Patent ID: 8920496

Claim:
An ossicular replacement prosthesis (ORP) for coupling an ossicular bone or an eardrum of a patient to another point in the middle ear of the patient, to replace all or part of the ossicular chain, the ORP comprising: a coupling having a variable configuration for accounting for pressure differentials, said coupling comprising a container, a piston, and a cover secured to the container and the piston thereby forming an enclosed chamber, the chamber filled with a fluid, the piston slidably mounted in a bore defined by the container for varying the configuration of the coupling and relative movement of the container and the piston, wherein an annular clearance is defined between an outer surface of the piston and an inner surface of the bore of the container for permitting displacement of the fluid within the chamber through said annular clearance, the relative movement of the container and the piston being controlled by said displacement of the fluid, wherein said chamber is configured to restrict said displacement of the fluid such that relative movement of the container and the piston is permitted in response to quasi-static changes in pressure, and is prevented in response to vibrational changes corresponding to sound frequencies.