Channel self-checking control circuit of electrical stimulation therapeutic apparatus

Abstract

The utility model relates to a channel self-checking control circuit of an electrical stimulation therapeutic apparatus, which comprises an MCU unit, a self-checking switching channel, an impedance sampling channel and an isolation operational amplifier module, the output end of the MCU unit is connected with a latch, the output end of the latch is connected with an interface module, the interface module is connected with the self-checking switching channel, and the impedance sampling channel is connected with the isolation operational amplifier module. The self-checking switching channel is electrically connected with the impedance sampling channel, and the output end of the impedance sampling channel is connected with an ADC pin of the MCU unit through the isolation operational amplifier module. According to the utility model, the detection switching channel, the impedance sampling channel and the isolation operational amplifier module are arranged, the breakover current of each output channel generates voltage difference through the sampling resistor, and the voltage difference signal enters the differential ADC of the MCU unit for sampling after being amplified and filtered; and a hardware basis is provided for judging whether the output channel is normal or not according to a comparison result of the sampling value and a preset threshold value.

Description

Technical Field

[0001] This utility model relates to the field of electrical stimulation therapy device technology, specifically to a channel self-test control circuit for an electrical stimulation therapy device. Background Technology

[0002] Low- and medium-frequency electrical stimulation (LDFS) therapy devices stimulate human nerve and muscle tissue by outputting currents of specific frequencies and intensities. This has effects such as exciting neuromuscular tissue, promoting local blood circulation, and relieving pain. The core component of such devices is the LDFS generation circuit, as disclosed in CN220935151U. This circuit generates electrical stimulation signals of different frequencies, waveforms, and amplitudes according to treatment needs, which are then applied to the human body through electrode devices. LDFS generation circuits typically have multiple channels, each corresponding to a set of electrodes, allowing independent control of the electrical stimulation output to meet targeted treatment needs for different body parts or specific therapeutic requirements.

[0003] Traditional treatment devices, when a channel is damaged, are difficult to locate and troubleshoot quickly, and can only be returned to the factory for repair. During this period, the equipment cannot be used, affecting the treatment effect.

[0004] Therefore, there is an urgent need for a self-testing circuit that can quickly locate faults, making fault diagnosis easier and improving maintenance efficiency. Summary of the Invention

[0005] This invention addresses the problem of difficulty in troubleshooting faults in existing low- and medium-frequency electrical stimulation generating circuits when a particular channel fails. It proposes a channel self-test control circuit for an electrical stimulation therapy device, comprising a switching channel, an impedance sampling channel, and an isolation operational amplifier module. The conduction current of each output channel generates a voltage difference through a sampling resistor. This voltage difference signal, after amplification and filtering, is sampled by the differential ADC of the MCU unit, providing a hardware basis for determining whether the output channel is functioning correctly based on the comparison between the sampled value and a preset threshold.

[0006] To achieve the above objectives, this utility model proposes a channel self-test control circuit for an electrostimulation therapy device, including an MCU unit, a self-test switching channel, an impedance sampling channel, and an isolation operational amplifier module. The output terminal of the MCU unit is connected to a latch, the output terminal of the latch is connected to an interface module, the interface module is connected to the self-test switching channel, the self-test switching channel is electrically connected to the impedance sampling channel, and the output terminal of the impedance sampling channel is connected to the ADC pin of the MCU unit via the isolation operational amplifier module.

[0007] The self-test switching channel includes multiple self-test switching circuits, and the impedance sampling channel includes multiple impedance sampling circuits. The multiple impedance sampling circuits and the multiple self-test switching circuits correspond one-to-one.

[0008] The impedance sampling circuit includes a boost power supply unit, an output circuit unit, and a signal processing unit. The boost power supply unit is connected to the output circuit unit, the output circuit unit is connected to the signal processing unit and a self-test switching circuit, and the signal processing unit is connected to an isolation operational amplifier module.

[0009] Furthermore, the boost power supply unit includes a DC5V power supply, an inductor L7, a diode D4, and a transistor Q18. The DC5V power supply is connected to the inductor L7, and the other end of the inductor L7 is connected to the anode of the diode D4 and the collector of the transistor Q18. The cathode of the diode D4 is connected to a capacitor C36 and an output circuit unit.

