Single fiber optical coherence tomography microsurgical instruments for computer and robot-assisted retinal surgery.

We present initial prototype and preliminary experimental demonstration of a new class of microsurgical instruments that incorporate common path optical coherence tomography (CP-OCT) capabilities. These instruments may be used freehand or with robotic assistance. We describe a prototype 25 gauge microsurgical pick incorporating a single 125 microm diameter optical fiber interfaced to a Fourier Domain CP-OCT system developed in our laboratory. For initial experimentation, we have interfaced this instrument with an extremely precise, cooperatively controlled robot. We describe the tool, system design, and demonstration of three control methods on simple phantom models: 1) enforcement of safety constraints preventing unintentional collisions of the instrument with the retinal surface; 2) the ability to scan the probe across a surface while maintaining a constant distance offset; and 3) the ability to place the pick over a subsurface target identified in a scan and then penetrate the surface to hit the target.