Miniaturized Wirelessly Powered and Controlled Implants for Vagus Nerve Stimulation

Abstract

Multisite stimulation has shown enhanced clinical outcomes in different biomedical applications. This work presents a novel System on Chip (SoC) solution that enables up to 16 implantable stimulators to be powered and controlled using a single transmitter. The implants can be powered at 40.68MHz industrial, scientific and medical (ISM) band up to 80mm in air. Each implant can tolerate up to 70° misalignment between the Tx and Rx coil, and they provide two channels for constant voltage stimulation. The frequency, voltage, and pulse width are sent wirelessly using pulse width modulated amplitude shift keying (PWM-ASK) to each chip. The performance of implantable devices was verified by bilateral in vivo (pig) vagus nerve stimulation (VNS) and in-vitro measurements. The implant has a diameter of 14mm and weighs 80mg.