Patent ID: 7662085

Claim:
An actuation system for assisting the operation of a human or animal heart, the actuation system comprising: an actuator element configured for extending proximate and exterior to a portion of a heart wall and operable for moving and actively indenting that portion of said heart wall to actively effect a reduction in the volume of the heart; a passive protective sheath positioned independent of the actuator element on the heart wall and configured to extend along the heart wall between the moving actuator element and the heart wall portion for protecting the heart wall portion from damage by the moving actuator element; the passive protective sheath including a fabric jacket and a plurality of studs interspersed throughout the fabric and having stud surfaces generally coextensive with surfaces of the fabric; the passive protective sheath being flexible and operable to transmit, to the heart wall portion, a moving force thereon by the moving actuator element for actively indenting the heart wall portion.