Chou, Ching (National Taiwan University), Lin, Yu-Wei (National Taiwan University), Lee, Yu-Hsiu (National Taiwan University)

A Spherical Mechanism Featuring Distal Actuation and Tool Exchange

Scheduled for presentation during the Regular Session "Surgical Robots" (WeAT4), Wednesday, July 16, 2025, 10:40−11:00, Room 108

Joint 10th IFAC Symposium on Mechatronic Systems and 14th Symposium on Robotics, July 15-18, 2025, Paris, France

This information is tentative and subject to change. Compiled on July 16, 2025

Abstract

The Remote Center of Motion (RCM) mechanism is widely-used in minimally invasive surgery (MIS), additive manufacturing, and medical imaging, where large or spherical workspace are essential. Spherical scissors mechanisms, a type of RCM mechanisms, offer significant advantages, including spherical workspace, singularity prevention and smooth pitch-roll motion, but face challenges such as high inertia from proximal motor placement and limited tool exchange capabilities. This work introduces a spherical scissors mechanism that integrates distal actuation via Bowden cables and a novel tool exchange mechanism. The proposed design positions all motors at the base, minimizing inertia and ensuring a compact footprint, while employing a pin-and-slot system for transverse tool exchange. The robot achieves four degrees of freedom (roll, pitch, tool rotation and insertion) within a compact volume. Preliminary validation demonstrates the feasibility of achieving RCM motion, efficient distal actuation, and reliable manual tool exchange, providing a foundation for future automation and expanded applications.