Electrode sheet falling detection circuit and detection method in electrical stimulation therapy

Abstract

The electrode sheet falling-off detection circuit in the electric stimulation treatment comprises an isolation power supply and an LM358 double operational amplifier, the isolation power supply provides 12V voltage for the LM358 double operational amplifier, the electrode sheet is connected to the 5th pin of the U2B of the LM358 double operational amplifier, the 5th pin of the U2B is connected to the GND2 through the resistance R2, the 5th pin of the U2B is connected to the 7th pin through the series-connected resistance R1 and the capacitor C3, the 7th pin is connected to the GND2 through the series-connected resistance R5, resistance R4 and resistance R3, the 7th pin of the LM358 double operational amplifier is connected to the 3rd pin of the U2A of the LM358 double operational amplifier through the resistance R6, the 2nd pin and the 1st pin of the U2A are connected, the 1st pin of the U2A is connected to the 1st pin of the optical coupling U3 through the resistance R7, the 2nd pin of the optical coupling U3 is connected to the GND2, and the 3rd pin of the optical coupling U3 is connected to the GND1, and the electrode sheet falling-off can be accurately judged.

Claims

1. An electrode detachment detection circuit in electrical stimulation therapy, comprising an isolation power supply and an LM358 dual operational amplifier, wherein the isolation power supply provides 12V voltage to the LM358 dual operational amplifier, characterized in that: The electrode is connected to pin 5 of U2B of the LM358 dual operational amplifier. Pin 5 of U2B is connected to GND2 through resistor R2. Pin 5 of U2B is connected to pin 7 through a series resistor R1 and capacitor C3. Pin 7 is connected to GND2 through a series resistor R5, resistor R4, and resistor R3. Pin 7 of the LM358 dual operational amplifier is connected to pin 3 of U2A of the LM358 dual operational amplifier through resistor R6. Pins 2 and 1 of U2A are connected. Pin 1 of U2A is connected to pin 1 of optocoupler U3 through resistor R7. Pin 2 of optocoupler U3 is connected to GND2. Pin 3 of optocoupler U3 is connected to GND1. Pin 4 of optocoupler U3 is connected to Vcc through resistor R8. The signal is output from pin 4 of optocoupler U3 to the frequency detection device. Pin 8 of the LM358 dual operational amplifier is connected to GND2 through capacitor C4. Pin 4 is also connected to GND2. The equivalent induced capacitance between the electrode and the ground is Csensor. Resistor R1, capacitor C3, resistor R2, and Csensor form a frequency selection network, which is connected to the non-inverting input and output terminals of U2B to form positive feedback and generate sinusoidal self-excited oscillation. Resistors R3, R4, and R5 form a negative feedback network. Adjusting resistor R4 can change the negative feedback coefficient, thereby adjusting the gain of the amplifier circuit so that the voltage gain meets the requirements of the circuit oscillation amplitude. The power supply of the frequency selection circuit is an isolated power supply, which can determine whether the electrode has fallen off before stimulating the output.

2. The electrode detachment detection circuit in electrical stimulation therapy according to claim 1, characterized in that: Diodes D1 and D2 are connected in parallel with resistor R5, and the cutoff directions of diodes D1 and D2 are opposite.

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