Telescoping Atrial Septum Needle Assembly
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Solution Overview
Problem
Current elongate needle assemblies face challenges in efficiently and safely traversing the atrial septum for medical procedures, particularly in maintaining precise control and preventing tissue damage during transseptal access.
Innovation Solution
A telescoping needle assembly comprising an outer cannula, a middle cannula, and a needle, where the cannulas and needle are designed for axial displacement within each other, with a handle that includes a locking mechanism to control the needle's extension and prevent skiving of tissue, allowing for controlled penetration of the atrial septum.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a standard elongate needle assembly is used to traverse the atrial septum, then the procedure can be performed with a simple structure, but precise control is lost and tissue damage risk increases
Solution Approach 1:
The needle assembly is divided into three separate telescoping segments (outer cannula, middle cannula, and inner needle) that can be independently controlled. Each segment has a defined function: the outer cannula provides initial access and protection, the middle cannula enables controlled advancement, and the inner needle performs the actual septal penetration. This segmentation allows precise control over each penetration phase while maintaining manageable structural complexity through modular design.
Solution Approach 2:
The assembly incorporates dynamic telescoping mechanisms that allow each cannula segment to extend and retract relative to the others. The outer cannula can telescope relative to the middle cannula, and the middle cannula can telescope relative to the inner needle, enabling controlled deployment and retraction sequences. This dynamic capability provides precise control over needle advancement and withdrawal while maintaining a compact profile when retracted.
2Ease of operation
If the needle is extended for septal penetration, then access across the atrial septum is enabled, but tissue skiving and foreign body embolization risk increases
Solution Approach 1:
The outer and middle cannulas are extended and positioned in advance to establish a protected pathway and guide the inner needle. The outer cannula is advanced first to create the initial tract, followed by the middle cannula which provides additional guidance and protection. Only after this preliminary positioning is complete is the inner needle extended through the protected pathway to perform the actual penetration, ensuring controlled advancement and minimizing tissue skiving.
Solution Approach 2:
The outer and middle cannulas serve as intermediary protective structures between the operator and the tissue. These cannulas with their rounded distal ends and smooth surfaces act as mediators that guide the sharp inner needle through the tissue while protecting against uncontrolled deviations. The intermediaries prevent the needle tip from skiving tissue and reduce the risk of embolization by maintaining a stable, protected penetration path.
3Reliability
If the needle assembly is kept compact for safety, then foreign body embolization risk is reduced, but controlled extension for penetration becomes difficult
Solution Approach 1:
The assembly employs a nested doll configuration where the inner needle is received within the middle cannula, which in turn is received within the outer cannula. When retracted, all segments nest together to form a compact unit that minimizes foreign body presence and embolization risk. When extension is required, each segment can be sequentially advanced in a controlled manner while remaining telescopically connected, maintaining both compact safety and controlled extendability.
Solution Approach 2:
The telescoping joints between cannula segments provide dynamic extension capability while maintaining compact retraction. Locking mechanisms at each telescoping interface allow the operator to securely hold each segment in its extended position during penetration, then smoothly retract them in sequence. This dynamic design enables controlled extension when needed while automatically returning to a compact safe configuration when retracted.
Data Source
AI summary
Devices used to provide transseptal access are disclosed. The devices may comprise at least one cannula, a needle, and a handle. The cannula and the needle may be configured to be inserted through a dilator while not damaging a lumen wall of the dilator. The handle may be configured to lock the needle in a retracted position. The devices may be configured to telescopically advance the needle through an atrial septum.