Patent ID: 8974375
Filing Date: 2015-03-10
Classification: A61B

Abstract:
1. A joint arrangement including a first joint member, a transmission member and drive means associated with the first joint member and a second joint member movably linked to the first joint member, wherein the transmission member is disposed at least partially around or against an inner surface of the first joint member and is drivable by the drive means to rotate about an axis lying longitudinally within the first joint member to cause movement of the first and second joint members relative to each other, wherein the first joint member is pivotably linked to the second joint member by a pivot and the joint arrangement comprises first and second tendon portions secured to the second joint member on either side of the pivot, the transmission member being arranged to transmit a force to the first and second tendon portions to cause movement of the second joint member relative to the first joint member, wherein the transmission member defines a spool on which the first and second tendons are wound such that rotation of the spool in one direction pays out the first tendon portion and takes in the second tendon portion and rotation of the spool in the other direction pays out the second tendon portion and takes in the first tendon portion, the joint arrangement includes a tendon routing arrangement defining an inflection point for each tendon portion to route each tendon portion from a direction generally along the spool to a direction generally along the first joint member away from the spool and transmission member, and an attachment point at which the first and second tendon portions are secured to the transmission member travels off a line defined by the inflection points as the transmission member rotates.