Microneedle Stent with Microvalves for CSF Drainage
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Solution Overview
Problem
Current shunting devices for hydrocephalus, such as ventriculo-peritoneal shunts, have high failure rates due to blockage, infection, and imprecise flow of cerebrospinal fluid (CSF), leading to frequent hospital visits, surgical revisions, and increased healthcare costs, and do not adapt well to changes in patient position or posture.
Innovation Solution
An implantable device with a stent comprising microneedles and one-way microvalves that mimic the function of arachnoid granulations, allowing CSF to flow from the subarachnoid space to the superior sagittal sinus based on pressure differential, eliminating the need for invasive surgery and reducing failure rates by providing multiple outlets and avoiding the use of power sources or complex electronics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single lumen tube is used in VP shunts, then the device structure is simple, but the failure rate is high due to blockage and breakage
Solution Approach 1:
The invention divides the single lumen tube into multiple separate lumens (at least two lumens: first lumen for CSF delivery and second lumen for drainage). This segmentation allows independent function of each lumen, reducing the risk that blockage or failure of one lumen will cause complete system failure, thereby improving reliability while maintaining reasonable structural complexity.
2Ease of operation
If a long course shunt tubing is used to connect head to abdomen, then CSF can be drained from ventricles to peritoneum, but the tubing is prone to breakage, kinking, and erosion through skin and viscera
Solution Approach 1:
The invention extracts and eliminates the long subcutaneous tubing component from the shunt system. Instead of routing CSF through a long external tube from head to abdomen, the system uses direct implantation of the multi-lumen device with lumens that terminate at appropriate locations, removing the vulnerable tubing segment that causes breakage, kinking, and erosion problems.
Solution Approach 2:
The invention changes the spatial arrangement by placing multiple functional lumens within a single implanted device structure, eliminating the need for long external routing. The lumens extend in different directions from a common implant site, distributing CSF flow paths through different anatomical dimensions rather than relying on a single long linear path.
3Adaptability or versatility
If programmable valves with electromagnetic adjustment are used, then CSF flow can be controlled, but the device requires power source and complex electronics that increase failure risk
Solution Approach 1:
The invention employs passive flow control mechanisms that automatically regulate CSF flow based on pressure differentials without requiring external power sources or electronic control systems. The valves and flow restrictors are designed to self-regulate flow rates in response to changing CSF production and intracranial pressure conditions, eliminating the need for batteries, motors, or electronic circuitry while maintaining adaptability.
4Productivity
If VP shunt is used for hydrocephalus treatment, then CSF can be diverted from brain to abdomen, but the procedure requires invasive surgery and frequent hospital visits for monitoring and revision
Solution Approach 1:
The invention incorporates multiple lumens and flow control features during the initial implantation procedure that anticipate and prevent future complications. The device is pre-configured with redundant lumens, flow restrictors, and valves that are designed to maintain functionality without requiring subsequent surgical revisions, thereby reducing the need for repeat hospital visits and procedures.
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
The device achieves precise control of CSF flow, reduces failure rates, and minimizes complications like infection and breakage, allowing for same-day minimally invasive surgery with reduced healthcare costs and improved patient outcomes.
Implementation Method 1
the microvalves permit the flow of CSF through the microneedles based on the pressure differential between the subarachnoid space at the distal end of the fluid transmitting members and the superior sagittal sinus at the proximal end of the microneedles
Data Source
AI summary
An implantable device for the treatment of hydrocephalus using a stent having a peripheral wall and an interior passageway and wherein a plurality of microneedles project outwardly from the peripheral and each needle includes a microneedle passageway from an aperture adjacent a distal end of the microneedle to a proximal end of the microneedle adjacent the peripheral wall. A corresponding plurality of one-way microvalves is positioned at the proximal ends of the microneedle and wherein the microneedle passageway is in fluid communication with the interior passageway whenever the one-way microvalve is open. When the stent is implanted in the superior sagittal sinus with the distal end of the plurality of microneedles positioned within the subarachnoid space and at least one of the plurality of microvalves is open, the stent permits cerebrospinal fluid to pass from the subarachnoid space to the superior sagittal sinus.