Surgical stapling instrument incorporating a multi-stroke firing mechanism with return spring rotary manual retraction system

• US 20060175375A1
• Filed: 02/07/2005
• Published: 08/10/2006
• Est. Priority Date: 02/07/2005
• Status: Active Grant

• Current Assignee: Ethicon Endo-Surgery, Inc. (Johnson & Johnson)
• Original Assignee: Ethicon Endo-Surgery, Inc. (Johnson & Johnson)
• Inventors: Shelton, Frederick E. IV, Swayze, Jeffrey S., Hoffman, Douglas B., Setser, Michael Earl, Doll, Kevin Ross
• Granted Patent: US 7,143,926 B2
• Time in Patent Office: Days
• US Class Current: 227/176.100
• CPC Class Codes: A61B 17/07207 the staples being applied sequentially
• CPC Class Codes: A61B 2017/2923 Toothed members, e.g. rack and pinion

Abstract

A surgical stapling and severing instrument particularly suited to endoscopic procedures incorporates a handle that produces separate closing and firing motions to actuate an end effector. In particular, the handle produces multiple firing strokes in order to reduce the required amount of force required to fire (i.e., staple and sever) the end effector. A linked transmission reduces the required handle longitudinal length, yet achieves a rigid, strong configuration when straightened for firing. A traction biased firing mechanism avoids binding in driving this straightened linked rack in cooperation with an anti-backup mechanism, with a lockout mechanism that prevents releasing the closure trigger during firing. Furthermore, an external indicator gives feedback to the surgeon as to how far firing has progressed, as well as providing a manual retraction capability.

Claims

1. A surgical instrument, comprising:

an end effector responsive to a longitudinal firing motion to perform a surgical operation;

a shaft connected to the end effector;

a firing member slidingly received by the shaft to transfer the firing motion to the end effector between an unfired position and a fully fired position;

a rack attached to the firing member;

a firing mechanism operably configured to engage and distally advance the rack during a firing stroke and to disengage thereafter;

a gear mechanism engaged to the rack;

a handle containing the rack, firing mechanism and gear mechanism; and

a retraction member mounted for rotation external to the handle and coupled for rotation to the gear mechanism.

2. The surgical instrument of claim 1, wherein the gear mechanism further comprises a transmission gear coupled to the rack to rotate in proportion thereto, the retraction member comprising a dial including a gripping member for indicating the amount of firing travel and for user actuation to backdrive the transmission gear and rack.

3. The surgical instrument of claim 2, further comprising:

a firing trigger;

the firing mechanism further operably configured to respond to a plurality of firing strokes to effect full firing travel by disengaging the firing trigger between firing strokes;

a retraction spring proximally attached to the rack to assert a retraction force thereon;

an anti-backup mechanism biased to bind the firing member between firing strokes; and

an anti-backup release mechanism to disengage the anti-backup mechanism after firing.

4. The surgical instrument of claim 1, wherein the gear mechanism further comprises an idler gear coupled to the rack, the idler gear rotating in a first direction when the rack moves distally and in a second direction when the rack moves proximally, the idler gear coupled to a one-way clutch that is in turn coupled to the retraction member, the one-way clutch operably configured to disengage when the retraction member is rotated in the first direction relative to the idler gear.

5. The surgical instrument of claim 1, wherein the gear mechanism further comprises a ratchet gear rotating in a first direction when the rack moves distally and a second direction when the rack moves proximally, and wherein the retraction member comprises a gear retraction lever and a retraction pawl, the retraction pawl positioned to engage the ratchet gear as the gear retraction lever is actuated to turn the ratchet gear in the second direction to retract the rack and firing member.

6. The surgical instrument of claim 1, further comprising a retraction spring proximally attached to the rack to urge retraction thereof, the retraction member manually assisting the retraction spring.

7. The surgical instrument of claim 6, wherein the firing mechanism is operably configured to be responsive to a plurality of firing strokes to advance the firing member down the shaft, the surgical instrument further comprising:

an anti-backup mechanism engageable to the firing member in response to a proximal movement thereof; and

an anti-backup release mechanism operatively configured to disengage the anti-backup mechanism;

wherein actuating the gear retraction lever is coupled to activate the anti-backup release mechanism.

8. The surgical instrument of claim 7, wherein the anti-backup mechanism comprises:

a locking plate including an aperture circumferentially encompassing the firing member, the locking plate pivotal between a locking position wherein the aperture lockingly engages the firing member and an unlocking position wherein the aperture slidingly engages the firing member,

an anti-backup spring biasing the locking plate to the locking position; and

an anti-backup release lever positioned to oppose the bias of the anti-backup spring;

wherein the gear retraction lever includes a cam member positioned to distally advance the anti-backup release lever.

