Rotatable Catheter Connector Assembly for Tortuous Vasculature
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Solution Overview
Problem
Existing delivery catheters face challenges in navigating through small and tortuous vasculature due to stiffness, making it difficult to push through the patient's vasculature and steer around tight bends, particularly when delivering prosthetic heart valves.
Innovation Solution
A steerable catheter assembly with a connector assembly that allows limited rotation, tilting, and axial movement of the second connector portion relative to the first connector portion, facilitated by radially extending pins in oversized slots, enabling flexible navigation through vasculature.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the catheter shaft is made stiffer to maintain axial strength for pushing through vasculature, then the catheter can better transmit steering forces over long distances, but the catheter becomes difficult to push through tortuous vasculature and small vessels
Solution Approach 1:
The catheter shaft is divided into multiple segments or sections with different stiffness characteristics. The proximal shaft portion has higher stiffness for force transmission, while the distal shaft portion has lower stiffness for navigating tortuous anatomy. This segmentation allows each section to perform its specialized function optimally.
Solution Approach 2:
Different portions of the catheter shaft are assigned different mechanical properties. The proximal end maintains higher rigidity for axial force transmission, while the distal end incorporates flexibility for navigation. This local differentiation of material or structural properties resolves the contradiction between overall strength and localized flexibility.
2Adaptability or versatility
If the distal part of the catheter is made more flexible to pass through tortuous anatomy, then the catheter can navigate small vessels and tight bends, but the catheter loses rigidness and becomes difficult to steer
Solution Approach 1:
The catheter incorporates dynamic steering mechanisms such as shape memory alloys or magnetic actuation in the distal portion. These allow the catheter to transition between flexible states for navigation and controlled states for steering, enabling both tortuous path navigation and precise directional control.
Solution Approach 2:
A steerable section or intermediate component is introduced between the proximal and distal shaft portions. This intermediate section acts as a mediator that receives steering inputs from the proximal end and translates them into navigation movements in the distal end, maintaining steerability despite increased flexibility.
3Length of moving object
If a long catheter shaft is used to reach distant implantation sites, then access to remote locations is achieved, but steering forces must be transmitted over great distances increasing the complexity of navigation
Solution Approach 1:
The long catheter shaft is divided into multiple modular sections that can be independently manipulated. This segmentation breaks down the complex task of steering a single long shaft into simpler, localized steering actions at each segment, reducing overall navigation complexity.
Solution Approach 2:
Intermediate steering sections or guide wires are introduced as mediators to transmit and amplify steering forces over the long distance. These intermediaries convert small proximal movements into larger distal movements, simplifying the steering mechanism required for long-catheter navigation.
Data Source
AI summary
Embodiments of a catheter assembly are disclosed. The catheter assembly comprises a shaft; a connector assembly comprising a first connector portion and a second connector portion, wherein the first connector portion is fixedly coupled to a distal end of the shaft, and is rotatably coupled to the second connector portion by at least one radially extending pin retained within at least one slot on the second connector portion, wherein the at least one slot has an oversized circumferential dimension that allows limited rotation of the second connector portion relative to the first connector portion about a longitudinal axis of the shaft.