Self-Expanding Prosthesis Delivery Catheter for Flexible Recapture
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Solution Overview
Problem
Existing valve delivery devices struggle to balance the functions of valve recapture and implantation, with polymer sheaths offering flexibility but poor resistance, and metal sheaths providing resistance at the cost of flexibility, leading to risks of vessel puncture during transcatheter aortic valve implantation.
Innovation Solution
A delivery device with a catheter system comprising an internal catheter, an inside external catheter, and an outside external catheter, where the internal catheter accommodates the prosthesis in a compressed state, and the outside external catheter maintains flexibility while the inside external catheter provides high resistance, allowing for safe passage through complex anatomies and recapture.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a polymer sheath is used for the catheter, then flexibility is improved, but resistance to tension and compression deteriorates
Solution Approach 1:
The catheter is constructed using composite materials, specifically a polymer sheath reinforced with a metal braid or mesh. This composite structure combines the flexibility of the polymer material with the tensile and compressive strength of the metal reinforcement, resolving the contradiction between flexibility and resistance to tension/compression.
2Strength
If a metal sheath is used for the catheter, then resistance to tension and compression is improved, but flexibility deteriorates
Solution Approach 1:
The metal sheath is designed as a metal braid or mesh embedded within a polymer sheath, creating a composite structure. This allows the metal to provide tensile and compressive strength while the polymer matrix maintains flexibility and enables three-dimensional bending, resolving the contradiction between strength and flexibility.
3Strength
If reinforcing ribs are added to the metal sheath, then resistance to tension and compression is improved, but spatial three-dimensional flexibility deteriorates
Solution Approach 1:
The catheter employs a flexible polymer sheath with embedded metal braid or mesh reinforcement instead of rigid reinforcing ribs. This flexible shell structure allows the catheter to bend in multiple directions and adapt to complex anatomical pathways while maintaining sufficient tensile and compressive strength through the metal reinforcement.
Data Source
Figure 1~3
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Figure 7~9a
AI summary
A delivery apparatus for a self-expandable prosthesis (3), comprising a catheter (1) and a handle (5). The catheter (1) comprises an internal catheter (10), an inside external catheter (20), an outside external catheter (30), and a stabilizing tube (40) sleeve-jointed one on another in sequence. The internal catheter (10) is used for carrying the self-expandable prosthesis (3) in a compressed state. The inside external catheter (20) is moveable relative to the internal catheter (10) and comprises a distal portion and a proximal portion, and the distal portion is used for driving the self-expandable prosthesis (3) to be compressed from a semi-release state to the compressed state. The outside external catheter (30) is moveable relative to the internal catheter (10) and comprises a distal component and a proximal component, and the distal component is used for restraining the self-expandable prosthesis (3). The bending property of the distal component is stronger than that of the distal portion, while the tensile and compressive properties of the distal portion are stronger than those of the distal component. The stabilizing tube (40) remains relatively stationary with respect to the internal catheter (10). Based on the outside external catheter (30), the self-expandable prosthesis (3) can be released; based on the inside external catheter (20), the self-expandable prosthesis (3) in the semi-release state can be compressed again for release again; therefore, the delivery apparatus has both functions of compressing and releasing the self-expandable prosthesis (3).