Pressure-Activated Slit Valve for High-Flow Venous Access
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Solution Overview
Problem
Pressure-activated safety valves in medical devices like PICCs and dialysis catheters struggle to handle fluid pressures and flow rates beyond traditional limits, particularly during procedures such as flushing obstructed lumens or administering high-flow rate fluids.
Innovation Solution
A valve design featuring a flexible disk gripped between two housings with a slit that opens at a predetermined threshold pressure to allow fluid flow and reseals below it, incorporating features like relief wells and bias structures to enhance performance under increased pressures and flow rates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stress or pressure
If a traditional flexible disk valve is used, then the device can maintain sealing at normal pressures, but it cannot handle fluid pressures and flow rates beyond traditional limits
Solution Approach 1:
The flexible disk is segmented with a radial slit that allows controlled opening at high pressures while maintaining sealing at normal pressures. The slit divides the disk into sectors that can independently deflect under pressure, enabling the valve to handle higher fluid pressures and flow rates while maintaining reliable sealing when closed.
Solution Approach 2:
The valve transitions from a static sealing structure to a dynamic system where the flexible disk can deflect and open under high pressure conditions. The disk dynamically responds to pressure changes, opening to permit flow when pressure exceeds the threshold and resealing when pressure drops, allowing the device to adapt to varying flow rate requirements.
2Stress or pressure
If the flexible disk is made more robust to handle higher pressures, then pressure handling improves, but the valve may fail to seal properly at normal pressures
Solution Approach 1:
The flexible disk exhibits different mechanical properties in different regions. The radial slit creates localized flexibility at specific sectors while maintaining overall structural integrity. This local quality variation allows the valve to require high threshold pressure for activation while ensuring easy sealing at normal pressures through the flexible disk's natural elasticity.
Solution Approach 2:
The valve utilizes changes in the flexible disk's physical state based on pressure conditions. At normal pressures, the disk maintains a sealed configuration. When pressure exceeds the threshold level, the disk undergoes a parameter change by deflecting and opening the slit, permitting flow. This parameter change enables the valve to transition between sealed and open states based on pressure conditions.
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 design effectively manages higher fluid pressures and flow rates, ensuring reliable sealing and fluid control in medical devices, thereby improving the performance and safety of vascular access devices.
Implementation Method 1
when acted upon by a fluid pressure of at least a predetermined threshold level opens to permit fluid flow between the first and second lumens and which, when acted upon by a fluid pressure less than the threshold level remains sealed
Implementation Method 2
a slitted, flexible disk extending across a lumen. The flexible disk is generally constructed so that, when subjected to a threshold fluid pressure, edges of the slit separate from one another
Data Source
AI summary
A valve comprises a first housing including a first lumen extending therethrough and defining a first disk-facing surface and a second housing including a second lumen extending therethrough and defining a second disk-facing surface, the second housing being mated to the first housing so that the second disk-facing surface faces the first disk-facing surface in combination with a flexible disk gripped between gripping portions of the first and second disk-facing surfaces, the disk including a slit extending therethrough which, when acted upon by a fluid pressure of at least a predetermined threshold level opens to permit fluid flow between the first and second lumens and which, when acted upon by a fluid pressure less than the threshold level remains sealed preventing fluid flow between the first and second lumens and a relief well between opposing portions of the first and second housings radially outside the gripping portions, a width of the relief well exceeding a width of a radially outer portion of the flexible disk so that the radially outer portion of the disk is free to move therewithin.