Lessons learned in the assembly of submillimeter endoscopes

The rapidly emerging field of submillimeter microendoscopy provides a critical tool for applying powerful, multimodal optical imaging techniques to the small lumens and structures of the body, where conventional imaging methods cannot reach. Designing the mechanical and optical components for these systems is nontrivial but shown to be achievable. However, the assembly process for these submillimeter systems can present unexpected challenges for researchers seeking to build their endoscopes. In this work, we discuss the lessons learned while assembling a submillimeter, multichanneled endoscope with multi-modality imaging and cell-collecting capabilities, for falloposcopic use. We introduce the challenges imposed by the mechanical specifications of the endoscopic device and the assembly of the imaging system. Some of these challenges include the design of a close-focus objective lens, proper tolerancing of the multilumen extrusion, lack of adhesion between the imaging components and the endoscope’s polymer housing, and stiffness of the fiber bundle. To address these challenges, we have iterated through new designs and construction techniques, including redesigning the extrusion, employing a metal ferrule to help with adhesion, and ensuring endoscope compatibility with standard medical guidewires. We hope that through sharing this information, others will be able to sidestep the assembly challenges we have faced during our assembly process, and therefore accelerate the research being done in the field of microendoscopy.