Catheter Tethering Assembly With Sliding Wire Device Release
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Solution Overview
Problem
Traditional implantable cardiac pacemakers with elongate lead wires face mechanical and MRI compatibility issues, prompting the development of compact, leadless intracardiac devices that require efficient delivery and securement systems.
Innovation Solution
A tethering assembly for delivery catheters that includes an attachment component with a movable wire, allowing securement and release of compact implantable medical devices at implant sites, facilitating ease of delivery and removal without complications.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If traditional elongate lead wires are used for implantable cardiac pacemakers, then the device can be implanted remotely from the heart, but mechanical and MRI compatibility issues arise
Solution Approach 1:
The patent removes the traditional elongate lead wire from the system and replaces it with a leadless intracardiac device that is wholly contained within a compact package. This extraction of the problematic lead wire eliminates the mechanical and MRI compatibility issues while maintaining the ability to implant the device remotely through a delivery catheter.
Solution Approach 2:
The leadless intracardiac device is nested within the delivery catheter during implantation. The device is delivered transvenously through the catheter to the implant site, then released and positioned within the heart. This nesting approach allows remote implantation while eliminating the need for external lead wires that cause compatibility problems.
2Ease of operation
If a delivery catheter is used to deliver the intracardiac device, then the device can be delivered to the implant site, but the attachment and release mechanisms become complex
Solution Approach 1:
The tethering assembly employs a dynamic wire mechanism that can transition between extended and retracted positions. When extended, the wire blocks the passageway to secure the device attachment member. When retracted, it allows release of the attachment member. This dynamic mechanism simplifies the delivery process while maintaining secure attachment during transit.
Solution Approach 2:
The wire acts as an intermediary element between the delivery catheter and the intracardiac device. By extending the wire into the passageway, it creates a mechanical block that secures the device attachment member without requiring complex locking mechanisms. The wire serves as a simple yet effective mediator for both attachment and release functions.
3Reliability
If the wire is extended into the passageway to secure the device, then the attachment member is prevented from moving, but the passageway is blocked
Solution Approach 1:
The wire is designed to be dynamically repositionable between an extended state (when it blocks the passageway to secure the attachment member) and a retracted state (when it allows the attachment member to be released). This dynamic capability enables reliable securement during delivery while facilitating easy release at the implant site through simple wire retraction.
Solution Approach 2:
Instead of using a complex locking mechanism that requires active unlocking, the design inverts the approach by using wire extension to create a passive mechanical block. The attachment member is secured not by positive locking but by the physical presence of the extended wire blocking its path. Release is achieved by reversing the action - retracting the wire to remove the block.
Data Source
AI summary
A tethering assembly for securing a medical device includes a shaft and a wire that extends in sliding engagement within a proximal lumen, a channel, and a distal receptacle of the shaft. A retainer zone of the shaft, through which the channel extends, stops a transition segment of the wire, which extends between a proximal and a distal segment of the wire, from moving into the shaft receptacle, thereby restraining a distal-most tip of the wire from moving through a distal-most opening of the receptacle. When a projecting member of the device has entered a secure zone of the receptacle, via movement through the distal-most opening and a tapering passageway thereof, the distal-most tip of the wire, which may be spring-biased, can move distally into the passageway so that the tip blocks the projecting member from moving distally, back through the passageway.