Design and fabrication of an implantable three-axis accelerometer for post-surgery monitoring of heart wall motion

The design and fabrication of miniaturized three-axis accelerometers to be used in the measurement of heart wall motion are presented in this paper. Results from animal studies carried out by the group have already demonstrated the usefulness of large commercial accelerometers for this medical application. The advanced sensors proposed here consist of full wafer thickness masses supported by thin cantilever beams. Piezoresistors, which are implanted into the surface of the thin beams, are used to measure any acceleration that the masses undergo.