“NEW “BENDING SECTION DOESN’T ALWAYS MEAN GOOD
There is always someone offering an after market bending section for sale. So why hasn’t anyone gotten rich selling them? The need is there. Third party flexible endoscope service companies will pay $900 for an Original Equipment Manufactures’ (OEM) bending section. An industry exists where deep pocket salesman buy good working endoscopes for $10,000 and cannibalize the parts for resale, reuse and healthy profits.
So why hasn’t a machine shop been able to produce a viable replacement bending section? Surprisingly there is more to designing a bending section than joining bands together with a couple of angulation wire rings.
A little background knowledge is helpful in determining a good replacement bending section from a bad one.
All of the examples of non-OEM aftermarket bending sections I have examined, all failed miserably. And all of them had surface finish issues. As the bending section angulates up and down the elements on the inside of the curve get shorter (retracting into the Insertion Tube) and the elements on the outside of the curve grow longer. This back and forth varies up to
2 inches each time. This means the combined travel distance of an element, during a medical procedure, can exceed ten feet. If the interior surface of the bands is not totally burr free,, the operator will unknowingly shred the light guides and ultimately hole one of the lumens. It would be a simple process and relatively inexpensive to electro polish the bands prior to assembly. However, endoscope replacement parts producers are willing to sell sub-standard parts to an unwitting customer knowing the customer has few avenues left to them in the search for replacement parts so they can repair the endoscope for the customer.
Outside surface quality is equally important. If a raised burr or rivet head catch on the netting of the mesh, the mesh wires will bend back and forth, ultimately separating, rather than slip sliding over the surface. A separated mesh wire will eventually push down into the elements wrecking havoc with the light guides or CCD wires. Or this wire could punch out through the bending rubber and possibly the patient.
Of the big three flexible endoscope manufactures; Fujinon, Olympus, and Pentax, Olympus has a reputation for miniaturization. Smaller cameras to easily slip into and retrieve from your pocket. and smaller diameter endoscope insertion tubes to pass into the body. But miniaturization usually causes reduced longevity. Fujinon and Pentax have larger inside diameters and place their eyelets or wire guides 90º around the inside of the bending section often centered behind or incorporated into the rivets used to link the bands toghether. But Olympus likes to design endoscopes that are easy sells for their sales force. A smaller diameter insertion tube with a comparatively larger biopsy channel. How can the doctors and purchasing department resist buying. But to make those dinamics work in the bending section, components need to be moved around. If the bending section were a clock with ‘up’ at 12 o’clock, forceps would appear in the image at 5 o’clock. To make room in the bending section for a large therapeutic biopsy channel the right eyelet is moved up and out of the way to 2:30 and the down eyelet is moved to 6:30. This way the biopy channel rests nestled down in between the right and down eyelets. The space in between elements in the bending section are so close they have to be threaded thrugh the eyelets during assembly and if any elements ‘crossover’ it will fail quickly in the field.
BENDING SECTION RIVETS
Rivet placement is critical. If the ears (tabs extended from the bands and holed to accommodate rivets) are not aligned 180º from each other, they will bind causing a stiff bending section. This will place stress on the angulation wire causing an early overhaul repair.
Bending sections can be replaced with OEM parts; expensive, susceptible to current wear and tear or they can be replaced with non-OEM replacement parts, which is less costly but more knowledge by the machining company is required than just reverse engineering the parts. Or you can have the original equipment manufactures bending section rebuilt, replace the worn out and damaged components in such a way that they work as good as or better than the original. This also eliminates legal entanglements related to the use of non OEM parts used on a medical device.
Llojenn Inc. (Bending Section Repair for Endoscopes)
2101A Churchville Road
Bel Air, MD 21015