[0010] The output voltage can be adjusted by the switching duty cycle of transistor Q18, and a fixed power supply voltage can be output by adjusting the fixed duty cycle.

[0011] Furthermore, the output circuit unit includes transistors Q11, Q12, Q13, Q14, and relay T1;

[0012] The cathode of diode D4 is connected to the emitter of transistor Q12 and the emitter of transistor Q14. The collector of transistor Q12 is connected to contact 7 of relay T1. Contact 2 of relay T1 is connected to the emitter of transistor Q11. Resistor R51 is connected to the collector of transistor Q11.

[0013] The collector of transistor Q14 is connected to contact 2 of relay T1, and contact 7 of relay T1 is connected to the emitter of transistor Q13. The collector of transistor Q13 is connected to resistor R51, and the other end of resistor R51 is connected to the anode of diode D2. The cathode of diode D2 is grounded.

[0014] Furthermore, the signal processing unit includes a resistor R200, a capacitor C42, a capacitor C155, a resistor R46, a capacitor C43, and a capacitor C155;

[0015] The resistor R51 is connected to the resistor R200. The other end of the resistor R200 is connected to the capacitors C42 and C155 and the isolation operational amplifier module. The other end of the capacitor C42 is grounded. The other end of the resistor R51 is connected to the resistor R46. The other end of the resistor R46 is connected to the capacitors C43 and C155 and the isolation operational amplifier module. The other end of the capacitor C43 is grounded.

[0016] During normal operation, the contacts of relay T1 are in one state, connecting the circuit to the human body treatment circuit. In self-test mode, relay T1 activates, switching to another state and changing the output from the human body treatment circuit to a standard impedance load (resistor R13, typically 1kΩ). The switching of the transistor on and off controls the current flow, creating a specific on-current. This current flows through sampling resistor R51, generating a voltage difference across R51. This voltage difference signal is used for subsequent channel detection.

[0017] Furthermore, the output circuit unit also includes resistor FB1, diode D1, transistor Q1, resistor R1, resistor R2 and resistor R13;

[0018] The contact 1 of relay T1 is connected to resistor FB1 and the cathode of diode D1. The other end of resistor FB1 is connected to a DC 12V power supply. The contact 8 of relay T1 is connected to the anode of diode D1 and the collector of transistor Q1. The emitter of transistor Q1 is connected to ground. The base of transistor Q1 is connected to resistors R1 and R2. The other end of resistor R2 is connected to capacitor C2. The other end of capacitor C2 and the other end of resistor R1 are connected to the interface module. The contacts 4 and 5 of relay T1 are respectively connected to the two ends of resistor R13.

[0019] Furthermore, the VOUTP pin of the isolated operational amplifier module is connected to a resistor R201, and the other end of the resistor R201 is connected to a capacitor C48 and the ADC pin of the MCU unit.

[0020] The VOUTN pin of the isolated operational amplifier module is connected to a resistor R202, and the other end of the resistor R202 is connected to a capacitor C49 and the ADC pin of the MCU unit.

[0021] The differential voltage signal across resistor R51 is input to pins VINP and VIINN of the isolation operational amplifier module via resistors R200 and R46, respectively. Resistors R200 and R46, along with capacitors C42 and C43, form a low-pass filter to filter the differential voltage signal across sampling resistor R51, removing high-frequency noise and allowing only the low-frequency useful signal to pass. The isolation operational amplifier module amplifies the filtered signal, increasing the weak differential voltage signal to a suitable amplitude so that the subsequent main control MCU unit can accurately acquire and process it. The amplified differential signal is then filtered again by a low-pass filter composed of resistors R201 and R202 and capacitors C48 and C49, further improving the signal quality.

