Variable Pitch Flexible Needle for Lung Biopsy
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Solution Overview
Problem
Existing biopsy needles are inflexible and difficult to maneuver in the lungs, particularly in accessing small peripheral airways, leading to challenges in diagnosing lung cancer due to limited angulation and potential loss of vacuum during tissue aspiration.
Innovation Solution
A flexible needle assembly with a spiral cut having a continuously variable pitch, covered by heatshrink tubing, which allows for greater articulation and reduces stress concentrations to prevent shunt creation and maintain vacuum pressure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a spiral cut is laser cut through the needle's wall to achieve needle flexibility, then greater endoscope angulation is permitted, but the heatshrink material may be under compression or tension stress leading to tearing or cracking and creation of a shunt
Solution Approach 1:
The patent applies parameter changes by modifying the pitch of the spiral cut from constant to variable. The spiral cut transitions from a first pitch in the first portion of the needle to a second pitch in the second portion, where the second pitch is greater than the first pitch. This gradual change in pitch reduces stress concentrations on the heatshrink material, preventing tearing or cracking while maintaining the desired needle flexibility and endoscope angulation capability.
2Reliability
If the heatshrink material covers the laser cut section to prevent shunt creation, then vacuum is maintained for tissue aspiration, but the material is subjected to high stress at the ends of the laser cut
Solution Approach 1:
The patent resolves this contradiction by implementing a variable pitch spiral cut where the pitch increases from the first portion to the second portion of the needle. This gradual pitch transition reduces the stress concentration on the heatshrink material at the ends of the laser cut, allowing the material to maintain vacuum integrity without tearing or cracking under compression or tension stress.
3Device complexity
If straight biopsy needles are used for tissue biopsy, then the needle structure is simple and rigid, but the needle limits bronchoscope articulation and is difficult to pass through tight corners
Solution Approach 1:
The patent applies this principle by introducing a spiral cut through the needle wall, which transforms the rigid straight needle into a flexible structure. The spiral cut allows the needle to articulate with the bronchoscope and navigate tight corners while maintaining structural integrity. The flexible needle can bend without compromising its ability to perform biopsy functions.
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
Enables better access to lung nodules and lymph nodes with increased sample quality and reduced diagnostic errors by providing enhanced flexibility and maintaining tissue aspiration efficiency.
Implementation Method 1
to allow for tissue aspiration via a vacuum from the needle tip through its entire length
Implementation Method 2
Needle flexibility is typically achieved via a spiral hole that is laser cut through the needle's wall along the needle's length
Data Source
AI summary
Disclosed embodiments include flexible tube assemblies, flexible needle assemblies, systems, methods of fabricating a flexible tube, and methods of fabricating a flexible needle. In an illustrative, non-limiting embodiment, a flexible tube assembly includes: a flexible tube having a proximal end with a proximal strain relief section and a distal end with a distal strain relief section, the proximal strain relief section being located between the proximal end and the distal strain relief section and the distal strain relief section being located between the distal end and the proximal strain relief section, the distal end defining an opening therein, at least a portion of at least one of the proximal strain relief section and the distal strain relief section defining therein a spiral cut with a continuously variable pitch; and tubing disposed in an airtight manner over an exterior surface of the flexible tube at least the portion of the at least one of the proximal strain relief section and the distal strain relief section defining therein the spiral cut with a continuously variable pitch.