US-12616545-B2 - Articulated member

US12616545B2US 12616545 B2US12616545 B2US 12616545B2US-12616545-B2

Abstract

An articulated member for a surgical instrument, the articulated member including: first proximal and distal joints, each rotatable about a respective axis that extends across a first rotation plane extending longitudinally through the articulated member; second proximal and distal joints, each rotatable about a respective axis that extends across a second rotation plane extending longitudinally through the articulated member perpendicularly to the first rotation plane so that the second proximal and distal joints are rotatable orthogonally relative to the first proximal and distal joints; and a plurality of coupling tendons extending through the articulated member via respective coupling tendon receiving portions. Each coupling tendon extends along the articulated member substantially spaced apart from both the first and second rotation planes so that rotation of one of the proximal and distal joints causes rotation of the other of the respective proximal and distal joints.

Inventors

Jianzhong Shang

Assignees

Precision Robotics Limited

Dates

Publication Date: 20260505
Application Date: 20221209
Priority Date: 20211221

Claims (14)

1 . An articulated member for a surgical instrument, the articulated member comprising a proximal end, a distal end and a plurality of rotatable joints positioned in series between the proximal end and the distal end, the plurality of rotatable joints comprising: a first proximal joint and a first distal joint, each of which is rotatable about a respective axis that extends across a first rotation plane extending longitudinally through the articulated member; a second proximal joint and a second distal joint, each of which is rotatable about a respective axis that extends across a second rotation plane extending longitudinally through the articulated member perpendicularly to the first rotation plane so that the second proximal and distal joints are rotatable orthogonally relative to the first proximal and distal joints; a plurality of coupling tendon receiving portions extending longitudinally through the articulated member spaced apart from both the first and second rotation planes; a junction positioned between the proximal and distal joints, the junction allowing passage of a coupling tendon from one coupling tendon receiving portion to a different coupling tendon receiving portion; and a plurality of coupling tendons extending through the articulated member via respective coupling tendon receiving portions, wherein each coupling tendon is fixed between the proximal end and the distal end and extends along the articulated member substantially spaced apart from both the first and second rotation planes so that rotation of one of the first proximal and distal joints causes rotation of the other of the first proximal and distal joints, and rotation of one of the second proximal and distal joints causes rotation of the other of the second proximal and distal joints, wherein, a first coupling tendon of the plurality of coupling tendons includes a first proximal portion and a first distal portion, the first proximal portion extending from the proximal end to the junction, the first distal portion extending from the distal end to the junction, the first coupling tendon passing through the junction in between the first proximal portion and the first distal portion, the first coupling tendon passing through the first rotation plane in passing through the junction, wherein, a second coupling tendon of the plurality of coupling tendons includes a second proximal portion and a second distal portion, the second proximal portion extending from the proximal end to the junction, the second distal portion extending from the distal end to the junction, the second coupling tendon passing through the junction in between the second proximal portion and the second distal portion, the second coupling tendon passing through the first rotation plane in passing through the junction, wherein, the first proximal portion and the first distal portion are spaced from the first rotation plane, the first rotation plane being located between the first proximal portion and the first distal portion, and wherein, the first and second coupling tendons overlap at the junction as viewed along the first rotation plane.
2 . An articulated member according to claim 1 , wherein the plurality of coupling tendon receiving portions comprises at least four coupling tendon receiving portions and the plurality of coupling tendons comprises at least four coupling tendons.
3 . An articulated member according to claim 2 , wherein the plurality of coupling tendon receiving portions each extend along a plane that extends longitudinally through the articulated member and equally offset from each of the first and second rotation planes.
4 . An articulated member according to claim 2 , wherein the articulated member is split into four parts by the first and second rotation planes and each part comprises a coupling tendon receiving portion extending therethrough.
5 . An articulated member according to claim 1 , further comprising a plurality of modules rotatably engageable with one another and positioned in series whereby at least one of the rotatable joints is formed by two adjacent modules.
6 . An articulated member according to claim 5 , wherein each module comprises a junction and plurality of coupling tendon receiving sections, each coupling tendon receiving section forming part of a respective coupling tendon receiving portion.
7 . An articulated member according to claim 5 , wherein: each module comprises a pair of sub-modules rigidly couplable together in at least two configurations, the at least two configurations comprising a parallel configuration and an orthogonal configuration; when the sub-modules are in the parallel configuration, two rotatable joints formed with two immediately adjacent modules are rotatable about respective axes extending across the same rotation plane; and when the sub-modules are in the orthogonal configuration, two rotatable joints formed with immediately adjacent modules are rotatable about respective axes extending across separate, orthogonal, rotation planes.
