TeleProbe: Zero-power Contactless Probing for Implantable Medical Devices

Abstract

The lack of post-deployment visibility into system behavior is one of the major challenges in ensuring the reliable operation of implantable medical devices (IMDs). While wireless connectivity is becoming common in IMDs for monitoring device status, conventional wireless links incur significant energy overheads for data acquisition, processing, and active radio transmission. While low-power transceivers have been introduced to reduce the energy consumed by the radio itself, the energy consumed by the microcontroller for processing data and controlling the radio has often been overlooked. As a result, in IMDs that have a stringent energy constraint, prolonged signal monitoring over a wireless channel is infeasible due to this prohibitively high power consumption. To address this challenge, we present TELEPROBE, which enables zero-power probing of signals in IMDs. TELEPROBE is a wireless, oscilloscope-like probing mechanism for IMDs that allows direct readout of analog/digital signals in real-time using an LC tank circuit, without any power overhead imposed on the IMD. We have designed and implemented fully functional prototypes of TeleProbe and demonstrated its utility in the context of two practical usage scenarios: in-situ power analysis and off-chip serial communication bus monitoring in IMDs.