Assistive Control through a Hapto-Visual Digital Twin for a Master Device Used for Didactic Telesurgery

This article explores the integration of a hapto-visual digital twin on a master device used for bilateral teleoperation. The device, known as a quasi-spherical parallel manipulator, is currently employed for remote center of motion control in teleoperated mini-invasive surgery. After providing detailed insights into the device's kinematics, including its geometric configuration, Jacobian\yell{,} and reachable workspace, the paper illustrates the overall control system, encompassing both hardware and software components. The article describes how a digital twin, which implements a haptic assistive control and a visually enhanced representation of the device, was integrated into the system. The digital twin was then tested with the device: in the experiments, one "student" \yell{end user} has to follow a predefined "teacher" trajectory. Preliminary results demonstrate how the overall system can pose a good starting point for didactic telesurgery operation. The control action, yet to be optimized and tested on different subjects, indeed seems to grant satisfying performance and accuracy.