Feedback control in an ultrasonic surgical instrument for improved tissue effects

摘要

Described is a method and apparatus for controlling the heat treatment of tissue in response to the measured temperature as an indication of tissue treatment status of the tissue being treated by an ultrasonic cutting and coagulating instrument. A method and apparatus for controlling the heat treatment of tissue in separate modes for ultrasonic cutting and ultrasonic coagulation is disclosed. Accordingly the present invention provides a temperature monitoring device and/or method which controls the tissue temperature at the end-effector of a therapeutic ultrasonic cutting and coagulating instrument as the tissue is being heated with ultrasonic vibrations from the end-effector. One or more temperature sensors are located at the end-effector, preferably on a clamping member. The temperature sensors measure the temperature of the tissue engaged by the end-effector either directly or indirectly. An alternate method and apparatus of the present invention provides an electrical tissue impedance measure in combination with an ultrasonic cutting and coagulating instrument to provide active feedback control of an ultrasonic generator.