title: Pain Control on Demand Based on Pulsed Radio-Frequency Stimulation of the Dorsal Root Ganglion Using a Batteryless Implantable CMOS SoC.
abstract: This paper presents the implementation of a batteryless CMOS SoC with low voltage pulsed radio-frequency (PRF) stimulation. This implantable SoC uses 402 MHz command signals following the medical implanted communication system (MICS) standard and a low frequency (1 MHz) for RF power transmission. A body floating type rectifier achieves 84% voltage conversion ratio. A bi-phasic pulse train of 1.4 V and 500 kHz is delivered by a PRF driver circuit. The PRF parameters include pulse duration, pulse frequency and repetition rate, which are controllable via 402 MHz RF receiver. The minimal required 3 V RF Vin and 2.2 V VDDr is achieved at 18 mm gap. The SoC chip is fabricated in a 0.35 μm CMOS process and mounted on a PCB with a flexible spiral antenna. The packaged PRF SoC was implanted into rats for the animal study. Von Frey was applied to test the mechanical allodynia in a blinded manner. This work has successfully demonstrated that implanted CMOS SoC stimulating DRG with 1.4 V, 500 kHz PRF could significantly reduce spinal nerve ligation (SNL) induced mechanical allodynia for 3-7 days.
authors.lastname: Hung-Wei Chiu
authors.lastname: Mu-Lien Lin
authors.lastname: Chii-Wann Lin
authors.lastname: I-Hsiu Ho
authors.lastname: Wei-Tso Lin
authors.lastname: Po-Hsiang Fang
authors.lastname: Yi-Chin Lee
authors.lastname: Yeong-Ray Wen
authors.lastname: Shey-Shi Lu