Vision-Based Control of a Handheld Surgical Micromanipulator With Virtual Fixtures

Abstract

Performing micromanipulation and delicate operations in submillimeter workspaces is difficult because of destabilizing tremor and imprecise targeting. Accurate micromanipulation is especially important for microsurgical procedures, such as vitreoretinal surgery, to maximize successful outcomes and minimize collateral damage. Robotic aid combined with filtering techniques that suppress tremor frequency bands increases performance; however, if knowledge of the operator’s goals is available, virtual fixtures have been shown to further improve performance. In this paper, we derive a virtual fixture framework for active handheld micromanipulators that is based on high-bandwidth position measurements rather than forces applied to a robot handle. For applicability in surgical environments, the fixtures are generated in real-time from microscope video during the procedure. Additionally, we develop motion scaling behavior around virtual fixtures as a simple and direct extension to the proposed framework. We demonstrate that virtual fixtures significantly outperform tremor cancellation algorithms on a set of synthetic tracing tasks (p < 0.05). In more medically relevant experiments of vein tracing and membrane peeling in eye phantoms, virtual fixtures can significantly reduce both positioning error and forces applied to tissue (p < 0.05).

Manipulator Design and Operation of a Six-Degree-of-Freedom Handheld Tremor-Canceling Microsurgical Instrument

“…Nonetheless, the error-reduction ratio can be compared under similar settings. The pointing task in the 6-DOF Micron is comparable to the task done in the 3-DOF Micron with a virtual fixture which applies a constant goal position to the tool tip [39]. The result with a hard-virtual fixture control shows similar performance in tremor-reduction: 81.8% reduction in maximum error compared to unaided trials.…”

“…Moreover, the automatic scanning functionality will be utilized in laser photocoagulation, combined with CCD cameras and stereo-vision algorithms to specify a desired trajectory in the 3D ASAP coordinates for control, as in [39]. For such an automated operation, tracking features should also be implemented to compensate for any eye movement induced by voluntary motion and/or tremor [41], [42].…”

From Passive Tool Holders to Microsurgeons: Safer, Smaller, Smarter Surgical Robots

“…Instead of blindly following the surgeon's motion, active constraints ensured that the robot operates only within a predefined allowable region. The notion of telemanipulation using active constraints is an integral component of many state-of-the-art surgical robots, especially in domains that require micrometre accuracy [34], [54], [55].…”

Co-manipulation with a library of virtual guiding fixtures

“…In a comanipulation context, the user directly interacts with the robot through physical contact (Raiola et al, 2015a;Becker et al, 2013;Dumora, 2014;Pezzementi et al, 2007). This allows a direct interaction between the robot and the user, and a more intuitive ability to perform the task since the user is better integrated in the procedure compared to the case where the user interacts with the environment through a teleoperated robot.…”