Stented Prosthetic Heart Valve Coupling Apparatus
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing stented prosthetic heart valves face challenges with durable attachment of tissue valve leaflets to the stent, leading to stress concentrations and potential structural issues due to the difference in rigidity between the leaflets and the stent, which can result in increased heart workload and the need for additional surgeries.
Innovation Solution
A coupling apparatus comprising a backing layer, guide plate, and pin is used to securely attach the leaflet layers to the stent, with tab regions sandwiched between the guide plate and pin, and flaps wrapped around strut segments to ensure a robust and aligned attachment, allowing for easy assembly and reduced stress concentrations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional attachment techniques (clamping, tying, gluing, stitching) are used to attach leaflets to the stent, then the leaflets can be secured to the stent frame, but stress concentrations occur at the attachment points due to the rigidity difference between the stent and flexible leaflet material
Solution Approach 1:
The attachment system is divided into separate functional components: a stent frame with attachment points, flexible leaflets with reinforcement zones, and a coupling apparatus comprising guide plates and pins. This segmentation allows each component to be optimized independently - the stent provides structural strength while the leaflets provide flexibility, and the coupling apparatus distributes stresses across multiple discrete attachment points rather than concentrating them at single locations
Solution Approach 2:
The coupling apparatus acts as an intermediary between the rigid stent frame and the flexible leaflet material. The guide plates and pins create a mechanical interface that transitions between the rigid stent structure and the flexible leaflet tissue, distributing attachment forces across broader areas and reducing stress concentrations at any single point
2Stability of the object's composition
If the stent is made relatively rigid to provide structural support, then the stent can maintain its shape and function, but the repetitive flexing motion of the flexible leaflets creates stress concentrations at the attachment points
Solution Approach 1:
The attachment system is designed to accommodate dynamic motion - the rigid stent frame remains stable while the flexible leaflets can undergo repetitive flexing motion. The coupling apparatus with its guide plates and pins creates a joint that allows controlled movement, distributing the dynamic stresses generated by leaflet flexing across multiple points rather than concentrating them at fixed attachment locations
3Manufacturing precision
If special design features (unique slots) are incorporated into the stent solely for attachment of tissue leaflets, then the leaflets can be oriented in an aligned arrangement, but the stent design becomes more complex
Solution Approach 1:
The alignment function is segmented from the primary structural function of the stent. Rather than incorporating complex special slots directly into the stent frame, the alignment is achieved through separate guide plates that are part of the coupling apparatus. These guide plates provide precise alignment features without requiring the stent itself to have complex geometry, thus achieving manufacturing precision while limiting stent design complexity
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A stented prosthetic heart valve including a stent, a plurality of leaflets, and a coupling apparatus. The stent includes a plurality of struts combining to define a generally tubular body, with the struts forming strut segments. The leaflets are mounted to the stent, and include a leaflet provided as part of a first leaflet layer that further forms a tab region. The coupling apparatus is configured for connecting the first leaflet layer to the stent, and includes a backing layer, a guide plate, and a pin. The guide plate and the pin are formed apart from the stent. In this regard, a portion of the backing layer and the tab region are secured between the guide plate and the pin. Further, another portion of the backing layer is attached to at least one of the strut segments to mount the leaflet of the first leaflet layer to the stent.