Abstract: An accelerometer device which can be mounted on a substrate, e.g., a circuit board enclosed in a medical device, includes an accelerometer sensing element having an axis of sensitivity and further includes first and second multilayer end caps. The substrate generally defines a mounting plane. The accelerometer sensing element includes a device body having a longitudinal axis extending between generally parallel first and second ends thereof and further includes a principal surface extending between the first and second ends of the device body parallel to the longitudinal axis. The axis of sensitivity of the sensing element is generally perpendicular to a plane defined by the principal surface. Further, the accelerometer sensing element includes conductive pad regions on each of the first and second ends of the device body.

Abstract: The present invention relates to accelerometer assemblies for implantable medical devices such as pacemakers, IPGs, PCDs, defibrillators, ICDs and the like. The accelerometer assembly of the present invention comprises a beam that deflects in response to being subjected to an externally provided force. Deflection of the beam generates a voltage in a piezoelectric material disposed in the assembly. At least one stop is provided to limit the vertical range of motion through which the beam may deflect to prevent failure, fracturing or breakage of the beam resulting from excessive deflection of the beam that might otherwise occur were the stop not present.

Abstract: Disclosed are method and apparatus for creating a cantilever accelerometer beam by mechanically forming an accelerometer from a piezoelectric substrate. The inherent structure of the accelerometer provides a means for employing surface mount technology (SMT), or a protective package may be utilized to couple the accelerometer to the hybrid circuit within an implantable pacemaker. The sensor's structure is defined by three members. The first and second members are used to couple the sensor to the hybrid circuit and the third member defines the cantilever accelerometer beam, which generates an electrical output signal indicative of a patient's activity.