Modular Stents With Shape-Memory Flow Regulation
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Solution Overview
Problem
Existing stent implant devices struggle to effectively manage blood flow in vascular anatomy with varying compliance, particularly in non-compliant blood vessels like the aorta, leading to reduced perfusion and potential heart failure due to pulsatile arterial blood flow.
Innovation Solution
The use of modular stent assemblies comprising multiple stent segments with non-circular biased axial cross-sections that cyclically alternate between circular and oval shapes in response to pressure changes, reshaping the blood vessel to enhance compliance without requiring vessel stretching, using shape-memory materials to store and release energy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single long stent is used to treat non-compliant blood vessels, then the stent can provide continuous support, but it cannot effectively manage pulsatile blood flow and improve vessel compliance
Solution Approach 1:
The stent is divided into multiple segments that can independently deform and reshape during the cardiac cycle. Each segment can cyclically transition between circular and non-circular configurations, allowing the stent to manage pulsatile flow while maintaining continuous vessel support through the segmented structure.
2Productivity
If the blood vessel is stretched to enhance compliance, then blood flow can be improved, but it carries risks of vessel damage and requires invasive procedures
Solution Approach 1:
The stent incorporates dynamic elements that can cyclically change their configuration in response to pulsatile blood flow. The segments deform from circular to non-circular shapes during systole and return to circular shapes during diastole, providing continuous compliance enhancement without requiring permanent vessel stretching or invasive modification of the vessel wall.
3Productivity
If multiple stent segments are used to reshape the vessel, then blood flow can be improved, but the device complexity increases
Solution Approach 1:
Multiple stent segments are connected through linking elements to form an integrated assembly that functions as a unified device. The segments work together cyclically, with each segment contributing to the overall vessel reshaping effect, thereby achieving improved blood flow while maintaining a cohesive device structure rather than separate independent components.
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
This approach improves blood flow by evening out vessel volume and pressure changes, enhancing cardiac efficiency and reducing pulsatile load, while avoiding risks associated with vessel grafting or resection.
Implementation Method 1
using shape-memory materials to store and release energy
Data Source
AI summary
A method of managing blood flow involves advancing a delivery system to a blood vessel segment and deploying a first stent from the first delivery system at a first position in the blood vessel segment, the first stent having a non-circular cross-sectional shape defining a major-axis diameter and a minor-axis diameter that is less than the major-axis diameter. A second stent is deployed from the delivery system at a second position spaced from the first position by a first axial gap, the second stent having the non-circular cross-sectional shape and being physically coupled to the first stent by first and second coupling arms positioned on opposite major-axis circumferential portions of the first and second stents, respectively. Systolic pressure is reduced through circularization of the first and second stents and diastolic pressure is increased through shape-memory return of the first and second stents to non-circular shapes.