Modified Luer Connector Taper Reduces Dead Space
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Solution Overview
Problem
The standard Luer connector design results in a significant dead space of 40-60 microliters, leading to wastage and increased costs when administering small doses of expensive medications or biologically active materials, as the existing connectors do not effectively minimize this volume.
Innovation Solution
A modified female Luer connector with an internal conical taper of 6% convergence angle and 7.5-10.5 mm length, featuring an entrance aperture diameter calculated as L*6%+3.940±0.025 mm, which allows a standard male Luer connector to penetrate closer to the end of the taper, reducing dead space while maintaining industry-standard mechanical properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of substance
If a standard Luer connector design is used, then the connector provides reliable fluid-tight seal and ease of connection, but it results in significant dead space of 40-60 microliters causing medication wastage
Solution Approach 1:
The patent modifies the female Luer connector by changing the convergence angle parameter from the standard 3.44 degrees to 6%, and adjusting the entrance aperture diameter to L*6%+3.940±0.025 mm where L is the taper length. These parameter changes reduce the dead space volume from 40-60 microliters to approximately 10 microliters while maintaining the fluid-tight seal through the modified conical taper geometry
2Loss of substance
If the female Luer connector length is reduced to minimize dead space, then dead space is reduced, but the connector may not meet ISO 80369 standards which specify 7.5-10.5 mm length
Solution Approach 1:
The patent optimizes the convergence angle to 6% and sets the taper length L within the ISO 80369 range of 7.5-10.5 mm, specifically designing the entrance aperture diameter as L*6%+3.940±0.025 mm. This parameter optimization achieves reduced dead space (approximately 10 microliters) while maintaining compliance with ISO 80369 standards for connector length and geometry
3Loss of substance
If the entrance aperture diameter is reduced to minimize dead space, then dead space is reduced, but the connector may compromise on retention forces and sealing capability
Solution Approach 1:
The patent sets the entrance aperture diameter to L*6%+3.940±0.025 mm where L is the taper length, creating an optimized balance between dead space reduction and retention force maintenance. The 6% convergence angle provides sufficient surface area for sealing while minimizing the volume of fluid trapped in the dead space region, achieving approximately 10 microliters dead space without compromising connector reliability
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 modified connector significantly reduces dead space, enhancing dose sparing and ensuring a reliable fluid-tight seal with enhanced retention forces and reduced leakage risk, while being compatible with industry-standard syringes.
Implementation Method 1
The connectors have matching male and female conical taper surfaces with an angle of 3.44 degrees (6%) which provide a reliable fluid-tight seal
Implementation Method 2
An analysis of the Luer connector structure as defined by ISO 80369 reveals that the design has an inherent dead space of 40-60 microliters between the end of the male syringe taper and the end of the female Luer taper
Data Source
AI summary
An injection configuration (10) for connection to a male Luer connector (100) includes a hub (12) having an internal conical taper (14) in fluid interconnection with a hollow needle (16). The internal conical taper has a convergence angle of 6% and a length L of 7.5-10.5 millimeters, and presents an entrance aperture diameter D of between 4.365 and 4.595 millimeters.