A wrist joint

Abstract

A wrist joint 100 for a surgical instrument 160 having a proximal end 164, a distal end 166, an end effector 102 mounted at the distal end and 166 at least one actuation tendon 108a, 108b for actuatin

Description

HK Application no : <S1_APPLICATION_NO> Our Ref : SHPA26 / 11364 <deadline> <iinitial><letter_date>Abstract A wrist joint 100 for a surgical instrument 160 has a proximal end 164, a distal end 166, an end effector 102 mounted at the distal end 166, and at least one actuating tendon 108a, 108b for actuating the end effector 102. The wrist joint 100 includes a proximal part 110 and a distal part 120, each having a proximal rolling surface 112 and a distal rolling surface 122, respectively, wherein respective axes 114, 124 pass through the proximal part 110 and the distal part 120, respectively, and are centrally located relative to the respective rolling surfaces 112, 122. The distal part 120 is rotatably coupled to the proximal part 110 such that the proximal rolling surface 112 and the distal rolling surface 122 can roll in contact with each other. A proximal guide assembly 130 and a distal guide assembly 132 are mounted on the proximal part 110 and the distal part 120, respectively. The guide surfaces 131 and 133 of the proximal guide assembly 130 and the distal guide assembly 132 are configured such that when the actuating tendons 108a and 108b extend from the proximal end 164 to the end effector 102, the actuating tendons 108a and 108b pass through them, thereby decoupling the actuation of the end effector 102 from the wrist movement.< / iinitial> < / deadline>

Claims

1. A wrist joint for a surgica! instrument having a proximal end, a distal end, an end effector mounted at the distal end and at least one actuation tendon for actuating the end effector, the wrist joint comprising:a proximal part having a proximal rolling surface, wherein a first axis extends through the proximal part;a distal part having a distal rolling surface, wherein a second axis extends through the distal part, the distal part being rotatably coupled to the proximal part such that the distal rolling surface is able to roll against the proximal rolling surface to provide wrist movement of the distal part relative to the proximal part;a proximal guiding assembly having a proximal guiding surface and mounted to the proximal part such that the proximal guiding surface is coaxial with the proximal rolling surface along the first axis; anda distal guiding assembly having a distal guiding surface and mounted to the distal part such that the distal guiding surface is coaxial with the distal rolling surface along the second axis,wherein the proximal and distal guiding surfaces are configured to guide the at least one actuation tendon therebetween as the at least one actuation tendon extends from the proximal end to the end effector, thereby decoupling actuation of the end effector from wrist movement.

2. The wrist joint of claim 1, further comprising a drive disc configured such that actuation of the drive disc provides the wrist movement of the distal part relative to the proximal part,3, The wrist joint of claim 2, wherein the drive disc is mounted to the proximal part for rotation about the first axis; and wherein the wrist joint further comprises a drive axle mounted to the drive disc along the second axis and coupled to the distal part such that rotation of the drive disc causes the distal rolling surface to roll against the proximal rolling surface.

4. The wrist joint of claim 2 or claim 3, further comprising a drive tendon having a middle portion coupled to the drive disc and opposing end portions extending towards the proximal end of the surgical instrument, wherein a first end portion is able to be pulled to rotate the drive disc in a first sense to provide wrist movement in a first direction and a second end portion is able to be pulled to rotate the drive disc in a second sense to provide wrist movement in a second direction.

5. The wrist joint of any one of the preceding claims, wherein the ratio between a diameter of the proximal guiding surface and a diameter of the proximal rolling surface may be equal to a ratio between a diameter of the distal guiding surface and a diameter of the distal rolling surface.

6. The wrist joint of claim 5, wherein the proximal guiding surface and the proximal rolling surface share an equal diameter, and the distal guiding surface and the distal rolling surface share an equal diameter,7. The wrist joint of any one of the preceding claims,, wherein the proximal guiding assembly comprises at least one proximal pulley mounted to the proximal part and rotatable about the first axis; and wherein the distal guiding assembly comprises at least one distal pulley mounted to the distal part and rotatable about the second axis.

8. The wrist joint of claim 7, wherein the proximal guiding assembly comprises a plurality of proximal pulleys and the distal guiding assembly comprises a plurality of distal pulleys, and wherein plurality of proximal pulleys and the plurality of distal pulleys are arranged symmetrically with respect to a central plane of the. surgical instrument, the central plane extending perpendicular to the first and second axes.

9. The wrist joint of any one of the preceding claims, wherein the proximal rolling surface comprises a plurality of proximal gear teeth extending radially from the first axis and the distal rolling surface comprises a plurality of distal gear teeth extending radially from the second axis, the plurality of proximal gear teeth and the plurality of distal gear teeth being engageable with one another such that the distal rolling surface is able to roll against the proximal rolling surface without slipping.

10. The wrist joint of claim 8, wherein the proximal rolling surface has a proximal pitch diameter equal to a diameter of the proximal guiding assembly and the distal rolling surface has a distal pitch diameter equal to a diameter of the distal guiding assembly.

11. A surgical instrument comprising:a proximal end and a distal end;an end effector mounted at the distal end;at least one actuation tendon for actuating the end effector;a wrist joint according to any one of the preceding claims positioned between the proximal end and the distal end, wherein the at least one actuation tendon extends between the first and second guiding assemblies.

12. The surgical instrument of claim 11, wherein the end effector comprises a first jaw rotatable about a first jaw axis extending perpendicularly to the first and second axes; and wherein the at least one actuation tendon comprises a first actuation tendon having a middle portion coupled to the first jaw and opposing end portions each passing between the proximal and distal guiding assemblies before extending towards the proximal end of the surgical instrument, the first actuation tendon being movable to rotate the first jaw.

13. The surgical instrument of claim 12, wherein the end effector comprises a second jaw rotatable about a second jaw axis extending perpendicularly to the first and second axes; and wherein the at least one actuation tendon comprises a second actuation tendon having a middle portion coupled to the second jaw and opposing end portions each passing between the proximal and distal guiding assemblies before extending towards the proximal end of the surgical instrument, the second actuation tendon being movable to rotate the second jaw.

14. The surgical instrument of claim 13, wherein the first and second jaws are rotatable independently of one another.

15. The surgical instrument of claim 13 or claim 14, wherein:the proximal guiding assembly comprises four proximal pulleys mounted to the proximal part and independently rotatable about the first axis;the distal guiding assembly comprises four distal pulleys mounted to the distal part and independently rotatable about the second axis; andeach end portion of each of the first and second actuation tendons passes between a respective pair of proximal and distal pulleys.

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