Asymmetric Needleless Connector Valve for Leak and Splash Control

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing needleless connectors suffer from fluid deposition on the valve head during implement removal, leading to potential fluid leakage and contamination risks due to the sensitivity of current valve geometries and manufacturing tolerances.

Innovation Solution

A needleless connector design featuring an asymmetrically-shaped valve with a long stem and primary seal positioned near the base, supported by a radial ledge, which provides controlled activation and retraction, preventing fluid splash and maintaining consistent seal preload despite manufacturing variations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional needleless valve geometry is used, then the valve can be manufactured with standard tolerances, but fluid deposits on the valve head and may separate to flow into the patient's bloodstream

Engineering Contradiction:
Improvefluid containment reliabilityVSAvoidfluid deposition and potential contamination
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies asymmetry by positioning the primary seal at the base of the valve rather than at the valve head, creating an asymmetric seal arrangement that prevents fluid from depositing on the valve head. The asymmetric geometry includes a longer valve stem and a seal location that is offset from the traditional symmetric center, thereby eliminating the harmful fluid deposition issue while maintaining manufacturing feasibility

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The patent introduces an intermediary structure in the form of a ledge that supports the primary seal at the base of the valve. This ledge acts as a mediator between the valve body and the seal, providing a stable mounting surface that ensures consistent seal contact and prevents fluid from reaching the valve head, thereby solving the contamination problem

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If the primary seal is positioned at the valve head, then the valve structure is compact, but the seal preload varies with manufacturing tolerances and fluid may leak

Engineering Contradiction:
Improveseal integrityVSAvoidseal preload consistency
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The patent applies preliminary action by pre-positioning the primary seal at the base of the valve where it is supported by a fixed ledge structure. This preliminary positioning ensures that the seal is pre-loaded correctly against the sealing surface, compensating for manufacturing tolerances in the valve body and housing. The seal is already in its optimal position before the valve is assembled and pressurized, ensuring consistent sealing performance

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent moves the primary seal from the traditional axial position at the valve head to a different spatial dimension at the base of the valve. This dimensional change repositions the seal in a location that is less sensitive to manufacturing variations, as the base structure provides more stable dimensional references. The seal is now positioned in a different spatial zone where tolerance accumulation is minimized

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Ease of operation

If the valve stem is short, then the valve structure is simpler, but the valve cannot be controlled to prevent fluid splash during activation

Engineering Contradiction:
Improvevalve activation controlVSAvoidvalve geometry complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent applies asymmetry by designing a valve stem that is longer than traditional designs, creating an asymmetric valve geometry. This longer stem provides better mechanical leverage and control during valve activation, allowing the valve to open and close more precisely. The asymmetric stem length enables better control of the valve element's movement, preventing fluid splash while maintaining a relatively simple overall structure

Inventive Principle:
Principle #4Asymmetry

Data Source

PatentEP4333962B1Needleless connector having check valve with asymmetric valve design and primary seal support
Publication Date: 2026.03.04 CAREFUSION 303 INC
  • EP4333962B1 patent drawingFigure 1A~1B

AI summary

A needleless connector may include a housing comprising a central longitudinal axis, a body portion, and a base portion. The body portion may include an inner surface forming an internal cavity, and a first port forming a first fluid passage to the internal cavity. The base portion may include a top section including a valve seal support, and a bottom section including a second port forming a second fluid passage to the internal cavity. The needleless connector may further include an asymmetrically-shaped valve disposed in the internal cavity. The asymmetrically-shaped valve may include a head portion, a valve body portion extending distally from the head portion, and a wall having an inner surface forming a valve cavity. The valve may be coupled with the housing such that the inner surface of the valve at the valve body portion is seated and radially supported on the valve seal support.