Surgical instrument incorporating an electrically actuated articulation locking mechanism

• US 20060025810A1
• Filed: 03/29/2005
• Published: 02/02/2006
• Est. Priority Date: 07/28/2004
• Status: Active Grant

• Current Assignee: Cilag Gmbh International (Johnson & Johnson)
• Original Assignee: Ethicon Endo-Surgery, Inc. (Johnson & Johnson)
• Inventors: Shelton, Frederick E. IV
• Granted Patent: US 8,057,508 B2
• Time in Patent Office: Days
• US Class Current: 606/205
• CPC Class Codes: A61B 17/00234 for minimally invasive surgery A61B17/0218, A61B17/0469, A61B17/12013, A61B17/1285, A61B17/29, A61B17/320016 take precedence
• CPC Class Codes: A61B 17/07207 the staples being applied sequentially
• CPC Class Codes: A61B 17/29 Forceps for use in minimally invasive surgery
• CPC Class Codes: A61B 2017/00398 using powered actuators, e.g. stepper motors, solenoids
• CPC Class Codes: A61B 2017/00871 polymeric
• CPC Class Codes: A61B 2017/2904 curved, but rigid
• CPC Class Codes: A61B 2017/2927 the angular position of the head being adjustable with respect to the shaft

Abstract

A surgical instrument particularly suited to endoscopic use articulates an end effector by including an articulation mechanism in an elongate shaft that incorporates an electrically actuated polymer (EAP) articulation locking mechanism actuator. Thereby, additional options for articulation become feasible, especially those that are actively powered and would otherwise dissipate heat and power if required to maintain position. Alternatively, a mechanically actuated articulation mechanism may be designed with reduced strength, and thus size, since the EAP articulation lock mechanism assists in preventing back driving after articulation. Versions of a. EAP articulation locking mechanism lock a pivoting articulation joint and others lock a flexible neck articulation joint.

Claims

1. A surgical instrument, comprising:

an end effector;

a handle portion comprising an articulation control and articulation locking control circuitry operably configured to produce an articulation locking signal;

an elongate shaft; and

an articulation mechanism comprising;

a proximal frame portion attached to the elongate shaft and in electrical communication with the articulation locking signal through the elongate shaft,

a distal frame portion attached to the end effector and rotatably coupled to the proximal frame portion,

an articulation actuator responsive to the articulation control of the handle portion and coupled between the proximal and distal support portions and operably configured to effect articulation therebetween, and

an electrical articulation locking mechanism engageable between the proximal and distal frame portions to maintain an articulation condition of the end effector.

2. The surgical instrument of claim 1, wherein the articulation control comprises circuitry operably configured to produce an articulation electrical signal, the articulation actuator comprising an electrical actuator responsive to the articulation electrical signal.

3. The surgical instrument of claim 1, wherein the electrical articulation locking mechanism includes an electroactive polymer actuator.

4. The surgical instrument of claim 1, wherein the proximal and distal frame portions of the articulation mechanism are pivotally attached forming a pivoting articulation joint.

5. The surgical instrument of claim 4, wherein the electrical articulation locking mechanism comprises:

a locking member attached to a selected one of the first and second frame member and biased when deenergized to extend toward and engage the other one of the first and second frame member; and

an electroactive polymer actuator operatively configured and positioned to overcome the bias on the locking member when activated to unlock the articulation joint.

6. The surgical instrument of claim 5, wherein the electrical articulation locking mechanism further comprises a longitudinally translating locking bolt longitudinally biased by a resilient member and an opposing longitudinal force by the electroactive polymer actuator when activated.

7. The surgical instrument of claim 5, wherein the electrical articulation mechanism further comprises a transversely translating electroactive polymer latch operatively configured and positioned to bend to an unlocked state when energized.

8. The surgical instrument of claim 4, wherein the elongate shaft comprises a frame assembly and a closure sleeve assembly, the articulation joint pivotally attaching the lower jaw of the end effector to a distal end of the frame assembly, the handle portion operatively configured to longitudinally couple a closure motion to the closure sleeve assembly, and a multiple pivot joint of the closure sleeve assembly encompassing the articulation joint and distally engaged to the upper jaw to effect pivoting of the upper jaw.

9. The surgical instrument of claim 4, wherein the articulation control comprises circuitry operably configured to produce an articulation electrical signal, the articulation actuator comprising an electrical actuator responsive to the articulation electrical signal.

10. The surgical instrument of claim 9, wherein a selected one of the proximal and distal frame portions present a moment arm pinned to the other one of the proximal and distal frame portions, the electrical actuator comprising a pair of electroactive polymer actuators opposingly coupled between the moment arm and the other of the proximal and distal frame portions to effect articulation.

11. The surgical instrument of claim 1, wherein the articulation mechanism further comprises a flexible articulation joint comprising an upper band and a lower band connecting the distal and proximal frame portions and a plurality of left vertical ribs and a plurality of right vertical ribs, each rib connected on a respective lateral side between the upper and lower bands, each plurality of left and right vertical ribs includes a locking recess, the electrical articulation locking mechanism comprising a left locking band and a right locking band, each positioned in the respective left and rock locking recess and operably configured to change longitudinal length to position a plurality of locking projections longitudinally registered for insertion between adjacent ribs when both the adjacent ribs and the locking band are in a longitudinally expanded state to thereby maintain the ribs in the expanded spacing.

