Ultrasonic Backscatter Communication for Implantable Medical Devices

TL;DR

This paper introduces an ultrasonic backscatter communication system for passive implantable medical devices, enabling battery-free operation with low BER and complexity, suitable for size- and energy-constrained healthcare applications.

Contribution

It presents a novel ultrasonic backscatter communication system with modulation schemes, codeword mapping, and theoretical BER analysis for passive IMDs.

Findings

Achieves low bit-error rate in simulations.

Demonstrates low complexity suitable for IMDs.

Validates theoretical analysis with Monte Carlo simulations.

Abstract

This paper proposes an ultrasonic backscatter communication (UsBC) system for passive implantable medical devices (IMDs) that can operate without batteries, enabling versatile revolutionary applications for future healthcare. The proposed UsBC system consists of a reader and a tag. The reader sends interrogation pulses to the tag. The tag backscatters the pulses based on the piezoelectric effect of a piezo transducer. We present several basic modulation schemes for UsBC by impedance matching of the piezo transducer. To mitigate the interference of other scatters in the human body, the tag transmits information bits by codeword mapping, and the reader performs codeword matching before energy detection in the reader. We further derive the theoretical bit-error rate (BER) expression. Monte Carlo simulations verify the theoretical analysis and show that passive UsBC can achieve low BER and low complexity, which is desirable for size- and energy-constrained IMDs.