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 Arms, the implant can lesion the muscle tissue by achieving a temperature of 55 °C. When the excitation increased to 1.6 Arms, the tissue temperature was increased to 83 °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 Arms.