A high power, fully implanted and battery free platform for chronic functional electrical stimulation enabled by passive resonator antenna design.

Abstract

Electrical stimulation of the neuromuscular system holds promise for both scientific and therapeutic biomedical applications. Supplying and maintaining the power necessary to drive stimulation chronically is a fundamental challenge in these applications, especially when high voltages or currents are required. Wireless systems, in which energy is supplied through near field power transfer, could eliminate complications caused by battery packs or external connections, but currently do not provide the harvested power and the voltages for applications such as muscle stimulation. Here, we introduce a passive resonator optimized power transfer design that overcomes these limitations, enabling voltage compliances of ± 20 V and power over 300 mW at device volumes of 0.2 cm2, thereby improving power transfer 500% over previous systems. This improved performance enables multichannel, biphasic, current-controlled operation at clinically relevant voltage and current ranges with digital control and telemetry. Implanted devices remain operational over 6 weeks in both intact and spinal cord injured rats and are capable of producing fine control of spinal and muscle stimulation.

Wireless Battery-free and Fully Implantable Organ Interfaces

“…Demonstrations of battery-free brain stimulation devices in recent years highlight an increasingly capable class of devices that utilize advanced levels of energy availability without the need for large volume displacement resulting from the use of batteries. Especially for small animal models, this provides advanced chronic stimulation abilities for complex studies; however, most recent demonstrations also highlight an avenue toward human application, especially for application with high duty cycle and power consumption. ,, …”

“…Especially for small animal models, this provides advanced chronic stimulation abilities for complex studies; however, most recent demonstrations also highlight an avenue toward human application, especially for application with high duty cycle and power consumption. 307,331,442…”

“…modalities. b) Plot showing power density in air and tissue for common power transfer modalities with publication dates. ,,− c) Illustration showing implantable device operation powered by a wrist-mounted RF transmitter . Reproduced with permission.…”