A flexible endoscope steers its tip with cables. Turning a control knob pulls a cable that runs the length of the insertion tube to the bending section at the tip. Up/down and, on most scopes, left/right each have their own pair of cables.
Cable systems drift. Cables stretch and slacken, and parts in the bending section and control body wear. A peer-reviewed bench study of 25 clinically used scopes found that only 2 of 20 colonoscopes and none of 5 gastroscopes reached the tip angulation specified by the manufacturer. The authors suggested a brief check before procedures.
This page is an inquiry checklist. It does not replace the manufacturer instructions for use (IFU), your facility procedure, or a repair assessment.
Common Symptoms
| Symptom | What users notice |
|---|---|
| Reduced deflection | The tip no longer bends as far as it used to in one or more directions |
| Play or backlash | The knob turns before the tip starts to move |
| Stiff knob | The knob needs more force than normal, or feels rough |
| Loose knob | The knob turns freely with little or no tip movement |
| Brake not holding | The angulation lock does not hold the tip in place |
| Tip does not return | The tip stays bent after the knob is released |
| One direction lost | Up, down, left, or right stops responding |
Several of these can appear together. Note each one you see.
What to Check Before Requesting a Repair
Use the inspection steps in the IFU for that scope. A simple check, with the scope straight and out of a patient, gives useful notes:
- Range. Turn each knob to its stop in each direction. Compare the tip angle with the specification in the IFU, or with a known-good scope of the same model.
- Response. Turn each knob slowly from neutral. Note how far it turns before the tip moves.
- Feel. Note stiffness, grinding, clicking, or a point where the knob suddenly gets easier.
- Locks. Engage each angulation lock and check whether the tip holds.
- Return. Release the knobs and check whether the tip comes back to straight.
The IFU for many scopes warns against using a scope whose angulation does not work smoothly, and against forcing the controls. Stop the check if a knob resists, and do not force it.
Related Damage to Report
Angulation faults often come with other signs. Report these too:
- A failed or marginal leak test. Fluid inside the bending section can affect the angulation system.
- Cuts, swelling, or wear on the bending rubber.
- Kinks, flattening, or wrinkles in the insertion tube.
- A recent difficult case, a drop, or a crush.
Sending the Request
For each scope, send the manufacturer, model, and serial number, the directions affected, what you measured or saw, and the related damage above. A short video of the tip while the knob is turned shows the fault more clearly than a description.
ProbeBridge coordinates flexible endoscope repair with specialist partner workshops in China. We confirm whether the scope can be evaluated, and agree the assessment, price, and terms, before anything ships. Start from the flexible endoscope repair page, or request a review directly.
Sources
- Rozeboom ED, Reilink R, Schwartz MP, Fockens P, Broeders IAMJ. Evaluation of the tip-bending response in clinically used endoscopes. Endoscopy International Open. 2016;4(4):E466. PMC4831938.
- Manufacturer instructions for use for the specific scope model.