Medical Connector Diaphragm Valve Minimizes Priming Volume
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Solution Overview
Problem
Existing medical connectors for fluid delivery systems have large priming volumes, leading to delays in therapy delivery at low flow rates, and cause fluid displacement issues during connection and disconnection, which can result in harmful retrograde flow and bacterial growth due to septum penetration.
Innovation Solution
A Luer-activated medical connector with a low priming volume design that uses a valve housing, diaphragm, and biasing element to achieve negative displacement during connection and positive displacement during disconnection, along with a swabbable surface for disinfection, minimizing fluid volume and preventing leakage under backpressure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If a traditional connector with large chamber is used, then the connector can seal and control fluid flow, but the priming volume becomes large causing delay in therapy delivery
Solution Approach 1:
The patent employs a flexible diaphragm instead of a rigid chamber to separate the actuator from the fluid path. The diaphragm deforms under actuation to open the fluid path and returns to its original position to close the path, eliminating the need for a large rigid chamber and significantly reducing priming volume while maintaining sealing and flow control functions.
2Reliability
If connection is made between two closed fluid systems, then fluid flow can be controlled, but fluid displacement occurs causing harmful retrograde flow
Solution Approach 1:
The patent inverts the traditional displacement behavior by designing the connector to provide negative displacement (draw fluid in) upon insertion and positive displacement (push fluid out) upon removal. This is achieved through the diaphragm's elastic deformation characteristics, which create a volume increase upon actuation that pushes fluid forward, preventing retrograde flow and eliminating the need for complex valve mechanisms.
3Reliability
If a septum is used at the connection site, then the connector can be sealed, but bacteria growth is promoted and leakage occurs under back pressure
Solution Approach 1:
The patent removes the septum from the connection site entirely, replacing it with a diaphragm located downstream in the fluid path. The diaphragm serves the sealing function without being exposed to the external environment where bacteria could contaminate it. This extraction of the sealing element from the vulnerable connection interface eliminates the bacteria growth problem while maintaining sealing integrity under back pressure.
Solution Approach 2:
The diaphragm is designed to be self-sealing under back pressure conditions, eliminating the need for additional valves or complex sealing mechanisms. The elastic properties of the diaphragm automatically maintain the seal without requiring external control systems or maintenance interventions.
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 connector allows for quicker therapy delivery at low flow rates, reduces fluid displacement, and prevents bacterial growth by minimizing priming volume and ensuring a clean, leak-proof interface, thereby enhancing medical fluid delivery efficiency and safety.
Implementation Method 1
a diaphragm in the valve housing, the diaphragm separating the valve plug from an inner volume in the valve housing and the diaphragm sealing the inner volume, such that upon actuation of the connector the valve plug deforms the diaphragm into the inner volume thereby unsealing the inlet port
Data Source
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AI summary
A connector is disclosed that has a housing having a fluid path from a first port through an internal cavity to a second port. The connector also includes a plug that has first and second positions within the internal cavity, where the plug blocks the fluid path between the first port and the internal cavity when in the first position. The plug has a diaphragm that separates the internal cavity into a first volume that is vented and a second volume that includes the fluid path. The plug also includes a biasing element that is disposed within the first volume and that urges the plug toward the first position. Displacement of the plug from the first position toward the second position opens the fluid path and increases the second volume.