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The vision probe (vp) was returned and evaluated by the failure analysis (fa) team.The vp was observed to have minimal loctite on the tip, which suggests that it is possible that the loctite did not sufficiently bond to the vision probe tip during manufacturing.It is also possible that high force was transferred to the adhesive bond at the tip when the shaft became kinked, leading to the fiber bond failing and the fiber being pulled back into the tip.Advance failure analysis was completed.Air leak test failed with steady stream of bubbles observed coming from the distal tip.Upon visual inspection of the tip, one of the two illumination fibers was observed to be recessed.Air leak test failure was observed at the location of the recessed illumination fiber and is due to an insufficient seal at the distal tip.Upon visual inspection, the shaft was observed to be kinked approximately 123mm and 510mm from the distal tip.The probable root cause of the kinked shaft is attributed to damage during use or reprocessing.The vision probe can become damaged when improperly handled or when excessive force is applied while inserting it down and removing it from the catheter tool channel.Root cause is attributed to mishandling/misuse.The vision probe was opened up to check backend components.No damage fluid intrusion was observed.Fiber service loops were observed in the backend.The fiber service loop in the backend allows for pistoning of the fibers within the vision probe shaft to accommodate changes in illumination fiber tension during catheter articulation and therefore vision probe shaft manipulation.The recessed fiber was removed from the shaft to inspect the distal tip.Upon manual manipulation of the fibers, one of the two fibers felt tight indicating that fiber movement might be slightly restricted.However, fiber service loops were present and no obstructions within the shaft were observed, indicating that the fiber was likely sufficiently free piston when the backend was closed.There is a potential for fragments of adhesive due to this failure mode as the adhesive bond failed at the distal tip which enters the patient.Note that no confirmed missing pieces were observed.
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