A closed loop PRF stimulation system for sympathetic nerve with an implantable micro-stimulator

The results of this preliminary experiment revealed overall successful rate of Palmar Hyperhidrosis (PH) post-PRF stimulation is 62.5%. We concluded that PRF, a reversible electrical stimulation is effect for PH, and most important, without side effect of CH. To avoid repeated endoscopic surgery and large volume device, we designed a miniature wireless radiofrequency microchip. This study involves the design of the implanted high voltage stimulator using the technique of the wireless power transmission. The stimulation system is closed loop from the external power source to the implanted electrical stimulator. The stimulator is powered by an external power source. When the stimulator is powered by the external PRF power source, the stimulator directly outputs PRF treatment to the sympathetic ganglion. The stimulator sample PRF waveform amplitude and feedback to the external controller for the stimulation voltage regulation. The MCU in the stimulator uses PWM to produce Manchester encoding with OOK modulation packet. The U2270B in the external controller is used to demodulate the feedback signal received from the skin. According to this decoded packet, MCU could control the DAC output to change the output voltage of DC-DC boost converter. The power source use the output voltage of DC-DC boost converter as the power amplifier's supply voltage. Thus, the system of stimulator can achieve the closed loop for the voltage regulation of the PRF stimulation.