Biocompatible packaging and testing of an endocardial accelerometer for heart wall motion analysis

A sensor system for the acquisition of acceleration signals from different locations on the heart wall during acute tests is described. A commercially available miniature three-axis accelerometer is mounted on a small, circular PCB. Three coating layers are applied to ensure the biocompatibility of the sensor: parylene-C, medical grade epoxy and PDMS. The device, intended for use during animal experiments, is shaped as a hemisphere with radius 2 mm. The sensor assembly is a dedicated design that allows insertion through the heart wall and fixation on the muscle. A dedicated data acquisition board enables to readout digital acceleration data and ECG signal, and to transmit it wirelessly to a remote receiver. The device was tested in-vitro for electrical isolation and water diffusion. Later, in-vivo performance was evaluated by acquiring acceleration signals from different sites on the cardiac muscle of a sheep. (C) 2015 The Authors. Published by Elsevier Ltd.