Design, implementation, and validation of an implantable multichannel telemetry system for chronic study of sudden cardiac death.

摘要

Sudden cardiac death (SCD) is one of the leading causes of death in the United State, but the prediction and prevention of SCD have not generally been successful. Dimension, flow, and pressure measurements will be instrumental in further the understanding of the arrhythmic events. I designed and tested a new multichannel telemetry system with dimension, flow, pressure, and electrogram measurements with lower power, smaller size, and less weight. This telemetry system can be divided into three parts: front end, backpack, and host PC. In the front end, I have designed and calibrated sensor electronics for dimension and blood flow measurement. I have adopted the electronics of pressure channels and cardiac electrograms from the previous telemetry system to better fit in the new system. A stainless steel watertight package for the front end was also designed, manufactured, and tested. The backpack included a control unit, Bluetooth radio, and batteries. The control unit digitized the analog signals from the front end and transmitted the data to the host PC. The host PC had another Bluetooth radio as a receiver and the data were archived and displayed on the host monitor. The whole system was powered by six AA batteries for 24 h. The peak power consumption in the new telemetry system was reduced from 5 W to 0.46 W, the weight for the system was reduced from 2.1 kg to 1.1 kg, and the volume was reduced from 2.6 L to 1.3 L. The whole system was successfully tested on the bench and in animals. To our knowledge, this is the first telemetry system that has integrated dimension, flow, and pressure measurements with cardiac electrograms. It is novel to bring dimension measurement and Doppler flow into one system. Dimension, flow, and pressure measurements are more direct indicators of heart function. The availability of these measurements in the chronic study of sudden cardiac death will help us to better characterize cardiac arrhythmias and will greatly enhance our ability to study events leading to spontaneous sudden cardiac death.