Development of a biotelemetric heart valve monitor using a 2.45 GHztransceiver, microcontroller, A/D converter, and sensor gain amplifiers

摘要

The development of a fully implantable micromachined device thatuses biotelemetry to monitor beat-to-beat aortic flow through artificialheart valves has been proposed. The purpose of this research was todesign and build a large-scale circuit that could prove the feasibilityof the essential concepts involved in such a device. The objectives wereto demonstrate the ability to acquire and condition data signals with amicrocontroller, show the capability to interface the microcontroller toa transceiver IC, RF transmit the acquired data to a PC, andsuccessfully recreate the captured signals with the data received by thePC. The final design is composed of a PIC16C76 microcontroller, theMicroStamp Engine 2.45 GHz transceiver IC, and two AD620 low powerinstrumentation amplifiers. This is the highest frequency evaluated fora biotelemetry system known to the authors. The circuit performs an8-bit A/D conversion on two input channels and serially relays theconverted data to the MicroStamp Engine, which transmits the data to aPC at 2.45 GHz. The system was tested using triangular wave inputsignals of various frequencies and amplitudes. The results showed anaverage of 4.1% error per reproduced waveform