Capacitive data links intended for implantable medical devices: A survey

We present in this paper a survey of the existing capacitive data telemetry systems for biomedical implants. Other existing techniques such as RF, inductive and optic links as well as energy providers are briefly discussed. In addition, the bidirectional full duplex capacitive communication technique using load shift keying is introduced. This technique has been used in other biomedical systems such as inductive links; here it is applied for capacitive links, which allows the system to establish a power-free up-link, to outside the body, with minor tradeoffs.