Electrical surgical instrument with optimized power supply and drive

• US 20070270790A1
• Filed: 02/12/2007
• Published: 11/22/2007
• Est. Priority Date: 05/19/2006
• Status: Active Grant

• Current Assignee: Cilag Gmbh International (Johnson & Johnson)
• Original Assignee: Ethicon Endo-Surgery, Inc. (Johnson & Johnson)
• Inventors: Palmer, Matthew A., Smith, Kevin W., Deville, Derek Dee, Rivera, Carlos, Bales, Thomas
• Granted Patent: US 8,038,046 B2
• Time in Patent Office: Days
• US Class Current: 606/32
• 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 17/072 for applying a row of staples in a single action , e.g. the staples being applied simultaneously
• CPC Class Codes: A61B 17/07207 the staples being applied sequentially
• CPC Class Codes: A61B 17/1114 of the digestive tract, e.g. bowels or oesophagus
• CPC Class Codes: A61B 17/115 Staplers for performing anastomosis in a single operation
• CPC Class Codes: A61B 17/1155 Circular staplers comprising a plurality of staples
• CPC Class Codes: A61B 2017/00017 Electrical control of surgical instruments
• CPC Class Codes: A61B 2017/00115 with audible or visual output with imaging means A61B90/37, A61B34/20
• CPC Class Codes: A61B 2017/00398 using powered actuators, e.g. stepper motors, solenoids
• CPC Class Codes: A61B 2017/00477 Coupling A61B2017/0046 takes precedence
• CPC Class Codes: A61B 2017/00734 battery operated
• CPC Class Codes: A61B 2017/07257 characterised by its anvil
• 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 2090/032 pressure limiting, e.g. hydrostatic
• CPC Class Codes: A61B 2090/064 for measuring force, pressure or mechanical tension
• CPC Class Codes: A61B 90/03 Automatic limiting or abutting means, e.g. for safety

Abstract

A surgical instrument includes an end effector having an actuation assembly to effect a surgical procedure when actuated. An electric motor has a rated operating voltage and is operationally connected to the end effector to operate the actuation assembly. A power supply is electrically connected to the motor and selectively powers the motor to actuate the actuation assembly at least 1 and less than 16 times during a clinical life of at least one of the end effector, the motor, or the power supply. The power supply has a battery cell with a critical current rate. When activated to power the motor and actuate the actuation assembly, the power supply operates the battery cell at a super-critical current rate during a non-zero super-critical pulse discharge period lasting less than approximately 16 seconds. The power supply operates the motor above the rated operating voltage during the super-critical pulse discharge period.

Claims

1. A surgical instrument, comprising:

a surgical end effector having at least one actuation assembly to effect a surgical procedure when actuated;

an electric motor having a rated operating voltage and being operationally connected to said end effector to operate said at least one actuation assembly; and

a power supply electrically connected to said motor and selectively powering said motor to actuate said at least one actuation assembly at least 1 and less than 16 times during a clinical life of at least one of said end effector, said motor, and said power supply, said power supply;

having at least one battery cell with a critical current rate;

when activated to power said motor and actuate said at least one actuation assembly, operating said at least one battery cell at a super-critical current rate during a non-zero super-critical pulse discharge period lasting less than approximately 16 seconds; and

operating said motor above said rated operating voltage during said super-critical pulse discharge period.

2. The instrument according to claim 1, wherein said super-critical pulse discharge period lasts between approximately 0.5 seconds and approximately 15 seconds.

3. The instrument according to claim 1, wherein said super-critical pulse discharge period lasts between approximately 1.5 seconds and approximately 4 seconds.

4. The instrument according to claim 1, wherein said super-critical pulse discharge period lasts approximately 3 seconds.

5. The instrument according to claim 2, wherein said power supply operates said at least one battery cell at a super-critical current rate throughout said super-critical pulse discharge period.

6. The instrument according to claim 1, wherein said at least one battery cell is at least one Lithium-based battery cell.

7. The instrument according to claim 1, wherein said at least one battery cell is a lithium-manganese dioxide cell.

8. The instrument according to claim 1, wherein said cell is selected to operate at said super-critical current rate for an aggregate pulse time of no greater than approximately 300 seconds.

9. The instrument according to claim 1, wherein an aggregate total time of said super-critical pulse discharge periods for said clinical life is no greater than approximately 300 seconds.

