Actuation mechanism

Abstract

An actuation mechanism, e.g. the end effector of a robotic surgical instrument, comprises a pair of jaws (e.g. forceps, graspers, scissors) that are directly coupled on an axis of relative rotation 20

Description

HK Application no : <S1_APPLICATION_NO> Our Ref : SHPA26 / 11363 <deadline> <iinitial><letter_date>An actuation mechanism (e.g., an end effector of a robotic surgical instrument) includes a pair of jaws (e.g., forceps, grippers, scissors) directly coupled to a relative rotation axis 208, which is offset relative to the rotation axis 204 of the other jaw. Thus, when a force is applied to rotate one jaw 206 about this relative rotation axis, at least a portion of the applied force is transmitted to the other jaw 202 via direct coupling. The jaw coupling is hinged via mating engagement pins 210. Each jaw can be cable-driven via a corresponding pulley; one pulley 214 forms a linkage mechanism, providing mechanical advantages through force amplification, while the other pulley is integrally formed with jaw 202 and does not provide force amplification.< / iinitial> < / deadline>

Claims

1. An actuation mechanism comprising:a first jaw rotatable about a first jaw axis; anda second jaw rotatable about a second jaw axis offset from the first jaw axis, wherein the first jaw is directly coupled to the second jaw on the second jaw axis,wherein, when a force is applied to rotate the second jaw about the second jaw axis, at least part of the applied force is transferred to the first jaw through the direct coupling between the first jaw and the second jaw.

2. The actuation mechanism of claim 1, wherein the first jaw is directly hingedly coupled to the second jaw.

3. The actuation mechanism of claim 2, wherein the first jaw is directly hingedly coupled to the second jaw via respective mating portions.

4. The actuation mechanism of claim 3, wherein one of the mating portions comprises a pin or protrusion and the other mating portion comprises a hole.

5. The actuation mechanism of any preceding claim, wherein the second jaw comprises a jaw engagement portion, wherein:the first jaw is configured to be actuated at a distance rl from the first jaw axis,the jaw engagement portion is configured to be actuated at a distance L22 from the second jaw axis, andthe first jaw and the second jaw are configured such that a ratio of rl to a distance Lil between the first jaw axis and a distal end of the first jaw is less than a ratio of L22 to a distance L21 between the second jaw axis and a distal end of the second jaw.

6. The actuation mechanism of any preceding claim, wherein each jaw is actuated by a tendon directly or through a non-force amplification driver.

7. The actuation mechanism of claim 5, wherein the jaw engagement portion is coupled to a force amplification driver, such that the applied force is an amplified force generated due to actuation of the force amplification driver.

8. The actuation mechanism of claim 7, wherein the second jaw is rotatable about the first jaw axis together with the first jaw in a wrist movement.

9. The actuation mechanism of claim 7, wherein the force amplification driver is configured to be rotatable about the first jaw axis and be actuated at a distance rd from the first jaw axis, and is configured to engage the jaw engagement portion at a distance rp from the first jaw axis that is less than rd.

10. The actuation mechanism of claim 9, wherein rd is substantially equal to rl.

11. The actuation mechanism of any preceding claim, wherein the first jaw and the second jaw are each rotatable between an open position and a closed position, and wherein at least part of the applied force to the second jaw is transferred to the first jaw when the first jaw and / or the second jaw are rotated toward their respective open or closed positions.

12. The actuation mechanism of claim 11 when dependent on any one of claims 7-10, wherein the force amplification driver comprises a drive engagement portion slidably engageable with the jaw engagement portion.

13. The actuation mechanism of claim 12, wherein the jaw engagement portion and the drive engagement portion are one or more of positioned and oriented to facilitate generation of the amplified force.

14. The actuation mechanism of claim 13, wherein one of the jaw engagement portion and the drive engagement portion is a male portion and the other is a female portion.

15. The actuation mechanism of claim 14, wherein the female portion comprises a slot or hole and the male portion comprises a pin or protrusion.

16. The actuation mechanism of claim 15, wherein the slot or hole comprises a curved portion and / or an angled portion.

17. The actuation mechanism of claim 5 or any preceding claim dependent thereon, wherein the second jaw axis and the jaw engagement portion of the second jaw are provided on opposing sides of the first jaw axis.

18. The actuation mechanism of claim 17, wherein the second jaw axis and the jaw engagement portion have an angular separation of at least 90 degrees, preferably at least 135 degrees, more preferably 180 degrees.

19. The actuation mechanism of any preceding claim, wherein the second jaw axis is on a longitudinal centre line between the first jaw and the second jaw.

20. The actuation mechanism of any one of claims 1-18, wherein the second jaw axis is offset from a longitudinal centre line between the first jaw and the second jaw.

21. The actuation mechanism of any preceding claim, wherein the second jaw axis is parallel to the first jaw axis.

22. The actuation mechanism of any preceding claim, wherein the first jaw and the second jaw are configured as scissor blades, forceps, a dissector, or a grasper.

23. The actuation mechanism of claim 7 or any claim dependent thereon, wherein only the second jaw is coupled to a force amplification driver.

24. The actuation mechanism of any preceding claim, comprising an axle arranged along the first axis, the first jaw and the force amplification driver are configured to be mounted on the axle, wherein the second jaw comprises a slot having clearance from engaging with the axle.

25. A surgical instrument comprising an end effector wherein the end effector comprises an actuation mechanism according to any preceding claim.

Images