Encapsulated Hourglass Stent Manufacturing via Mandrel Sintering
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current systems for treating congestive heart failure lack effective methods for manufacturing encapsulated hourglass shaped stents that can securely lodge in the atrial septum to manage blood flow between the left and right atria, and existing stents face issues with tissue ingrowth and thrombus formation.
Innovation Solution
A method for manufacturing encapsulated hourglass shaped stents using a mandrel assembly with conical regions, where an expandable stent is placed on the mandrel, a biocompatible material is associated with the stent, and the assembly is compressed to form a stent-graft, with layers of biocompatible material bonded through heating to create a monolithic layer, preventing tissue ingrowth and thrombus formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an expandable stent is used to lodge in the atrial septum, then blood flow management between atria is achieved, but tissue ingrowth and thrombus formation occur
Solution Approach 1:
The stent is nested within an encapsulating layer of biocompatible material (such as ePTFE), creating a nested structure where the inner stent provides structural support and blood flow management while the outer encapsulating layer prevents tissue ingrowth and thrombus formation. This nested configuration allows both functions to coexist without interference.
Solution Approach 2:
The device combines multiple materials with complementary properties: a metallic or polymer stent framework for structural integrity and blood flow control, combined with an encapsulating layer of biocompatible material (e.g., expanded polytetrafluoroethylene) that provides thrombus resistance and prevents tissue ingrowth. This composite structure leverages the advantages of each material while mitigating their individual disadvantages.
2Reliability
If an encapsulated stent-graft is manufactured, then long-term patency is achieved, but manufacturing complexity increases
Solution Approach 1:
The encapsulating layer is pre-formed and prepared before the stent is inserted. The biocompatible material is预先 shaped into an encapsulating configuration that will surround the stent, allowing the encapsulation process to proceed systematically rather than requiring complex in-situ formation during implantation.
Solution Approach 2:
A mandrel assembly serves as an intermediary tool during manufacturing. The mandrel provides a form around which the encapsulating layer is formed and secured to the stent. This intermediary device simplifies the encapsulation process by providing a stable reference structure that guides the formation and attachment of the encapsulating layer without requiring complex direct bonding procedures.
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 encapsulated hourglass shaped stents provide long-term patency and prevent tissue ingrowth, effectively managing blood flow between the atria, thereby addressing the limitations of existing stent technologies in treating congestive heart failure.
Implementation Method 1
layers of biocompatible material bonded through heating to create a monolithic layer
Data Source
AI summary
Systems and methods for the manufacture of an hourglass shaped stent-graft assembly having an hourglass shaped stent, graft layers, and an assembly mandrel having an hourglass shaped mandrel portion. Hourglass shaped stent may have superelastic and self-expanding properties. Hourglass shaped stent may be encapsulated using hourglass shaped mandrel assembly coupled to a dilation mandrel used for depositing graft layers upon hourglass shaped mandrel assembly. Hourglass shaped mandrel assembly may have removably coupled conical portions. The stent-graft assembly may be compressed and heated to form a monolithic layer of biocompatible material. Encapsulated hourglass shaped stents may be used to treat subjects suffering from heart failure by implanting the encapsulated stent securely in the atrial septum to allow blood flow from the left atrium to the right atrium when blood pressure in the left atrium exceeds that on the right atrium. The encapsulated stents may also be used to treat pulmonary hypertension.