Systems and methods for controlling motor velocity of a surgical stapling and cutting instrument
A motorized surgical instrument is provided. The surgical instrument includes a displacement member. A motor is coupled to the displacement member. A control circuit is coupled to the motor. A position sensor is coupled to the control circuit. A timer circuit is coupled to the control circuit to measure elapsed time. The control circuit is configured to receive the position of the displacement member from the position sensor, receive elapsed time from the timer circuit, and control velocity of the motor based on the position of the displacement member and the elapsed time. A method of controlling motor velocity of the surgical instrument also is disclosed.
1. A surgical instrument, comprising:
a displacement member configured to translate within the surgical instrument;
a motor coupled to the displacement member to translate the displacement member;
a control circuit coupled to the motor;
a position sensor coupled to the control circuit, the position sensor configured to measure a position of the displacement member;
a timer/counter circuit coupled to the control circuit, the timer/counter circuit configured to measure elapsed time;
wherein the control circuit is configured to:
receive the position of the displacement member from the position sensor;
receive the elapsed time from the timer/counter circuit;
correlate the position of the displacement member and the elapsed time; and
control velocity of the motor based on the correlation of the position of the displacement member and the elapsed time.
2. The surgical instrument of claim 1 , wherein the control circuit is configured to:
set the velocity of the motor to a first velocity;
receive an initial position A o of the displacement member from the position sensor;
receive a reference time t 1 from the timer/counter circuit corresponding to the initial position A o of the displacement member; and
determine an anticipated position A 1 of the displacement member at a time t 2 based on the first velocity.
3. The surgical instrument of claim 2 , wherein the control circuit is configured to:
receive an actual position B 1 of the displacement member at the time t 2 from the position sensor;
compare the actual position B 1 of the displacement member at the time t 2 with the anticipated position A 1 of the displacement member at the time t 2 ; and
adjust the velocity of the motor to a second velocity based on a difference between the actual position B 1 of the displacement member at the time t 2 and the anticipated position A 1 of the displacement member at the time t 2 .
4. The surgical instrument of claim 3 , wherein the control circuit is configured to: increase the velocity of the motor when the actual position B 1 of the displacement member at the time t 2 is greater than the anticipated position A 1 of the displacement member at the time t 2 .
5. The surgical instrument of claim 3 , wherein the control circuit is configured to:
decrease the velocity of the motor when the actual position B 1 of the displacement member at the time t 2 is less than the anticipated position A 1 of the displacement member at the time t 2 .
6. The surgical instrument of claim 3 , wherein the control circuit is configured to:
determine actual tissue thickness based on a difference between the actual position B 1 of the displacement member at the time t 2 and the anticipated position A 1 of the displacement member at the time t 2 .
7. The surgical instrument of claim 6 , wherein the control circuit is configured to:
determine that the actual tissue thickness is less than anticipated when the actual position B 1 of the displacement member at the time t 2 is greater than the anticipated position A 1 of the displacement member at the time t 2 .
8. The surgical instrument of claim 6 , wherein the control circuit is configured to:
determine that the actual tissue thickness is greater than anticipated when the actual position B 1 of the displacement member at the time t 2 is less than the anticipated position A 1 of the displacement member at the time t 2 .
9. A surgical instrument, comprising:
an I-beam member configured to translate within an end effector of the surgical instrument;
a motor coupled to the I-beam member to translate the I-beam member within the end effector;
a control circuit coupled to the motor;
a position sensor coupled to the control circuit, the position sensor configured to measure a position of the I-beam member;
a timer/counter circuit coupled to the control circuit, the timer/counter circuit configured to measure elapsed time;
wherein the control circuit is configured to:
receive the position of the I-beam member from the position sensor;
receive the elapsed time from the timer/counter circuit;
correlate the position of the I-beam member and the elapsed time; and
control velocity of the motor based on the correlation of the position of the I-beam member and the elapsed time.
10. The surgical instrument of claim 9 , wherein the control circuit is configured to:
set the velocity of the motor to a first velocity;
receive an initial position A o of the I-beam member from the position sensor;
receive a reference time t 1 from the timer/counter circuit corresponding to the initial position A o of the I-beam member; and
determine an anticipated position A 1 of the I-beam member at a time t 2 based on the first velocity.
