Variable Stiffness Catheter with Pneumatic Actuation for Transradial Access
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Solution Overview
Problem
Current neurointerventional radiology procedures face challenges in navigating the complex cerebral vasculature, particularly with transradial access due to acute angle branching and vessel tortuosity, leading to increased procedure time, risk of complications, and reduced treatment specificity, as existing devices are not specifically designed for this approach.
Innovation Solution
A variable stiffness catheter with a flexible elongated tube and embedded actuator lumens that allow for shape manipulation through fluid pressure or vacuum, enabling bends and stiffness adjustments to navigate tight turns, utilizing a pneumatic system for improved navigation in transradial access procedures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If traditional rigid catheters are used for transradial access, then the catheter structure is simple and easy to manufacture, but the catheter cannot navigate tight turns and acute angle branching in the cerebral vasculature
Solution Approach 1:
The catheter employs a dynamic structure with alternating flexible and stiff sections that can change their mechanical properties in response to physiological conditions. The flexible sections allow the catheter to conform to tortuous vasculature and navigate tight turns, while the stiff sections provide structural support for device delivery. This dynamic adaptability enables the catheter to optimize its navigation capability throughout the procedure.
Solution Approach 2:
The catheter is divided into multiple functional segments including flexible sections, stiff sections, and transition zones. This segmentation allows each portion to perform its specific function optimally - flexible sections for navigation, stiff sections for device support, and transition zones for smooth mechanical property changes. The segmented design resolves the contradiction by distributing different mechanical requirements to different segments rather than requiring the entire catheter to be uniformly complex.
2Ease of operation
If multiple different catheters and guidewires are used to navigate complex vasculature, then navigation capability is improved, but procedure time increases and the risk of complications increases
Solution Approach 1:
The catheter integrates multiple functions into a single device, combining navigation capabilities, device delivery functionality, and adaptability to various vascular configurations. This multi-functional design eliminates the need to exchange multiple catheters and guidewires during the procedure, thereby reducing procedure time and minimizing the risk of complications associated with repeated vascular access attempts.
Solution Approach 2:
The catheter is pre-configured with alternating flexible and stiff sections before the procedure, allowing it to be advanced through the entire vasculature in a single continuous motion. This preliminary configuration enables the catheter to navigate complex anatomical pathways without requiring intermediate exchanges or adjustments, improving both navigation capability and procedure safety.
3Strength
If a single stiff catheter is used, then the catheter provides good structural support for device delivery, but the catheter cannot conform to tortuous vasculature and navigate tight turns
Solution Approach 1:
The catheter features spatially varying mechanical properties with flexible sections positioned in regions requiring conformability and stiff sections positioned in regions requiring structural support. This local quality differentiation allows the catheter to simultaneously achieve both goals - the flexible sections conform to tortuous vasculature while the stiff sections maintain the ability to deliver devices effectively.
Solution Approach 2:
The catheter construction incorporates different materials or material configurations in different sections to achieve the desired mechanical properties. The flexible sections use materials with lower stiffness to allow conformability, while the stiff sections use materials with higher stiffness to provide structural support. This composite approach resolves the contradiction between strength and conformability by optimizing material selection for each specific functional requirement.
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
The catheter system enhances procedure speed and specificity, reduces healthcare resource utilization, and decreases the number of devices needed, thereby improving clinical outcomes and reducing complications.
Implementation Method 1
each actuator segment is configured to preferentially expand when the plurality of fluidly connected chambers is pressurized by a fluid, causing the tube wall to bend
Implementation Method 2
each actuator segment is configured to contract when the plurality of fluidly connected chambers is exposed to a vacuum, causing the tube wall to stiffen
Data Source
AI summary
The present invention provides a variable stiffness catheter comprising a pneumatic actuator lumen system that allows manipulation of shape and curvature at one or more locations along the catheter.