Systems and methods for controlling displacement member velocity for a surgical instrument
View Patent ↗A motorized surgical instrument is disclosed. The surgical instrument includes a displacement member movable between a first position and a second position to effect a motion at an end effector, a motor coupled to the displacement member, the motor configured to drive the displacement member between the first position and the second position, and a control circuit coupled to the motor. The control circuit is configured to receive a signal indicative of force from a sensor, the signal indicative of the force applied by a closure tube to the end effector, determine a closure force applied by the closure tube to the end effector; determine whether the closure force is within a threshold of an expected closure force, and set a motor velocity to drive the motor at a velocity that corresponds to the closure force relative to the expected force.
1. A surgical instrument comprising:
a displacement member movable between a first position and a second position to effect a motion at an end effector;
a motor coupled to the displacement member, the motor configured to drive the displacement member between the first position and the second position; and
a control circuit coupled to the motor, the control circuit configured to:
receive a signal indicative of force from a sensor, the signal indicative of the force applied by a closure tube to the end effector;
determine a closure force applied by the closure tube to the end effector;
determine whether the closure force is within a threshold of an expected closure force; and
set a motor velocity to drive the motor at a velocity that corresponds to the closure force relative to the expected closure force.
2. The surgical instrument of claim 1 , further comprising a sensor coupled to the control circuit, the sensor configured to detect a force exerted at an interaction point between the end effector and the closure tube.
3. The surgical instrument of claim 2 , wherein the closure force comprises the force exerted at the interaction point between the end effector and the closure tube.
4. The surgical instrument of claim 1 , wherein the control circuit is configured to retrieve the expected closure force from a memory.
5. The surgical instrument of claim 1 , wherein the control circuit is configured to compare a value of the closure force to a value of the expected closure force and to determine whether the closure force is within the threshold of the expected closure force based on the results of the comparison.
6. The surgical instrument of claim 1 , wherein the control circuit is configured to compare a first difference between the closure force and a prior expected closure force and a second difference between the expected closure force and the prior expected closure force and to determine whether the closure force is within the threshold of the expected closure force based on the results of the comparison.
7. The surgical instrument of claim 1 , further comprising:
the end effector; and
the closure tube coupled to the end effector, the closure tube configured to apply the closure force to the end effector.
8. A surgical instrument comprising:
a closure system configured to apply a closure force to an end effector to transition the end effector between an open position and a closed position;
a displacement member coupled to the closure system, the displacement member movable between a first position and a second position to effect a motion at the end effector;
a motor coupled to the displacement member, the motor configured to drive the displacement member between the first position and the second position; and
a control circuit coupled to the motor, the control circuit configured to:
determine the closure force exerted by the closure system;
retrieve an expected closure force;
determine whether the closure force is within a tolerance of the expected closure force; and
set the motor to drive the displacement member at a velocity, wherein the velocity corresponds to the closure force relative to the expected closure force.
9. The surgical instrument of claim 8 , further comprising a sensor coupled to the control circuit, the sensor configured to detect the closure force.
10. The surgical instrument of claim 9 , wherein the sensor is disposed at an interaction point between the closure system and the end effector.
11. The surgical instrument of claim 8 , wherein the control circuit is configured to retrieve the expected closure force from a memory.
12. The surgical instrument of claim 8 , wherein the control circuit is configured to compare a value of the closure force to a value of the expected closure force and to determine whether the closure force is within the tolerance of the expected closure force based on the comparison.
13. The surgical instrument of claim 8 , wherein the control circuit is configured to compare a first difference between the closure force and a prior expected closure force and a second difference between the expected closure force and the prior expected closure force and to determine whether the closure force is within the tolerance of the expected closure force based on the results of the comparison.
14. The surgical instrument of claim 8 , further comprising:
the end effector; and
the closure system coupled to the end effector, the closure system configured to apply the closure force to the end effector.
15. A method of controlling a motor in a surgical instrument, the surgical instrument comprising a closure system configured to apply a closure force to an end effector to transition the end effector between an open position and a closed position, a displacement member coupled to the closure system, the displacement member movable between a first position and a second position to effect a motion at the end effector, the motor coupled to the displacement member, the motor configured to drive the displacement member between the first position and the second position, and a control circuit coupled to the motor, the method comprising:
determining the closure force exerted by the closure system;
retrieving an expected closure force;
determining whether the closure force is within a tolerance of the expected closure force; and
setting a motor velocity for driving the motor, wherein the motor velocity corresponds to the closure force relative to the expected closure force.
16. The method of claim 15 , further comprising retrieving, by the control circuit, the expected closure force from a memory.
17. The method of claim 15 , further comprising sensing, by a sensor coupled to the control circuit, a force exerted by the closure system at an interaction point with the end effector.
18. The method of claim 17 , further comprising determining, by the control circuit, the closure force exerted by the closure system.
19. The method of claim 15 , further comprising comparing, by the control circuit, a value of the closure force to a value of the expected closure force and determining, by the control circuit, whether the closure force is within the tolerance of the expected closure force based on the results of the comparison.
20. The method of claim 15 , further comprising comparing, by the control circuit, a first difference between the closure force and a prior expected closure force and a second difference between the expected closure force and the prior expected closure force and determining, by the control circuit, whether closure force is within the tolerance of the expected closure force based on the results of the comparison.
21. A surgical instrument comprising:
a displacement member movable between a first position and a second position to effect a motion at an end effector;
a motor coupled to the displacement member, the motor configured to drive the displacement member between the first position and the second position; and
a control circuit coupled to the motor, the control circuit configured to:
determine a closure force applied by a closure tube to the end effector;
compare the closure force to an expected closure force; and
set a motor velocity to drive the motor at a velocity based on the comparison.
22. A surgical instrument comprising:
a closure system configured to apply a closure force to an end effector to transition the end effector between an open position and a closed position;
a displacement member coupled to the closure system, the displacement member movable between a first position and a second position to effect a motion at the end effector;
a motor coupled to the displacement member, the motor configured to drive the displacement member between the first position and the second position; and
a control circuit coupled to the motor, the control circuit configured to:
determine the closure force exerted by the closure system;
compare the closure force to an expected closure force; and
set the motor to drive the displacement member at a velocity based on the comparison.
23. A method of controlling a motor in a surgical instrument, the surgical instrument comprising a closure system configured to apply a closure force to an end effector to transition the end effector between an open position and a closed position, a displacement member coupled to the closure system, the displacement member movable between a first position and a second position to effect a motion at the end effector, the motor coupled to the displacement member, the motor configured to drive the displacement member between the first position and the second position, and a control circuit coupled to the motor, the method comprising:
determining the closure force exerted by the closure system;
comparing the closure force to an expected closure force; and
setting a motor velocity for driving the motor, wherein the motor velocity is based on the comparison.