Collapsible Ureteral Stent Bladder End for Retrograde Flow Prevention
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional ureteral stents cause patient discomfort due to contact with sensitive bladder regions and retrograde urine flow when urine collects in the stent's end structure, leading to hydrostatic pressure-induced pain and irritation.
Innovation Solution
A ureteral stent design featuring a collapsible bladder end portion with a bulky, lightweight structure formed from biocompatible materials like polymers or polymer solutions, which flares outward to prevent migration and allows urine drainage while collapsing to prevent fluid re-entry into the stent when not in use, reducing contact with sensitive bladder areas.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the stent end structure is designed to drain urine effectively, then drainage function is improved, but urine collects in the end structure causing retrograde flow and patient discomfort
Solution Approach 1:
The bladder end portion is designed to dynamically change shape between an expanded state during urine drainage and a collapsed state when preventing retrograde flow. The collapsible structure allows the end portion to collapse under its own weight or external pressure, closing off the lumen to prevent urine from flowing backward into the stent, while expanding to facilitate drainage when needed.
Solution Approach 2:
The stent is divided into distinct functional segments: an elongated portion for ureteral support, a first end portion with retention configuration for kidney anchoring, and a second end portion with collapsible structure for bladder placement. This segmentation allows each portion to independently perform its specific function without interfering with others.
2Reliability
If the stent end portion is made bulky to prevent migration, then retention is improved, but contact with sensitive bladder regions increases causing patient discomfort
Solution Approach 1:
The second end portion transitions between an expanded configuration that provides bulk for retention and a collapsed configuration that minimizes contact with sensitive bladder regions. When the stent is properly positioned, the collapsible end portion collapses under its own weight or bladder pressure, reducing its profile and minimizing irritation to the bladder wall while maintaining anchoring through the flared shape during placement.
Solution Approach 2:
The collapsible end portion is constructed from flexible biocompatible materials that can deform and collapse under pressure. This flexibility allows the structure to adapt its shape - expanding during insertion to ensure proper positioning and collapsing afterward to minimize contact with sensitive tissues while maintaining retention through the flared geometry.
3Reliability
If the stent maintains a flared configuration to prevent migration, then retention is improved, but fluid can enter the lumen causing patient discomfort
Solution Approach 1:
The collapsible end portion dynamically transitions between expanded and collapsed states based on fluid flow conditions. During normal operation, the structure collapses to close off the lumen entrance, preventing fluid entry while maintaining the flared shape for retention. The collapsible nature ensures that even when flared for anchoring, the lumen remains protected from fluid ingress.
Data Source
AI summary
A stent is designed to be placed within a patient's ureter to facilitate drainage from the patient's kidneys to the bladder. An elongated portion of the stent includes a length sufficient to extend substantially within the ureter from the kidney to the bladder, and defines a lumen extending therethrough. A first end portion extends from one end of the elongated portion and is adapted to assume a retaining configuration when placed substantially within the kidney. A second end portion extends from another end of the elongated portion and flares outward when placed substantially within the bladder to maintain position. The second end portion allows fluids to flow through the lumen and into the bladder and is collapsible to prevent fluid from passing from the bladder to the kidney.