A Wireless Batteryless Implantable Radiofrequency Lesioning Device Powered by Intermediate-range Segmented Coil Transmitter

A batteryless implantable radiofrequency lesioning (RFL) device powered by magnetic coupling is presented. The implant is composed of bipolar RFL electrodes, an energy-receiving coil, and a resonant capacitor circuit for maximizing the received power and providing an appropriate voltage for the electrodes. A 40-cm transmitting coil designed to wrap around the patient's body is used to generate a uniform magnetic field in a large volume so precise coil alignment is not necessary. The transmitting coil is divided to 24 segments by resonant capacitors to significantly reduce the excitation voltage to a safe level. The system was tested using ex-vivo chicken muscle tissue. Experimental results show that with a transmitting coil excitation of 1.2 A(rms), the implant can lesion the muscle tissue by achieving a temperature of 55 degrees C. When the excitation increased to 1.6 A(rms), the tissue temperature was increased to 83 degrees C. FEA simulation results demonstrate that the human body SAR is lower than the safety limit of 2 W kg(-1) suggested by international guidelines when the excitation is 1.6 A(rms).