MOTOR-DRIVEN SURGICAL CUTTING INSTRUMENT

• US 20120265230A1
• Filed: 06/01/2012
• Published: 10/18/2012
• Est. Priority Date: 09/23/2008
• Status: Active Grant

• Current Assignee: Cilag Gmbh International (Johnson & Johnson)
• Original Assignee: Ethicon Endo-Surgery, Inc. (Johnson & Johnson)
• Inventors: Yates, David C., Shelton, Frederick E. IV, Smith, Bret W., Swensgard, Brett E., Laurent, Ryan J.
• Granted Patent: US 8,602,287 B2
• Time in Patent Office: Days
• US Class Current: 606/170
• CPC Class Codes: A61B 17/068 Surgical staplers , e.g. containing multiple staples or clampsstaplers containing only one staple A61B17/10; magazines or containers for staples A61B17/105; for performing anastomosis A61B17/115; staplers in general B25C5/00
• CPC Class Codes: A61B 17/07207 the staples being applied sequentially
• CPC Class Codes: A61B 17/105 Wound clamp magazines for packaging sharps A61B50/3001
• CPC Class Codes: A61B 17/32 Surgical cutting instruments A61B18/042 takes precedence; suture cutters A61B17/0467; instruments for ligaturing or cutting A61B17/128; instruments for rupturing the amniotic membrane A61B17/4208; specially adapted knives for eye surgery A61F9/0133
• CPC Class Codes: A61B 17/3205 Excision instruments
• CPC Class Codes: A61B 2017/00017 Electrical control of surgical instruments
• CPC Class Codes: A61B 2017/00154 pulsed
• CPC Class Codes: A61B 2017/00398 using powered actuators, e.g. stepper motors, solenoids
• CPC Class Codes: A61B 2017/00734 battery operated
• CPC Class Codes: A61B 2017/07271 characterised by its cartridge
• 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 2017/2923 Toothed members, e.g. rack and pinion
• CPC Class Codes: A61B 2017/2927 the angular position of the head being adjustable with respect to the shaft
• CPC Class Codes: A61B 2017/320052 Guides for cutting instruments by marking A61B2090/395
• CPC Class Codes: G16Z 99/00 Subject matter not provided for in other main groups of this subclass

Abstract

A motor-driven surgical cutting and fastening instrument that comprises an end effector, a shaft connected to the end effector, and handle connected to the shaft. The end effector may comprise a cutting instrument that, when actuated, longitudinally traverses the end effector to cut tissue clamped in the end effector. The handle may comprise an electric motor for actuating the cutting instrument and a motor control circuit for controlling the motor. The motor control circuit may comprise a power source connected to the motor for electrically powering the motor and a current control circuit, connected to the power source, for varying the current supplied to the motor from the power source. The current control circuit may vary the current supplied to the motor, and consequently, the output torque supplied by the motor, such that the motor has at least (i) a first, low power operational mode for a first portion of a cutting stroke cycle of the cutting instrument, and (ii) a second, high power operational mode for a second portion the cutting stroke cycle of the cutting instrument.

Claims

1. A surgical instrument comprising:

an end effector that clamps tissue, the end effector comprising a moveable member;

an electric motor that drives the moveable member of the end effector when the electric motor is forwarded rotated; and

a motor control circuit connected to the electric motor, wherein the motor control circuit is for monitoring a parameter of the electric motor that is indicative of movement of the moveable member of the end effector, and wherein the motor control circuit is for adjustably controlling the electric motor based on the monitored parameter to thereby adjustably control movement of the moveable member of the end effector during forward rotation of the electric motor.

2. The surgical instrument of claim 1, wherein:

the moveable member of the end effector comprises a cutting instrument that, when actuated, longitudinally traverses the end effector along a cutting travel path to cut tissue clamped in the end effector, wherein the cutting travel path has an initial position at a beginning of the cutting travel path and an end-of-stroke position at an end of the cutting travel path; and

the electric motor is for actuating the cutting instrument of the end effector.

3. The surgical instrument of claim 2, further comprising a cutting instrument position sensor that senses the parameter of the electric motor that is indicative of movement of the moveable member of the end effector, wherein the movement of the moveable member of the end effector that comprises a position of the cutting instrument in the end effector along the cutting travel path.

4. The surgical instrument of claim 3, wherein the motor control circuit comprises:

a power source connected to the electric motor for electrically powering the electric motor; and

a current control circuit, connected to the power source, for varying the current supplied to the electric motor from the power source, wherein the current control circuit controls the electric motor according to a switching architecture and based on the position of the cutting instrument along the cutting travel path relative to the end-of-stroke position and the initial position, as sensed by the cutting instrument position sensor, wherein the switching architecture comprises;

a first, low power operational mode for a first portion of a cutting travel path of the cutting instrument when the cutting instrument is within a first non-zero threshold distance along the cutting travel path from the initial position; and

a second, high power operational mode for a second portion the cutting travel path of the cutting instrument when the cutting instrument is between the first non-zero threshold distance and a second non-zero threshold distance from the initial position of the cutting travel path, wherein the first non-zero threshold distance is less than the second non-zero threshold distance, and where greater current is supplied to the motor during the second, higher power operational mode than during the first, low power operational mode.

