Comparison of Depth Estimation Setups from Stereo Endoscopy and Optical Tracking for Point Measurements

TL;DR

This paper compares stereo endoscopy and optical tracking for 3D point measurement accuracy in minimally-invasive cardiac surgery, finding that image-based triangulation often yields more precise depth estimates.

Contribution

It provides a comparative analysis of stereo vision and optical tracking methods for intraoperative 3D point measurement in cardiac procedures.

Findings

Image-based triangulation offers more accurate depth measurements than stylus tracking.

Deep learning detection improves the accuracy of landmark localization.

Stereo setup performs reliably in intraoperative scenarios.

Abstract

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.