Balloon Catheter Retractable Sheath Locking Mechanism

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Solution Overview

Problem

Balloon catheters used in surgical procedures face challenges with variable length adjustments and premature drug coating activation due to internal pressure and exposure to intravascular fluids, requiring a solution for precise length control and protection of the medicated coating.

Innovation Solution

A balloon catheter with a retractable sheath and locking mechanism for adjustable length, combined with a mechanical stop to prevent balloon escape and a watertight seal to maintain the drug coating until the treatment site, along with recapture elements for efficient repacking and redeployment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Length of moving object

If a balloon catheter is made too long to cover the treatment area, then the treatment coverage is improved, but the risk of damaging surrounding tissue increases

Engineering Contradiction:
Improveballoon lengthVSAvoidtissue damage risk
Core Design Contradiction:
Length of moving objectVSObject-affected harmful factors

Solution Approach 1:

The balloon catheter employs a retractable sheath mechanism that allows dynamic adjustment of the exposed balloon length. The sheath can be retracted to expose different portions of the balloon, enabling the operator to precisely control the length of the balloon that is deployed into the blood vessel, thus matching the treatment area exactly without risking damage to surrounding tissues from excessive length.

Inventive Principle:
Principle #15Dynamics

2Object-affected harmful factors

If a balloon catheter is made too short to match the treatment area, then the risk of tissue damage is reduced, but the treatment effectiveness decreases

Engineering Contradiction:
Improvetissue damage riskVSAvoidtreatment effectiveness
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The retractable sheath allows the operator to extend the balloon length as needed to match the treatment area, ensuring complete coverage for effective treatment. The dynamic adjustment capability ensures that the balloon can be made long enough to treat the entire blockage or affected region, maintaining treatment effectiveness while avoiding the need to use a permanently long balloon that would risk tissue damage.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The balloon is designed as a continuous structure that can be selectively exposed in segments through the retractable sheath. This segmentation allows the operator to expose only the necessary portion of the balloon corresponding to the treatment area, ensuring adequate coverage for effective treatment while minimizing exposure beyond the treatment zone to prevent tissue damage.

Inventive Principle:
Principle #1Segmentation

3Measurement precision

If multiple sized balloon catheters are stocked to match different treatment areas, then treatment precision is improved, but device complexity and inventory management increases

Engineering Contradiction:
Improvetreatment area matching precisionVSAvoidinventory complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The balloon catheter with a retractable sheath serves multiple functions: it can be configured to match different treatment areas by adjusting the sheath retraction distance, replacing the need for multiple fixed-size balloons. A single catheter device can accommodate various treatment scenarios from small to large vessels and different blockage lengths, simplifying inventory while maintaining precise treatment area matching capability.

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

4Reliability

If the balloon is exposed to intravascular fluids before reaching the treatment zone, then the drug coating is activated prematurely, but the treatment effectiveness at the target site is reduced

Engineering Contradiction:
Improvedrug delivery effectivenessVSAvoiddrug activation timing
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The retractable sheath acts as an intermediary protective barrier between the drug-coated balloon and the intravascular fluids. The sheath remains in place during navigation through the vascular system, preventing premature contact between the drug coating and blood. The sheath is retracted only when the balloon reaches the treatment zone, ensuring the drug is activated and delivered at the correct location and time, preventing both premature activation and ensuring treatment effectiveness.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP3290080B1Balloon catheter having a retractable sheath and locking mechanism with balloon recapture element
Publication Date: 2019.10.09 PIGOTT JOHN P
  • EP3290080B1 patent drawingFigure 1
  • EP3290080B1 patent drawingFigure 2
  • EP3290080B1 patent drawingFigure 3

AI summary

An intravascular balloon catheter device is disclosed having an inner member, an outer member disposed about the inner member and further comprising a balloon. A sheath is disposed about the outer member that moves relative to the balloon so as to selectively expose some or all of the balloon for inflation. A clamp may be used to selectively secure the sheath at a desired position relative to the balloon. A balloon recapture element may permit incremental adjustment to the balloon length and facilitate balloon recapture.