Notched Biopsy Stylet for Tortuous Navigation
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Solution Overview
Problem
Minimally invasive biopsy needle devices face challenges when navigating through tortuous passages due to binding issues between the needle body and cannula, leading to impaired functionality and tissue sample fragmentation.
Innovation Solution
A notched biopsy needle system with a stylet having a reduced diameter along specific lengths to enhance flexibility and prevent binding, featuring a first outer diameter slightly less than the cannula lumen and a second outer diameter that is significantly smaller to navigate through tight curves, reducing the likelihood of interference and improving sample capture.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the needle stylet has a consistent diameter along its length, then the structural strength is maintained, but binding occurs between the needle body and cannula during navigation through tortuous passages
Solution Approach 1:
The needle stylet features varying diameters along its length, with the distal portion having a larger diameter for strength and the proximal portion having a smaller diameter for flexibility. This local variation in geometric properties allows different sections to perform different functions: the distal section maintains structural integrity while the proximal section provides flexibility to navigate tortuous passages without binding.
Solution Approach 2:
The patent changes the geometric parameter (diameter) of the needle stylet along its length. By reducing the diameter of the proximal portion relative to the distal portion, the flexural rigidity is reduced in that section, enabling it to bend and conform to tortuous access paths without causing binding between the needle body and cannula.
2Ease of operation
If the needle stylet has a reduced diameter to enhance flexibility, then binding is prevented, but the structural strength may be compromised
Solution Approach 1:
The needle stylet features varying diameters along its length, with the distal portion having a larger diameter for strength and the proximal portion having a smaller diameter for flexibility. This local variation in geometric properties allows different sections to perform different functions: the distal section maintains structural integrity while the proximal section provides flexibility to navigate tortuous passages without binding.
3Reliability
If the needle body binds with the cannula during navigation, then functionality is impaired, but tissue sample fragmentation occurs
Solution Approach 1:
The patent changes the geometric parameter (diameter) of the needle stylet along its length. By reducing the diameter of the proximal portion relative to the distal portion, the flexural rigidity is reduced in that section, enabling it to bend and conform to tortuous access paths without causing binding between the needle body and cannula, thereby preventing tissue sample fragmentation.
Data Source
AI summary
A biopsy stylet and needle system is provided that is configured for navigation and spring-loaded deployment through at least one tortuous or otherwise confined length. The system includes a needle cannula through which a notched biopsy stylet is disposed. The notched biopsy stylet includes at least one outer diameter length that is about the same as, but preferably very slightly less than, the inner diameter of the needle cannula. The notched biopsy stylet also includes at least one outer diameter length that has a smaller diameter, the lengthwise position of which corresponds to the tortuous or otherwise confined length through which the system is to be operated. The smaller stylet diameter length is configured to prevent binding between the stylet and the needle cannula and/or between the needle cannula and an overlying access cannula or other access passage structure.