Segmented Stylet Access Needle for Contrast Fluid Flow
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Solution Overview
Problem
Existing access needles with solid stylets obstruct the flow of contrast fluid through the cannula lumen, making it difficult to use fluoroscopy for precise localization of the needle tip during minimally invasive procedures.
Innovation Solution
The design of access needles with a coiled wire or multiple wire strand stylets that allow for a flexible body length, providing a path for fluid communication through the cannula lumen, enabling the passage of contrast fluid and facilitating fluoroscopic visualization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a solid wire stylet is used to provide reinforcement and sharp tip, then the stylet can provide structural support and piercing capability, but the stylet blocks the flow of contrast fluid through the cannula lumen
Solution Approach 1:
The solid wire stylet is segmented into multiple wire strands (e.g., 3-7 strands) arranged in a bundle. This segmentation reduces the overall cross-sectional area occupied by the stylet while maintaining structural support, allowing contrast fluid to flow through the spaces between the strands.
Solution Approach 2:
The stylet is configured as a porous or mesh-like structure with interstices between wire strands. This porous configuration allows contrast fluid to pass through the stylet structure itself, enabling both reinforcement and fluid flow functions simultaneously.
2Ease of operation
If a solid wire stylet is used to provide a sharp piercing tip, then the needle can effectively puncture tissue, but the stylet obstructs fluoroscopic visualization of the needle tip location
Solution Approach 1:
The segmented wire strand configuration reduces the bulk of the stylet, allowing contrast fluid to more effectively surround and delineate the needle tip location on fluoroscopic imaging, improving measurement precision while maintaining piercing capability.
Solution Approach 2:
The stylet has varying properties along its length - the distal end maintains a solid or densely packed configuration for sharp piercing, while the proximal portion uses a more open wire strand configuration to allow contrast fluid flow and improve fluoroscopic visualization of the needle tip.
3Quantity of substance
If the cannula lumen is enlarged to accommodate both stylet and contrast fluid flow, then contrast fluid can pass through, but the needle diameter increases causing more trauma to the patient
Solution Approach 1:
By segmenting the stylet into multiple thin wire strands, the effective cross-sectional area occupied by the stylet is reduced, creating sufficient space within the original cannula lumen for contrast fluid flow without requiring an increase in overall needle diameter, thereby minimizing patient trauma.
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 configuration allows for efficient and unimpeded passage of contrast fluid, enhancing the accuracy of needle tip localization and reducing exposure time to radiation during procedures.
Implementation Method 1
the flexible body of the stylet provides a path of fluid communication through the entire lumen of the cannula such that a contrast fluid can effectively pass through the lumen of the cannula
Implementation Method 2
If this method is used for location purposes, the access needle may comprise an echogenic tip at its distal end. Ideally, EUS can then be used to determine the location of the echogenic tip.
Implementation Method 3
fluoroscopy can be used to detect a dye or contrast fluid that has been placed within the patient's body. Specifically, x-rays are emitted through the body of the patient to determine the exact location of the contrast fluid.
Data Source
AI summary
Access needles and methods of using the needles are set forth in this disclosure. The needles can include a handle and a cannula having a proximal end operatively connected to the handle, a distal end, and a lumen extending through the body of the cannula. A protective sheath may surround the cannula. Further, a stylet may be removably disposed within the lumen of the cannula. The stylet includes a piercing tip at a distal end and a flexible body length extending proximally from the piercing tip to the handle. The flexible body of the stylet provides a path of fluid communication through the lumen of the cannula such that a contrast fluid can effectively pass through the lumen of the cannula. Methods of introducing cannulas to target locations within a body of a patient are also set forth in this disclosure.