Tele-operated robotic surgical system offers a paradigm shift in the way minimally invasive surgeries are carried out. Typically, tele-operated robotic systems consist of master arms, slave arms and camera arm along with the controllers for motion control. The design and analysis of a master-slave surgical robot is proposed in this thesis for improved performance and safety. The surgical robot has a pair of master arm and slave arms. One of the key design challenges in designing a master arm is making a rigid arm without compromising on the usable workspace. A fractionated mechanism for the master arm is proposed here as a design solution to address this issue. Also, this design inherently self-compensates imbalances due to gravity to a certain extent and requires only minimum number of balancing masses. A semi-compliant grasper design is proposed for acquiring the grasping input from the surgeon, which allows backlash-free operation and offers superior performance due to utilization of flexures in its design.

The slave arms are designed to meet the kinematic constraints needed for Minimally Invasive Surgery (MIS). Each slave arm has a Remote Centre of Motion (RCM) mechanism, based on a watt type-1 linkage that maintains the kinematic constraint. The remote centre of motion mechanism is statically balanced with two counter masses. A compliant, statically balanced, RCM mechanism is also proposed to replace the conventional RCM which provides possibility of haptic feedback, weight reduction and backlash-free operation.

The integration of various modules of the system and the realization of the surgical robot will be explained in detail. A laboratory prototype of the electronically tethered, tele-operated surgical robotic system has been fabricated and tested. The proposed design of the master arm with fractionated DoF was found to be effective with high stiffness, and balancing with minimal number of balancing masses