9. The surgical instrument of claim 7, wherein the gear mechanism further comprises:

an idler gear engaged to the rack and sized to make one revolution in response to full firing travel of the rack;

a cam wheel responsive to the idler gear to distally move the anti-backup release lever at the end of full firing travel; and

a transmission gear engaged to the idler gear and containing the ratcheting gear.

10. The surgical instrument of claim 7, further comprising a handle containing the rack, firing mechanism, and gear mechanism and further comprising a hold-up structure, wherein the gear retraction lever further comprises a hub including a recess sized to receive the ratcheting gear, a pawl attached to pivot in the recess, and the hold-up structure positioned to hold the pawl above the ratcheting gear when the gear retraction lever is unactuated.

11. The surgical instrument of claim 1, wherein the end effector comprises:

an elongate channel connected to the shaft;

an anvil pivotally coupled to the elongate channel for clamping tissue; and

a staple cartridge received in the elongate channel;

wherein the firing member distally terminates in a firing bar operably configured to actuate the staple cartridge to form staples in the clamped tissue, the actuation of the gear retraction lever withdrawing the firing bar from the end effector to allow opening thereof.

12. A surgical instrument, comprising:

an end effector responsive to a longitudinal firing motion to perform a surgical operation;

a shaft connected to the end effector;

a firing member slidingly received by the shaft to transfer the firing motion to the end effector between an unfired position and a fully fired position; and

a handle comprising;

a firing trigger,

a rack attached to the firing member;

a firing mechanism responsive to a plurality of firing strokes from the firing trigger to advance the rack and thus the firing member down the shaft;

a retraction spring biasing the firing member proximally away from the shaft;

an anti-backup mechanism engageable to bind the firing member in response to a proximal movement thereof;

an anti-backup release mechanism operatively configured to disengage the anti-backup mechanism for retraction; and

a manual retraction mechanism comprising an idler gear engaged to the rack and coupled by a one-way clutch to an externally accessible actuator.

13. The surgical instrument of claim 12, wherein the idler gear is engaged to a camming member operatively coupled to the anti-backup release mechanism when the externally accessible actuator is manually positioned to disengage the anti-backup mechanism.

14. The surgical instrument of claim 12, wherein the one-way clutch of the manual retraction mechanism further comprises a ratchet gear coupled for rotation to the idler gear to rotate in a first direction when the rack moves distally and a second direction when the rack moves proximally, and comprises a retraction pawl connected to the externally accessible actuator, the retraction pawl positioned to engage the ratchet gear as the externally accessible actuator is actuated to turn the ratchet gear in the second direction to retract the rack and firing member.

15. The surgical instrument of claim 14, wherein the externally accessible actuator comprises a lever attached to a hub having a recess encompassing the ratchet gear and the ratchet pawl, the hub presenting a camming surface to the anti-backup release mechanism as actuated by the lever to disengage the anti-backup mechanism while retracting the rack.

16. The surgical instrument of claim 12, wherein the end effector comprises:

an elongate channel connected to the shaft;

an anvil pivotally coupled to the elongate channel for clamping tissue; and

a staple cartridge received in the elongate channel;

wherein the firing member distally terminates in a firing bar operably configured to actuate the staple cartridge to form staples in the clamped tissue, the actuation of the gear retraction lever withdrawing the firing bar from the end effector to allowing opening thereof.

17. The surgical instrument of claim 12, further comprising a handle having a downward grip, wherein the rack further comprises a link rank downwardly bendable into the downward grip.

18. A surgical instrument, comprising:

a staple applying assembly;

an elongate shaft attached to the staple applying assembly;

a firing member slidingly received in the shaft to actuate the staple applying assembly to staple and sever tissue;

a handle, comprising;

a rack attached to the firing member,

a firing trigger including a firing pawl,

a firing mechanism operatively configured to engage the pawl of a firing mechanism in response to actuation of the firing trigger,

a gear mechanism engaged to the rack,

an externally accessible manual retraction actuator, and

a means for manually backdriving the gear mechanism by manipulating the externally accessible manual retraction actuator to retract the rack.

19. The surgical instrument of claim 18, wherein the firing mechanism is operably configured to be responsive to a plurality of firing strokes to advance the firing member down the shaft, the surgical instrument further comprising:

an anti-backup mechanism engageable to the firing member in response to a proximal movement thereof; and

an anti-backup release mechanism operatively configured to disengage the anti-backup mechanism;

wherein the means for manually backdriving the gear mechanism by manipulating the externally accessible manual retraction actuator to retract the rack further includes a means for actuating the anti-backup release mechanism.

20. The surgical instrument of claim 19, further comprising a means for automatic retraction of the firing member upon full firing travel.