[0022] The beneficial effects of this utility model through the above technical solution are as follows:

[0023] This invention enables automatic channel detection. The MCU unit provides the output strength, and the self-test switching relay T1 switches between the human body treatment output circuit and the standard impedance (1kΩ) to achieve individual testing of each output channel. The conduction current of each output channel generates a voltage difference through the sampling resistor R51. This voltage difference signal is amplified and filtered before being sampled by the differential ADC of the MCU unit. The comparison between the sampled value and a preset threshold determines whether the output channel is normal. This allows for rapid location of faulty channels, facilitating subsequent maintenance. Attached Figure Description

[0024] Figure 1 This is one of the circuits in the channel self-test control circuit of an electrostimulation therapy device according to this utility model;

[0025] Figure 2 This is the second circuit of the channel self-test control circuit of an electrostimulation therapy device according to this utility model;

[0026] Figure 3 This is the third circuit of the channel self-test control circuit of an electrostimulation therapy device according to this utility model;

[0027] Figure 4 This is the fourth circuit of the channel self-test control circuit of an electrostimulation therapy device according to this utility model;

[0028] Figure 5 This is the fifth circuit of the channel self-test control circuit of an electrostimulation therapy device according to this utility model;

[0029] Figure 6 This is the sixth circuit of the channel self-test control circuit of an electrostimulation therapy device according to this utility model.

[0030] Reference numerals: MCU unit 1, latch 2, interface module 3, isolation operational amplifier module 4, self-test switching circuit 5, impedance sampling circuit 6, boost power supply unit 601, output circuit unit 602, signal processing unit 603. Detailed Implementation

[0031] Example 1

[0032] like Figures 1-6 As shown, a channel self-test control circuit of an electrostimulation therapy device includes an MCU unit 1, a self-test switching channel, an impedance sampling channel, and an isolation operational amplifier module 4. The output terminal of the MCU unit 1 is connected to a latch 2, the output terminal of the latch 2 is connected to an interface module 3, the interface module 3 is connected to the self-test switching channel, the self-test switching channel is electrically connected to the impedance sampling channel, and the output terminal of the impedance sampling channel is connected to the ADC pin of the MCU unit 1 via the isolation operational amplifier module 4.

[0033] The self-test switching channel includes multiple self-test switching circuits 5, and the impedance sampling channel includes multiple impedance sampling circuits 6. The multiple impedance sampling circuits 6 and the multiple self-test switching circuits 5 correspond one-to-one.

[0034] The impedance sampling circuit 6 includes a boost power supply unit 601, an output circuit unit 602, and a signal processing unit 603. The boost power supply unit 601 is connected to the output circuit unit 602. The output circuit unit 602 is connected to the signal processing unit 603 and the self-test switching circuit 5. The signal processing unit 603 is connected to the isolation operational amplifier module 4.

[0035] The boost power supply unit 601 includes a DC 5V power supply, an inductor L7, a diode D4, and a transistor Q18. The DC 5V power supply is connected to the inductor L7. The other end of the inductor L7 is connected to the anode of the diode D4 and the collector of the transistor Q18. The cathode of the diode D4 is connected to a capacitor C36 and an output circuit unit 602.

[0036] The boost power supply section consists of inductor L7, diode D4, transistor Q18, and capacitor C36. The output voltage can be adjusted by the switching duty cycle of transistor Q18. Adjusting the duty cycle will output a fixed power supply voltage.

[0037] The output circuit unit 602 includes transistors Q11, Q12, Q13, and Q14, and a relay T1;

[0038] The cathode of diode D4 is connected to the emitter of transistor Q12 and the emitter of transistor Q14. The collector of transistor Q12 is connected to contact 7 of relay T1. Contact 2 of relay T1 is connected to the emitter of transistor Q11. Resistor R51 is connected to the collector of transistor Q11.

[0039] The collector of transistor Q14 is connected to contact 2 of relay T1, and contact 7 of relay T1 is connected to the emitter of transistor Q13. The collector of transistor Q13 is connected to resistor R51, and the other end of resistor R51 is connected to the anode of diode D2. The cathode of diode D2 is grounded.

[0040] The power supply voltage passes through four transistors and the standard load impedance of 1kΩ resistor to form a conduction current, which then flows through R51 and D2 to form a conduction circuit.

[0041] The signal processing unit 603 includes a resistor R200, a capacitor C42, a capacitor C155, a resistor R46, a capacitor C43, and a capacitor C155.

