3D light-field endoscopic imaging using a GRIN lens array

Abstract

Endoscopic observation of biological tissues with quantitative depth perception, effective volumetric recognition of anatomical features, and efficient 3D navigation is critical for optical diagnostics and minimally invasive surgery for various target diseases. Light-field techniques have recently emerged as a promising approach to 3D photography and microscopy due to their scanning-free, highly scalable, and volumetric imaging capabilities. These advantages hold great potential for application to optical endoscopy, as the existing clinical endoscopy systems rely primarily on a 2D projection or use polarized glasses to provide visual parallax of complex 3D structures. Here, we report a light-field endoscopy prototype using a GRIN lens array (GLA). The GLA-based system maintains consistent spatial measurements with clinical endoscopic systems, a compact size in comparison with compound objective lenses, as well as the ability to maximally capture the angular information necessary for 3D imaging. We also present a computational strategy combining a wave-optics model and a hybrid point-spread function for high-resolution volumetric reconstruction. The system achieves spatial resolutions of 20–60 μm and 100–200 μm in the lateral and axial dimensions, respectively, across an imaging volume of ∼5 mm × 5 mm × 10 mm. We anticipate the prototype to offer a promising paradigm for glasses-free, high-resolution 3D medical endoscopy.