A Conformal Wireless Power System for Battery-Free Implantable Optogenetic Treatment of Obstructive Sleep Apnea

Optogenetic stimulation is an innovative technology exploited to phasically activate/deactivate deep brain structures. The stimulation happens through an implanted micro-light emitting diode that needs continuous powering. The development of a minimally invasive energy supplementation system expands the use of optogenetic stimulation to several biomedical research fields among which the treatment of human pathologies such as obstructive sleep apnea. With this aim, the design of a wireless power transfer inductive link operating at 13.56 MHz is proposed. The system is composed of an external block consisting of series-connected transmitting coils engineered to provide uniform and omnidirectional magnetic field inside a cylindrical chamber hosting a small-size mouse. Two miniaturized lightweight receiving coils with proper reciprocal orientation are designed to be implanted subcutaneously on the mouse dorsum. The overall system performance is predicted for two different mouse positions and rotations inside the chamber; in the most favorable scenario, a rectified dc output power of 60 mW for an input power of 0.3 W is predicted, which is sufficient to sustain the LED operations.