Implant Delivery Catheter Control for Trackability and Pushability
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Solution Overview
Problem
Existing catheters for trans-vascular implant delivery face challenges with trackability, pushability, sheathing/re-sheathing, and robustness, affecting the positioning and performance of prosthetic implants during and after deployment.
Innovation Solution
A percutaneous catheter system with a primary rotary knob and threaded wheel mechanism, combined with a secondary rotational mechanism, provides precise macro and micro movements for the capsule and implant, featuring safety and feedback mechanisms for controlled deployment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a conventional catheter delivery system is used, then the implant can be delivered trans-vascularly, but the system suffers from poor trackability and pushability affecting positioning accuracy
Solution Approach 1:
The catheter shaft is designed with varying flexibility along its length, with the distal section being more flexible and the proximal section being stiffer. This dynamic structural design allows the catheter to navigate tortuous vasculature effectively while maintaining pushability from the operator's hand, thereby improving both trackability and positioning accuracy simultaneously
Solution Approach 2:
Different sections of the catheter shaft are assigned different mechanical properties - the distal section has higher flexibility for navigation while the proximal section has higher stiffness for force transmission. This local differentiation of material properties resolves the contradiction between trackability and pushability
2Length of moving object
If the capsule moves over the collapsed implant for delivery, then the implant can be transported through narrow arteries, but sheathing and re-sheathing operations are difficult
Solution Approach 1:
A low-friction coating is applied to the surface of the collapsed implant, acting as an intermediary layer between the capsule and the implant. This coating reduces friction and facilitates smooth sheathing and re-sheathing operations while maintaining the implant's compressibility for transport through narrow arteries
3Reliability
If the catheter structure is made robust for stable implant deployment, then deployment performance improves, but the catheter profile increases making it harder to navigate
Solution Approach 1:
The catheter employs a dynamic structure where the shaft flexibility and support characteristics change along its length and can be adjusted during deployment. The proximal section provides robust support for deployment while the distal section remains flexible for navigation, achieving both robust deployment performance and low profile for navigation
4Ease of operation
If the catheter is made flexible for better trackability, then navigation through tortuous vessels improves, but pushability and force transfer from handle to tip deteriorates
Solution Approach 1:
The catheter shaft is constructed with locally differentiated mechanical properties where the proximal section has higher stiffness for force transmission and the distal section has higher flexibility for navigation. This local quality differentiation allows the catheter to simultaneously achieve good trackability and pushability
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
Enhances the delivery and deployment performance of prosthetic implants with improved ergonomic use, sturdy design, and precise control, ensuring accurate positioning and retrieval.
Implementation Method 1
a primary rotary knob engaged with a threaded wheel through threads. The threaded wheel connected with a primary screw shaft
Data Source
Figure 1
Figure 1A~1B
Figure 2
AI summary
The invention relates to prosthetic implant catheter delivery system. The delivery system includes a handle, a capsule, a tip, and a catheter assembly. The catheter assembly includes an outer shaft, a stability shaft, a catheter shaft, an inner shaft, and a guidewire shaft where the catheter shaft and the inner shaft (combinedly with the guidewire shaft) are utilized in the implant loading, positioning, and deployment. Only stability shaft is fixed. The handle includes screw-based primary rotational mechanism and secondary rotational mechanism. The secondary rotational mechanism also includes a push-pull mechanism. The delivery system has improved pushability and controllability.