Stent Apex Bore Design for Trigger Wire Restraint
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing stents face issues with trigger wire attachment and barb entanglement during compression, leading to potential damage to both the stent and trigger wires, particularly in cannula-cut stents with acute bends.
Innovation Solution
The stent design features alternating apices with bores for trigger wire attachment, reducing the need for multiple trigger wires and minimizing barb entanglement by using bores instead of vertices, thereby minimizing damage during delivery.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If trigger wires are looped through vertices of cannula-cut stents to restrain the stent during delivery, then the stent can be compressed to a reduced delivery profile, but the trigger wires become crimped and damaged at the vertices during compression
Solution Approach 1:
The patent extracts the trigger wire attachment point from the vertex region and relocates it to the apex region. By forming bores through the apices rather than through vertices, the trigger wires are positioned in a location that does not experience crimping during compression, thereby maintaining wire integrity while still enabling restrained delivery.
Solution Approach 2:
The bores are pre-formed through the apices during stent manufacturing, before delivery. This preliminary preparation allows trigger wires to be attached in a position that avoids compression-induced damage, eliminating the need for complex attachment mechanisms at the vertices.
2Volume of moving object
If trigger wires are threaded through vertices to restrain stent during delivery, then stent can be compressed to reduced diameter, but barbs become entangled with stent struts and trigger wires during compression
Solution Approach 1:
The patent removes barbs from the apex regions where trigger wires are attached. By relocating barbs to other stent surfaces away from the apex-vertex regions, the design eliminates the entanglement problem that occurs when barbs interact with compressed trigger wires and stent struts during delivery.
3Reliability
If multiple trigger wires are used to restrain stent apices, then stent can be securely held during delivery, but device complexity increases
Solution Approach 1:
The patent designs the apices to be universally attachable to trigger wires through pre-formed bores. Each apex can serve as an attachment point, allowing flexible configuration where one or more trigger wires can be used depending on the specific delivery requirements, simplifying the overall system while maintaining reliable restraint.
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 design allows for effective compression and expansion of the stent while reducing the risk of trigger wire and stent strut damage, and minimizes barb entanglement, facilitating safer and more efficient delivery.
Implementation Method 1
In a stent made of a shape-memory alloy such as nitinol, the shape-memory alloy may be employed to cause the stent to return to a predetermined configuration upon removal of the sheath or other device maintaining the stent in its predeployment configuration.
Data Source
AI summary
The present embodiments provide a stent for use in a medical procedure that comprises a series of proximal apices disposed at a proximal end of the stent and a series of distal apices disposed at a distal end of the stent. A trigger wire is adapted to be coupled to at least one of the proximal apices to restrain a proximal end of the stent during delivery. In a first embodiment, a first proximal apex comprises a bore for receiving the trigger wire, and a second proximal apex, disposed adjacent to the first proximal apex, comprises at least one barb. The trigger wire therefore is only coupled to selected ones of the proximal apices. In an alternative embodiment, a first proximal apex comprises a first bore and a second, adjacent proximal apex comprises a second bore, such that a single trigger wire may be disposed through the first and second bores to restrain the first and second proximal apices during delivery.