12. The surgical instrument of claim 11, wherein the articulation control comprises circuitry operably configured to produce an articulation electrical signal, the articulation actuator comprising an electroactive polymer actuator connected between adjacent ribs responsive to the articulation electrical signal to change spacing therebetween.

13. The surgical instrument of claim 12, wherein the left and right electroactive polymer actuators each comprise a plate actuator operably configured to bend in at least one lateral direction when energized.

14. The surgical instrument of claim 12, wherein the left and right electroactive polymer actuators each comprise at least one electroactive polymer fiber actuator operably configured to longitudinally contract when activated, the respective distal and proximal ends of the left and right electroactive polymer fiber actutors being attached to respective distal and proximal ends of the articulation joint.

15. The surgical instrument of claim 12, further comprising a plurality of left electroactive polymer stack actuators each positioned between adjacent ones of the plurality of left vertical ribs and comprising a plurality of right electroactive polymer stack actuators each positioned between adjacent ones of the plurality of right vertical ribs.

16. A surgical instrument, comprising:

an elongate shaft including a frame assembly;

an end effector;

a pivoting articulation joint formed in the frame assembly, the frame assembly comprising a distal frame portion attached to the end effector and a proximal frame portion pivotally attached to the distal frame portion;

a handle portion attached to a proximal end of the elongate shaft and operatively configured to selectively communicate an actuating electrical signal and an unlocking electrical signal to the elongate shaft;

an electroactive polymer articulation actuator positioned in the pivoting articulation joint responsive to the actuating electrical signal to articulate the distal frame portion relative to the proximal frame portion; and

an electroactive polymer unlocking actuator connected to the pivoting articulation joint and responsive to the unlocking electrical signal to unlock the articulation joint during articulation.

17. The surgical instrument of claim 16, wherein the end effector comprises a staple applying assembly comprising an elongate channel, a staple cartridge engaged in the elongate channel, and an anvil pivotally attached to the elongate channel presenting a staple forming surface to the staple cartridge, the elongate shaft further comprising a firing bar translating with the staple applying assembly to sever tissue clamped between the anvil and staple cartridge and to actuate the staple cartridge to effect stapling.

18. The surgical instrument of claim 16, further comprising an articulation locking mechanism comprising:

a longitudinally translating locking member attached to a selected one of the proximal and distal frame portions and biased to extend toward and engage the other one of the proximal and distal frame portions; and

the electroactive polymer unlocking actuator operatively configured and positioned to overcome the bias on the longitudinally translating locking member when activated to unlock the articulation joint.

19. The surgical instrument of claim 18, wherein the articulation locking mechanism further comprises a gear segment on the other of the proximal and distal frame portions, the longitudinal translating locking member comprising a locking bolt having a proximal crossbar section constrained within a recess in the selected one of the proximal and distal frame portions, a spring positioned within the recess against the crossbar section to urge the locking bar into engagement with the gear segment, the electroactive polymer unlocking actuator positioned in the recess and comprising a selected one of a contracting EAP actuator positioned to pull the cross bar against the spring bias and an expanding EAP actuator positioned to push the cross bar against the spring bias when activated by the unlocking electrical signal.

20. A surgical instrument, comprising:

an elongate shaft including a frame assembly;

an end effector;

a flexible articulation joint formed in the frame assembly, the frame assembly comprising a distal frame portion attached to the end effector, a proximal frame portion pivotally attached to the distal frame portion, a flexible articulation joint comprising an upper band and a lower band connecting the distal and proximal frame portions and a plurality of left vertical ribs and a plurality of right vertical ribs, each rib connected on a respective lateral side between the upper and lower bands, each plurality of left and right vertical ribs including a locking recess;

a handle portion attached to a proximal end of the elongate shaft and operatively configured to selectively communicate an unlocking electrical signal to the elongate shaft;

an electroactive polymer articulation locking mechanism comprising a left locking band and a right locking band each positioned in the respective left and rock locking recess and operably configured to change longitudinal length to position a plurality of locking projections longitudinally registered for insertion between adjacent ribs when both the adjacent ribs and the locking band are in a longitudinally expanded state to thereby maintain the ribs in the expanded spacing.

21. The surgical instrument of claim 20, wherein the handle portion is further operably configured to produce an articulation electrical signal to the elongate shaft, the flexible articulation joint further comprising an electroactive polymer articulation actuator positioned in the flexible articulation joint responsive to the actuating electrical signal to articulate the distal frame portion relative to the proximal frame portion.

22. The surgical instrument of claim 21, wherein the electroactive polymer articulation actuator further comprises a selected one of an electroactive polymer plate actuator operably configured to bend in at least one lateral direction when energized, a electroactive polymer fiber actuator operably configured to longitudinally contract when activated, the respective distal and proximal ends of the left and right electroactive polymer fibers actutors being attached to respective distal and proximal frame portions of the articulation joint, and a plurality of left electroactive polymer stack actuators each positioned between adjacent ones of the plurality of left vertical ribs and comprising a plurality of right electroactive polymer stack actuators each positioned between adjacent ones of the plurality of right vertical ribs.