Tendon routing and anchoring for cable-driven single-port surgical manipulators with spring backbones and luminal constraints

We employ a master-slave architecture with a tendon-driven actuation mechanism to achieve robotic functionality for the potential application in minimally invasive osseous tumor removal. We improved tendon routing, anchoring, and fixation for the spring backbone bending method based on cable-driven principles. We explored different methods of engineering the tendon guides as well as studied their effects on the flexibility of the spring stem. Engineering of the tendon guides within such small channel dimensions of 3 mm was a challenge, which we overcame by designing our own customized set of tools and drilling systems. The complete end-effector is comprising of the spring backbone, instrument head, actuating tendons, and guides. By investigating different tendon routing and anchoring mechanisms, this study shows the functionality of multichannel spring backbone manipulations, with single-port centimeter-level diameter luminal constraints and each single-channel with outer diameter of less than 2–3 mm.