Hypotube Catheter Flexibility Enhancing Features
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Solution Overview
Problem
Standard angiography catheters often fail under high pressures during procedures due to their limited pressure ratings, and microcatheters have restricted lengths and flexibility due to their thin walls and small diameters, making them unsuitable for navigating complex vasculature effectively.
Innovation Solution
A catheter design incorporating a hypotube with flexibility-enhancing features such as circumferential or helical cuts, combined with a liner to control fluid flow and maintain structural integrity, allowing for increased flexibility and pressure resistance while maintaining pushability and trackability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If standard angiography catheters are used, then they can withstand normal operating pressures, but they fail under high pressures exceeding 1,050-1,200 psi
Solution Approach 1:
The patent changes the material parameter from thermoplastic to metal hypotube, which fundamentally alters the pressure resistance capability. The hypotube construction with flexibility-enhancing features maintains flexibility while achieving pressure ratings exceeding 5,000 psi, resolving the contradiction between pressure resistance and reliability.
2Length of moving object
If microcatheters have thin walls and small diameters for navigation, then they can access tiny vessels, but their length is limited to about 150 cm
Solution Approach 1:
The patent applies flexibility-enhancing features to the hypotube including circumferential cuts, helical cuts, longitudinal slots, and undulating patterns. These features create controlled flexibility that maintains pushability and trackability while enabling catheter lengths exceeding 150 cm, resolving the contradiction between length and ease of operation.
3Ease of operation
If microcatheters are tapered to provide pushability and trackability, then they can navigate vessels, but their wall thickness and outer diameter are not uniform
Solution Approach 1:
The patent implements local quality by placing flexibility-enhancing features at specific locations along the catheter length. The cuts and slots are strategically positioned to provide flexibility where needed while maintaining uniform wall thickness and geometry in other regions, resolving the contradiction between ease of operation and shape uniformity.
4Ease of operation
If stainless steel hypotubes are used, then they enhance glide ability, but they kink when forced through tortuous paths
Solution Approach 1:
The patent applies dynamics by making the hypotube structure adaptable to applied forces. The flexibility-enhancing features allow the tube to dynamically adjust its shape in response to bending forces, preventing kink formation while maintaining glide ability through tortuous paths.
5Stability of the object's composition
If nitinol hypotubes are used, then they are kink-resistant, but they are much more expensive to manufacture
Solution Approach 1:
The patent changes the material parameter from expensive nitinol to more economical stainless steel or other metals, while compensating for kink resistance through structural modifications. The flexibility-enhancing features and wall geometry are optimized to achieve kink resistance at lower material cost, resolving the contradiction between kink resistance and ease of manufacture.
Data Source
AI summary
A catheter includes a hypotube and a liner. The hypotube may extend substantially along a length of the catheter. The liner may extend along a majority of a length of the hypotube, and may extend along substantially an entirety of the length of the hypotube. The hypotube includes flexibility enhancing features along its length. In addition, the hypotube may include one or more operational features, which may enable various procedures to be performed with the catheter. The liner may be positioned adjacent to an interior surface of a wall of the hypotube, or it may be positioned adjacent to an exterior surface of the wall of the hypotube. Any operational features of the hypotube may be exposed through or beyond a longitudinal extent of the liner or a portion thereof. Methods for manufacturing catheters that include hypotubes and liners are also disclosed.