Solid Bladder Ureteral Stent Design for Reflux Prevention
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Solution Overview
Problem
Conventional ureteral stents cause discomfort and medical issues due to their design, which leads to urinary reflux, flank pain, and increased patient discomfort, as they keep ureter orifices open, preventing normal urine flow and irritating bladder tissues.
Innovation Solution
A ureteral stent design featuring a solid bladder portion without a lumen, a tubular kidney portion, and tethers connecting them, allowing the bladder portion to float and the ureter orifice to move between compressed and uncompressed states, ensuring urine flows only from the kidney to the bladder, reducing reflux and irritation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If a conventional ureteral stent with a lumen is used, then the stent can maintain structural integrity and provide support, but it prevents the ureter orifice from moving between compressed and uncompressed states, causing urinary reflux and flank pain
Solution Approach 1:
The bladder portion is constructed as a solid structure without a lumen, allowing the ureter orifice to move freely between compressed and uncompressed states. This solid yet flexible construction maintains stent integrity while enabling natural orifice movement to prevent urinary reflux and flank pain.
2Object-affected harmful factors
If a solid bladder portion without a lumen is used, then the ureter orifice can move freely between compressed and uncompressed states, but the bladder portion requires a larger diameter to maintain necessary uncoil force
Solution Approach 1:
The bladder portion diameter is optimized to balance two requirements: large enough to maintain necessary uncoil force for stent support, yet small enough to allow insertion into a scope alongside a pusher tube. This parameter optimization enables free movement of the ureter orifice to prevent urinary reflux while maintaining structural integrity.
3Strength
If the bladder portion diameter is increased to maintain uncoil force, then the stent can provide adequate support, but it cannot be inserted into a scope alongside a pusher tube, complicating the delivery process
Solution Approach 1:
The bladder portion diameter is precisely controlled to maintain adequate uncoil force for stent support while remaining small enough to fit within the delivery scope alongside the pusher tube. This optimized diameter simplifies the delivery process, allowing the stent to be inserted through standard ureteroscopes without requiring separate guidewire loading.
4Ease of operation
If the bladder portion is loaded onto a guidewire, then the stent can be delivered through the ureteral passageway, but the delivery process becomes more complex and time-consuming
Solution Approach 1:
The design eliminates the need to load the bladder portion onto a guidewire by optimizing its diameter to fit alongside the pusher tube within the delivery scope. This extraction of the guidewire loading step simplifies the delivery process and reduces procedural time while maintaining the capability to deliver the stent through the ureteral passageway.
Data Source
AI summary
Provided is a ureteral stent for placement in a bladder, a kidney and a ureteral passageway connecting the bladder and the kidney. The ureteral stent includes a solid bladder portion free of a lumen positionable in the bladder, a tubular kidney portion positionable in the kidney and the ureteral passageway, and a tether connecting the bladder portion and the ureter portion to allow the bladder portion to float in the bladder and to allow a ureter orifice connecting the ureteral passageway to the bladder to move between a compressed state and an uncompressed state. By not having a lumen, the solid bladder portion allows the bladder to have a smaller diameter while maintaining a necessary uncoil force. The smaller diameter also allows the bladder portion to be inserted into a scope alongside a pusher tube, thereby avoiding loading the bladder portion onto a guidewire.