10. The instrument according to claim 1, wherein:

said cell has a positive temperature coefficient device with a PTC threshold; and

said cell operates at said super-critical current rate and below said PTC threshold over said super-critical pulse discharge period.

11. The instrument according to claim 1, wherein said motor is pulse modulated.

12. The instrument according to claim 1, wherein said motor has an efficiency of between approximately 60% and approximately 90%.

13. The instrument according to claim 12, wherein said motor is a coreless, brush-type, DC motor.

14. The instrument according to claim 12, wherein said motor operates at an unloaded speed of between approximately 20,000 and approximately 40,000 rpm.

15. The instrument according to claim 1, wherein said power supply generates approximately 32 watts of electrical power to said motor.

16. The instrument according to claim 1, further comprising an intermediate actuator connecting said motor to said at least one actuation assembly, said intermediate actuator generating approximately 16 watts of mechanical power to said at least one actuation assembly.

17. The instrument according to claim 16, wherein said power supply, said motor, and said intermediate actuator generates an output force sufficient to move approximately 82 kg over approximately 60 mm in approximately 3 seconds.

18. The instrument according to claim 17, wherein said intermediate actuator has a maximum power selected to deliver approximately 82 kg over approximately 60 mm in approximately 3 seconds.

19. The instrument according to claim 1, wherein said motor and said power supply have a combined efficiency sufficient to deliver approximately 16 watts of mechanical power to said at least one actuation assembly.

20. The instrument according to claim 1, wherein said motor has a gear train with an efficiency of between approximately 85% and approximately 99%.

21. The instrument according to claim 20, wherein said gear train has a final drive and said final drive is a rack and pinion assembly.

22. The instrument according to claim 21, wherein said motor moves said rack and pinion assembly at approximately 0.8 inches per second.

23. The instrument according to claim 21, wherein said rack and pinion assembly is directly connected to at least part of said end effector.

24. The instrument according to claim 20, wherein said motor and said gear train has an overall electrical-to-final mechanical efficiency of approximately 49%.

25. The instrument according to claim 20, wherein said gear train reduces a speed of said motor to approximately 60 rpm.

26. The instrument according to claim 20, wherein said gear train has an approximate reduction of 500:

1.

27. The instrument according to claim 1, wherein:

said at least one actuation assembly is first and second actuation assemblies; and

said power supply generates twice as much electrical power as mechanical power to actuate one of said actuation assemblies.

28. The instrument according to claim 27, wherein said power supply generates approximately 32 watts of electrical power and said one actuation assembly generates approximately 16 watts of mechanical power over approximately 3 seconds.

29. The instrument according to claim 27, wherein said power for actuating said one actuation assembly is set to move approximately 82 kg over approximately 60 mm in approximately 3 seconds.

30. The instrument according to claim 1, wherein said power supply has a series connection of between four and six power cells selected from the group consisting of CR123 power cells and CR2 power cells.

31. The instrument according to claim 1, wherein said at least one battery cell has a PTC activation of at least 3 minutes for approximately 4 amps.

32. The instrument according to claim 1, wherein said at least one battery cell has a PTC activation of approximately 2 minutes for 5 amps.

33. The instrument according to claim 1, wherein said at least one battery cell has a PTC activation of approximately 50 seconds for 6 amps.

34. The instrument according to claim 1, wherein:

said motor has a peak efficiency and a gear train; and

said gear train is selected to retain said motor at approximately said peak efficiency throughout said super-critical pulse discharge period.

35. The instrument according to claim 1, wherein:

said motor has a gear train;

said gear train has;

an output shaft turning at a revolution rate; and

a final drive in the form of a rack and pinion assembly; and

said output shaft turns at a revolution rate to optimize a number of inches of travel of said rack for a single revolution of said output shaft over said super-critical pulse discharge period.

36. The instrument according to claim 1, wherein:

said motor has a drive train; and

said power supply, said drive train, and said motor are optimized for total efficiency to deliver a maximum power over a desired time period.

37. The instrument according to claim 1, wherein said power supply is a hybrid cell including primary and secondary Lithium-based battery cells electrically connected to one another.

38. The instrument according to claim 37, wherein said primary cell powers said motor and said secondary cell recharges said primary cell.

39. The instrument according to claim 38, wherein said primary cell is at least one rechargeable Lithium-ion cell and said secondary cell is at least one lithium-manganese dioxide cell.

40. The instrument according to claim 38, wherein said primary cell is at least one capacitor and said secondary cell is at least one lithium-manganese dioxide cell.