Dexterity Enhancement for Flexible Endoscopic Interventional Tools

Project Summary/Abstract: The objective of this proposal is to create a new low-cost transendoscopic laser/basket aiming tool that makes ureteroscopic kidney stone removal easier for physicians, so that fewer patients require invasive surgery. Clinical significance comes from the 230,000 patients per year (in the USA alone) with larger stone sizes, for whom surgeons currently face a dilemma. They must either choose invasive surgery, or perform a lengthy ureteroscopy which increases complication rates, and consumes excessive operating room time. Our central hypothesis is that by increasing laser and basket dexterity, our new device will reduce the procedure time by more than 25% for patients with larger stones. Achieving this would make many more patients candidates for ureteroscopy; it will make it possible to remove larger stones almost as quickly as smaller stones are removed today. Innovation comes from harnessing elastic interactions in asymmetrically stiff, thin-walled tubes to create a steerable aiming tip that is (1) small enough to pass through a standard ureterosocope port, while (2) carrying a laser fiber or kidney stone basket within its open central lumen. The stiffness asymmetry of the tubes (which are attached at their tips) transforms small axial motions applied at the endoscope handle into dexterous local bending at the endoscope tip. The result is an inexpensive, disposable, luminal device for dexterously steering laser fibers and kidney stone baskets, which is compatible with existing endoscopes, laser fibers, and baskets. Our approach in Aim 1 is to build an OR-ready version of our device by using catheter-inspired tip design processes with a surgeon interface amenable to practical, scalable manufacturing. Aim 2 incorporates rigorous quality and human factors-based design enhancements and refinements so that our device is ready to undergo the FDA 510(k) clearance process immediately at the end of Phase II. Aim 3 focuses on statistically powered experiments to evaluate our hypotheses that our new steerable aiming tip will reduce average surgical duration by 25% – which will bring operative time for patients with larger stones in line with the current (small stone) standard of care – and reduce maximum duration for many more large stone patients, bringing it to within clinical guidelines for maximum safe ureteroscopy duration. Success in validating these hypotheses will strongly motivate future Phase III activities (supported by private capital after the conclusion of this Phase II SBIR) where we complete the FDA 510(k) clearance process, and launch our device on the market.