Variable Braid Angle Dilator Shaft for Lesion Access
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Solution Overview
Problem
Anatomic constraints often hinder the advancement of endovascular treatment devices to reach and treat lesions, particularly chronic total occlusions, which limits the effectiveness of current endovascular therapies.
Innovation Solution
A dilator shaft with a braided section featuring braid threads woven at varying angles to provide adjustable flexibility and stiffness, allowing for improved steerability and pushability, enabling better access and treatment of lesions, including both soft and hard CTO caps.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a braid-reinforced dilator shaft is used to provide sufficient stiffness for penetrating lesions, then the dilator shaft gains penetration capability, but the steerability and pushability are compromised
Solution Approach 1:
The braid angle is varied along the longitudinal axis of the dilator shaft, with different sections having different braid angles to provide locally optimized properties. The proximal section has a smaller braid angle for higher stiffness and pushability, while the distal section has a larger braid angle for better steerability and flexibility, resolving the contradiction between overall stiffness and local steerability requirements
2Force
If a braid-reinforced dilator shaft is used to ensure sufficient stiffness for force transmission, then penetration capability is improved, but the flexibility and steerability are reduced
Solution Approach 1:
Different sections of the dilator shaft are designed with different braid angles to provide locally optimized properties. The proximal section uses a smaller braid angle to maximize force transmission and pushability, while the distal section uses a larger braid angle to maintain flexibility and steerability, allowing the shaft to transmit force effectively while remaining steerable
3Ease of manufacture
If the braid threads are woven at a constant angle to simplify manufacturing, then production is easier, but the ability to provide variable flexibility and stiffness along the shaft is limited
Solution Approach 1:
The braid angle is varied along the longitudinal axis of the dilator shaft, with different sections having different braid angles to provide locally optimized properties. This allows the shaft to have variable flexibility and stiffness along its length, enabling both effective penetration and steerable navigation, while the manufacturing process remains relatively simple by using continuous braiding with varying parameters
Data Source
AI summary
A dilator for an endovascular treatment of a lesion within a patient includes a dilator shaft extending along a longitudinal axis (L), the dilator shaft having a braid including an arrangement of braid threads woven to form the braid. A first group of the braid threads and a second group of the braid threads are woven with one another and are arranged to cross one another at an angle (α, β) therebetween. At a first axial location of the dilator shaft the first group of the braid threads and the second group of the braid threads are arranged to cross one another at a first angle therebetween, and at a second axial location of the dilator shaft the first group of the braid threads and the second group of the braid threads are arranged to cross one another at a second angle therebetween different than the first angle.