[0042] The resistor R51 is connected to the resistor R200. The other end of the resistor R200 is connected to the capacitors C42 and C155 and the isolation operational amplifier module 4. The other end of the capacitor C42 is grounded. The other end of the resistor R51 is connected to the resistor R46. The other end of the resistor R46 is connected to the capacitors C43 and C155 and the isolation operational amplifier module 4. The other end of the capacitor C43 is grounded.

[0043] The VOUTP pin of the isolated operational amplifier module 4 is connected to a resistor R201, and the other end of the resistor R201 is connected to a capacitor C48 and the ADC pin of the MCU unit 1.

[0044] The VOUTN pin of the isolated operational amplifier module 4 is connected to a resistor R202, and the other end of the resistor R202 is connected to a capacitor C49 and the ADC pin of the MCU unit 1.

[0045] Resistor R51 is a sampling resistor. After passing through a low-pass filter consisting of a pair of resistors and capacitors (resistors R200, R46, C42, and C43), it enters the isolation operational amplifier module 4. The output is amplified by a fixed factor of 8.1, and the output is still a pair of differential signals. After passing through another pair of resistor-capacitor low-pass filters (resistors R201, R202, C48, and C49), it is output to the ADC pin of MCU unit 1.

[0046] The output circuit unit 602 also includes resistor FB1, diode D1, transistor Q1, resistor R1, resistor R2 and resistor R13;

[0047] The contact 1 of relay T1 is connected to resistor FB1 and the cathode of diode D1. The other end of resistor FB1 is connected to a DC 12V power supply. The contact 8 of relay T1 is connected to the anode of diode D1 and the collector of transistor Q1. The emitter of transistor Q1 is connected to ground. The base of transistor Q1 is connected to resistors R1 and R2. The other end of resistor R2 is connected to capacitor C2. The other end of capacitor C2 and the other end of resistor R1 are connected to the interface module 3. The contacts 4 and 5 of relay T1 are respectively connected to the two ends of resistor R13.

[0048] Resistor R1 controls the base of transistor Q1 to drive relay T1 to perform position switching. The normally closed contacts of relay T1 are contacts 2 and 7, which are connected to each other and form a human body treatment output circuit. After transistor Q1 is turned on, it drives relay T1 to operate, and contacts 4 and 5 become connected, forming a circuit with the fixed 1kΩ standard impedance R13.

[0049] In this embodiment, both the self-test switching circuit 5 and the self-test switching circuit 5 have 6 channels. The MCU unit 1 uses STMicroelectronics' STM32H723ZET, and the latch 2 uses a 74HC573D chip. The main function of the latch 2 is to control the relay of the next-level self-test switch to increase its driving capability.

[0050] The isolation operational amplifier module 4 uses the CA-IS1300G25G chip. The isolation operational amplifier module 4 amplifies the current acquisition signal before the isolation operational amplifier by 8.1 times and then sends it to the ADC input port of MCU unit 1 to sample the current value.

[0051] The self-test switching channel outputs 6 control signals through latch 2 to control 6 electrical stimulation output channels respectively. Each channel is switched by a transistor driving a relay. In self-test mode, the relay switches the output from the human body treatment circuit to the standard impedance load of 1kΩ, which can test whether the output channel is normal.

[0052] The impedance sampling channel has 6 identical channels. During operation, the boost power supply unit 601 adjusts the fixed duty cycle to output a fixed power supply voltage. The output circuit unit 602 forms a known current path to measure the performance of the output channel. The signal processing unit 603 is equipped with a low-pass filter composed of a pair of resistors and capacitors. After the signal is processed by the low-pass filter, it enters the isolation operational amplifier module 4.

[0053] The 12-bit ADC analog-to-digital converter built into MCU unit 1 can accurately convert differential voltage signals. MCU unit 1 compares the AD value of the differential signal with a self-set threshold range. If it is within the threshold, it means that there is no problem with the channel. If it is outside the threshold, an error message is given for that port.

[0054] The embodiments described above are merely preferred embodiments of this utility model and are not intended to limit the scope of implementation of this utility model. Therefore, all equivalent changes or modifications made to the structure, features and principles described in the patent claims of this utility model should be included within the scope of the patent application of this utility model.

