A Compact Monocular Dual-View 3D Endoscope Imaging System Based on Dichroic Prism for Minimally Invasive Surgery

During minimally invasive surgery (MIS), three-dimensional (3D) endoscopes provide valuable 3D perception of the patient's internal structures. However, due to the requirement of two cameras and a relatively large baseline distance, the imaging front-end of the conventional binocular 3D (CB3D) endoscope usually lacks compactness. We aim to develop a novel compact monocular dual-view 3D (MDV3D) endoscope imaging system.

We develop a novel optical design for the MDV3D endoscope that exploits the dichroic prism's reflection capability to its internal light to realize MDV3D imaging, ensuring the 3D endoscope's imaging front-end with high compactness. Additionally, we propose a 3D reconstruction optimization method (MB-BEDE) to address the challenge of insufficient accuracy of 3D surface information posed by the typically micro baseline distance between the two virtual cameras in the MDV3D endoscope. Through seamless integration of our MDV3D endoscope and MB-BEDE method, we can obtain reliable real-time 3D information.

Evaluation experiments demonstrate our system's capability to provide accurate 3D surface information. Notably, compared to the CB3D endoscope imaging system occupying two channels in the robotic single-port laparo-endoscopic surgery (SPLS) platform, our system only requires one channel with a 5.60 mm diameter, presenting the advantage of creating more operating space for surgical instruments during robotic SPLS procedures.

The proposed system and method present a novel solution for developing compact and cost-effective 3D endoscope imaging systems in MIS, particularly in robotic SPLS.