Design and Implementation of a Test-bed for Virtual RCM Algorithms

Abstract

Remote Center of Motion (RCM) is a critical kinematic constraint in minimally invasive robotic surgery, ensuring that surgical instruments pivot around a fixed incision point to minimize tissue trauma. While virtual RCM algorithms offer significant kinematic flexibility, their dependence on real-time computational accuracy and actuator precision necessitates rigorous physical validation. This paper presents the design and implementation of a cost effective, rapid prototyping hardware test-bed developed for evaluating the algorithms and practical constraints of virtual RCM strategies. The Forward and Inverse Kinematics (FK/IK) were mathematically modeled using Product of Exponential (PoE) and validated through MATLAB based simulations. The developed platform comprises a 5- Degree of Freedom (DOF) robotic manipulator fabricated via Fused Deposition Modeling (FDM) 3D printing and actuated by servo motors. The system is controlled by a custom designed, in house fabricated Printed Circuit Board (PCB), processed through Computer Numerical Control (CNC) routing to ensure signal integrity and stable power distribution. The architecture features a Raspberry Pi master controller interfaced with a PCA9685 16-channel Pulse Width Modulation (PWM) driver for high resolution motion control. The results demonstrate that this implementation provides an accessible environment for simulating RCM algorithms, bridging the gap between idealized simulations and physical hardware execution in RCM research.