A Generic RCM Constraint Algorithm based on Optimization of a Modular RAMIS System

The paper presents a novel modular robotic-assisted minimally invasive surgery (RAMIS) system which uses two cooperative 7-DOF manipulators as the surgical robots. To implement virtual remote center of motion (RCM) constraint, optimization-based numeric inverse kinematic (IK) algorithm is also proposed. The algorithm relaxes the traditionally strict RCM point constraint to region constraint, which can provide more flexibility for teleoperation, enlarge the workspace of RAMIS system and avoid joint limits or singularities. By changing the size of constraint region, we can also easily switch between strict and region constraint, which improves the applicability of our RAMIS system. We validate our algorithm and system numerically and visually through simulation, real-world and surgical tasks experiments. It is shown that our algorithm is effective and practical, and our system is capable of complex surgical tasks such as suturing a grape or a pork liver.