Claims

1. A channel self-checking control circuit of an electric stimulation therapeutic instrument, comprising an MCU unit (1), characterized in that, It also includes a self-test switching channel, an impedance sampling channel and an isolation operational amplifier module (4). The output terminal of the MCU unit (1) is connected to a latch (2). The output terminal of the latch (2) is connected to an interface module (3). The interface module (3) is connected to the self-test switching channel. The self-test switching channel is electrically connected to the impedance sampling channel. The output terminal of the impedance sampling channel is connected to the ADC pin of the MCU unit (1) via the isolation operational amplifier module (4). The self-test switching channel includes multiple self-test switching circuits (5), and the impedance sampling channel includes multiple impedance sampling circuits (6). The multiple impedance sampling circuits (6) and the multiple self-test switching circuits (5) correspond one-to-one. The impedance sampling circuit (6) includes a boost power supply unit (601), an output circuit unit (602), and a signal processing unit (603). The boost power supply unit (601) is connected to the output circuit unit (602). The output circuit unit (602) is connected to the signal processing unit (603) and the self-test switching circuit (5). The signal processing unit (603) is connected to the isolation operational amplifier module (4).

2. The channel self-checking control circuit of an electrical stimulation therapeutic apparatus according to claim 1, wherein, The boost power supply unit (601) includes a DC5V power supply, an inductor L7, a diode D4, and a transistor Q18. The DC5V power supply is connected to the inductor L7. The other end of the inductor L7 is connected to the anode of the diode D4 and the collector of the transistor Q18. The cathode of the diode D4 is connected to a capacitor C36 and an output circuit unit (602).

3. The channel self-checking control circuit of an electro-stimulation therapeutic apparatus according to claim 2, wherein, The output circuit unit (602) includes transistors Q11, Q12, Q13, Q14 and relay T1; The cathode of diode D4 is connected to the emitter of transistor Q12 and the emitter of transistor Q14. The collector of transistor Q12 is connected to contact 7 of relay T1. Contact 2 of relay T1 is connected to the emitter of transistor Q11. Resistor R51 is connected to the collector of transistor Q11. The collector of transistor Q14 is connected to contact 2 of relay T1, and contact 7 of relay T1 is connected to the emitter of transistor Q13. The collector of transistor Q13 is connected to resistor R51, and the other end of resistor R51 is connected to the anode of diode D2. The cathode of diode D2 is grounded.

4. The channel self-checking control circuit of an electrical stimulation therapeutic apparatus according to claim 3, wherein, The signal processing unit (603) includes resistor R200, capacitor C42, capacitor C155, resistor R46, capacitor C43 and capacitor C155; The resistor R51 is connected to the resistor R200. The other end of the resistor R200 is connected to the capacitors C42 and C155 and the isolation operational amplifier module (4). The other end of the capacitor C42 is grounded. The other end of the resistor R51 is connected to the resistor R46. The other end of the resistor R46 is connected to the capacitors C43 and C155 and the isolation operational amplifier module (4). The other end of the capacitor C43 is grounded.

5. The channel self-checking control circuit of an electro-stimulation therapeutic apparatus according to claim 3, wherein, The output circuit unit (602) also includes resistor FB1, diode D1, transistor Q1, resistor R1, resistor R2 and resistor R13; The contact 1 of the relay T1 is connected to the cathode of the resistor FB1 and the diode D1. The other end of the resistor FB1 is connected to a DC 12V power supply. The contact 8 of the relay T1 is connected to the anode of the diode D1 and the collector of the transistor Q1. The emitter of the transistor Q1 is connected to the ground wire. The base of the transistor Q1 is connected to the resistor R1 and the resistor R2. The other end of the resistor R2 is connected to the capacitor C2. The other end of the capacitor C2 and the other end of the resistor R1 are connected to the interface module (3). The contacts 4 and 5 of the relay T1 are respectively connected to the two ends of the resistor R13.

6. The channel self-test control circuit of an electrostimulation therapy device according to claim 1, characterized in that, The VOUTP pin of the isolated operational amplifier module (4) is connected to a resistor R201, and the other end of the resistor R201 is connected to a capacitor C48 and the ADC pin of the MCU unit (1). The VOUTN pin of the isolated operational amplifier module (4) is connected to a resistor R202, and the other end of the resistor R202 is connected to a capacitor C49 and the ADC pin of the MCU unit (1).

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