Asynchronous Needle Capture for Suture Delivery
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Solution Overview
Problem
Existing suture delivery devices for closing vascular punctures require high actuation force to deploy multiple needles, which can be cumbersome and increase operator skill requirements, and may lead to complications like ischemia or thrombosis due to inaccurate needle positioning.
Innovation Solution
A suture delivery device with an elongated deployment shaft, a needle deployment assembly, a stabilizer, and a catcher assembly that asynchronously engages and retains needles, reducing the actuation force needed to deploy and capture needles by engaging subsets of needles at different times, allowing for reproducible and efficient suturing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple needles are deployed simultaneously to suture tissue, then suturing effectiveness is improved, but actuation force required increases significantly
Solution Approach 1:
The catcher assembly is divided into multiple capture points arranged in different radial positions and/or axial positions. Each capture point engages a subset of needles at different times during the retraction stroke, rather than all needles being engaged simultaneously. This segmentation of the capture function reduces the peak actuation force required while maintaining effective suturing through cumulative needle engagement.
2Ease of operation
If actuation force is reduced by engaging needles asynchronously, then ease of operation is improved, but device complexity increases
Solution Approach 1:
The catcher assembly features capture points nested within the catcher tube structure, with each capture point positioned at different radial and axial locations. This nested arrangement allows multiple capture points to be integrated into a single cohesive assembly that engages needles sequentially during retraction, reducing operational complexity despite the multi-point capture mechanism.
3Reliability
If needles are positioned accurately far from opening, then hemostasis quality is improved, but needle deployment precision requirements increase
Solution Approach 1:
The needle deployment assembly includes positioning features such as guides or stops that pre-position needles at optimal distances from the vessel opening before deployment occurs. This preliminary positioning ensures that when needles are deployed, they automatically penetrate at the correct depth and location to achieve effective hemostasis, reducing the need for high-precision manual positioning while maintaining hemostasis quality.
Data Source
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AI summary
An elongated deployment shaft carrying a needle deployment assembly with needles carrying sutures and a stabilizer. A catcher tube over the shaft having a catcher assembly at a distal end may retain a portion of the needles when passed through the tissue into engagement with catcher assembly. The catcher and needle deployment assemblies are configured to asynchronously engage the plurality of needles when moved distally beyond the catcher assembly. A sheath over the catcher tube may sandwich the tissue against the stabilizer when expanded. A first actuator may move catcher tube distally to decrease distance between proximal and distal ends of the stabilizer expand it and may move the sheath distally to sandwich the tissue. A second actuator may deflect the needles outward to move proximally through the tissue and engage the catcher and return a portion of each not retained by the catcher to a distal position.