Sterile Sheath Catheter Structure for Low-Shear Insertion

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Solution Overview

Problem

Current self-catheterization devices fail to maintain sterility, protect against bacterial introduction, and reduce shear stress, leading to increased urinary tract infections and high healthcare costs.

Innovation Solution

A device with a flexible, sterile sheath that deploys around the catheter tip during insertion, covering the outer surface and preventing contamination while minimizing tissue damage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If a protective bag or sheath is positioned around the catheter device, then contamination from external sources is reduced, but bacteria present at the urethral opening can still be dragged into the bladder and the device does not protect against tissue damage from shear stress

Engineering Contradiction:

Improvecontamination from external sourcesVSAvoidprotection against bacterial introduction

Core Design Contradiction:

Object-affected harmful factorsVSReliability

Solution Approach 1:

The catheter device is pre-configured with a sterile protective membrane positioned at the tip before insertion. This preliminary arrangement ensures that the sterile barrier is already in place to prevent bacterial introduction from the urethral opening, addressing the limitation of external sheaths that do not protect against drag-induced contamination

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

A flexible sterile protective membrane is used to cover the catheter tip and outer surface. This thin film maintains sterility while allowing the catheter to flex and move during insertion, reducing shear stress on urethral tissue compared to rigid protective sheaths

Inventive Principle:

Principle #30Flexible shells and thin films

2Object-affected harmful factors

If a protective membrane is deployed from the catheter tip during insertion, then contamination protection is improved, but the device allows accidental removal of the membrane exposing tissues to contaminants

Engineering Contradiction:

Improvecontamination protectionVSAvoidmaintainment of sterility

Core Design Contradiction:

Object-affected harmful factorsVSReliability

Solution Approach 1:

The protective membrane is designed with dynamic retention features that adapt during insertion. The membrane remains securely attached during the insertion process but can be intentionally removed after catheterization is complete, preventing accidental exposure while allowing controlled access when needed

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

An intermediary retention mechanism is introduced between the membrane and catheter body. This intermediate structure ensures the membrane stays in place during insertion without requiring direct attachment that could lead to accidental detachment, maintaining sterility throughout the procedure

Inventive Principle:

Principle #24Intermediary (Mediator)

3Device complexity

If the catheter is inserted directly without additional protective structures, then device complexity is reduced, but shear stress from insertion causes tissue damage along the inner surface of the urethra

Engineering Contradiction:

Improvedevice structureVSAvoidtissue damage from shear stress

Core Design Contradiction:

Device complexityVSObject-affected harmful factors

Solution Approach 1:

A flexible protective membrane is applied to the catheter tip and shaft. This thin film reduces friction and shear stress during insertion by providing a smooth, low-resistance surface that glides through the urethra, protecting tissue without adding complex mechanical structures

Inventive Principle:

Principle #30Flexible shells and thin films

Solution Approach 2:

The protective structure is segmented into distinct zones: a sterile membrane at the tip for contamination prevention, and an extended protective portion along the shaft for tissue protection during insertion. This segmentation allows each zone to perform its specific function while keeping the overall device structure simple

Inventive Principle:

Principle #1Segmentation

Data Source

PatentUS12605524B2Device for clean catheterization

Publication Date: 2026.04.21 GILBERT CATHERINE

AI summary

A device for catheterization is disclosed. Such a device includes a hollow catheter, a cylindrical sheath, and a flange through which the catheter passes. Before insertion, the sheath begins at a first opening near the catheter tip and extends into the catheter to a first circumferential fold, then back towards the catheter tip to a second circumferential fold about the tip to the exterior surface, and ends at a second opening attached to the flange. As the device is inserted up to a length, the flange abuts the cavity opening, and a corresponding length of the sheath deploys from the catheter interior, around the first and second circumferential folds, to the catheter outer surface. Once fully inserted, all, or a substantial portion, of the sheath initially positioned within the catheter has been deployed to the outer surface, thereby forming a protective barrier between the catheter and the surrounding tissues.