Keywords: Control , Hardware , Medical robotics, haptic interfaces, surgical simulation, robotic tools for surgery, virtual environments

In this thesis, telesurgery and surgical simulation are treated as parallel research problems of haptic interfacing to real and virtual surgical environments, respectively. The analytical tools of systems and control theory and robotics are used to address several research problems in these areas.

The work on telesurgery is centered around the UC Berkeley/UC San Francisco Laparoscopic Telesurgical Workstation, focusing on the design and analysis of the system, with details of the design specifications, solution of the forward and inverse kinematics, and control issues. This is followed by a discussion on the general issues on the testing of the system. A novel approach using open surgical suturing motion data to evaluate the kinematics of a robotic telesurgical manipulator without prototyping a physical system is proposed within this context.

High fidelity teleoperation controller design for the telesurgical system is studied, and a theoretical and experimental framework is established for design and evaluation of teleoperation controllers for telemanipulation of deformable objects. In this study, the teleoperator control design is specifically for manipulation of deformable objects and uses a task based optimization scheme which explicitly takes into account human perceptual capabilities for the task at hand, telesurgery and stiffness discrimination. Integrated with this control design approach, two quantitative methods to analytically compare sensory schemes for teleoperators are proposed and a new experimental methodology to evaluate teleoperation control algorithms is presented for a stiffness discrimination task.

Dynamic simulation of deformable objects for interactive virtual environments is explored with emphasis on formulation of the problem, enabling technologies, and various modeling methods in the literature, mostly focusing on putting the existing methodologies into a unifying framework.

Finally, the problem of high fidelity haptic interaction with deformable objects in virtual environments is studied from a control theory point of view. A novel method to interface with deformable objects addressing the issues resulting from the difference between the haptic and deformable model simulation update rates is motivated, developed, and analyzed using the tools of modern control theory.



Keywords: Medical robotics, haptic interfaces, surgical simulation, robotic tools for surgery, virtual environments