Patent ID: 7594903

Claim:
An apparatus, comprising: a shaft having a wall and a lumen defined by the shaft; a tendon sheath disposed on at least one of the shaft or within the shaft wherein the tendon sheath extends from a proximal portion of the shaft to a distal portion of the shaft, the tendon sheath comprising at least first and second tubular components spaced apart from one another on opposite sides of the shaft and approximately 180 degrees from each other at a proximal portion of the tendon sheath, and a third tubular component at a distal portion of the tendon sheath; a pair of tendons movably disposed within the tendon sheath, wherein proximal portions of respective ones of the pair of tendons are disposed in the first tubular component and the second tubular component, wherein one of either distal portions of the pair of tendons are disposed in the third tubular component, or the pair of tendons are coupled together to a single tendon and the single tendon is disposed in the third tubular component, wherein the third tubular component is on a side of the shaft and has a different longitudinal axis than a longitudinal axis of each of the first tubular component and the second tubular component, an anchor member coupled to the distal portion of the shaft, wherein one of either the distal portions of the pair of tendons are coupled to the anchor member at approximately a same location on the anchor member, or the third tendon is coupled to the anchor member; and a force-balancing element coupled to the pair of tendons, the force-balancing element to balance a force between the pair of tendons when the distal portion of the shaft is deflected from a first position to a different second position.