Design and Evaluation of a Flexible Sensorized Robotic OCT Neuroendoscope

Endoscopic optical coherence tomography (OCT) has demonstrated its capability to visualize the fine microstructures and subtle lesions inside human organs in vivo. However, the limited imaging depth and the lack of distal dexterity of the current rigid OCT endoscope prohibits its proactive assessment and clinical utilities in the confined, sensitive, and yet relatively large (a few centimeters) surgical space, such as the lesion in deep brain. In this work, we developed a flexible sensorized robotic OCT neuroendoscope, which combines a 2-degree-of-freedom (DOF) cable-driven continuum manipulator (CM) with an ultrahigh-resolution 800-nm OCT probe and a multi-core fiber Bragg grating (MCFBG) fiber sensor. The MCFBG measurements of the bending posture of the endoscope was validated through experiments. By leveraging the OCT A-line signals, axial distance was precisely measured between the OCT probe tip and the surrounding tissue boundary. The feasibility of OCT neuroendoscope was further demonstrated to navigate and steer inside a porcine brain-simulated lesion phantom in an ex-vivo experiment. Our OCT neuroendoscope offers distal maneuverability and ultrahigh-resolution imaging capability at an axial resolution of about 2.4 μm (in air), suggesting its clinical potential for minimally-invasive imaging-guided diagnosis and treatment in deep brain in vivo.