Abstract:
We report on the development of a combined sympathetic nerve activity and blood pressure telemeter for long term implantation in freely moving small animals. The devices simultaneously records and transmits blood pressure, temperature and sympathetic nerve data on the 2.4 GHz ISM band with a range of 5 m. Blood pressure is measured with a 400 Hz bandwidth, fluid filled catheter at a resolution of 0.1 mmHg. Sympathetic nerve activity is measured differentially using stainless steel electrodes attached to the renal nerve. The telemeter measures 29x37x12min (a volume of approximately 9.5 cm(3)) and weighs 17g, making it suitable for use in rats with a weight greater than 170 g. Battery life is 12 h when used continuously, however the device's lifespan is effectively indefinite due to the use of in vivo inductively coupled battery charging. Example data recorded in a conscious unconstrained rat is provided which verifies the telemeters operation.
