TORQUE OPTIMIZATION FOR SURGICAL INSTRUMENTS
A control system having speed management control. The control system can be in signal communication with a battery, and the battery can be coupled to a motor. The speed management control can include a pulse width modulation circuit, which can control the duration of pulses supplied from the battery to the motor. The motor can include a primary set of coils and a secondary set of coils. The control system can direct surplus current to the secondary set of coils to maximize the torque generated by the motor.
1 . A surgical stapler, comprising:
an end effector comprising a plurality of deployable staples and a firing element;
a motor configured to drive said firing element, wherein said motor comprises a primary set of coils and a secondary set of coils; and
a control system in signal communication with said motor, wherein said control system comprises:
a battery;
a pulse width modulation circuit configured to control the duration of current pulses supplied from said battery to said motor; and
a switch configured to switch the electric motor between a plurality of operating states, wherein the plurality of operating states comprises:
a first operating state in which the primary set of coils are configured to drive said firing element; and
a second operating state in which said primary set of coils and said secondary set of coils are configured to drive said firing element.
2 . The surgical stapler of claim 1 , wherein the battery supplies current pulses to said primary set of coils at a voltage that corresponds to the maximum torque of said primary set of coils during the first operating state.
3 . The surgical stapler of claim 2 , wherein a surplus current is supplied to said secondary set of coils during the second operating state.
4 . The surgical stapler of claim 3 , wherein said control system maximizes the surplus current supplied to said secondary set of coils during the second operating state based on the volt-ampere limit of said battery.
5 . The surgical instrument of claim 1 , wherein said motor generates a first amount of torque during the first operating state, wherein said motor generates a second amount of torque during the second operating state, and wherein the second amount of torque is greater than the first amount of torque.
6 . The surgical stapler of claim 5 , wherein said motor drives said firing element in a first direction during the first operating state, wherein said motor drives said firing element in a second direction during the second operating state, and wherein the second direction is opposite to the first direction.
7 . The surgical stapler of claim 6 , wherein the first direction comprises a distally advancing direction, and wherein the second direction comprises a proximally retracting direction.
8 . The surgical stapler of claim 1 , wherein said motor comprises a stepper motor.
9 . A surgical stapler, comprising:
an end effector comprising a plurality of deployable staples and a firing element;
a control system, comprising:
a battery; and
a pulse width modulation circuit configured to control the duration of current pulses supplied from said battery; and
a motor in signal communication with said control system and configured to drive said firing element, wherein said motor comprises:
a primary set of coils configured to generate a first amount of torque, wherein the first amount of torque drives said firing element in a first direction; and
a secondary set of coils configured to generate a second amount of torque, wherein the first amount of torque and the second amount of torque drive said firing element in a second direction.
10 . The surgical stapler of claim 9 , wherein said battery is configured to supply current pulses to said primary set of coils at a voltage that corresponds to the maximum torque of said primary set of coils.
11 . The surgical stapler of claim 10 , wherein said battery operably supplies a surplus current to said secondary set of coils.
12 . The surgical stapler of claim 9 , wherein said control system maximizes the torque generated by said primary set of coils and the secondary set of coils when driving said firing element in the second direction.
13 . The surgical stapler of claim 9 , wherein the second direction is opposite to the first direction.
14 . The surgical stapler of claim 5 , wherein the second direction comprises a proximal direction.
15 . The surgical stapler of claim 1 , wherein said motor comprises a stepper motor.
16 . A surgical stapler, comprising:
an end effector comprising a plurality of deployable staples and a firing element;
a motor configured to drive said firing element, wherein said motor comprises a primary set of coils; and
a control system in signal communication with said motor, wherein said control system comprises:
a battery; and
a pulse width modulation circuit configured to control the duration of current pulses supplied from said battery to said primary set of coils.
17 . The surgical stapler of claim 16 , wherein said motor further comprises a secondary set of coils, and wherein said control system comprises a switch configured to operably supply current from said battery to said secondary set of coils.
18 . The surgical stapler of claim 17 , wherein said battery supplies current to said primary set of coils during a first operating state, and wherein said battery supplies current to said primary set of coils and said secondary set of coils during a second operating state.
19 . The surgical stapler of claim 18 , wherein said motor drives said firing element distally during the first operating state, and wherein said motor drives said firing element proximally during the second operating state.
20 . The surgical stapler of claim 16 , wherein said control system optimizes the torque generated by said motor.
21 . (canceled)