11. The surgical instrument of claim 10 , wherein the control circuit is configured to:
receive an actual position B 1 of the I-beam member at the time t 2 from the position sensor;
compare the actual position B 1 of the I-beam member at the time t 2 with the anticipated position A 1 of the I-beam member at the time t 2 ; and
adjust the velocity of the motor to a second velocity based on a difference between the actual position B 1 of the I-beam member at the time t 2 and the anticipated position A 1 of the I-beam member at the time t 2 .
12. The surgical instrument of claim 11 , wherein the control circuit is configured to:
increase the velocity of the motor when the actual position B 1 of the I-beam member at the time t 2 is greater than the anticipated position A 1 of the I-beam member at the time t 2 .
13. The surgical instrument of claim 11 , wherein the control circuit is configured to:
decrease the velocity of the motor when the actual position B 1 of the I-beam member at the time t 2 is less than the anticipated position A 1 of the I-beam member at the time t 2 .
14. The surgical instrument of claim 11 , wherein the control circuit is configured to:
determine actual tissue thickness based on a difference between the actual position B 1 of the I-beam member at the time t 2 and the anticipated position A 1 of the I-beam member at the time t 2 .
15. The surgical instrument of claim 14 , wherein the control circuit is configured to:
determine that the actual tissue thickness is less than anticipated when the actual position B 1 of the I-beam member at the time t 2 is greater than the anticipated position A 1 of the I-beam member at the time t 2 .
16. The surgical instrument of claim 14 , wherein the control circuit is configured to:
determine that the actual tissue thickness is greater than anticipated when the actual position B 1 of the I-beam member at the time t 2 is less than the anticipated position A 1 of the I-beam member at the time t 2 .
17. A method of controlling motor velocity in a surgical instrument, the surgical instrument comprising a displacement member configured to translate, a motor coupled to the displacement member to translate the displacement member, a control circuit coupled to the motor, a position sensor coupled to the control circuit, the position sensor configured to measure a position of the displacement member, a timer/counter circuit coupled to the control circuit, the timer/counter circuit configured to measure elapsed time, the method comprising:
receiving, by the control circuit, the position of the displacement member from the position sensor;
receiving, by the control circuit, the elapsed time from the timer/counter circuit;
correlating, by the control circuit, the position of the displacement member and the elapsed time; and
controlling, by the control circuit, the motor velocity based on the correlation of the position of the displacement member and the elapsed time.
18. The method of claim 17 , comprising:
setting, by the control circuit, the motor velocity to a first velocity;
receiving, by the control circuit, an initial position A o of the displacement member from the position sensor;
receiving, by the control circuit, a reference time t 1 from the timer circuit corresponding to the initial position A o of the displacement member; and
determining, by the control circuit, an anticipated position A 1 of the displacement member at a time t 2 based on the first velocity.
19. The method of claim 18 , comprising:
receiving, by the control circuit, an actual position B 1 of the displacement member at the time t 2 from the position sensor;
comparing, by the control circuit, the actual position B 1 of the displacement member at the time t 2 with the anticipated position A 1 of the displacement member at the time t 2 ; and
adjusting, by the control circuit, the motor velocity to a second velocity based on a difference between the actual position B 1 of the displacement member at the time t 2 and the anticipated position A 1 of the displacement member at the time t 2 .
20. The method of claim 19 , comprising:
increasing, by the control circuit, the motor velocity when the actual position B 1 of the displacement member at the time t 2 is greater than the anticipated position A 1 of the displacement member at the time t 2 .
21. The method of claim 19 , comprising:
decreasing, by the control circuit, the motor velocity when the actual position B 1 of the displacement member at the time t 2 is less than the anticipated position A 1 of the displacement member at the time t 2 .
22. The method of claim 19 , comprising:
determining, by the control circuit, actual tissue thickness based on a difference between the actual position B 1 of the displacement member at the time t 2 and the anticipated position A 1 of the displacement member at the time t 2 .
23. The method of claim 22 , comprising:
determining, by the control circuit, that the actual tissue thickness is less than anticipated when the actual position B 1 of the displacement member at the time t 2 is greater than the anticipated position A 1 of the displacement member at the time t 2 .
24. The method of claim 22 , comprising:
determining, by the control circuit, that the actual tissue thickness is greater than anticipated when the actual position B 1 of the displacement member at the time t 2 is less than the anticipated position A 1 of the displacement member at the time t 2 .