Ultrasonic Backscatter Communication for Implantable Medical Devices

• Published in: IEEE transactions on molecular, biological, and multi-scale communications biological, and multi-scale communications, 2022-12, Vol.8 (4), p.292-296
• Main Authors: Wang, Qianqian, Guan, Quansheng, Cheng, Julian, Tang, Yuankun
• Format: Article
• Language: English
• Subjects: Acoustic applications; Backscatter; Backscattering; Bit error rate; codeword matching; Communications systems; Electronic implants; energy detection; Energy efficiency; Impedance matching; Interference; Interrogation; intra-body communication; Medical devices; Medical electronics; Modulation; piezoelectric effect; Piezoelectricity; Radio frequency; Switches; Transducers; Ultrasonic backscatter communication
• ISSN: 2372-2061; 2332-7804; 2372-2061
• DOI: 10.1109/TMBMC.2022.3182572

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 the passive UsBC can achieve low BER and low complexity, which is desirable for size- and energy-constrained IMDs.