Catheter With Selectively Variable Flexibility
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Solution Overview
Problem
Catheters often face challenges in having a flexibility that is suitable for navigation through bodily passageways but not for delivering medical devices, or vice versa, due to their rigidity or stiffness.
Innovation Solution
A catheter design featuring an elongate tubular outer and inner member with a movable tubular braid of filaments in an annular cavity, where the braid's position is changed by applying vacuum or pressure to vary flexibility between two configurations, allowing for navigation and medical device delivery.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the catheter is made flexible to navigate through bodily passageways, then navigation is enabled, but the catheter becomes too flexible for reliable medical device delivery
Solution Approach 1:
The catheter employs a dynamic reconfigurable braid structure that can transition between a first configuration (more rigid) for device delivery and a second configuration (more flexible) for navigation. The braid's filaments can be repositioned relative to the inner and outer members to change the catheter's overall flexibility, allowing it to adapt to different operational requirements.
Solution Approach 2:
The catheter changes its mechanical parameter (flexibility) by reconfiguring the braid structure. By applying vacuum or pressure to the annular cavity, the braid filaments are moved to different positions, changing the catheter's rigidity parameter from a first value (suitable for delivery) to a second value (suitable for navigation).
2Reliability
If the catheter is made rigid for medical device delivery, then device delivery reliability is improved, but the catheter becomes too rigid for navigation through bodily passageways
Solution Approach 1:
The catheter employs a dynamic reconfigurable braid structure that can transition between a first configuration (more rigid) for device delivery and a second configuration (more flexible) for navigation. The braid's filaments can be repositioned relative to the inner and outer members to change the catheter's overall flexibility, allowing it to adapt to different operational requirements.
Solution Approach 2:
The catheter changes its mechanical parameter (flexibility) by reconfiguring the braid structure. By applying vacuum or pressure to the annular cavity, the braid filaments are moved to different positions, changing the catheter's rigidity parameter from a first value (suitable for delivery) to a second value (suitable for navigation).
3Stability of the object's composition
If the braid filaments are fixed to provide stable structure, then structural stability is improved, but the catheter cannot adapt flexibility for different procedures
Solution Approach 1:
The catheter employs a dynamic reconfigurable braid structure that can transition between a first configuration (more rigid) for device delivery and a second configuration (more flexible) for navigation. The braid's filaments can be repositioned relative to the inner and outer members to change the catheter's overall flexibility, allowing it to adapt to different operational requirements.
Solution Approach 2:
The catheter changes its mechanical parameter (flexibility) by reconfiguring the braid structure. By applying vacuum or pressure to the annular cavity, the braid filaments are moved to different positions, changing the catheter's rigidity parameter from a first value (suitable for delivery) to a second value (suitable for navigation).
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
Enables selective variation of flexibility to suit both navigation through bodily passages and delivery of medical devices, reducing the risk of foreign substance release and trauma from potential leaks or stress failures.
Implementation Method 1
a vacuum source for applying a vacuum to the cavity sufficient to cause the tubular braid of filaments to frictionally engage both the inner and outer member
Implementation Method 2
cause the tubular braid of filaments to frictionally engage both the inner and outer member
Data Source
AI summary
A catheter having a selectively variable degree of flexibility includes an elongate tubular outer member and an elongate tubular inner member disposed within the outer member. The catheter further includes a cavity disposed in between the outer and inner members. A tubular braid of filaments may be disposed within the cavity. The outer and inner members are movable relative to each other along intermediate portions thereof when in a first configuration, and are not movable relative to each other when in a second configuration. When the inner and outer members are in the first configuration, the tubular braid of filaments is movably disposed relative to at least one of the outer member and the inner member. When the inner and outer members are in the second configuration, the inner and outer members clamp the tubular braid of filaments in a fixed position relative to the inner and outer members.