A telemetry-instrumentation system for chronically implanted glucose and oxygen sensors

An implantable potentiostat-telemetry system for in vivo operation of glucose and oxygen sensors is described. The device conveys signals from implanted chemical-specific sensors to a remote receiver via radio telemetry. Reference signals encoded in the analog FM transmission allow the receiver to automatically compensate for variability between simultaneously operated transmitters. The implant has several programmable operating modes that provide different signal gain and power consumption. All-CMOS circuitry is used, allowing operation for up to three months on a single lithium cell. Design, fabrication, and operation of the device are described.