Heart Valve Delivery Sheath Fine Adjustment for Precise Positioning
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Solution Overview
Problem
Existing transcatheter delivery systems for prosthetic heart valves face challenges in accurately positioning the prosthetic heart valve due to friction issues and difficulty in making precise adjustments, leading to potential complications such as paravalvular leakage or the need for a permanent pacemaker.
Innovation Solution
A delivery device with a sheath, handle, and adjustment mechanism, including a fine adjustment mechanism, allows for precise positioning of the prosthetic heart valve by sliding the sheath relative to an outer stability shaft, enabling accurate deployment at the desired site.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a conventional delivery device is used to deliver a prosthetic heart valve, then the valve can be delivered through the vasculature, but friction between the introducer device and delivery sheath causes unexpected movement of the prosthesis, leading to positioning inaccuracies
Solution Approach 1:
The delivery device is segmented into multiple independent components: an introducer device, a delivery device with delivery sheath, and a stabilization member. The stabilization member is further segmented into a proximal portion and a distal portion that can independently interact with different surfaces (aortic wall and aortic valve annulus), allowing each segment to perform its specific function without interfering with others.
Solution Approach 2:
The stabilization member acts as an intermediary component between the delivery sheath and the aortic structures. It provides a stable reference frame by engaging with the aortic wall and valve annulus, mediating the positioning process and eliminating the direct frictional interaction that causes unwanted movement between the introducer and delivery sheath.
2Ease of operation
If the handle is moved proximally or distally to adjust valve position, then the delivery sheath moves, but the prosthetic heart valve does not move relative to the aortic valve, making fine positioning adjustments difficult
Solution Approach 1:
The stabilization member is designed to dynamically engage and disengage from the aortic structures. During the positioning phase, it engages with the aortic wall and valve annulus to provide stability. During deployment, it disengages to allow the delivery sheath to move freely. This dynamic behavior allows the system to switch between stability and mobility as needed.
Solution Approach 2:
The system changes the friction parameter at different stages. The stabilization member creates high friction engagement with the aortic wall and valve annulus during positioning to prevent movement, then reduces friction during deployment to allow smooth release of the prosthetic valve. This parameter change enables both precise positioning and easy deployment.
3Adaptability or versatility
If the delivery device is designed to allow movement of the delivery sheath for positioning adjustments, then positioning flexibility is improved, but friction with the introducer device causes unexpected movement and reduces positioning accuracy
Solution Approach 1:
The stabilization member provides a counterbalancing force against the frictional forces between the introducer and delivery sheath. By engaging with the aortic wall and valve annulus, it creates opposing forces that stabilize the delivery device, counteracting the unwanted movement caused by friction and allowing precise positioning adjustments.
Data Source
AI summary
A delivery device for percutaneously delivering a stented prosthetic heart includes a sheath, a handle, and adjustment device including a fine adjustment mechanism, and an outer stability shaft. The sheath defines a lumen and is configured to compressively constrain the stented prosthetic heart valve. The handle is coupled to the proximal portion of the sheath and includes an actuator mechanism coupled to a proximal portion of the sheath that is configured to selectively move the sheath relative to the housing to release the stented prosthetic heat valve. The adjustment device is coupled to the handle and includes an adjustment lumen through which the sheath and the handle slidably extend. The outer stability shaft is coupled to the adjustment device. The fine adjustment mechanism is configured to selectively move the handle and the sheath relative to the adjustment device and the outer stability shaft.