8 . An articulated member according to claim 1 , further comprising an actuating tendon receiving portion extending at least partially through the articulated member and configured to receive an actuating tendon for causing rotation of at least one of the rotatable joints.
9 . An articulated member according to claim 1 , wherein the distal end of the articulated member is couplable to an end effector.
10 . An articulated member according to claim 9 , further comprising an end effector tendon receiving portion configured to receive an end effector tendon for actuating the end effector, wherein the end effector tendon receiving portion extends longitudinally through the articulated member and is positioned to intersect each of the axes about which the rotatable joints are rotatable.
11 . A surgical instrument comprising an articulated member according to claim 1 and an end effector coupled to the distal end of the articulated member.
12 . A surgical instrument comprising: a plurality of articulated members according to claim 1 , wherein the articulated members are coupled together in series and the plurality of articulated members has a proximal end and a distal end; and an end effector coupled to the distal end of the plurality of articulated members.
13 . A surgical instrument according to claim 12 , further comprising a drive module for driving articulation of at least one of the plurality of articulated members, wherein the drive module is coupled to the proximal end of the plurality of articulated members.
14 . A surgical instrument according to claim 13 , further comprising an elongate shaft coupling the proximal end of the plurality of articulated members to the drive module.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This Application is a National Stage Application under 35 U.S.C. § 371 of PCT Application No. PCT/GB2022/053150, filed Dec. 9, 2022 which claims priority to UK Patent Application No. GB2118678.8, filed Dec. 12, 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 articulated member for a surgical instrument. The invention has particular application in the field of surgical robotics to facilitate the movement 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 comprising a member that requires articulation through rotation of a plurality of joints. 2. Description of the Related Art Known surgical instruments forming part of robotic surgical systems comprise a shaft, an articulated portion and an end effector. The shaft may extend from other components of the surgical robot which control and drive movement of the articulated portion and the end effector. The shaft may thereby facilitate positioning of the articulated portion and end effector in the required area relative to a patient. The articulated 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. In known surgical instruments the joints of the articulated portion are controlled independently. This means articulated portions with a high number of joints to provide greater range of movement are complex and expensive due to the number of components required to drive movement of each joint. Alternatively, to keep complexity and cost down, the number of joints is reduced and the range of movement achievable is limited. SUMMARY OF THE INVENTION According to a first aspect of the invention there is provided an articulated member for a surgical instrument, the articulated member comprising a proximal end, a distal end and a plurality of rotatable joints positioned in series between the proximal end and the distal end, the plurality of rotatable joints comprising: a first proximal joint and a first distal joint, each of which is rotatable about a respective axis that extends across a first rotation plane extending longitudinally through the articulated member;a second proximal joint and a second distal joint, each of which is rotatable about a respective axis that extends across a second rotation plane extending longitudinally through the articulated member perpendicularly to the first rotation plane so that the second proximal and distal joints are rotatable orthogonally relative to the first proximal and distal joints;a plurality of coupling tendon receiving portions extending longitudinally through the articulated member spaced apart from both the first and second rotation planes;a junction positioned between the proximal and distal joints, the junction allowing passage of a coupling tendon from one coupling tendon receiving portion to a different coupling tendon receiving portion; anda plurality of coupling tendons extending through the articulated member via respective coupling tendon receiving portions, wherein each coupling tendon is fixed between the proximal end and the distal end and extends along the articulated member substantially spaced apart from both the first and second rotation planes so that rotation of one of the first proximal and distal joints causes rotation of the other of the first proximal and distal joints, and rotation of one of the second proximal and distal joints causes rotation of the other of the second proximal and distal joints. To understand why rotation of one of the first proximal and distal joints causes rotation of the other of the first proximal and distal joints (and why rotation of one of the second proximal and distal joints similarly causes rotation of the other of the second proximal and distal joints) consider the articulated member when the first proximal joint has been rotated in a first sense. The plurality of coupling tendons extends across the first proximal joint via respective coupling tendon receiving portions which are spaced apart from the first rotation plane. Therefore, rotation of the first proximal joint in the first sense causes lengths of the plurality of coupling tendons required to extend across the first proximal joint to vary. Due to the plurality of coupling tendons being fixed between the proximal and distal ends, the change in length of each coupling tendon that is required to extend across the first proximal joint must be counteracted by a corresponding change of length of the coupling tendon required to extend across the first distal joint. Hence, the first distal joint is caused to actuate simultan