A novel implantable blood pressure telemetry device: Comparison between Data Sciences and Telemetry Research systems

Abstract

The pending expiry (May 2008) of a Data Sciences (DSI) patent in the area of blood pressure telemetry permits the development of alternative technologies. A key aspect in providing new telemetry systems is a comparison to existing technology. Important aspects include stability of the calibration over time and the ability to capture the pulsitile blood pressure waveform. In a group of 6 rats and 5 rabbits DSI blood pressure transmitters (C40 or D70 models) were implanted in conjunction with Telemetry Research (TR) transmitters. Both systems incorporate a fluid filled catheter of similar dimensions with a biocompatible gel in the tip. The blood pressure waveform was collected via telemetry for up to 2 months after implantation. The signal was sampled at 500 Hz and digitally transmitted to a receiver up to 5 m away The battery of TR transmitter was recharged within the rat using inductive power transfer technology. The pulsitile waveform associated with each heart beat was reflected similarly in all cases although the frequency response of DSI telemeters was limited to ~40 Hz (–3 dB rolloff point). The calibrated offset level between the two transmitters was not more than 5 mmHg at all times over a 2 month period. We conclude that the Telemetry Research blood pressure transmitters offer comparable performance to existing technology but with extra design advantages (rechargeable, co-housing of animals, greater range).