Patent ID: 8038693

Claim:
An ultrasonic surgical instrument, comprising: an ultrasonic transmission member having a proximal end and a distal end; an ultrasonically-actuated cutting element having a tissue contacting surface, the cutting element located at the distal end of the transmission member; a clamp member supported adjacent to the cutting element for clamping tissue, the clamp member including a sensing mechanism that senses load variations on tissue; a handle member located at the proximal end of the transmission member that moves the clamp member relative to the cutting element; and a feedback mechanism operatively coupled to the sensing mechanism that supplies information related to the load variations; wherein an output of the cutting element is adjusted based on the sensed load variations supplied from the feedback mechanism; and wherein the load variations are sensed by a laser interferometry configuration including an interferometer configured to identify and analyze at least (i) resonance frequencies of ultrasonic motion across a length of the ultrasonic surgical instrument and (ii) intensity of scattered laser light at an output of the interferometer.