Design and preliminary development of a conceptual robot mechanism for eye surgery

Abstract

Millionsof patients suffering from eye disease cannot receive timely treatment due to alack of qualified surgeons. Medical robots which have the potential to solvethis problem are attracting significant attention in the research community.Minimally invasive surgery (MIS) is a popular surgical technique because of theadvantages of small scars, little blood loss and pain, low risk of infection,short hospitalisation, and rapid recovery. However, successful MIS robots arescarce, and more research is required to develop low-cost surgical robots.

This thesis designs andpreliminarily develops a conceptual MIS robot mechanism as the slave robot of amaster-slave robotic system for eye surgery with high accuracy and precision,high stiffness, good dexterity, small size, and low cost. Through thoroughanalysis of manual operations and interviews with surgeons, the designrequirements are defined. Based on these requirements, a new parallel remotecentre of motion (RCM) mechanism is created to achieve 7-degree-of-freedom(DOF) motions. Kinematic design of the new RCM mechanism is conducted. Usingthis new RCM mechanism, a detailed design of the robot is carried out and aprototype is built. The robot control strategy is developed, and the procedurefor robot-assisted surgical operation using the constructed prototype isplanned.

Experimentsare conducted using the prototype to validate the robot design and evaluate therobot performance. Results show that the robot can meet the 7-DOF motion rangerequirements and stiffness requirements, though the accuracy still needsfurther improvements. A self-critique is conducted to identify the limitations,and possible solutions to address these limitations are presented. To improvethe accuracy and precision and reduce the weight, three new design concepts areproposed. Future research directions include improvement in accuracy andprecision and development of the master-slave robotic system.