Coupled Inner Liner Catheter for Guidewire Isolation

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Solution Overview

Problem

Existing tissue-removing catheters face challenges in effectively isolating the guidewire from the rotating components, leading to potential damage and inefficiencies in tissue removal processes.

Innovation Solution

A tissue-removing catheter design featuring an inner liner with a coupling assembly, including a bushing and bearings, that isolates the guidewire from the drive coil and tissue-removing element, allowing for the guidewire to remain stationary while the rotating components operate, thereby reducing friction and protecting the guidewire from damage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the guidewire is directly exposed to the rotating tissue-removing element, then the catheter structure is simpler, but the guidewire suffers from friction and potential damage

Engineering Contradiction:

Improvecatheter structureVSAvoidfriction and damage to guidewire

Core Design Contradiction:

Device complexityVSObject-affected harmful factors

Solution Approach 1:

The patent introduces an inner liner as an intermediary component between the guidewire and the rotating tissue-removing element. The inner liner receives the guidewire and isolates it from the rotating components, thereby eliminating direct contact and the associated friction and damage while maintaining a relatively simple overall catheter structure

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The catheter is segmented into distinct functional components: the inner liner that protects the guidewire, the drive coil that provides rotational force, and the tissue-removing element that performs the actual tissue removal. This segmentation allows each component to perform its specific function independently, with the inner liner specifically tasked with protecting the guidewire from harmful contact

Inventive Principle:

Principle #1Segmentation

2Strength

If the inner liner is directly coupled to the tissue-removing element, then the coupling is stronger, but the guidewire lumens may be damaged due to contact with rotating components

Engineering Contradiction:

Improvecoupling strengthVSAvoiddamage to guidewire lumens

Core Design Contradiction:

StrengthVSObject-affected harmful factors

Solution Approach 1:

The patent employs a coupling assembly as an intermediary mechanism between the inner liner and the tissue-removing element. This coupling assembly includes a bushing and bearing arrangement that provides strong mechanical coupling while maintaining isolation between the inner liner and the rotating tissue-removing element, preventing damage to the guidewire lumens

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The coupling assembly extracts the harmful rotational contact from the inner liner-guidewire interface. By using the bushing and bearing arrangement, the patent separates the rotational motion of the tissue-removing element from the stationary inner liner, allowing the inner liner to remain strongly coupled to the tissue-removing element while protecting the guidewire from rotational damage

Inventive Principle:

Principle #2Taking out (Extraction)

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

The design ensures the guidewire remains stable and undamaged, facilitating efficient tissue removal with reduced friction and heat generation, enhancing the catheter's operational reliability and effectiveness.

Implementation Method 1

The exterior surface of the bushing contacts the interior surface of the bearing along less than 50% of an internal surface area of the interior surface of the bearing

Methodology Applied

Scientific EffectFriction: Friction

Data Source

PatentUS12544099B2Tissue-removing catheter with coupled inner liner

Publication Date: 2026.02.10 MEDTRONIC VASCULAR INC

AI summary

The present disclosure provides a tissue-removing catheter that includes an elongate body with proximal and distal end portions, a tissue-removing element, an inner liner, and a coupling assembly. The tissue-removing element removes tissue by rotation from the elongate body. The inner liner defines a guidewire lumen received within the elongate body and is coupled to the tissue-removing element at its distal end portion. The coupling assembly includes a bushing attached to the distal end portion of the inner liner and a bearing disposed around the bushing with an exterior surface of the bushing contacting an interior surface of the bearing along less than 50% of an internal surface area of the interior surface of the bearing. At least one of the exterior surface of the bushing and the interior surface of the bearing may define a non-uniform dimension extending along a length of one of the bushing and bearing.