Safety arrangements for ultrasonically-vibratable surgical tools

Abstract

An ultrasonically-vibratable surgical tool for cement (7) removal in revision arthroplasty has a source of ultrasonic vibrations operatively linked to an operative tip (5) which acts on the cement (7) within a lumen (8) of a bone such as a femur (1). When acting on the cement (7), the tool vibrates substantially at a single resonant frequency. If the operative tip (5) should contact a hard material, such as a bone wall (6) of the femur (1), additional supplementary vibrations are generated at other frequencies. The tool comprises a microphone or other vibration detector to pick up these supplementary vibrations, which may be in the audible or ultrasonic ranges. When supplementary vibrations are detected at frequencies characteristic of contact between the operative tip (5) and bone, a user of the tool is alerted and operation of the tool is interrupted.

Dependencies are inferred from the claim text.