Catheter Movable Flap Occludes Perforations

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Solution Overview

Problem

Current catheters for cerebrospinal fluid drainage often experience blockages due to brain tissue ingression during insertion and removal, leading to increased risk of infection and high replacement costs, as they fail to effectively seal perforations and cause tissue damage.

Innovation Solution

A catheter design featuring a planar exterior surface with movable, foldable flaps that occlude perforations during insertion and removal, preventing brain tissue ingression and maintaining fluid communication when stationary, manufactured using methods like moulding or 3D printing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional catheters with fixed perforations are used for CSF drainage, then fluid communication is maintained, but brain tissue ingresses through perforations during insertion and removal causing blockages

Engineering Contradiction:
Improveshunt blockage preventionVSAvoidbrain tissue ingression
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The catheter employs dynamic flaps that can move between open and closed positions. During insertion and removal, the flaps close to prevent tissue ingression. During normal operation, the flaps remain open to allow CSF drainage. This dynamic behavior resolves the contradiction between maintaining fluid communication and preventing tissue blockage.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The flaps are positioned to close before tissue encounters the perforations during insertion. This preliminary closing action prevents tissue from entering the catheter lumen before the catheter is fully inserted, thereby preventing blockages while maintaining open perforations for drainage when stationary.

Inventive Principle:
Principle #10Preliminary action

2Object-affected harmful factors

If catheters without protective mechanisms are used, then insertion is simpler, but tissue damage and 'cheese grater' effect occur during insertion and removal

Engineering Contradiction:
Improvetissue damageVSAvoidcatheter structure
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The catheter uses flexible flap structures that can deform and move to cover the perforations during insertion and removal. These thin film elements provide protective coverage without significantly increasing the catheter's overall size or complexity, while effectively preventing tissue damage and cheese grater effect.

Inventive Principle:
Principle #30Flexible shells and thin films

3Reliability

If perforations remain open during insertion, then fluid communication is maintained, but tissue blocks the perforations causing shunt failure

Engineering Contradiction:
Improveshunt functionalityVSAvoiddrainage efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The flaps dynamically adjust their position based on catheter movement. When the catheter is stationary and functioning, the flaps are open to maintain drainage efficiency. During insertion and removal, the flaps close to prevent tissue blockage, ensuring shunt functionality is preserved for future use.

Inventive Principle:
Principle #15Dynamics

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

Significantly reduces shunt blockages and tissue damage by preventing the 'cheese grater' effect, ensuring efficient drainage and minimizing the need for costly replacements while enhancing patient safety.

Implementation Method 1

a movable covering operatively connected to the body to occlude said perforation in response to relative movement between the catheter and tissue during insertion into and withdrawal from said tissue

Methodology Applied
Scientific EffectMechanical movement:

Implementation Method 2

a catheter for removing cerebrospinal fluid from the brain, the catheter comprising an elongate body having an internal lumen

Methodology Applied
Scientific EffectFluid flow:

Data Source

PatentEP3576827B1Medical insert
Publication Date: 2022.09.14 KOEFMAN ALEXANDER
  • EP3576827B1 patent drawingFigure 1(a)~1(c)
  • EP3576827B1 patent drawingFigure 2(a)~2(c)
  • EP3576827B1 patent drawingFigure 3(a)~4(b)

AI summary

The invention provides a catheter comprising an elongate body having an exterior surface with a substantially planar portion, a perforation that extends through the planar exterior surface to an internal lumen, providing fluid communication between the lumen and said surface, and a movable covering to occlude the perforation when the catheter body is moved relative to brain tissue during insertion and withdrawal from said tissue. The invention extends to a method of removing excess cerebrospinal fluid from a patient through use of the catheter. The coverings fold according to the direction of movement to cover an adjacent trailing perforation against ingress of tissue fragments.