Prosthetic Valve Delivery Assembly With Cord Release Control
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Solution Overview
Problem
Challenges in the controlled implantation of self-expandable prosthetic valves include rapid expansion during sheath retraction, entanglement of sutures, and potential suture failure, making precise placement difficult and increasing trauma risk.
Innovation Solution
A prosthetic implant delivery assembly using cords or tethers with multi-stranded constructions, such as braided or twisted designs, to secure the prosthetic valve to a delivery apparatus, allowing controlled release and minimizing entanglement and ensuring precise positioning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single suture or plurality of sutures is used to releasably attach the prosthetic valve to the delivery catheter, then the prosthetic valve can be positioned at the implantation site, but entanglement between sutures and potential suture failure occurs
Solution Approach 1:
The single suture attachment method is segmented into multiple separate cords or tethers (typically 2-4), each independently attached to the delivery catheter. This segmentation eliminates entanglement between continuous sutures while maintaining secure attachment through distributed load bearing across multiple independent elements.
Solution Approach 2:
The problematic suture material is extracted and replaced with alternative attachment mechanisms such as cords, tethers, or mechanical locking features that do not exhibit the entanglement characteristics of traditional sutures. This substitution removes the harmful entanglement effect while preserving the attachment function.
2Productivity
If the delivery sheath is retracted to deploy the self-expandable prosthetic valve, then the valve can be implanted, but rapid expansion occurs making controlled implantation difficult
Solution Approach 1:
The prosthetic valve is pre-loaded in a compressed state within the delivery sheath, and the sheath is positioned at the target implantation site before deployment. This preliminary positioning ensures that when rapid expansion occurs, the valve expands at the correct location with controlled orientation, combining speed with precision.
Solution Approach 2:
The delivery sheath acts as an intermediary constraint that controls the expansion process. By designing the sheath with specific release mechanisms (such as radial cuts or controlled rupture zones), the rapid expansion is guided to occur in a controlled manner, maintaining implantation precision while enabling quick deployment.
3Speed
If rapid expansion of the prosthetic valve occurs during sheath retraction, then deployment is quick, but trauma to the native site increases
Solution Approach 1:
The delivery system incorporates cushioning or damping mechanisms that are activated during deployment to mitigate the impact of rapid expansion. This may include compliant materials in the delivery catheter, controlled expansion zones, or energy-absorbing features that reduce the mechanical shock and trauma to the native valve site while maintaining quick deployment.
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
Enables controlled radial expansion and secure attachment of prosthetic valves, reducing the risk of entanglement and trauma, and facilitating precise implantation at the desired location.
Implementation Method 1
The prosthetic valve can then be radially expanded, for example, by self-expandable material when a delivery sheath is retracted
Data Source
AI summary
A delivery assembly includes a prosthetic valve having a frame and a delivery apparatus including a cord-retaining device, one or more slideable release members, and one or more separate cords each having a first end portion and a second end portion. The cord-retaining device can include a proximal portion, a distal portion, and one or more tabs. Each cord can be arranged through an aperture in the frame and have its respective first end portion coupled to one of the one or more tabs and its respective second end portion coupled to one of the one or more slideable release members. The one or more slideable release members can be moved axially to decouple the second end portions of the cords from the one or more slideable release members to release the prosthetic valve from the delivery apparatus.