Shadow Maintenance for Automatic Light-Probe Control in Ophthalmic Surgeries Using Only 2D Information

In ophthalmic surgeries, the light probe is respon- sible for providing safe intraocular illumination and ensuring the visibility of the instrument and its shadow as the only available reference for qualitative depth estimation and landing point prediction in fundus microscopic images. To achieve sus- tainable shadow-based estimation during surgeries, we propose controlling the light probe automatically to limit the shadow position around the instrument tip using only 2D information from the microscope. We also integrate an intensity balancing sub-module to guarantee the normal intensity distribution and the safe depth of light-tip placement. Without motor- based pose coordination between the light probe and the instrument, experiments analyze the performance of our image- based shadow maintenance with only image information under the constraints of RCM and discuss the working volume and segmentation limitations during simulation and real-robot tests.