Transcatheter Delivery Catheter Capsule Stop Mechanism
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Solution Overview
Problem
Current transcatheter delivery systems for prosthetic heart valves face challenges in navigating tortuous anatomy and ensuring precise deployment without interfering with patient anatomy or disengaging from the delivery catheter, particularly in complex procedures like heart valve replacement.
Innovation Solution
The delivery catheter assembly features a capsule with an elongate body and a stop mechanism that restricts movement during deployment, preventing assembly interference and disengagement, by controlling fluid flow to advance the capsule and unsheathe the prosthesis incrementally, ensuring precise placement and secure attachment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the capsule is allowed to move freely during deployment, then the prosthesis can be delivered through tortuous anatomy, but the capsule may interfere with patient anatomy or disengage from the delivery catheter
Solution Approach 1:
The stop is pre-positioned on the elongate body at a specific location before deployment begins. This preliminary positioning ensures that when fluid pressure advances the capsule, the stop will automatically engage the catheter at the predetermined point, preventing over-advancement and disengagement while allowing sufficient travel to navigate tortuous anatomy.
Solution Approach 2:
The stop acts as an intermediary element between the capsule and the delivery catheter. It provides a mechanical interface that allows the capsule to move relative to the catheter during navigation, then prevents further movement by engaging a corresponding feature on the catheter, thus mediating between the need for movement and the need for restraint.
2Speed
If fluid is continuously delivered to advance the capsule, then deployment speed is improved, but the capsule may over-advance and interfere with patient anatomy
Solution Approach 1:
The stop provides mechanical feedback to the fluid delivery system. As fluid pressure advances the capsule, the stop eventually engages the catheter, creating a mechanical stop that provides immediate feedback to limit further advancement. This feedback mechanism prevents over-advancement even though fluid continues to be delivered, ensuring the capsule does not interfere with patient anatomy.
Solution Approach 2:
The stop is pre-positioned to counteract the potential harmful effect of over-advancement before it can occur. By having the stop in place beforehand at a predetermined location, the system preemptively prevents the capsule from advancing too far, even under continuous fluid pressure, thus eliminating the need for complex control systems to monitor and prevent anatomy interference.
3Manufacturing precision
If the stop mechanism is added to restrict capsule movement, then deployment precision is improved, but device complexity increases
Solution Approach 1:
The delivery catheter assembly is segmented into distinct functional components: the catheter, the elongate body, the capsule, and the stop. This segmentation allows each component to be optimized for its specific function while maintaining overall simplicity. The stop is a separate, simple element that can be manufactured independently and attached to the elongate body, avoiding the need for complex integrated mechanisms.
Solution Approach 2:
The stop function is extracted as a separate, simple component rather than being integrated into a complex control system. By taking out the movement restriction function and implementing it with a simple stop element on the elongate body, the design achieves deployment precision without adding significant complexity to the overall device structure.
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
This solution enables safe and precise delivery and deployment of prosthetic heart valves, reducing the risk of complications and improving procedural outcomes by maintaining the capsule's engagement with the catheter and preventing overextension, thus enhancing the accuracy and reliability of transcatheter procedures.
Implementation Method 1
the stop is operable to impede fluid flow through the fluid path and into the reservoir
Implementation Method 2
directing fluid along a fluid path over the elongate body and into a reservoir of the capsule to cause the capsule to advance with respect to the catheter
Data Source
AI summary
Transcatheter prosthesis delivery catheter assemblies having a catheter and a lumen extending through the catheter. Such assemblies also have a elongate body having an outer surface and extending at least partially within the lumen. The elongate body has a stop. Delivery catheter assemblies also include a capsule interconnected to the catheter with the elongate body, the capsule including a reservoir. A fluid path extends from the lumen to the reservoir, within the capsule. A prosthesis is loaded within the capsule. Methods can include delivering the capsule though a patient's vasculature to a treatment site and directing fluid in a direction from the lumen, over the elongate body and into the reservoir to cause the capsule to advance with respect to the catheter, at least partially unsheathing the prosthesis, until the stop restricts further movement of the capsule and prevents further fluid from being transferred from the lumen to the reservoir.