New Steady-Hand Eye Robot with Micro-Force Sensing for Vitreoretinal Surgery.

In retinal microsurgery, surgeons are required to perform micron scale maneuvers while safely applying forces to the retinal tissue that are below sensory perception. Real-time characterization and precise manipulation of this delicate tissue has thus far been hindered by human limits on tool control and the lack of a surgically compatible endpoint sensing instrument. Here we present the design of a new generation, cooperatively controlled microsurgery robot with a remote center-of-motion (RCM) mechanism and an integrated custom micro-force sensing surgical hook. Utilizing the forces measured by the end effector, we correct for tool deflections and implement a micro-force guided cooperative control algorithm to actively guide the operator. Preliminary experiments have been carried out to test our new control methods on raw chicken egg inner shell membranes and to capture useful dynamic characteristics associated with delicate tissue manipulations.