Ureteral Plug Catheter for Stone Removal
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Solution Overview
Problem
Current medical procedures for removing kidney stones and ureteral stones, such as shock wave lithotripsy, transurethral lithotripsy, and percutaneous nephrolithotomy, face challenges including high recurrence rates, long procedure times, and potential patient complications like ischemia and infection, due to difficulties in accurately capturing and removing stones.
Innovation Solution
A method involving an elongated member with a ureteral plug and irrigation port is used to occlude the ureter lumen, allowing fluid to wash away stones from the ureter, facilitating their removal by positioning the plug beyond the stones and using fluid flow to dislodge and flush them out.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If traditional procedures like URS or PCNL are used to remove stones, then stones can be removed from the body, but the procedure time becomes excessively long and stone-free rate remains low
Solution Approach 1:
The device segments the stone removal process into distinct functional zones: the occlusion balloon isolates the stone location, the irrigation port delivers flushing fluid, and the retrieval basket collects stones. This segmentation enables simultaneous stone isolation, flushing, and collection, dramatically reducing procedure time compared to sequential traditional methods.
Solution Approach 2:
The device merges multiple functions into a single integrated catheter system: occlusion (balloon), irrigation (port), and stone retrieval (basket). This consolidation eliminates the need for multiple separate instruments and procedural steps, directly addressing the excessive procedure time issue while maintaining high stone-free rates.
2Ease of operation
If shock wave lithotripsy is used to break stones, then the procedure is simple to perform, but the recurrence rate of kidney stones becomes unacceptably high
Solution Approach 1:
The device introduces an intermediary flushing mechanism (irrigation port with fluid delivery) between stone fragmentation and natural passage. This intermediary step actively washes fragmented stones through the ureter, preventing retention and reducing recurrence, while maintaining the simplicity of the overall procedure through single-device operation.
3Productivity
If percutaneous nephrolithotomy is performed for large calculus, then stones can be effectively treated, but patient complications such as infection and ischemia become undesirably high
Solution Approach 1:
The device extracts stones through a minimally invasive transurethral route rather than requiring percutaneous access. The catheter is inserted through the natural urinary tract (urethra → bladder → ureter), eliminating the need for skin incisions and direct kidney access, thereby dramatically reducing complications like infection and ischemia while maintaining effective stone removal capability.
4Measurement precision
If ureteroscope is used to visualize and remove stones, then stones can be captured, but the access route becomes narrow and long making the procedure difficult to implement
Solution Approach 1:
The device combines visualization and stone removal functions into a single catheter system. The occlusion balloon provides mechanical isolation that aids visualization, while the integrated irrigation and retrieval functions eliminate the need for separate ureteroscope manipulation, simplifying the access route and procedure despite maintaining accurate stone targeting capability.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enhances the 'stone-free' rate by efficiently removing stones with reduced recurrence and complications, improving the effectiveness of the procedure while minimizing patient risk.
Implementation Method 1
washing away the calculus in the ureter in a direction away from the ureteral plug part by discharging fluid from the irrigation port into the lumen and toward the calculus
Implementation Method 2
occluding the lumen in the ureter while the ureteral plug part is positioned beyond the calculus
Data Source
AI summary
A method of removing/retrieving calculus in a ureteral lumen involves moving a ureteral plug part along the ureter lumen to position the ureteral plug part between the calculus and the kidney. The method additionally includes occluding the ureteral lumen at a location at which the ureteral plug part is located, and introducing fluid into the ureter lumen at a point between the location of the occlusion and the calculus so that the fluid washes the calculus toward the bladder. Another aspect involves a method in which an drainage tube is positioned in the ureteral lumen so that a ureteral plug part and an irrigation port are positioned distally of the calculus while an operation part of the drainage tube is positioned proximally of the calculus. The method includes occluding the ureteral lumen, washing the ureteral lumen, and releasing the occlusion and uncoupling the operation part from the ureteral plug.