Resilient Catheter Snare Control for IMD Retrieval

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Solution Overview

Problem

Current medical retrieval systems face challenges in efficiently retrieving implantable medical devices (IMDs) due to limited directional control and manipulation in three-dimensional spaces, leading to increased retrieval time and difficulty in navigating smaller spaces.

Innovation Solution

The system incorporates an elongate outer tubular member with a longitudinally extending lumen and a retrieval assembly featuring a fixed-curve catheter, which is controllable between a straight and curved configuration, allowing for enhanced steering and orientation of the snare to improve IMD retrieval.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a straight catheter is used for retrieval, then the device structure is simple, but the control over snare orientation in three-dimensional spaces is limited

Engineering Contradiction:
Improvecontrol over snare orientationVSAvoidcatheter structure
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The catheter incorporates a resizable curve section that can dynamically change its curvature between expanded and contracted states. This allows the catheter to adapt its shape based on operational needs, providing enhanced directional control when the curve is expanded, while maintaining a compact profile when contracted. The dynamic transformation resolves the contradiction by enabling complex three-dimensional maneuvering capability without permanently increasing structural complexity.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The introduction of a curved section in the catheter allows it to navigate and control orientation in three-dimensional spaces more effectively. The curve section can be expanded to provide bending capability for steering the snare, and contracted to maintain a straight profile when not needed. This curvature mechanism directly addresses the limitation of straight catheters in providing multi-directional control.

Inventive Principle:
Principle #14Spheroidality (Curvature)

2Ease of operation

If the distal curve is always extended for better orientation control, then the control precision is improved, but the retrieval time increases

Engineering Contradiction:
Improveorientation control precisionVSAvoidretrieval time
Core Design Contradiction:
Ease of operationVSLoss of time

Solution Approach 1:

The resizable curve section can be rapidly transformed between expanded and contracted states based on the immediate operational requirements. When precise orientation control is needed during snare engagement, the curve is expanded. When navigation is straightforward or during retrieval extraction, the curve is contracted to streamline the catheter profile and facilitate faster movement. This dynamic adaptation eliminates the need to maintain the expanded curve state throughout the entire procedure, thereby reducing total retrieval time while preserving control precision when needed.

Inventive Principle:
Principle #15Dynamics

3Ease of operation

If a fixed-curve catheter is used, then the directional control is improved, but the adaptability to different anatomical locations is reduced

Engineering Contradiction:
Improvedirectional controlVSAvoidadaptability to anatomical locations
Core Design Contradiction:
Ease of operationVSAdaptability or versatility

Solution Approach 1:

The resizable curve section allows the catheter to dynamically adapt its configuration to match different anatomical pathways. By expanding the curve in specific directions, the catheter can navigate complex vascular or tissue geometries. By contracting the curve, it can be advanced through straighter pathways or withdrawn after use. This dynamic reconfigurability provides both directional control and adaptability to various anatomical locations, resolving the contradiction between fixed geometry and versatility.

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

This configuration reduces retrieval time by providing greater control over the snare in three-dimensional spaces, facilitating easier engagement and extraction of IMDs, even in complex anatomical locations.

Implementation Method 1

The fixed-curve catheter may include a resilient material forming a distal curve relative to a longitudinal axis of the fixed-curve catheter

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3863534B1Medical device retrieval tool with adjustable curve
Publication Date: 2024.03.13 MEDTRONIC INC
  • EP3863534B1 patent drawingFigure 1
  • EP3863534B1 patent drawingFigure 2
  • EP3863534B1 patent drawingFigure 3

AI summary

An example implantable medical device (IMD) retrieval system may include an elongate outer tubular member including a longitudinally extending lumen terminating in a distal cup that is configured to receive the IMD; and a retrieval assembly including a retrieval member that includes an elongate member terminating in at least one snare that is moveable between an expanded configuration and a contracted configuration; and a fixed-curve catheter that includes a resilient material forming a distal curve and defining a lumen in which the retrieval member extends in sliding engagement, where the fixed-curve catheter extends in sliding engagement within the lumen of the elongate outer tubular member.