Catheter Inner Liner Cuts for Flexibility and Strength
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Medical catheters face challenges in navigating tortuous vasculature due to inadequate tensile strength and flexibility, leading to poor navigability and control during procedures, particularly in accessing distal vascular sites.
Innovation Solution
A catheter design featuring a distal section with partial cuts in the inner liner wall, increasing bending flexibility while maintaining tensile strength, combined with a support member and outer jacket, enhances navigability and control by allowing for variable stiffness and improved pushability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the inner liner is made with a single continuous wall structure, then the tensile strength is maintained, but the bending flexibility is insufficient for navigating tortuous vasculature
Solution Approach 1:
The inner liner is segmented through partial cuts that divide the continuous wall into sections while maintaining overall integrity. These cuts create discrete segments that can flex independently, enabling the catheter to navigate tortuous vasculature while the outer jacket and support members maintain tensile strength.
Solution Approach 2:
The partial cuts are applied locally to specific sections of the inner liner rather than uniformly throughout. This allows different regions of the catheter to have different flexibility characteristics, with cut sections providing enhanced bending capability in tortuous vascular regions while maintaining strength in other areas.
2Ease of operation
If partial cuts are made in the inner liner wall, then the bending flexibility is improved, but the tensile strength may be compromised
Solution Approach 1:
Instead of making complete cuts through the inner liner wall, partial cuts are implemented that extend only a portion of the way through the wall thickness. This partial action provides sufficient flexibility improvement while retaining enough material continuity to maintain adequate tensile strength.
Solution Approach 2:
The catheter employs a composite structure where the inner liner with partial cuts is combined with an outer jacket and support members. This composite construction allows the inner liner to provide flexibility through its cut structure while the outer jacket and reinforcement elements compensate for any tensile strength reduction.
3Reliability
If the catheter is designed with high structural integrity, then the reliability is improved, but the navigability through constricting vessels is reduced
Solution Approach 1:
The catheter design allows dynamic adaptation of its mechanical properties through the partial cuts in the inner liner. The cut sections enable the catheter to dynamically flex and conform to constricting vessel geometries while the outer jacket and support members maintain overall structural integrity and reliability.
Solution Approach 2:
The inner liner with partial cuts functions as a flexible shell that can adapt to complex vascular geometries. The partial cuts create a structure that is flexible enough to navigate constricting vessels while the multi-layer construction maintains the necessary structural integrity for reliable operation.
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
A catheter (10) including a catheter body (12) including an outer jacket (24) and an inner liner (18). The inner liner may include a proximal section (18A) including a proximal end of the inner liner and a distal section (18B) including a distal end of the inner liner. The distal section may include an inner liner defining a plurality of cuts (20). Each cut may extend at least partially through the liner wall. The one or more cuts defined in the liner wall of the distal section of the inner liner may increase a bending flexibility of the distal section relative to the proximal section of the inner liner, while maintaining a suitable tensile strength of the distal section.