Ultrasonic surgical shears and method for sealing a blood vessel using same

1. An ultrasonic surgical instrument, comprising:

an end effector, comprising:

an ultrasonic blade; and

a clamp arm movable relative to the ultrasonic blade between an open position and a closed position; and

a handle assembly, comprising:

a handle comprising a pivot pin;

a trigger pivotable relative to the handle about the pivot pin; and

a yoke operably coupled to the trigger, wherein the yoke is longitudinally movable between a proximal position and a distal position based on pivotable movement of the trigger relative to the handle, wherein the yoke defines an opening, wherein the pivot pin extends into the opening, and wherein the opening defines an actuator travel stop configured to contact the pivot pin to prevent overtravel of the trigger.

2. The ultrasonic surgical instrument of claim 1 , wherein the clamp arm is movable toward the closed position based on the yoke moving toward the proximal position.

3. The ultrasonic surgical instrument of claim 2 , wherein the yoke is movable toward the proximal position based on pivotable movement of the trigger toward the handle.

4. The ultrasonic surgical instrument of claim 1 , wherein the handle assembly further comprises a link pivotably coupled to the trigger and the yoke.

5. The ultrasonic surgical instrument of claim 1 , wherein the end effector further comprises a tissue pad coupled to the clamp arm, wherein the tissue pad is configured to apply pressure to a blood vessel captured between the ultrasonic blade and the tissue pad.

6. The ultrasonic surgical instrument of claim 5 , further comprising:

an inner tube, wherein movement of the clamp arm is based on longitudinal movement of the inner tube; and

a collar assembly operably coupled to the inner tube and the yoke.

7. The ultrasonic surgical instrument of claim 6 , wherein the yoke further comprises:

a first arm comprising a first pawl; and

a second arm comprising a second pawl, wherein the first pawl and the second pawl are configured to engage teeth of the collar assembly.

8. The ultrasonic surgical instrument of claim 6 , wherein the collar assembly comprises a force limiting spring, and wherein the force limiting spring is configured to cause the tissue pad to apply a predetermined clamping pressure to the blood vessel between and including 60 psi and 210 psi.

9. The ultrasonic surgical instrument of claim 5 , wherein the actuator travel stop is configured to limit the pressure to no greater than 210 psi.

10. The ultrasonic surgical instrument of claim 5 , further comprising means for sensing the pressure applied to the blood vessel by the tissue pad.

11. The ultrasonic surgical instrument of claim 10 , further comprising a display operably coupled to the means for sensing, wherein the display is configured to display the pressure sensed by the means for sensing.

12. An ultrasonic surgical system, comprising:

an end effector, comprising:

an ultrasonic blade;

a clamp arm pivotable relative to the ultrasonic blade between an open position and a clamped position; and

a tissue pad coupled to the clamp arm, wherein the tissue pad is configured to apply pressure to a blood vessel captured between the ultrasonic blade and the tissue pad; and

a housing, comprising:

a handle comprising a pivot pin;

a trigger pivotable relative to the handle about the pivot pin; and

a yoke operably coupled to the trigger, wherein the yoke is longitudinally movable between a proximal position and a distal position based on pivotable movement of the trigger relative to the handle, and wherein the yoke defines an aperture, wherein the pivot pin is disposed within the aperture, and wherein the aperture defines a stop configured to contact the pivot pin to prevent overtravel of the trigger.

13. The ultrasonic surgical system of claim 12 , wherein the clamp arm is movable toward the clamped position based on the yoke moving toward the proximal position.

14. The ultrasonic surgical system of claim 13 , wherein the yoke is movable toward the proximal position based on pivotable movement of the trigger toward the handle.

15. The ultrasonic surgical system of claim 12 , further comprising:

an inner tube, wherein movement of the clamp arm is based on longitudinal movement of the inner tube; and

a collar assembly operably coupled to the inner tube and the yoke.

16. The ultrasonic surgical system of claim 15 , wherein the collar assembly comprises a force limiting spring, and wherein the force limiting spring is configured to cause the tissue pad to apply a predetermined clamping pressure to the blood vessel between and including 60 psi and 210 psi.

17. The ultrasonic surgical system of claim 12 , wherein the stop is configured to limit the pressure to no greater than 210 psi.

18. The ultrasonic surgical system of claim 12 , further comprising:

means for sensing the pressure applied to the blood vessel by the tissue pad; and

a display configured to display the pressure sensed by the means for sensing.

19. An ultrasonic surgical system, comprising:

an end effector, comprising:

an ultrasonic blade;

a clamp arm pivotable relative to the ultrasonic blade between an open position and a closed position; and

a tissue pad coupled to the clamp arm, wherein the tissue pad is configured to apply pressure to a blood vessel captured between the ultrasonic blade and the tissue pad; and

a housing, comprising:

a handle comprising a pivot pin;

a trigger pivotable relative to the handle about the pivot pin; and

a yoke, wherein the clamp arm is moveable between the open position and the closed position based on movement of the yoke, wherein the yoke is movable based on pivotable movement of the trigger relative to the handle, and wherein the yoke comprises a stop configured to contact the pivot pin to prevent overtravel of the trigger.

20. The ultrasonic surgical system of claim 19 , wherein the stop is configured to limit the pressure to no greater than 210 psi.