Surgical stapler having a powered handle
A powered handle for a surgical stapler can have a drive system including an electric motor. The powered handle can include a manual articulation mechanism to articulate a jaw assembly coupled to a reload shaft connected to the handle. The manual articulation mechanism can include a ball screw mechanism that translates an articulation member responsive to rotation of an articulation knob. The articulation mechanism includes a release function that allows the jaw assembly to return to a longitudinally centered orientation. The powered handle includes a battery pack serving as a power supply for the drive system. A control system can control actuation of the motor based on user inputs and operating parameters of the stapler. The powered handle can include a manual return mechanism.
1. A handle assembly for a surgical stapler, the handle assembly comprising:
a handle body comprising a stationary handle and a trigger pivotably coupled to the handle body;
an electric motor disposed within the handle body;
an actuation shaft slidable within the handle body along a longitudinal axis and rotatable within the handle body about the longitudinal axis, the actuation shaft comprising a rack formed thereon; and
a manual return mechanism, the manual return mechanism comprising:
a shaft rotation mechanism configured to rotate the shaft from the first position to the second position; and
a shaft retraction mechanism configured to proximally retract the actuation shaft;
wherein the actuation shaft is rotatable from a first position wherein the rack is operationally engaged with the electric motor to longitudinally slide the actuation shaft to a second position wherein the rack is disengaged from the electric motor and engaged with the manual return mechanism.
2. The handle assembly of claim 1 , wherein the electric motor comprises an output shaft and further comprising a motor gear coupled to the output shaft and an auxiliary gear in driven engagement with the motor gear and engaged with the rack with the rack in the first position.
3. The handle assembly of claim 2 , further comprising a guide member supporting the auxiliary gear and the actuation shaft and maintaining meshed engagement between the auxiliary gear and the rack.
4. The handle assembly of claim 1 , wherein the shaft rotation mechanism comprises a shaft rotation collar disposed on the actuation shaft.
5. The handle assembly of claim 4 , wherein the shaft rotation collar comprises a shaft rotation rack formed thereon.
6. The handle assembly of claim 5 , wherein the shaft rotation mechanism further comprises a disengagement tab positioned on an outer surface of the handle body, the disengagement tab comprising a disengagement rack formed thereon in engagement with the shaft rotation rack.
7. The handle assembly of claim 6 , wherein removal of the disengagement tab from the outer surface of the handle body rotates the actuation shaft from the first position to the second position.
8. The handle assembly of claim 1 , wherein the shaft retraction mechanism comprises:
a return lever;
a return pawl; and
a pivot joint pivotably coupling the return lever to the return pawl.
9. The handle assembly of claim 8 , wherein the return pawl is engaged with the rack with the actuation shaft in the second position.
10. The handle assembly of claim 9 , wherein actuation of the return lever through a return cycle advances the actuation shaft proximally with the actuation shaft in the second position.
11. The handle assembly of claim 8 , wherein the shaft retraction mechanism further comprises an interference lobe protruding from the return lever to interfere with rotation of the actuation shaft from the second position to the first position.