Method for closed loop control of motor velocity of a surgical stapling and cutting instrument

• US 10,307,170 B2
• Filed: 06/20/2017
• Issued: 06/04/2019
• Est. Priority Date: 06/20/2017
• Status: Active Grant

• Current Assignee: Cilag Gmbh International (Johnson & Johnson)
• Original Assignee: Ethicon, LLC (Johnson & Johnson)
• Inventors: Parfett, Raymond E., Adams, Shane R., Shelton, IV, Frederick E., Harris, Jason L.
• Primary Examiner(s): Masih, Karen
• Application Number:
  US15/628,045
• Publication Number:
  US 20180360470A1
• Time in Patent Office: 714 Days
• CPC Class Codes: A61B 17/07207 the staples being applied sequentially
• CPC Class Codes: A61B 17/1626 Control means; Display units
• CPC Class Codes: A61B 2017/00017 Electrical control of surgical instruments
• CPC Class Codes: A61B 2017/00039 Electric or electromagnetic phenomena other than conductivity, e.g. capacity, inductivity, Hall effect
• CPC Class Codes: A61B 2017/00398 using powered actuators, e.g. stepper motors, solenoids
• CPC Class Codes: A61B 2017/07278 characterised by its sled or its staple holder
• CPC Class Codes: A61B 2017/07285 characterised by its cutter
• CPC Class Codes: A61B 2017/320052 Guides for cutting instruments
• CPC Class Codes: A61B 34/76 Manipulators having means for providing feel, e.g. force or tactile feedback

Abstract

A method of adjusting velocity in a motorized surgical instrument is provided. The surgical instrument comprises a displacement member configured to translate within the surgical instrument over a plurality of predefined zones, 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 the position of the displacement member and a timer circuit coupled to the control circuit, the timer circuit configured to measure elapsed time. The method includes setting a directed velocity of the displacement member; determining an actual velocity of the displacement member; determining an error between the directed velocity of the displacement member and the actual velocity of the displacement member; and controlling the actual velocity of the displacement member based on the magnitude of the error.

Claims

1. A method of adjusting velocity in a motorized surgical instrument, the motorized surgical instrument comprising a displacement member configured to translate within the motorized surgical instrument over a plurality of predefined zones, 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, and a timer circuit coupled to the control circuit, the timer circuit configured to measure elapsed time, the method comprising:

determining, by the control circuit, a location of the displacement member within one of the plurality of predefined zones;

setting, by the control circuit, a directed velocity of the displacement member based on a zone in which the displacement member is located;

determining, by the control circuit, an actual velocity of the displacement member;

determining, by the control circuit, an error between the directed velocity of the displacement member and the actual velocity of the displacement member; and

controlling, by the control circuit, the actual velocity of the displacement member based on a magnitude of the error and the zone in which the displacement member is located, wherein different errors are assigned to different zones;

wherein the error in at least one of the plurality of predefined zones is based on at least one of a short term error (S), cumulative error (C), rate of change error (R), and number of overshoots error (N).

2. The method of claim 1, wherein the motorized surgical instrument further comprises an end effector, wherein the displacement member is configured to translate within the end effector.

3. The method of claim 1, wherein the error is determined over a predetermined increment of time.

4. The method of claim 1, wherein the error is determined over a predetermined increment of distance.

5. The method of claim 1, further comprising determining, by the control circuit, a zone in which the displacement member is located.

6. A method of adjusting velocity in a motorized surgical instrument, the motorized surgical instrument comprising a displacement member configured to translate within the motorized surgical instrument over a plurality of predefined zones, 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, and a timer circuit coupled to the control circuit, the timer circuit configured to measure elapsed time, the method comprising:

determining, by the control circuit, a location of the displacement member within one of the plurality of predefined zones;

setting, by the control circuit, a directed velocity of the displacement member based on a zone in which the displacement member is located;

determining, by the control circuit, an actual velocity of the displacement member;

determining, by the control circuit, an error between the directed velocity of the displacement member and the actual velocity of the displacement member; and

controlling, by the control circuit, the actual velocity of the displacement member based on a magnitude of the error and the zone in which the displacement member is located, wherein different errors are assigned to different zones;

wherein the error in at least one of the plurality of predefined zones is based on at least one of a short term error (S), cumulative error (C), rate of change error (R), or number of overshoots error (N) and any combination thereof.

7. The method of claim 6, wherein the motorized surgical instrument further comprises an end effector, wherein the displacement member is configured to translate within the end effector.

8. The method of claim 6, wherein the error is determined over a predetermined increment of time.

9. The method of claim 6, wherein the error is determined over a predetermined increment of distance.

10. The method of claim 6, further comprising determining, by the control circuit, a zone in which the displacement member is located.