US-12616493-B2 - Jaw actuation mechanism

US12616493B2US 12616493 B2US12616493 B2US 12616493B2US-12616493-B2

Abstract

An actuation mechanism including: first and second jaws rotatable about a jaw axis, having first and second slots, respectively; and a slider moveable along a slider axis. The slider includes first and second protrusions slidably receivable within the first and second slots, respectively, wherein each slot extends in a direction which is non-parallel to the slider axis when the respective protrusion is engaged with the slot. A return is attachable to the actuation mechanism and an actuation member is operably engageable with both the slider and the return. The actuation member includes first and second ends, a first portion that extends from the first end to the return, and a second portion that extends from the return to the second end. The first portion is fixable to the slider whereby individual movement of the first and second portions relative to the return causes the slider to move.

Inventors

Tamas Csaba Hernadi
Jianzhong Shang

Assignees

Precision Robotics Limited

Dates

Publication Date: 20260505
Application Date: 20220207
Priority Date: 20210219

Claims (9)

1 . An actuation mechanism comprising: a first jaw rotatable about a jaw axis and comprising a first slot; a second jaw rotatable about the jaw axis and comprising a second slot; a slider moveable along a slider axis between a first position and a second position and movably engageable with the first and second jaws, which slider comprises a first protrusion slidably receivable within the first slot and a second protrusion slidably receivable within the second slot, wherein each slot extends in a direction which is non-parallel to the slider axis when the respective protrusion is engaged with the slot; a return attachable to the actuation mechanism and spaced apart from the slider; and an actuation member operably engageable with both the slider and the return, the actuation member comprising a first end, a second end, a first portion that extends from the first end to the return, and a second portion that extends from the return to the second end, the first portion being fixable to the slider whereby movement of the first portion away from the return causes the slider to move towards the first position and movement of the second portion away from the return causes the slider to move towards the second position, wherein the actuation member is slidably engageable with the slider between the return and the second end, wherein the slider comprises a first member receiving portion and a second member portion, and the actuation member is fixable to the slider via the first member receiving portion and slidably receivable within the second member receiving portion.
2 . An actuation mechanism according to claim 1 wherein the return comprises a pulley rotatable about a return axis and the actuation member passes around the pulley between the first portion and the second portion.
3 . An actuation mechanism according to claim 2 wherein the return further comprises an axle that extends along the return axis and supports the pulley.
4 . An actuation mechanism according to claim 3 wherein the return axis is coaxial with the jaw axis.
5 . An actuation mechanism according to claim 4 wherein the first and second jaws are rotatably engageable with the axle such that the first and second jaws are supported by, and rotatable about, the axle.
6 . An actuation mechanism according to claim 1 wherein each jaw comprises a tool portion, movement of the slider towards the first position causes rotation of the first and second jaws towards a closed configuration in which the tool portions contact one another and movement of the slider towards the second position causes rotation of the first and second jaws towards an open configuration in which the tool portions are spaced apart.
7 . An actuation mechanism according claim 6 wherein the tool portions are configured as scissor blades, forceps, a dissector or a grasper.
8 . An actuation mechanism according to claim 1 further comprising a housing comprising a first guide and a second guide; wherein, when the slider moves along the slider axis, the first protrusion is guided by the first guide and the second protrusion is guided by the second guide.
9 . A surgical instrument comprising a shaft, an articulated portion coupled to the shaft and an end effector coupled to the articulated portion, which end effector comprises an actuation mechanism according to claim 1 .

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This Application is a National Stage Application under 35 U.S.C. § 371 of PCT Application No. PCT/GB2022/050316, filed Feb. 7, 2022 which claims priority to UK Patent Application No. GB2102387.4, filed Feb. 19, 2021, the entire contents of which are incorporated by reference herein. BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to an actuation mechanism, and specifically, but not exclusively to an actuation mechanism which facilitates the actuation of two jaw members with a single pair of tendons. The invention has particular application in the field of surgical robotics to facilitate the actuation of two jaw members forming part of a surgical instrument end effector for minimally invasive surgical procedures, although the invention is not limited to such application and may also have use in other medical/surgical devices or other robotic devices comprising a tendon driven end effector with two or more movable parts, such as jaw members. Herein the invention is primarily described in relation to application in the field of surgical robotics. However, this is for demonstrative purposes only and is not to the exclusion of the invention's application in other fields. 2. Description of the Related Art Known surgical instruments forming part of robotic surgical systems comprise a shaft, an articulation portion and an end effector. The shaft may extend from other components of the surgical robot which control and drive movement of the articulation portion and the end effector. The shaft may thereby facilitate positioning of the articulation portion and end effector at the required area of a patient. The articulation portion may comprise a plurality of joints positioned adjacent to one another to provide degrees of freedom of movement to the end effector relative to the shaft. Lastly, the end effector may be adapted to carry out particular actions required in surgical procedures. Known end effectors include end effectors with two movable jaw members such as graspers, forceps, scissors and dissectors, for example. Some known end effectors are tendon driven meaning that each possible articulation of the end effector is caused by the pulling of a tendon which is anchored to the, or part of the, end effector. Further, known end effectors are driven by antagonistic pairs of tendons to ensure that each articulation may be reversed. For example, if the actuation of a jaw member in a first direction is caused by the pulling of a first tendon then actuation of the jaw member in a second, opposite direction may require the pulling of a second (antagonistic) tendon. SUMMARY OF THE INVENTION According to a first aspect of the invention there is provided an actuation mechanism comprising: a first jaw rotatable about a jaw axis and comprising a first slot; a second jaw rotatable about the jaw axis and comprising a second slot; a slider moveable along a slider axis between a first position and a second position and movably engageable with the first and second jaws, which slider comprises a first protrusion slidably receivable within the first slot and a second protrusion slidably receivable within the second slot, wherein each slot extends in a direction which is non-parallel to the slider axis when the respective protrusion is engaged with the slot; a return attachable to the actuation mechanism and spaced apart from the slider; and an actuation member operably engageable with both the slider and the return, the actuation member comprising a first end, a second end, a first portion that extends from the first end to the return, and a second portion that extends from the return to the second end, the first portion being fixable to the slider whereby movement of the first portion away from the return causes the slider to move towards the first position and movement of the second portion away from the return causes the slider to move towards the second position. In use, when the slider moves along the slider axis between the first and second positions, each of the first and second protrusions may slide within their respective slot. As each slot extends in a direction non-parallel to the slider axis, movement of each protrusion within its respective slot causes the slot to move relative to the slider axis. Movement of each slot is facilitated by rotation of the respective jaw about the jaw axis, therefore movement of the slider causes the jaws to rotate about the jaw axis. Further, each jaw and particularly each slot may be configured so that the jaws rotate about the jaw axis in an opposite sense to one another, i.e. a movement of the slider will cause the first jaw to rotate in a first sense and the second jaw to rotate in a second sense opposite to the first. The first portion of the actuation member extends from the first end of the actuation member to the return and may be fixed to the slider so that, in use, movement of the first portion away from return c