Expandable Stent Prevents Tissue Suction in VAD Inlet
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Solution Overview
Problem
Existing ventricular assist devices (VADs) face issues such as heart tissue being pulled into the pump inlet and suction conditions, particularly in patients with reduced left ventricular diameters or conditions like hypertrophic cardiomyopathy, leading to malfunction and potential injury.
Innovation Solution
A ventricular assist system incorporating an expandable stent positioned within the ventricle to secure the inlet opening and prevent heart tissue from being sucked into the pump, featuring a one-way valve and sealing element to maintain a stable environment, and a cylindrical stent with struts to maintain the ventricle wall away from the inlet.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a VAD pump inlet is positioned within the ventricle to enable blood pumping, then pumping function is achieved, but heart tissue may be pulled into the inlet causing malfunction and injury
Solution Approach 1:
A stent is introduced as an intermediary structure positioned between the pump inlet and the heart tissue. The stent acts as a physical barrier that prevents direct contact and suction of heart tissue into the pump inlet, while still allowing blood flow to pass through to the pump.
Solution Approach 2:
The stent is deployed in advance to create a protective barrier before the harmful suction effect can occur. By establishing this preventive structure beforehand, the system counteracts the potential harmful action of tissue being pulled into the inlet during pump operation.
2Adaptability or versatility
If the ventricle has reduced diameter or thick rigid walls (hypertrophic cardiomyopathy), then heart structure is altered, but VAD inlet positioning becomes difficult and suction conditions worsen
Solution Approach 1:
The stent provides localized structural support and spacing specifically at the pump inlet region. This local intervention creates adequate clearance between the inlet and heart tissue without requiring changes to the overall VAD design or extensive surgical modifications, making it adaptable to various ventricle sizes and conditions.
3Object-affected harmful factors
If the stent is expanded to secure the inlet opening and prevent tissue suction, then protection function is achieved, but the stent must pass through a narrow channel in the anchor element
Solution Approach 1:
The stent is designed with dynamic properties that allow it to transition between a compressed delivery state and an expanded functional state. During delivery, the stent is compressed to fit through the narrow channel in the anchor element. Once positioned, it expands to provide the necessary protective barrier function.
Solution Approach 2:
The stent is nested within a delivery catheter or constrained structure during the delivery phase, allowing it to pass through the narrow channel in the anchor element. After positioning, the constraining structure is removed or collapsed, allowing the stent to expand to its functional size.
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 system effectively prevents heart tissue from entering the pump inlet, reducing the risk of suction conditions and ensuring stable operation, even in patients with reduced left ventricular capacity.
Implementation Method 1
The anchor element may include a channel extending therethrough. A one-way valve may be positioned at least partially within the channel.
Implementation Method 2
The system may include a sealing element configured to be positioned within the channel proximal to the one-way valve to seal the channel.
Implementation Method 3
The channel may have a diameter and the stent may have a collapsed condition and an expanded condition, the diameter of the channel being adapted to allow the stent to pass through the channel when the stent is in the collapsed condition.
Data Source
AI summary
A ventricular assist system includes a ventricular assist device (“VAD”) and an expandable stent. The VAD may include a pump and an inlet element defining an inlet opening communicating with the pump, the inlet element being adapted for positioning with the inlet opening disposed within a ventricle of a heart when the system is in an operative condition. The expandable stent may be adapted for positioning within the ventricle when the system is in the operative condition. The pump may be operated to draw blood from the ventricle and return the blood to the artery, and a wall of the ventricle may be held away from the inlet opening with the stent. The stent may be passed through a channel in the ventricular assist device while the stent is in a collapsed condition.