Separable Tendon-Driven Robotic Manipulator with a Long, Flexible, Passive Proximal Section

TL;DR

This paper introduces a separable tendon-driven robotic manipulator designed for medical use, featuring reusable electronics and disposable parts, with control and compensation methods that improve accuracy across various proximal section configurations.

Contribution

It presents a novel separable TDRM with a reusable electronic body and disposable components, along with an open-loop control strategy and compensation techniques for hysteresis and tension.

Findings

Distal tip error was significantly reduced across tests.

Controller effectively managed static and dynamic proximal section angles.

Hysteresis and tension compensation improved device accuracy.

Abstract

This work tackles practical issues which arise when using a tendon-driven robotic manipulator (TDRM) with a long, flexible, passive proximal section in medical applications. Tendon-driven devices are preferred in medicine for their improved outcomes via minimally invasive procedures, but TDRMs come with unique challenges such as sterilization and reuse, simultaneous control of tendons, hysteresis in the tendon-sheath mechanism, and unmodeled effects of the proximal section shape. A separable TDRM which overcomes difficulties in actuation and sterilization is introduced, in which the body containing the electronics is reusable and the remainder is disposable. An open-loop redundant controller which resolves the redundancy in the kinematics is developed. Simple linear hysteresis compensation and re-tension compensation based on the physical properties of the device are proposed. The controller and compensation methods are evaluated on a testbed for a straight proximal section, a curved proximal section at various static angles, and a proximal section which dynamically changes angles; and overall, distal tip error was reduced.