These small diameter (less than 3mm) borescopes can be used to inspect endoscope's internal working channels during reprocessing . It is imperative to do visual inspection during endoscope reprocessing to make sure high quality cleanness and safety. The external of endoscopes can be inspected with optical magnifiers or video magnifiers/microscopes. The internal of endoscopes need a small diameter borescope for careful inspections. 

Common problems of the internal channels during endoscope (gastroscopes, colonoscopes, duodenoscopes, and  echoendoscopes) reprocessing 
  • corrosion
  • crack and scratches
  • physical damages
  • debris
  • discoloration
  • moisture
  • foreign objects like fiber, lint, brush bristles and particles
"Inspection of the internal channels with a borescope is a quality-driven process and will help a facility to assess the condition of their endoscopes, the overall reprocessing procedures and potentially the drying process."

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--​Proper endoscope cleaning requires visual cues — even for the invisible
Normal procedure steps of endoscope reprocessing:
  1.  Pre-cleaning
  2. Leak test
  3. Manual cleaning
  4. Visual inspection 
            Outside exam with magnifier or microscope
            Internal channel inspection with borescope
  5. High level disinfection or sterilization
  6. Dry and storage