Stretch Resistant Embolic Coil Mechanical Release
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing catheter-based embolic coil deployment systems face challenges in accurately placing and releasing stretch-resistant embolic devices within the tortuous vasculature of the human brain, particularly in aneurysms, due to limitations in precision and reliability of detachment mechanisms.
Innovation Solution
A vascular occlusive embolic device deployment system comprising a flexible catheter, a pusher member, an embolic coil coupled to a retaining ring, and a detachment mechanism involving an engagement member and a detachment member that interlocks the coil to the pusher member, allowing for precise placement and release of the embolic device at a predetermined site within a vessel.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a stretch-resistant embolic coil is used to prevent stretching during withdrawal, then the reliability of device placement is improved, but the device complexity increases due to the need for additional stretch-resistant members and mechanical release mechanisms
Solution Approach 1:
The engagement member is divided into separate functional components: a retaining portion that engages the coil and a release portion that interacts with the detachment member. This segmentation allows the stretch-resistant coil to be delivered through complex vasculature while providing a reliable mechanical release mechanism that can be actuated distally, resolving the contradiction between reliability and complexity by organizing complex functions into modular segments.
Solution Approach 2:
The detachment member acts as an intermediary element between the operator and the engagement member. By providing a distal detachment mechanism that can be actuated from within the vessel, the system enables reliable release of the stretch-resistant coil without requiring complex proximal manipulation, thus improving placement reliability while managing device complexity through the use of a mediating release component.
2Ease of operation
If a mechanical release mechanism with distal detachment is used, then the ease of operation is improved by allowing repositioning and removal, but the device complexity increases due to additional components like engagement members and detachment members
Solution Approach 1:
Instead of providing a release mechanism at the proximal end of the catheter, the invention inverts the approach by providing a detachment member at the distal end that can be actuated from within the vessel. This inversion allows the operator to release or reposition the coil after it has been deployed, significantly improving ease of operation. The engagement member structure, while adding some complexity, is designed with a simple aperture and resilient properties that minimize the overall complexity increase.
Solution Approach 2:
The engagement member is designed with resilient properties that allow it to dynamically engage and disengage from the coil. The aperture in the engagement member can accommodate the coil during delivery and then release it when the detachment member is actuated. This dynamic design enables repositioning and removal capabilities, improving ease of operation while keeping the structural complexity manageable through the use of elastic deformation rather than complex mechanical joints.
3Measurement precision
If fluoroscopic visualization is used to monitor coil movement, then the measurement precision is improved for tracking coil position, but the loss of time increases due to the need for continuous imaging and manual manipulation
Solution Approach 1:
The stretch-resistant coil is pre-formed with a specific configuration and attached to the engagement member before delivery. The engagement member is pre-loaded into the catheter with the coil in a constrained state. This preliminary preparation allows the coil to be delivered quickly through the vasculature under fluoroscopic guidance and then rapidly released or repositioned by simple actuation of the detachment member, reducing the overall deployment time while maintaining precise position tracking through imaging.
Solution Approach 2:
The mechanical release mechanism allows the operator to quickly release the coil from the catheter by actuating the detachment member, skipping the time-consuming process of manual coil manipulation that would be required with adhesive or solder-based systems. The coil can be rapidly deployed or repositioned in response to fluoroscopic feedback, reducing the overall procedure time while maintaining measurement precision through continuous imaging guidance.
Data Source
Figure 1
Figure 1A
Figure 2A~2C
AI summary
A medical device (10) for placing an embolic device (23) at a predetermined site within a vessel of the body including a delivery catheter (12) and a flexible pusher member (16) having a lumen therethrough and being slidably disposed within the lumen (14) of the catheter. A stretch resistant embolic device (23) is retained within the delivery catheter (12) by a mechanical interlocking mechanism which includes an engagement member (18) which is attached to the distal end of the pusher member (16) and extends through a retaining ring (28) at the proximal end of the embolic device (23). A detachment member extends through an aperture (22) at the distal end of the engagement member (18) thereby locking the embolic device (23) onto the pusher member (16). The engagement member (18) engages a retaining ring (28) on the embolic device (23). When the embolic device (23) is advanced to the predetermined site within the vessel, the detachment member (30) is withdrawn from the aperture (22) to thereby release the embolic device (23) at the treatment site.