Motor-free telerobotic endomicroscopy for steerable and programmable imaging in complex curved and localized areas

Abstract

Aberrations in intraluminal epithelia are precursors to a plethora of critical conditions, including various cancers, where early detection is crucial for patient prognosis. Optical Coherence Tomography (OCT) endoscopy has emerged as a promising imaging technique that provides high resolution in micrometers and imaging depth in millimeters. However, conventional proximal-scanning OCT endoscopes face challenges in imaging tortuous lumens. Motor-driven distal-scanning OCT endoscopes afford potential solutions but pose thermal and electrical risks to tissues. Crucially, these systems lack the requisite compact steering mechanisms for effective navigation within complex luminal organs, commonly involving tooltip deformations, including bending, torsion, and compression. Here, we present a motor-free telerobotic OCT endoscope of a 1.28 ~ 2.28-mm long magnetic rotator integrating a rotatable diametrically magnetized cylinder permanent magnet (RDPM) with a light reflector. Utilizing an external magnetic field effectively mitigates heat effects induced by current and voltage, yielding a maximum voltage of less than 0.02 mV and a temperature rise of no more than 0.5 °C even during continuous operation lasting one hour. Furthermore, a learning-based approach is developed to correct the common OCT imaging distortions resulting from nonuniform rotation within curved luminal organs. The endoscope demonstrates remarkable maneuverability, enabling steerable angles up to 110° under a magnetic field strength of ~ 500 mT and a gradient of ~ 0.06 mT/mm. In-vivo studies on mouse colons validate the endoscope's ability to deliver reliable angular control for localized 3D imaging, unaffected by bending and without the need for feedback. This advancement in intraluminal microimaging introduces a new guidewire-independent technique in endomicroscopy, enhancing safety and potentially improving patient care.