Compact Modular Surgical System with a Novel RCM Mechanism for Laparo-Endoscopic Single-Site Surgery

Abstract

This paper presents a novel robotic system designed to address the challenges of a robotic-assisted Laparo-Endoscopic single-site (LESS) surgery. While numerous studies have explored mechanisms enabling Remote Center of Motion (RCM) for minimally invasive procedures, few have investigated the interactions of multiple (≥2) manipulators within an integrated system. The proposed robotic system features an arc-shaped mainframe for positioning and mounting of five-bar Spherical Parallel Mechanism (SPM). A conventional straight-shaft surgical tool is inserted through a linear guide rail aligned with the pointing axis leading into the RCM. To account for the physical dimensions of the closed-chain linkages, a modified Denavit-Hartenberg parameterization is adopted to assign spherical linkage frames. This design approach ensures self-collision avoidance within the parallel mechanism and enables systematic evaluation of the distal end-effector’s linear motion characteristics. Furthermore, we investigate the basic functions of SPM manipulators through a prototype experiment, providing preliminary insights that could inform future enhancement of surgical techniques for robotic-assisted LESS procedures.