Methods for controlling a surgical stapler
A method for controlling a powered surgical stapler that includes an end effector with jaws that are movable between an open and a closed position and a firing member that is movable between a starting position and an ending position within the end effector. The jaws and firing member are controlled by separate rotary systems and the end effector includes a firing member lockout system that prevents axial movement of the firing member unless the surgical staple cartridge is in ready to fire condition.
1 . A firing control system, comprising:
a control circuit operatively coupled to a firing motor, the firing motor configured to drive a firing member; and
a non-transitory computer-readable storage medium including a computer program comprising instructions executable by the control circuit to:
monitor current of the firing motor; and
operate the firing motor to alternatively drive the firing member distally towards an ending position of the firing member and reversely towards a starting position of the firing member, based on the monitored current, during a firing stroke of the firing member until the firing member reaches the ending position,
wherein, the control circuit is further configured to:
in response to the monitored current exceeding a predetermined current threshold, operate the firing motor to drive the firing member reversely towards the starting position of the firing member for a first predetermined distance, and
in response to the firing member being driven reversely for the first predetermined distance, operate the firing motor to drive the firing member distally towards the ending position of the firing member for a second predetermined distance.
2 . The firing control system of claim 1 , wherein the control circuit is further configured to:
stop the firing motor for a predetermined time each time before operating the firing motor to drive the firing member in a different direction.
3 . The firing control system of claim 1 , wherein operating the firing motor to alternatively drive the firing member distally towards the ending position of the firing member and reversely towards the starting position of the firing member comprises:
operating the firing motor to drive the firing member distally towards the ending position of the firing member for a first predetermined distal distance; and
in response to the firing member being driven distally for the first predetermined distal distance, operating the firing motor to drive the firing member reversely towards the starting position of the firing member for a first predetermined proximal distance.
4 . The firing control system of claim 3 , wherein the control circuit is further configured to:
in response to the firing member being driven reversely for the first predetermined proximal distance, operate the firing motor to drive the firing member distally towards the ending position of the firing member for a second predetermined distal distance; and
in response to the firing member being driven distally for the second predetermined distal distance, operate the firing motor to drive the firing member reversely towards the starting position of the firing member for a second predetermined proximal distance.
5 . The firing control system of claim 1 , wherein operating the firing motor to alternatively drive the firing member distally towards the ending position of the firing member and reversely towards the starting position of the firing member comprises:
operating the firing motor to drive the firing member distally towards the ending position of the firing member for a first predetermined distal time; and
in response to the firing member being driven distally for the first predetermined distal time, operating the firing motor to drive the firing member reversely towards the starting position of the firing member for a first predetermined proximal time.
6 . The firing control system of claim 5 , wherein the control circuit is further configured to:
in response to the firing member being driven reversely for the first predetermined proximal time, operate the firing motor to drive the firing member distally towards the ending position of the firing member for a second predetermined distal time; and
in response to the firing member being driven distally for the second predetermined distal time, operate the firing motor to drive the firing member reversely towards the starting position of the firing member for a second predetermined proximal time.
7 . A surgical instrument assembly, comprising:
an end effector;
a firing member configured to axially move between a starting position and an ending position within the end effector;
a firing motor configured to drive the firing member to axially move within the end effector;
a control circuit operatively coupled to the firing motor; and
a non-transitory computer-readable storage medium including a computer program comprising instructions executable by the control circuit to:
monitor a parameter of the firing motor; and
operate the firing motor to alternatively drive the firing member distally towards the ending position of the firing member and reversely towards the starting position of the firing member, based on the monitored parameter, during a firing stroke of the firing member until the firing member reaches the ending position,
wherein the end effector comprises an anvil comprising a sensor configured to measure the parameter of the firing motor.
8 . The surgical instrument assembly of claim 7 , wherein the parameter is at least one of current or position of the firing motor.
9 . The surgical instrument assembly of claim 7 , wherein the monitored parameter is current of the firing motor, and the control circuit is configured to:
in response to the monitored current exceeding a predetermined current threshold, operate the firing motor to drive the firing member reversely towards the starting position of the firing member for a first predetermined distance.
10 . The surgical instrument assembly of claim 9 , wherein the control circuit is further configured to:
in response to the firing member being driven reversely for the first predetermined distance, operate the firing motor to drive the firing member distally towards the ending position of the firing member for a second predetermined distance.
11 . The surgical instrument assembly of claim 7 , wherein the control circuit is further configured to:
stop the firing motor for a predetermined time each time before operating the firing motor to drive the firing member in a different direction.
12 . The surgical instrument assembly of claim 7 , wherein operating the firing motor to alternatively drive the firing member distally towards the ending position of the firing member and reversely towards the starting position of the firing member comprises:
operating the firing motor to drive the firing member distally towards the ending position of the firing member for a first predetermined distal distance; and
in response to the firing member being driven distally for the first predetermined distal distance, operating the firing motor to drive the firing member reversely towards the starting position of the firing member for a first predetermined proximal distance.
13 . The surgical instrument assembly of claim 12 , wherein the control circuit is further configured to:
in response to the firing member being driven reversely for the first predetermined proximal distance, operate the firing motor to drive the firing member distally towards the ending position of the firing member for a second predetermined distal distance; and
in response to the firing member being driven distally for the second predetermined distal distance, operate the firing motor to drive the firing member reversely towards the starting position of the firing member for a second predetermined proximal distance.
14 . The surgical instrument assembly of claim 7 , wherein operating the firing motor to alternatively drive the firing member distally towards the ending position of the firing member and reversely towards the starting position of the firing member comprises:
operating the firing motor to drive the firing member distally towards the ending position of the firing member for a first predetermined distal time; and
in response to the firing member being driven distally for the first predetermined distal time, operating the firing motor to drive the firing member reversely towards the starting position of the firing member for a first predetermined proximal time.
15 . The surgical instrument assembly of claim 14 , wherein the control circuit is further configured to:
in response to the firing member being driven reversely for the first predetermined proximal time, operate the firing motor to drive the firing member distally towards the ending position of the firing member for a second predetermined distal time; and
in response to the firing member being driven distally for the second predetermined distal time, operate the firing motor to drive the firing member reversely towards the starting position of the firing member for a second predetermined proximal time.
16 . A method for controlling a surgical instrument assembly comprising an end effector, a firing member, and a firing motor, the firing motor configured to drive the firing member to axially move between a starting position and an ending position within the end effector, the method comprising:
monitoring a parameter of the firing motor; and
operating the firing motor to alternatively drive the firing member distally towards the ending position of the firing member and reversely towards the starting position of the firing member, based on the monitored parameter, during a firing stroke of the firing member until the firing member reaches the ending position,
wherein, the monitored parameter comprises current of the firing motor, the method further comprises:
in response to the monitored current exceeding a predetermined current threshold, operating the firing motor to drive the firing member reversely towards the starting position of the firing member for a first predetermined distance, and
in response to the firing member being driven reversely for the first predetermined distance, operating the firing motor to drive the firing member distally towards the ending position of the firing member for a second predetermined distance.
17 . The method of claim 16 , wherein the monitored parameter further comprises position of the firing motor.