Expandable Introducer Sheath for TAVI Delivery Catheter
Solution Overview
Problem
Current delivery systems for interventional devices into blood vessels face complications such as trauma, blood loss, and vessel rupture due to high stress on access sites, especially during sheathless access and withdrawal, and the use of inline sheaths can lead to complications during quick system retrieval or with calcifications.
Innovation Solution
A delivery system featuring an introducer with a fastening mechanism that securely attaches to the interventional device, allowing for controlled expansion and contraction of the sheath, reducing stress on the vessel access site and maintaining a critical diameter approximated to the interventional device's outer diameter, thereby minimizing complications.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If sheathless access is used, then the interventional device can be inserted directly into the vessel, but the vessel access site experiences massive stress and requires continuous observation, increasing the risk of trauma, blood loss, or rupture
Solution Approach 1:
The patent introduces an introducer sheath as an intermediary device between the interventional device and the vessel wall. This sheath distributes the mechanical stress over a larger area during insertion and withdrawal, reducing localized trauma and rupture risks while maintaining direct access capability
Solution Approach 2:
The introducer sheath acts as a protective cushion that is placed in the vessel before the interventional device is inserted. It pre-establishes a stress-distributing structure that protects the vessel wall from concentrated forces during the insertion and withdrawal processes
2Reliability
If an inline sheath is used, then hemostatic sealing and guidance are ensured, but frequent and quick system retrieval carries a high risk of complications
Solution Approach 1:
The patent separates the functions of the introducer sheath from the interventional device, allowing the sheath to remain in the vessel while the interventional device is removed. This segmentation enables the sheath to maintain hemostatic sealing and guidance capabilities independently, reducing complications during quick retrieval operations
3Adaptability or versatility
If an expandable introducer sheath is used, then the critical vessel diameter is defined by the expanded outer diameter, but the blood vessel is stretched radially which could lead to complications with calcifications or incorrect vessel diameter determination
Solution Approach 1:
The patent implements a dynamic expandable sheath that can change its outer diameter based on the specific interventional procedure requirements. The sheath expands to the necessary diameter during insertion to provide adequate guidance and hemostatic sealing, then contracts to minimize vessel stretching during withdrawal, thereby reducing rupture risks in calcified or vulnerable vessels
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 reduces stress on the vessel access site and peripheral vessels, minimizing the risk of trauma and rupture, while allowing for controlled expansion and contraction of the sheath to accommodate the interventional device, enhancing safety during insertion and withdrawal.
Implementation Method 1
The fastening mechanism can be an inflatable balloon connected to a hub and configured to press against the interventional device when being inflated to fasten the introduces to the interventional device
Implementation Method 2
The fastening mechanism can be an electromagnet an electrical coil wound around a metal core, wherein the electromagnet is arranged on a proximal portion of the introduces and is configured to attract a metal sheath of the interventional device when an electrical current is applied to the electrical coil to fasten the introduces to the interventional device
Data Source
AI summary
A delivery system includes an interventional device having a distal end portion and an introducer configured to insert the interventional device into a vessel of a patient. The introducer has a tubular sheath configured to be inserted into the vessel defining a lumen to guide the interventional device into the vessel. The introducer includes a fastening mechanism configured to releasably fasten the introducer to the interventional device to prevent movement of the introducer with respect to the interventional device along a longitudinal axis.