Soft-Tip Urinary Catheter for Reduced Insertion Force

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Solution Overview

Problem

The insertion of urinary catheters into the urethra, particularly for male users, is often cumbersome and risky due to the catheter's length, curvature, and the need to navigate through obstructed areas, which can lead to injury.

Innovation Solution

A urinary catheter with a conically tapering tip that has an outer diameter equal to or lower than the tubular shaft, and a hardness of 60 micro Shore A or lower, allowing for easy insertion and reduced risk of kinking or injury.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Length of moving object

If the catheter is made longer to reach the bladder in male users, then the catheter can extend through the whole length of the urethra, but the insertion becomes more cumbersome and risky

Engineering Contradiction:
Improvecatheter lengthVSAvoidinsertion ease
Core Design Contradiction:
Length of moving objectVSEase of operation

Solution Approach 1:

The catheter is divided into distinct segments with different properties: a long tubular shaft for reaching the bladder and a separate soft tip portion for safe insertion. This segmentation allows the shaft to maintain sufficient length while the tip provides ease of insertion by conforming to urethral contours.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different parts of the catheter have different hardness properties. The tip portion has a hardness of 60 micro Shore A or lower to provide softness and conformability during insertion, while the main shaft maintains higher structural integrity. This local differentiation resolves the contradiction between length and insertion ease.

Inventive Principle:
Principle #3Local quality

2Strength

If the catheter tip is made harder to maintain structural integrity, then the catheter can resist kinking, but the risk of injury during insertion increases

Engineering Contradiction:
Improvekink resistanceVSAvoidinjury risk
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

The catheter employs local quality differentiation by making only the tip portion soft (60 micro Shore A or lower) while the main shaft retains adequate structural strength. This localized softness reduces injury risk during insertion without compromising overall kink resistance of the catheter.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The catheter is segmented into a soft tip portion and a stronger shaft. The tip portion specifically addresses the injury risk concern with its softened material, while the shaft maintains kink resistance through its structural design and material properties.

Inventive Principle:
Principle #1Segmentation

3Ease of operation

If the catheter tip outer diameter is reduced to facilitate insertion, then the catheter can pass through obstructed areas more easily, but the tip becomes more prone to kinking

Engineering Contradiction:
Improveinsertion easeVSAvoidkink resistance
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The tip portion is given local quality characteristics with reduced outer diameter and softened material (60 micro Shore A or lower) to facilitate passage through obstructed areas. The main shaft maintains sufficient diameter and structural integrity to prevent kinking, resolving the contradiction between insertion ease and reliability.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP3744381B2Urinary catheter having a soft tip
Publication Date: 2025.02.19 DENTSPLY IH AB
  • EP3744381B2 patent drawingFigure 1
  • EP3744381B2 patent drawingFigure 2~4c
  • EP3744381B2 patent drawingFigure 4d~4f

AI summary

A urinary catheter is disclosed, comprising a tubular shaft extending between an insertable end and a discharge end, and a tip fixedly connected to said insertable end of the tubular shaft. The tip has an outer diameter which at all places is equal to or lower than the outer diameter of the tubular shaft, and is very soft, so that the hardness of the tip is equal to or lower than 60 micro Shore A. It has been found that such a soft tip provides a catheter which is easier to insert into the urethra, in particular in urethras providing various types of obstacles. A corresponding method of manufacturing is also disclosed.