Asymmetric Occluder Disks for ASD Closure with Inadequate Rims
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Solution Overview
Problem
Existing occluder devices for atrial septal defects (ASD) face challenges in patients with inadequate rims, particularly in the retroaortic area, leading to device malposition and making transcatheter closure impossible in many cases.
Innovation Solution
An asymmetric occluder device with uniquely-shaped ovoid disks and a waist, featuring a larger distal disk and denser short arms, designed to securely anchor on both adequate and inadequate rims using shape memory materials and magnetic properties, ensuring proper seating and preventing dislodgement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a symmetric occluder device is used, then the device structure is simple and easy to manufacture, but the device cannot securely anchor on inadequate rims leading to malposition
Solution Approach 1:
The occluder device employs asymmetric disks with different diameters (first disk with diameter D1, second disk with diameter D2 where D1 ≠ D2) to adapt to the asymmetric anatomy of the defect and surrounding tissue. The larger disk is positioned on the side with adequate tissue while the smaller disk accommodates the inadequate rim area, enabling secure anchoring without compromising manufacturing feasibility
Solution Approach 2:
The device features varying disk densities in different regions, with the first disk having a first density and the second disk having a second density. This local quality variation allows optimized tissue engagement - denser regions provide stronger anchoring in inadequate rim areas while less dense regions facilitate proper seating in adequate tissue areas
2Ease of manufacture
If the occluder device is made with uniform density, then the manufacturing process is simplified, but the device cannot adapt to both adequate and inadequate rim areas
Solution Approach 1:
The occluder device incorporates non-uniform density distribution where the first disk has a first density and the second disk has a second density. This allows the device to provide enhanced support in inadequate rim areas while maintaining compatibility with adequate tissue regions, achieving adaptability through controlled material property variation
3Ease of operation
If a standard occluder device is used, then the device is easy to deploy, but the device may dislodge in patients with inadequate rims
Solution Approach 1:
The asymmetric disk configuration with different diameters creates optimized engagement surfaces for the delivery system while maintaining ease of deployment. The larger disk provides a broader platform for delivery catheter engagement while the smaller disk adapts to the inadequate rim geometry, ensuring both easy deployment and secure retention
Solution Approach 2:
The varying density distribution enhances device retention by providing denser, more stable regions in areas prone to dislodgement while maintaining overall device deployability. The first density and second density are optimized to provide localized stability without compromising the ease of deployment through the delivery system
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 device effectively seals ASDs by securely anchoring on both adequate and inadequate rims, reducing the risk of dislodgement and embolism, and allowing for transcatheter closure without the need for surgical intervention.
Implementation Method 1
each member is shaped into two semi-ovoid designs to form two half-discs by the memory-shaping capability of the Wires forming the members
Data Source
AI summary
An asymmetric occlusion device for occluding an opening in a body tissue where part of the opening is defined by a partial inadequate rim. The asymmetric occlusion device includes a waist portion having a distal end extending to a proximal end. The waist portion is of non-woven material extending around a longitudinal axis opening. The occlusion device further includes a pair of asymmetric occluder disks attached to the waist. The asymmetric distal and proximal occluder disks are formed of shape memory material. The asymmetric occluder disks include a short arm extending from the waist and an extended arm extending from the waist. The extended arm exceeds the length of the first short arm. The density of the first short arm exceeds the density of the second extended arm.