Comparison of Depth Estimation Setups from Stereo Endoscopy and Optical Tracking for Point Measurements
This work addresses the problem of accurate intraoperative measurements for surgeons, but it is incremental as it compares existing methods on specific phantoms and replicas.
The paper compared depth estimation from stereo endoscopy versus optical tracking for point measurements in mitral valve repair, finding that a tailored image-based method provided more accurate triangulated depth measurements than stylus-based approaches.
To support minimally-invasive intraoperative mitral valve repair, quantitative measurements from the valve can be obtained using an infra-red tracked stylus. It is desirable to view such manually measured points together with the endoscopic image for further assistance. Therefore, hand-eye calibration is required that links both coordinate systems and is a prerequisite to project the points onto the image plane. A complementary approach to this is to use a vision-based endoscopic stereo-setup to detect and triangulate points of interest, to obtain the 3D coordinates. In this paper, we aim to compare both approaches on a rigid phantom and two patient-individual silicone replica which resemble the intraoperative scenario. The preliminary results indicate that 3D landmark estimation, either labeled manually or through partly automated detection with a deep learning approach, provides more accurate triangulated depth measurements when performed with a tailored image-based method than with stylus measurements.