Needle Device with Movable Optical Fiber Insert
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Solution Overview
Problem
Current needle devices with integrated optical fibers for tissue inspection lack real-time feedback during procedures due to issues like light loss and autofluorescence from cladding materials, and fail to maintain sharpness and proper tissue contact.
Innovation Solution
A needle device with a multilumen concept, featuring a sharp, beveled tip and an insert with optical fibers that can be moved in and out of the cannula for precise optical measurements, ensuring good contact with tissue and minimizing blood accumulation in voids.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If optical fibers are integrated into the needle tip with bevelled ends, then optical measurements can be performed at the tissue interface, but total internal reflection causes light to exit through the cladding material producing unwanted autofluorescence that hampers measurement accuracy
Solution Approach 1:
The harmful cladding material is removed from the fiber tip region. The patent describes fibers where the cladding is stripped back to expose only the core at the tip, eliminating the source of unwanted autofluorescence while maintaining the fiber's structural integrity and optical guidance functions in the shaft region.
Solution Approach 2:
The fiber structure is made non-uniform along its length. The shaft region maintains the complete fiber structure (core-cladding-buffer) for mechanical strength and light guidance, while the tip region has stripped cladding to enable direct core-to-tissue contact and eliminate autofluorescence. This local modification optimizes each region for its specific function.
2Reliability
If fibers are extended beyond the bevel of the cannula to ensure tissue contact, then good optical contact with tissue is achieved, but voids between fiber end and tissue fill with blood reducing measurement quality
Solution Approach 1:
The fiber tip is made movable relative to the cannula bevel through a sliding mechanism. The fiber can dynamically adjust its position to protrude slightly beyond the bevel during measurement to ensure tissue contact, then retract to minimize void formation and blood accumulation. This dynamic adjustment optimizes both contact quality and void minimization.
Solution Approach 2:
The fiber position is pre-adjusted to protrude just beyond the bevel before the measurement procedure begins. This preliminary positioning ensures immediate tissue contact upon insertion while minimizing the size of voids that could fill with blood, optimizing measurement conditions from the start of the procedure.
3Productivity
If an insert with integrated fibers is made movable within the cannula, then real-time optical inspection is enabled during biopsy procedures, but the device complexity increases
Solution Approach 1:
The fiber-containing insert is nested within the cannula, with the insert having a smaller cross-sectional dimension than the cannula's internal diameter. This nesting arrangement allows the insert to move freely within the cannula for real-time measurements while the cannula provides external structural support and protection, reducing overall device complexity.
Solution Approach 2:
The movable insert serves multiple functions: it provides the optical measurement capability, acts as a stylet to maintain cannula patency during insertion, and can be adjusted to different positions for various measurement depths. This multi-functionality reduces the need for separate components, simplifying the overall device design.
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 real-time optical tissue inspection with reduced autofluorescence interference and maintains the needle's sharpness, allowing for accurate discrimination between healthy and diseased tissue during procedures.
Implementation Method 1
a movable insert (200) arranged within the hollow shaft (100) and comprising at least one optical fiber (300)
Implementation Method 2
the fibers in the stylet are bevelled and as a result a significant part of the light in the fiber will undergo total internal reflecton at the tip of the needle
Data Source
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AI summary
A needle device according to the invention comprises a hollow shaft, an elongated insert and an operating means. The hollow shaft has a first distal end portion with a bevel, the elongated insert has a second distal end portion and is movably arranged within the hollow shaft, and the operating means is shiftable between a first condition and a second condition. Furthermore, the operating means is interconnected with the elongated insert, so that the second distal end portion is located within the hollow shaft and proximally to the bevel, when the operating means is in the first condition, and that the second distal end portion is located outside the hollow shaft and distally to the bevel, when the operating means is in the second condition.