500μm field-of-view probe-based confocal microendoscope for large-area visualization in the gastrointestinal tract

Rapid large-area tissue imaging at the cellular resolution is important for clinical diagnosis.We present a probe-based confocal microendoscope(p CM)with a field-of-view(FOV)diameter over 500μm,lateral resolution of 1.95μm,and outer diameter of 2.6 mm,compatible with the biopsy channel of conventional gastroscopes.Compared to a conventional p CM,our system's FOV increased by a factor of 4 while maintaining the probe size and cellular resolution—comparable to the FOV of Zeiss Axio Observer's 20×=0.8 numerical aperture objective lens.Ex vivo imaging of wide areas in healthy and diseased rat gastrointestinal tract tissues demonstrates the system's practicality.