Implantable Blood Pressure Telemetry System

A telemetry system for long-term monitoring of the blood pressure of unrestrained animals is described. The wholly implantable transmitter is equipped with a pressure transducer suitable for chronic intravascular use. To achieve high performance and long battery life, a greater number of components were used than in conventional implantable devices. Pulse interval modulation is used with a mean sampling rate significantly higher than twice the maximum signal frequency. Together with a controlled pulse window in the receiver, an effective reduction of ignition spark interferences with the weak transmitted signal could therewith be achieved.