Tissue-Removing Catheter with Variable Stiffness Drive Member

Solution Overview

Problem

Existing tissue-removing catheters face challenges in effectively navigating through curved paths and obstructions within body lumens while maintaining sufficient pushability and tissue removal efficiency.

Innovation Solution

The catheter design incorporates an elongate drive member with first and second longitudinal portions of varying stiffness, where the first portion is stiffer for pushability and the second portion is more flexible for navigation, coupled with a rotatable tissue-removing element for efficient tissue removal.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If the drive member is made uniformly stiff throughout its length, then pushability is improved, but the ability to navigate through curved paths and obstructions deteriorates

Engineering Contradiction:

ImprovepushabilityVSAvoidnavigation capability

Core Design Contradiction:

ForceVSAdaptability or versatility

Solution Approach 1:

The drive member is divided into multiple sections with different stiffness characteristics. The proximal section has higher stiffness to provide pushability, while the distal section has lower stiffness to enable navigation through curved paths. This segmentation allows each portion to perform its specialized function optimally.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different portions of the drive member are assigned different mechanical properties (stiffness) according to their specific functional requirements. The proximal portion is made stiffer for force transmission, while the distal portion is made more flexible for navigation, creating local quality variations along the drive member's length.

Inventive Principle:

Principle #3Local quality

2Adaptability or versatility

If the drive member is made uniformly flexible throughout its length, then the ability to navigate through curved paths and obstructions is improved, but pushability deteriorates

Engineering Contradiction:

Improvenavigation capabilityVSAvoidpushability

Core Design Contradiction:

Adaptability or versatilityVSForce

Solution Approach 1:

The drive member is divided into multiple sections with different stiffness characteristics. The proximal section has higher stiffness to provide pushability, while the distal section has lower stiffness to enable navigation through curved paths. This segmentation allows each portion to perform its specialized function optimally.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different portions of the drive member are assigned different mechanical properties (stiffness) according to their specific functional requirements. The proximal portion is made stiffer for force transmission, while the distal portion is made more flexible for navigation, creating local quality variations along the drive member's length.

Inventive Principle:

Principle #3Local quality

3Device complexity

If a single stiffness design is used for the drive member, then device complexity is reduced, but the ability to simultaneously achieve pushability and trackability deteriorates

Engineering Contradiction:

Improvedrive member structureVSAvoidoverall performance

Core Design Contradiction:

Device complexityVSAdaptability or versatility

Solution Approach 1:

The drive member is divided into multiple sections with different stiffness characteristics. The proximal section has higher stiffness to provide pushability, while the distal section has lower stiffness to enable navigation through curved paths. This segmentation allows each portion to perform its specialized function optimally.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different portions of the drive member are assigned different mechanical properties (stiffness) according to their specific functional requirements. The proximal portion is made stiffer for force transmission, while the distal portion is made more flexible for navigation, creating local quality variations along the drive member's length.

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS20250040955A1Tissue-Removing Catheter with Flexible and Stiff Portions

Publication Date: 2025.02.06 MEDTRONIC VASCULAR INC

AI summary

The present disclosure provides a tissue-removing catheter for removing tissue in a body lumen. The tissue-removing catheter includes an elongate drive member and a tissue-removing element. The elongate drive member has proximal and distal ends with a length and a longitudinal axis extending between the proximal and distal ends. The elongate drive member is sized and shaped to be received in the body lumen and rotates about its longitudinal axis. The elongate drive member further includes first and second longitudinal portions. The first longitudinal portion is proximal to and stiffer than the second longitudinal portion. The tissue-removing element is operatively coupled to the distal end of the elongate drive member and rotates by the elongate drive member to remove the tissue in the body lumen.