Enhancing Coil for Vaso-occlusive Delivery Wire
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current vaso-occlusive coil delivery systems face issues with buckling, kinking, or bending of the pusher wire's detachment zone, leading to premature detachment and potential misplacement of the occlusive device during navigation through the vascular system.
Innovation Solution
A delivery wire assembly featuring a core wire with a distal detachment zone surrounded by an enhancing coil, which transfers distally directed force without damaging the detachment zone, and is electrically connected to form part of the electrolytic detachment circuit, ensuring the occlusive device is advanced through the vasculature without compromising the detachment zone.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the detachment zone is made exposed and susceptible to electrolysis for device release, then the occlusive device can be reliably detached from the pusher wire, but the detachment zone becomes the weakest part and is prone to buckling, kinking, or bending during navigation
Solution Approach 1:
The patent applies beforehand cushioning by surrounding the detachment zone with a coil structure that provides mechanical support and protection. This coil acts as a protective element that prevents buckling, kinking, or bending of the detachment zone during navigation through the vascular system, while still allowing electrolytic detachment to occur when needed.
2Adaptability or versatility
If the pusher wire is made flexible for navigation through vasculature, then the device can be delivered to remote sites, but the detachment zone becomes more susceptible to fatigue failure and premature detachment
Solution Approach 1:
The coil surrounding the detachment zone provides beforehand cushioning by absorbing mechanical stresses and protecting the detachment zone from fatigue failure during navigation. This allows the pusher wire to remain flexible for vascular navigation while the coil structure prevents premature detachment.
3Ease of operation
If the detachment zone is exposed to ionic solution for electrolytic detachment, then the device can be released from the pusher wire, but the exposed section becomes vulnerable to electrolysis damage and disintegration
Solution Approach 1:
The coil structure acts as an intermediary element that allows electrolytic detachment to occur while protecting the detachment zone from excessive electrolysis damage. The coil provides a controlled environment for the electrolytic process while preventing complete disintegration of the detachment zone.
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 enhancing coil configuration minimizes damage to the detachment zone, reducing the risk of premature detachment and ensuring reliable placement of the occlusive device, thereby preventing the need for additional procedures to retrieve misplaced coils.
Implementation Method 1
the enhancing coil is preferably configured to transfer a distally directed force from the delivery wire assembly to objects located distal of the delivery wire assembly without damaging the distal detachment zone
Implementation Method 2
The detachment zone is typically made of stainless steel and is located just proximal of the vaso-occlusive device. An electrolytically severable junction is susceptible to electrolysis and disintegrates when the pusher wire is electrically charged in the presence of an ionic solution, such as blood or other bodily fluids.
Implementation Method 3
In 'bipolar' systems, return electrodes are located on the pusher wire, e.g. on a delivery wire conduit, but electrically insulated from the conductive path ending in the detachment zone. The anode is made up of a polyimide insulated core wire, which runs through the pusher wire, is attached to the electrical contact at the proximal end, and forms the detachment zone at the distal end.
Data Source
AI summary
A delivery wire assembly for delivering an occlusive device to a location in a patient's vasculature, includes delivery wire conduit defining a conduit lumen, a core wire disposed in the conduit lumen, the core wire having a distal detachment zone, and an enhancing coil disposed around the distal detachment zone, the enhancing coil configured to transfer a distally directed force from the delivery wire assembly to objects located distal of the delivery wire assembly without damaging the distal detachment zone. In one embodiment, the enhancing coil includes a proximal section having a first diameter, a distal section having a diameter larger than the diameter of the proximal section, and a transition section connecting the respective proximal and distal sections, wherein the transition section flares radially in a distal direction.