A Wireless-Powered Battery-Less Electrical Stimulator With Delay-Shift Keying (DSK) Based Downlink Data Communication

This paper presents a 6.78-MHz wireless power and bidirectional data transfer system, which is intended for applications involving battery-less implantable gastric electrical stimulation (GES). The 0X/1X regulating rectifier achieves output voltage regulation without an additional DC-DC converter, thus enhancing power conversion efficiency (PCE) within the $R_{X}$ . By utilizing transmission power regulation (TPR), $T_{X}$ can adaptively adjust the transmission power according to the loading of the $R_{X}$ , reducing the power consumption during sleep mode. Moreover, this paper proposes an innovative delay-shift keying (DSK) technique for forward data transmission, enabling simultaneous voltage regulation and achieving a power conversion efficiency (PCE) of 86.1% during data transmission. Both the $T_{X}$ and the $R_{X}$ chips were fabricated in a 0.18- $\mu $ m BCD process, incorporating both 5-V and 12-V devices. During sleep mode, the consumption of the $T_{X}$ is measured at 9.24 mW, which is a 64.3% reduction compared to the same system without PA deactivation. The rectifier and charge pump achieve peak efficiencies of 86.7% and 85.8%, respectively, at a stimulus current of 6mA.

I. Introduction

Recently, more people are grappling with gastrointestinal problems, such as gastrointestinal disorder, which disrupts the natural muscle contractions in patients’ stomachs. Gastric electrical stimulation (GES) has been recognized as an effective approach to manage this medically resistant condition by numerous studies [1], [2], [3].