor Q4, pin 3 is connected to the first electrode E1, and pin 4 is connected to the output terminal of boost circuit 1. The other end of resistor R4 is connected to a 5V power supply, and the other end of resistor R7 is connected to microcontroller 4. The base of NPN transistor Q6 is connected to resistor R23, and the emitter is grounded. Pin 1 of relay Q7 is connected to resistor R24, pin 2 is connected to the collector of transistor Q6, pin 3 is connected to constant current module 2, and pin 4 is connected to the second electrode E2. The other end of resistor R24 ​​is connected to a 5V power supply, and the other end of resistor R23 is connected to microcontroller 4.

[0053] In the first electrode right drive circuit and the second electrode right drive circuit, the base of NPN transistor Q5 is connected to resistor R8, and its emitter is grounded. Pin 1 of relay Q3 is connected to resistor R5, pin 2 is connected to the collector of transistor Q5, pin 3 is connected to the second electrode E2, and pin 4 is connected to the output of boost circuit 1. The other end of resistor R5 is connected to a 5V power supply, and the other end of resistor R8 is connected to microcontroller 4. The base of NPN transistor Q8 is connected to resistor R19, and its emitter is grounded. Pin 1 of relay Q9 is connected to resistor R16, pin 2 is connected to the collector of transistor Q8, pin 3 is connected to constant current module 2, and pin 4 is connected to the first electrode E1. The other end of resistor R16 is connected to a 5V power supply, and the other end of resistor R19 is connected to microcontroller 4.

[0054] In one or more embodiments of this application, the first electrode and the second electrode are used to apply the adjustable stimulation signal output by the stimulation output drive circuit 3 to the human body to achieve the function of electrostimulation therapy.

[0055] Specifically, the first electrode E1 and the first electrode E2 are connected to human skin to provide stimulation output. When the main control microcontroller 4E1_L and E2_L are at a high level, the transistor Q4 is turned on, the relay Q2 is turned on, and the OUTE1 signal is at a high level. After OUTE1 reaches a high level, an equivalent resistance is connected between OUTE1 and OUTE2 through the human skin. At this time, transistor Q6 conducts, solid-state relay Q7 opens, and OUTE2 is connected to the constant current circuit. Under the control of the constant current circuit, a square wave is output. The output duration is controlled by E1_L and E2_L. When the main control microcontroller's 4E1_R and E2_R are high, transistor Q5 conducts, relay Q3 opens, and the OUTE2 signal is high. After OUTE2 has a high voltage, an equivalent resistance is connected between OUTE1 and OUTE2 through the human skin. At this time, transistor Q8 conducts, solid-state relay Q9 opens, and OUTE1 is connected to the constant current circuit. Under the control of the constant current circuit, a square wave is output. By controlling the timing sequence of E1_L, E1_R, E2_L, and E2_R, different stimulation waveforms can be output.

[0056] The above are merely specific embodiments of this utility model, but the protection scope of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. The protection scope of this utility model should be determined by the protection scope of the stated claims.

Claims

1. An isolated constant current stimulation output circuit, characterized in that, The constant current stimulation output circuit includes a boost circuit, a constant current module, a stimulation output drive circuit, and a microcontroller. The boost circuit and the constant current module are electrically connected to the stimulation output drive circuit, and the microcontroller is signal-connected to both the constant current module and the stimulation output drive circuit. The boost circuit is used to output a high-voltage electrical signal; The constant current module is used to output a constant current: The stimulation output drive circuit receives a constant current from a high-voltage electrical signal and, under the control of a microcontroller, outputs an adjustable stimulation signal.

2. The isolated constant current stimulation output circuit according to claim 1, characterized in that, The boost circuit includes an active crystal oscillator module, an amplifier circuit module, a transformer module, and a half-wave rectifier module. The output terminal of the active crystal oscillator module is connected to the input terminal of the amplifier circuit module, the output terminal of the amplifier circuit module is connected to the input terminal of the transformer module, and the output terminal of the transformer module is connected to the input terminal of the half-wave rectifier module. The half-wave rectifier module is used to output a high-voltage electrical signal.

3. The isolated constant current stimulation output circuit according to claim 1, characterized in that, The constant current module includes an isolation module, a digital-to-analog converter module, a voltage follower module, and a feedback adjustment module. The isolation module is connected to the digital-to-analog converter module, the voltage follower module, and the feedback adjustment module in sequence. The microcontroller is connected to the isolation module via a signal connection. An external power supply powers the feedback adjustment module, and the feedback adjustment module outputs a constant current.

4. The isolated constant current stimulation output circuit according to claim 3, characterized in that, The digital-to-analog conversion module is a DAC7311 digital-to-analog conversion chip.

5. The isolated constant current stimulation output circuit according to claim 3, characterized in that, The feedback adjustment module is used to stabilize the output current at the target value through a negative feedback mechanism based on the analog voltage signal output by the voltage follower module and the sampled value of the sampling resistor.

6. The isolated constant current stimulation output circuit according to claim 1, characterized in that, The stimulation output driving circuit includes a first electrode left driving circuit, a first electrode right driving circuit, a second electrode left driving circuit, a second electrode right driving circuit, and an absorption capacitor. The first electrode left driving circuit and the second electrode right driving circuit are both electrically connected to the high-voltage output terminal of the boost circuit to receive high-voltage electrical signals. The second electrode left driving circuit and the first electrode right driving circuit are both electrically connected to the output terminal of the constant current module to receive constant current. The first electrode left drive circuit and the first electrode right drive circuit are both electrically connected to the first electrode and are used to output an adjustable stimulation signal to the first electrode. The left drive circuit and the right drive circuit of the second electrode are both electrically connected to the second electrode and are used to output adjustable stimulation signals to the second electrode. The absorption capacitor is connected between the first electrode and the second electrode and is used to absorb the peak current output by the stimulus.

7. The isolated constant current stimulation output circuit according to claim 6, characterized in that, The first and second electrodes are used to apply the adjustable stimulation signal output by the stimulation output drive circuit to the human body to achieve the function of electrical stimulation therapy.

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