Analysis and Characterization of Capacitive Links for Biomedical Data Telemetry

This paper presents a comprehensive analysis and characterization of capacitive wireless links, specifically designed for applications demanding high data throughput.

The research delves into the various challenges associated with achieving high data-rates in tuned capacitive links, by first introducing the concept of bandwidth-constrained capacitive channel and its equivalent electrical model, followed by theoretical analysis of the link and the corresponding channel transfer function. Moreover, the impact of channel characteristics, noise and modulation scheme on the signal integrity is investigated, highlighting the limitations on the data throughput and proposing solutions to ensure high data throughput while maintaining an efficient power transfer. Ex vivo testing and computer simulations are performed to validate the theoretical models, assessing the performance of capacitive links at 7 MHz.

Extensive simulations and ex vivo measurements done on a capacitive link tuned for operation at 7 MHz, which results in highest reported data rate of 15 Mbps in a capacitive link, reveal consistent findings throughout the study. The theoretical predictions favoring phase-based modulations for high data throughput and energy efficient communications with high reliability is confirmed through ex vivo measurements.

The paper concludes with recommendations for the choice of modulation in bandwidth-constrained capacitive channels based on the desired power and data transfer requirements.

This research advances biomedical telemetry by demonstrating the potential of capacitive links to meet the demanding requirements of high-speed data transmission in medical applications, paving the way for improved patient monitoring and therapeutic interventions.