Four-leaflet Mitral Valve with Asymmetric D-shaped Frame
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Solution Overview
Problem
Conventional prosthetic heart valves with circular support frames do not optimally conform to the non-circular mitral annulus, leading to suboptimal blood flow and increased stress on the valve, potentially reducing longevity and causing tissue ingrowth.
Innovation Solution
A prosthetic heart valve with a support frame defining a non-circular orifice, such as elliptical or D-shaped, and four flexible leaflets that mimic the native anatomy, with leaflets of varying sizes to better match the mitral annulus shape, reducing stress and improving blood flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a circular support frame is used in prosthetic heart valves, then manufacturing is simplified and structural symmetry is achieved, but the valve does not conform to the non-circular mitral annulus shape, leading to suboptimal blood flow and increased stress
Solution Approach 1:
The support frame is designed with a non-circular configuration including a major axis and minor axis of different lengths, creating an asymmetric structure that conforms to the D-shaped mitral annulus. This asymmetric design allows the valve to better match the native anatomy, improving blood flow patterns and reducing stress concentrations that would occur with a circular frame, thereby enhancing reliability and preventing tissue ingrowth.
2Device complexity
If a circular support frame is used, then structural simplicity is maintained, but blood flow is suboptimal due to mismatch with the non-circular mitral annulus
Solution Approach 1:
The support frame employs asymmetric geometry with distinct major and minor axes to replicate the natural D-shaped contour of the mitral annulus. This asymmetric configuration optimizes blood flow dynamics by eliminating stagnant zones and improving hemodynamic efficiency, while the overall structural design remains relatively simple and manufacturable.
3Device complexity
If a circular support frame is used, then the valve structure is simpler, but stress on the valve is increased, potentially reducing longevity
Solution Approach 1:
The non-circular support frame with optimized major and minor axes distributes mechanical stress more evenly across the valve structure by conforming to the natural geometry of the mitral annulus. This reduces stress concentrations that would occur at the interfaces between a circular frame and the non-circular annulus, thereby enhancing the valve's strength and longevity without requiring complex reinforcement structures.
Data Source
AI summary
A prosthetic mitral heart valve having four separate flexible leaflets. The heart valve includes a support frame that may be non-circular, for example elliptical or “D-shaped”. The support frame may have an undulating outflow edge defined by four inflow cusps and four outflow commissures to which each of the flexible leaflets attaches. The support frame may comprise an undulating wireform and a surrounding stent defining a structure having four cantilevered posts projecting in the outflow direction to support the four leaflets. The heart valve is designed to be secured in the annulus and function as a standalone unit without papillary muscle connections to the leaflets. The four leaflets may be arranged in two opposed pairs, one pair being smaller than the other pair. The larger pair of leaflets may be identical, or differently sized. Existing sizes of heart valve leaflets may be utilized with the smaller leaflets being at least two leaflet sizes smaller than the larger leaflets in odd millimeter increments.