Implantable Device Rounded Struts Stress Distribution
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Solution Overview
Problem
Cardiac implants, such as those used in annuloplasty procedures for mitral valve repair, face chronic stresses and strains due to heart muscle palpitation, leading to potential failure and inefficiency in maintaining valve competence.
Innovation Solution
A tubular frame implant with elongate struts featuring rounded corners and a collar system that allows for axial translation, distributing strain through corner radius modification via processes like laser cutting, grinding, or micro-blasting to enhance resiliency and reduce stress concentrations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If sharp-cornered struts are used in the implant frame, then manufacturing is simpler, but stress concentrations occur leading to reduced reliability under chronic cardiac stresses
Solution Approach 1:
The patent applies local quality by rounding only the corners of the struts where stress concentrations occur, rather than changing the entire strut geometry. This localized modification reduces stress concentrations at critical points while maintaining the overall structural integrity and manufacturing simplicity of the straight strut design.
Solution Approach 2:
The patent implements spheroidality by replacing sharp corners with rounded corners having a specified radius of curvature. This curvature eliminates stress concentration points at the strut corners, allowing the implant to better withstand chronic palpatory forces from heart muscle contraction while maintaining manufacturing feasibility through standard rounding processes.
2Adaptability or versatility
If the collar is fixed in position, then the structure is simpler, but it cannot adapt to varying annulus sizes and shapes
Solution Approach 1:
The patent applies dynamics by making the collar movable along the struts rather than fixed. The collar can translate axially to accommodate different annulus sizes and shapes, providing adaptability through a simple linear movement mechanism that maintains structural simplicity while enabling size adjustment.
Solution Approach 2:
The patent implements segmentation by separating the collar from the strut structure, allowing independent movement. The collar is a distinct component that can slide along the struts, enabling the system to adapt to varying annular geometries without requiring complex integrated mechanisms.
3Reliability
If rounded corners are applied to all struts, then stress distribution is improved, but manufacturing time and cost increase
Solution Approach 1:
The patent applies local quality by rounding only the necessary corners of struts that experience stress concentrations, rather than uniformly rounding all corners of all struts. This selective approach maintains stress distribution benefits while reducing manufacturing time and cost by limiting the rounding process to critical areas only.
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
The modified implant effectively distributes chronic palpatory forces, increasing resiliency and reducing strain concentrations, thereby improving the durability and functionality of cardiac implants.
Implementation Method 1
modifying a corner radius to distribute strain resulting from stresses related to interaction of implant components due to the chronic palpatory motion of the heart
Implementation Method 2
corner radius modification via processes like laser cutting, grinding, or micro-blasting
Implementation Method 3
corner radius modification via processes like laser cutting, grinding, or micro-blasting
Implementation Method 4
corner radius modification via processes like laser cutting, grinding, or micro-blasting
Data Source
AI summary
An implant includes a frame comprising a tubular body formed by a plurality of interconnected struts that are manufactured to reduce stresses and strains resulting from component interaction during chronic use. At least a portion of a longitudinal corner of one or more struts of the frame may be chamfered, rounded, or otherwise modified to distribute stresses experienced at the strut corner throughout the strut body. Chamfering and/or rounding corners along at least a portion of a strut of the frame may reduce stresses on the frame caused by interactions between the frame and other components of the implant. The implant may be manufactured by cutting (e.g., laser cutting) a plurality of struts from a tubular metal alloy, polymer, or the like forming the tubular body, and softening at least a portion of an edge of the strut by cutting, grinding, and/or micro-blasting the edges of the corner.