An Overview of Data Telemetry in Inductively Powered Implantable Biomedical Devices

In modern implantable medical devices (IMDs), wireless data transmission between inside and outside of the body is essential to control IMD parameters and report the acquired data to the external part of the system. Unlike conventional far-field data communication, which is more suitable for free space, near-field data transfer techniques have been widely adopted for transcutaneous data links in IMDs. These data links should be designed for robustness against misalignments and interference, while maintaining high power efficiency, sufficient bandwidth, and communication range in either uplink (IMD to outside) and/or downlink (wearable external part to IMD). In this article, we review fundamental principles and practical considerations for designing short-range transcutaneous data telemetry, along with novel techniques presented in the literature, which are categorized in uplink/downlink, passive/active, single/multi-carrier, and carrier-less pulse-based data telemetry methods.