Accurate Jaw Closure Force in a Catheter Based Instrument

• US 20110295313A1
• Filed: 05/25/2010
• Published: 12/01/2011
• Est. Priority Date: 05/25/2010
• Status: Active Grant

• Current Assignee: Covidien LP (Medtronic Plc)
• Original Assignee: Tyco Healthcare Group LP (Medtronic Plc)
• Inventors: Kerr, Duane E.
• Granted Patent: US 11,278,345 B2
• Time in Patent Office: Days
• US Class Current: 606/205
• CPC Class Codes: A61B 18/1445 at the distal end of a shaft, e.g. forceps or scissors at the end of a rigid rod
• CPC Class Codes: A61B 2017/00314 Separate linked members
• CPC Class Codes: A61B 2017/00323 Cables or rods
• CPC Class Codes: A61B 2017/2925 Pistol grips
• CPC Class Codes: A61B 34/71 Manipulators operated by drive cable mechanisms

Abstract

A surgical instrument includes a housing, an end effector and an elongated shaft extending therebetween. The end effector is movable between open and closed configurations. The elongated shaft includes a distal portion that is movable between aligned and articulated configurations. The surgical instrument further includes a driving assembly that induces motion in the end effector between open and closed configuration and maintains a closure pressure in the range of about 3 kg/cm² to about 16 kg/cm² between aligned and articulated configurations of the elongated shaft.

Claims

1. A surgical instrument, comprising:

a housing;

an end effector operable from the housing to surgically manipulate tissue, the end effector including first and second opposable jaw members movable from an open configuration for receiving tissue to a closed configuration for manipulating tissue;

an elongated shaft extending between the housing and the end effector, the elongated shaft defining a longitudinal axis, and the elongated shaft further defining an aligned configuration and an articulated configuration with respect to the longitudinal axis; and

a driving assembly including a first spring and a drive wire, the driving assembly configured to induce motion in the jaw members between the open configuration and the closed configuration, the driving assembly further configured to maintain a closure pressure in the range of about 3 kg/cm² to about 16 kg/cm² between the aligned configuration and the articulated configuration of the elongated shaft.

2. The surgical instrument according to claim 1, wherein the first spring defines a spring constant dimensioned to maintain a consistent closure pressure between the aligned configuration and the articulated configuration.

3. The surgical instrument according to claim 2, wherein the spring constant is dimensioned to induce motion in the jaw members between the open configuration and the closed configuration when the elongated shaft is in the articulated configuration.

4. The surgical instrument according to claim 2, wherein the spring constant is dimensioned to induce motion in the jaw members between the open configuration and the closed configuration when the elongated shaft is in the aligned configuration.

5. The surgical instrument according to claim 1, wherein the elongated shaft includes proximal and distal portions, the proximal portion extending from the housing, and the distal portion connected to the proximal portion by at least one articulation joint such that the distal portion is movable between the aligned configuration and the articulated configuration.

6. The surgical instrument according to claim 1, wherein the elongated shaft is made of a flexible material.

7. The surgical instrument according to claim 1, wherein the driving assembly further includes a tube circumferentially surrounding the drive wire, the tube defining a plurality of spaced protrusions on an inner wall thereof, the spaced protrusions configured to maintain the drive wire in the center of the tube during translation thereof when the elongated shaft is disposed in the articulated configuration.

8. The surgical instrument according to claim 7, wherein the spaced protrusions on the inner wall of the tube include a friction coefficient substantially less than a friction coefficient of the elongated shaft.

9. A surgical instrument, comprising:

a housing;

an end effector operable from the housing to surgically manipulate tissue, the end effector including first and second opposable jaw members movable from an open configuration for receiving tissue to a closed configuration for manipulating tissue;

an elongated shaft extending between the housing and the end effector, the elongated shaft defining a longitudinal axis, and the elongated shaft further defining an aligned configuration and an articulated configuration with respect to the longitudinal axis; and

a driving assembly including a first spring and a drive wire, the driving assembly configured to induce motion in the jaw members between the open configuration and the closed configuration, the driving assembly further configured to maintain a closure pressure in the range of about 3 kg/cm² to about 16 kg/cm² between the aligned configuration and the articulated configuration of the elongated shaft,

wherein the driving assembly further includes a clutch assembly in connection with the drive wire and the end effector to maintain a consistent closure pressure between the articulated configuration and the aligned configuration of the elongated shaft.

10. The surgical instrument according to claim 9, wherein the clutch assembly imparts a constant closure force on the first and second opposable jaw members.

11. The surgical instrument according to claim 9, wherein the clutch assembly includes a clutch connected to the drive wire and a second spring disposed between the clutch and the end effector.

12. The surgical instrument according to claim 11, wherein the clutch slips when a driving force beyond a predetermined amount is applied thereto.

13. The surgical instrument according to claim 12, wherein the clutch converts the driving force to a driven force of a reduced amount applied to the second spring.

14. The surgical instrument according to claim 11, wherein the second spring is configured to stretch for a predetermined distance.

15. The surgical instrument according to claim 11, wherein the clutch and the second spring are disposed linearly with respect to the end effector.

16. The surgical instrument according to claim 9, wherein the clutch assembly includes a friction plate and a second spring disposed laterally with respect to the end effector.

17. A surgical instrument, comprising:

a housing;

an end effector operable from the housing to surgically manipulate tissue, the end effector including first and second opposable jaw members movable from an open configuration for receiving tissue to a closed configuration for manipulating tissue;

an elongated shaft extending between the housing and the end effector, the elongated shaft defining a longitudinal axis, and the elongated shaft further defining an aligned configuration and an articulated configuration with respect to the longitudinal axis; and

a driving assembly including a first spring and a drive wire, the driving assembly configured to induce motion in the jaw members between the open configuration and the closed configuration, the driving assembly further configured to maintain a closure pressure in the range of about 3 kg/cm² to about 16 kg/cm² between the aligned configuration and the articulated configuration of the elongated shaft,

wherein the driving assembly further includes a rolling mechanism that includes a roller bearing feature connected to the first spring, a control wire connected to the distal end of the elongated shaft, a lever with a first end connected to the roller bearing feature and a second end connected to the control wire, and a second spring with a first end connected to the roller bearing feature and a second end connected to the drive wire, the rolling mechanism configured to maintain a consistent closure force between the articulated configuration and the aligned configuration of the elongated shaft.

18. The surgical instrument according to claim 17, wherein the control wire is disposed under tension when the elongated shaft is in the articulated configuration.

19. The surgical instrument according to claim 17, wherein the control wire and the lever limit proximal movement of the drive wire due to over-compression of the first spring.

20. The surgical instrument according to claim 17, wherein the roller bearing feature facilitates proximal movement of the drive wire.