System for controlling ultrasonic clamping and cutting instruments
View Patent ↗A control system for use with an ultrasonic surgical instrument includes a generator supplying electrical energy to an ultrasonic surgical instrument, the electrical energy supplied by the generator being controlled such that power applied by the instrument is maintained constant once a predetermined pressure threshold is met. The control system operates by assigning a nominal power at which the ultrasonic instrument is to operate and adjusting the current and voltage applied to the ultrasonic surgical instrument so as to maintain the power applied by the ultrasonic surgical instrument at approximately the nominal power.
1. An ultrasonic surgical system, comprising:
an instrument and an ultrasonic signal generator linked to the instrument for supplying a desired signal to the instrument, the instrument includes an ultrasonic transducer, a housing and an end-effector;
the ultrasonic signal generator includes a control system, the control system includes a generator supplying electrical energy to the instrument, the electrical energy supplied by the generator being controlled such that power applied by the instrument is maintained constant once a predetermined pressure threshold is met.
2. The ultrasonic surgical system according to claim 1 , wherein the power applied by the instrument is equal to the product of the current and voltage generated by the generator.
3. The ultrasonic surgical system according to claim 2 , further including means for measuring impedance passing through the instrument and controlling the power level based upon the measured impedance.
4. The ultrasonic surgical system according to claim 3 , wherein the means for controlling the power level includes adjusting current passing through the instrument based upon the measured impedance.
5. The ultrasonic surgical system according to claim 1 , wherein voltage supplied by the generator is increased as the force applied continues to increase.
6. The ultrasonic surgical system according to claim 3 , further including means for measuring impedance passing through the instrument and controlling the power level based upon the measured impedance.
7. The ultrasonic surgical system according to claim 6 , wherein the means for controlling the power level includes adjusting current passing through the instrument based upon the measured impedance.
8. The ultrasonic surgical system according to claim 1 , further including means for balancing vibration levels of the instrument with pressure applied by the instrument.