A Novel Combined Approach to Better Predict Sealing Performance of Luer Lock Connectivity

Area of Science:

• Biomedical Engineering
• Materials Science
• Medical Device Design

Background:

• Luer systems are standard medical device interfaces, critical for safety and dose accuracy.
• Assessing the sealing performance of Luer connections, particularly glass-plastic interfaces, is essential.
• Previous studies focused on glass-rubber contact; this is the first for glass-plastic.

Purpose of the Study:

• To analyze the connectivity and sealing performance of glass syringe and plastic needle Luer hubs.
• To investigate the factors influencing leakage in Luer connections.
• To validate theoretical predictions with experimental measurements.

Main Methods:

• Combined Finite Element Analysis (FEA) for contact pressure and area.
• Surface topography measurement across a wide wavelength range (nm to mm).
• Multiscale Contact Mechanics (MCM) using Persson's theory to calculate interfacial flow (leakage).

Main Results:

• FEA provided contact pressures and nominal contact areas for the glass-plastic interface.
• MCM successfully predicted air and liquid leakage based on surface topography and material properties.
• Theoretical predictions showed good agreement with experimental leak measurements via pressure decay.

Conclusions:

• The combined FEA and MCM approach is effective for analyzing Luer system sealing.
• Understanding surface topography and elasto-plasticity is key to predicting and ensuring good sealing.
• This methodology advances the safety and reliability of medical devices utilizing Luer interfaces.