Segmented Tissue-Removing Catheter Blade for Vessel Safety
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Solution Overview
Problem
Current tissue-removing catheters face challenges in effectively cutting and removing plaque and other occlusive materials from blood vessels and other body lumens, particularly in maintaining patency and efficiently handling both hard and soft tissues.
Innovation Solution
The tissue-removing catheter features a tissue-removing element with a cutting blade and cutting teeth radially inward of the blade, integrated with a drive shaft for rotation, which includes primary and secondary tissue-removing components with specific geometries such as rake angles, relief angles, and inner shearing members to engage and remove tissue efficiently.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a cutting blade is used to remove tissue, then tissue removal effectiveness is improved, but the risk of vessel rupture increases
Solution Approach 1:
The cutting blade is segmented into multiple discrete cutting teeth arranged circumferentially around the catheter axis. Each cutting tooth acts as an independent cutting element, distributing the cutting forces across multiple points rather than concentrating them at a single location. This segmentation allows effective tissue removal while reducing the risk of vessel rupture by preventing excessive force concentration.
Solution Approach 2:
The cutting teeth are designed with specific local geometric properties including rake angles, relief angles, and tooth profiles optimized for cutting tissue. Each cutting tooth has a leading edge geometry tailored for shearing tissue fibers, while the spacing and distribution of teeth provide varying local cutting actions across the tissue cross-section, improving effectiveness while controlling harmful forces.
2Productivity
If cutting teeth are positioned radially inward of the cutting blade, then tissue removal efficiency is improved, but device complexity increases
Solution Approach 1:
The cutting structure is divided into two radial zones: an outer cutting blade with cutting teeth and an inner set of cutting teeth positioned radially inward. This segmentation creates a multi-layered cutting approach where outer teeth engage tissue first, followed by inner teeth, improving removal efficiency through staged cutting action while maintaining a relatively simple overall structure.
Solution Approach 2:
The cutting elements are arranged in multiple radial dimensions rather than a single plane. By positioning cutting teeth both on the outer blade and radially inward, the design adds a radial dimension to the cutting arrangement, enabling three-dimensional tissue engagement that improves efficiency without significantly increasing structural complexity.
Data Source
AI summary
A tissue-removing catheter includes a tissue-removing element operatively connected to a drive shaft for rotation of the tissue-removing element about an axis of rotation in a cutting direction. In some embodiments, the tissue removing element has a cutting blade and cutting teeth positioned radially inward of the cutting blade with respect to the axis of rotation. The cutting blade and cutting teeth are fixed with respect to one another to form first and second cuts in tissue as the tissue-removing element rotates. In certain embodiments, the tissue-removing element includes a cutting blade and raised elements spaced apart inward of the cutting blade relative to the axis of rotation to define an annular tissue-receiving channel between the cutting blade and the raised elements. A bottom surface of the channel can define cutting teeth.