Development of a Drivetrain for Remote Actuation of End-Effectors in Robot Assisted Surgery

Kurzfassung

In the context of collaborative robot-assisted surgery, the design of robotic tools that don’t obstruct the surgeon’s workspace is essential. The key to designing such tools is to reduce their weight and volume. This thesis approaches this problem through the development of a drivetrain that allows the spatial separation of the tool’s actuation from the tool flange. The developed drivetrain is based on flexible shafts, routed along the links of the robot. Preliminary to the design of the prototype, a testbed was set up to investigate the nonlinear torsional stiffness of the flexible shafts. Subsequently, a heuristic model is proposed that considers both the bending state and the winding angle of the flexible shaft transmission. Further, this approach allows the introduction of a generic tool interface, allowing the design of a great variety of tools, based on the presented drivetrain. The developed drivetrain was tested for its peak torque and basic tracking capabilities. Finally, the thesis includes a discussion, summarizing the implications for a second prototype, that result from this first prototype.