5. The surgical instrument of claim 4, wherein the current control circuit comprises:

a switch connected to the power source;

a resistor connected in parallel with the switch; and

a control circuit for controlling the switch.

6. The surgical instrument of claim 4, wherein the current control circuit comprises a variable resistor.

7. The surgical instrument of claim 4, wherein the current control circuit comprises a pulse width modulation control circuit.

8. The surgical instrument of claim 4, wherein the current control circuit comprises a frequency modulation control circuit.

9. The surgical instrument of claim 4, wherein the current control circuit comprises an amplifier circuit.

10. The surgical instrument of claim 4, wherein:

the cutting instrument has a return travel path that follows the cutting travel path, wherein the return travel path begins at the end-of-stroke position and ends at the initial position; and

the switching architecture of the current control circuit reverses a rotational direction of the motor for the return travel path when the cutting instrument reaches the end-of-stroke position.

11. The surgical instrument of claim 10, wherein the switching architecture of the current control circuit removes current from the motor on the cutting travel path when the cutting instrument is within the second non-zero threshold distance from the initial position.

12. The surgical instrument of claim 11, wherein the switching architecture of the current control circuit removes current from the motor along the return travel path of the cutting instrument prior to the cutting instrument reaching the initial position.

13. The surgical instrument of claim 12, wherein the motor control circuit does not include an integrated circuit.

14. The surgical instrument of claim 10, wherein the switching architecture of the current control circuit reverts to the first, low power operational mode when the cutting instrument is within the second non-zero threshold distance from the initial position.

15. The surgical instrument of claim 10, wherein the switching architecture comprises a third operational mode for when the cutting instrument is farther than the second non-zero threshold distance from the initial position, wherein greater current is supplied to the motor during the second, higher power operational mode than during the third operational mode, and the current supplied to the motor during the first, low power operational mode is different from the current supplied to the motor during the third operational mode.

16. A method of operating a cutting and fastening instrument, wherein the cutting and fastening instrument comprises:

an end effector, wherein the end effector comprises a cutting instrument that, when actuated, longitudinally traverses the end effector along a cutting travel path to cut tissue clamped in the end effector, wherein the cutting travel path has an initial position at a beginning of the cutting travel path and an end-of-stroke position at an end of the cutting travel path;

an electric motor for actuating the cutting instrument of the end effector;

a motor control circuit for controlling the motor; and

a power source connected to the motor for electrically powering the motor;

the method comprising varying current supplied from the power source to the electric motor according to a switching architecture and based on a sensed position of the cutting instrument in the end effector as the cutting instrument traverses the cutting travel path, wherein the switching architecture comprises;

a first, low power operational mode for a first portion of a cutting travel path of the cutting instrument when the cutting instrument is within a first non-zero threshold distance along the cutting travel path from the initial position; and

a second, high power operational mode for a second portion the cutting travel path of the cutting instrument when the cutting instrument is between the first non-zero threshold distance and a second non-zero threshold distance from the initial position of the cutting travel path, wherein the first non-zero threshold distance is less than the second non-zero threshold distance, and where greater current is supplied to the motor during the second, higher power operational mode than during the first, low power operational mode.

17. The method of claim 16, wherein:

the cutting instrument has a return travel path that follows the cutting travel path, wherein the return travel path begins at the end-of-stroke position and ends at the initial position; and

the switching architecture of the motor control circuit reverses a rotational direction of the motor for the return travel path when the cutting instrument reaches the end-of-stroke position.

18. The method of claim 17, wherein the switching architecture of the motor control circuit removes current from the motor on the cutting travel path when the cutting instrument is within the second non-zero threshold distance from the initial position.

19. The method of claim 18, wherein the switching architecture of the motor control circuit removes current from the motor along the return travel path of the cutting instrument prior to the cutting instrument reaching the initial position.

20. The method of claim 17, wherein the switching architecture of the motor control circuit reverts to the first, low power operational mode when the cutting instrument is within the second non-zero threshold distance from the initial position.

21. The method of claim 17, wherein the switching architecture comprises a third operational mode for when the cutting instrument is farther than the second non-zero threshold distance from the initial position, wherein greater current is supplied to the motor during the second, higher power operational mode than during the third operational mode, and the current supplied to the motor during the first, low power operational mode is different from the current supplied to the motor during the third operational mode.