Catheter Needle Guard with Spring-Loaded Retraction

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Solution Overview

Problem

Existing catheter devices fail to effectively retract and protect the needle after use, leading to potential blood leakage and user inconvenience in managing the needle's position.

Innovation Solution

A catheter device with a valve member that closes the catheter hub after needle removal and can be opened by a syringe or intravenous line insertion, utilizing a spring-loaded needle hub and frictional forces to ensure the needle is safely retracted into a protective position within a tubular receptacle.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the needle is left exposed after catheter insertion, then the catheter hub remains open and blood can emerge, but the needle is easily accessible for immediate use; if the needle is retracted into the receptacle, then the catheter hub is protected from blood leakage, but the needle becomes less accessible

Engineering Contradiction:
Improveprevention of blood leakageVSAvoidaccessibility of needle
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The needle hub is nested within the tubular receptacle, allowing the needle to be retracted into a protective position inside the receptacle while maintaining the ability to be quickly deployed when needed

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The spring is pre-loaded to automatically retract the needle hub into the receptacle immediately after catheter insertion, preventing blood leakage before the user can manually intervene

Inventive Principle:
Principle #10Preliminary action

2Ease of operation

If a locking member is used to hold the needle hub in the distal position, then the needle remains exposed and accessible, but the mechanism becomes more complex; if no locking member is used, then the mechanism is simpler, but the needle cannot be reliably held in the ready position

Engineering Contradiction:
Improvesimplicity of mechanismVSAvoidholding of needle position
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The needle hub transitions from a static locked position to a dynamic spring-loaded position, allowing automatic retraction while maintaining simplicity of structure

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The spring automatically performs the retraction function without requiring a complex locking mechanism, making the system self-actuating and simpler in design

Inventive Principle:
Principle #25Self-service

3Reliability

If the valve member remains closed after needle removal, then blood leakage is prevented, but fluid cannot be administered through the catheter; if the valve member is opened, then fluid administration is enabled, but blood can emerge from the catheter hub

Engineering Contradiction:
Improveprevention of blood leakageVSAvoidfluid administration capability
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The valve member serves multiple functions: it prevents blood leakage when closed and enables fluid administration when opened, allowing the same component to adapt to different operational requirements

Inventive Principle:
Principle #6Universality (Multi-functionality)

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

Prevents blood leakage by automatically closing the catheter hub and ensures safe needle retraction into a protective position, enhancing user safety and convenience during and after catheter use.

Implementation Method 1

a needle hub (11) displaceably guided in the tubular receptacle (8) and held in a ready position by a locking member (12) against the action of a spring (13) which impinges the needle hub (11) in the proximal direction

Methodology Applied
Scientific EffectSpring: Spring

Implementation Method 2

utilizing a spring-loaded needle hub and frictional forces to ensure the needle is safely retracted into a protective position within a tubular receptacle

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP3626292B1Catheter device with needle guard
Publication Date: 2023.03.01 B BRAUN MELSUNGEN AG
  • EP3626292B1 patent drawingFigure 1~3
  • EP3626292B1 patent drawingFigure 4
  • EP3626292B1 patent drawingFigure 5~6

AI summary

Catheter device comprising a catheter hub (2) in which a valve member (7) is disposed, a needle (9) fixed in a needle hub (11), the needle extending through the valve member (7) in the catheter hub in a ready position, and a tubular receptacle (8) in which the needle hub (11) is displaceably guided and biased by a spring (13) in a proximal direction relative to the receptacle (8), wherein the needle hub (11) is releasably held in the ready position in the receptacle (8) against the force of the spring (13).