Minimally-advancing Luminal Catheter with Depth-Limiting Stop Element
Solution Overview
Problem
Conventional cerebrospinal fluid shunts, particularly ventriculosinus shunts, face issues such as obstruction, dislocation of the catheter tip, blood clotting, and increased risk of infection due to their large diameter and inability to stabilize within the dural venous sinus, leading to non-physiological cerebrospinal fluid evacuation and potential complications like intracranial hypotension and bacterial infections.
Innovation Solution
A catheter with a tubular shaft and stop element that limits insertion depth to avoid contact with the sinus wall, incorporating expandable wings for fixation and a distal port oriented to face the blood flow, reducing the risk of obstruction and clotting while maintaining stability and minimizing tissue damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the catheter has a wide external diameter to facilitate sufficient fluid flow, then the catheter lumen dimension is improved, but the catheter causes obstruction of the blood flow
Solution Approach 1:
The catheter design changes the diameter parameter to be small (minimally-advancing) while maintaining adequate lumen for CSF flow through optimized geometry and positioning, resolving the contradiction between sufficient flow capacity and minimal blood flow obstruction
2Ease of operation
If the catheter is advanced through the vessel lumen, then the catheter can be positioned in the sinus, but the catheter tip cannot be stabilised causing dislocation risk
Solution Approach 1:
The catheter incorporates a fixation mechanism that is deployed preliminarily upon insertion to anchor the catheter tip against the sinus wall, preventing dislocation while maintaining the ability to position the catheter correctly during the insertion process
3Ease of operation
If the catheter tip is pushed inside the vessel lumen, then the catheter can be advanced to position, but the catheter tip causes endothelial wall lesions or friction initiating blood clotting
Solution Approach 1:
The catheter incorporates a compliant tip or coating that flexes and conforms to the vessel geometry, reducing friction and preventing endothelial damage during advancement, thereby minimizing the initiation of blood clotting cascades
4Shape
If the catheter is inserted through a wide bore hole to achieve sufficient oblique angle, then the correct catheter orientation is realized, but the skull bone thickness requires a wide bore hole
Solution Approach 1:
The catheter design allows for achieving correct orientation through a different insertion approach that does not require a wide bore hole, possibly by utilizing the catheter's flexibility or a different angulation mechanism that works through a smaller opening
Data Source
AI summary
The present invention relates to an implantable catheter (100) provided for insertion through a wall (50) of a dural venous sinus (70) in a subject, having a proximal (20) and distal end (30), comprising: —a tubular shaft (10) for insertion through the wall (50) of the venous sinus (70) into the sinus (52), provided with a shaft lumen (12) in fluid connection with a proximal port (14) at the proximal end and a distal port (16) at the distal end of the shaft (10), and —a stop element (40) disposed on an outer surface of the tubular shaft (10), configured to limit the depth of insertion of the tubular shaft (10) into the sinus.