Valve Stent Delivery Sheath With Floating Limiter for Controlled Release
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Solution Overview
Problem
Existing delivery devices for implantable heart valves face challenges in precisely controlling the release and repositioning of the valve stent due to excessive friction and the risk of the stent being suddenly released or falling out of the fixing component, leading to positioning deviations and potential surgical replacement.
Innovation Solution
A delivery device with a core tube, guiding head, fixing head, outer sheath, and movable limiting bars that maintain engagement between the implantable instrument's connecting ear and positioning portion, reducing friction and allowing for controlled release and repositioning through the use of movable limiting bars that constrain and guide the stent during deployment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the valve stent is compressed and delivered through the delivery device, then the valve stent can be delivered into the human body, but excessive friction is generated between the valve stent and the inner wall of the blood vessel
Solution Approach 1:
A lubricating coating layer is applied to the inner wall of the delivery catheter and the outer surface of the valve stent. This lubricating layer acts as an intermediary substance that reduces the friction force between the valve stent and the delivery catheter during delivery and release, enabling smoother movement and better control
2Reliability
If the connecting ear is engaged in the fixing component for stent release, then the valve stent can be constrained, but the constraint force is insufficient and the connecting ear can easily spring out causing complete release
Solution Approach 1:
The fixing component is divided into multiple independent clamping units, each with its own clamping arm that can independently engage with the connecting ear. This segmentation allows the constraint force to be distributed across multiple contact points, increasing the overall constraint force and preventing the connecting ear from springing out during release
Solution Approach 2:
The clamping arms are designed with curved surfaces that match the shape of the connecting ear, increasing the contact area between the clamping arms and the connecting ear. This curvature design enhances the constraint force distribution and prevents slippage during the release process
3Manufacturing precision
If the valve stent is gradually released through engagement and outer sheath constraint, then precise release can be achieved, but the structure becomes complex requiring multiple components
Solution Approach 1:
The fixing component is integrated directly onto the delivery catheter as a unified structure, combining the functions of constraint and release control into a single integrated component. This merging reduces the number of separate parts while maintaining the gradual release capability through the coordinated action of multiple clamping arms working together
Data Source
AI summary
An easy-to-control interventional instrument delivery device, comprising a core tube (7), a guiding head (2) and a fixing head (3) being fixed onto the core tube (7); the guiding head (2) is fixed at a distal end of the core tube (7), and the fixing head (3) extends from a proximal end side of the core tube (7), an interventional instrument mounting position being located between the guiding head (2) and the fixing head (3); the outer periphery of the interventional instrument mounting position is provided with an axially slidable outer sheathing tube (5), further being provided with a floating limiting strip (1); a proximal end of the floating limiting strip (1) is a starting end (13) that is connected near the fixed head (3), and a distal end is a terminal end (11, 101) that floats between the interventional instrument mounting position and the outer sheathing tube (5). The easy-to-control interventional instrument delivery device is capable of fastening an end portion of a valve stent (8) during stent release so as to prevent the stent (8) from completely falling out during release, and reduces the relative friction between the delivery device and the valve during stent release and recovery.