Vision Assisted Control for Manipulation using Virtual Fixtures: Experiments at Macro and Micro Scales

We present the design and implementation of a visionbased system for micron-scale, cooperative manipulation of a surgical tool. The system is based on a control algorithm that implements a broad class of guidance modes called virtual xtures. A virtual xture, like a real xture, limits the motion of a tool to a prescribed class or range. The implemented system uses vision as a sensor for providing a reference trajectory, and the control algorithm then provides haptic feedback involving direct, shared manipulation of a surgical tool. We have tested this system on the JHU Steady Hand robot and provide experimental results for path following and positioning on structures at both macroscopic and microscopic scales.