Segmented Needle Tube for Tissue Sampling
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Solution Overview
Problem
Current tissue sampling devices using thin needle tubes struggle to collect sufficient biological tissue for histological diagnosis due to limited diameter constraints, leading to inefficient sampling and increased operational complexity.
Innovation Solution
A tissue sampling device with a needle tube featuring a distal portion having a slit that extends toward the proximal side, allowing the distal portion to protrude radially outside the sheath, increasing the lumen volume and enabling easier sampling of biological tissue.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the diameter of the needle tube is increased to sample more biological tissue, then the amount of tissue sampled is increased, but the stiffness of the needle tube increases making it difficult to lead into the body cavity through the endoscope channel
Solution Approach 1:
The needle tube is divided into two distinct portions: a distal portion with a larger outer diameter for effective tissue sampling, and a proximal portion with a smaller outer diameter for flexible insertion through the endoscope channel. This segmentation allows each portion to have optimized dimensions for its specific function, resolving the contradiction between sampling capacity and insertability.
Solution Approach 2:
Different portions of the needle tube have different outer diameters tailored to their specific functional requirements. The distal portion has a larger diameter locally to maximize tissue sampling volume, while the proximal portion maintains a smaller diameter locally to ensure flexibility during insertion. This local quality variation resolves the contradiction by applying different dimensional characteristics to different spatial locations of the same component.
2Ease of operation
If a thin needle tube is used to maintain flexibility for insertion, then ease of leading into body cavity is improved, but the amount of biological tissue that can be sampled is extremely small
Solution Approach 1:
The needle tube is segmented into distal and proximal portions with different outer diameters. The distal portion has a larger diameter to sample sufficient tissue volume, while the proximal portion has a smaller diameter to maintain flexibility for easy insertion through the endoscope channel, resolving the contradiction between sampling capacity and insertability.
Solution Approach 2:
The needle tube exhibits local quality variation where the distal portion has a larger outer diameter optimized for tissue sampling and the proximal portion has a smaller outer diameter optimized for flexibility during insertion. This localized dimensional differentiation allows the needle tube to simultaneously achieve both adequate sampling volume and easy insertability.
3Ease of operation
If the needle tube diameter is restricted by the treatment tool insertion channel, then ease of insertion is maintained, but the lumen volume is insufficient for adequate tissue sampling
Solution Approach 1:
The needle tube is segmented into a distal portion with larger outer diameter and proximal portion with smaller outer diameter. The distal portion's larger diameter provides sufficient lumen volume for tissue sampling, while the proximal portion's smaller diameter ensures easy passage through the endoscope channel, resolving the contradiction between lumen volume and insertability.
Solution Approach 2:
The needle tube has local quality variation in its outer diameter along its length. The distal portion locally has a larger diameter to maximize lumen volume for tissue sampling, while the proximal portion locally has a smaller diameter to facilitate easy insertion through the constrained endoscope channel, resolving the volume-versus-insertability contradiction.
Data Source
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AI summary
A tissue sampling device includes a flexible sheath 34; a needle tube 35 which is inserted into the sheath 34 so as to advance and retreat and with which biological tissue is punctured; and an operating unit which is provided on a proximal side of the sheath 34 and is used for operating the advancing and retreating of the needle tube 35. This needle tube 35 has a distal portion provided with a slit 50 extending toward the proximal side from a distal opening 35c, and when the distal portion is in a state of protruding from a distal end of the sheath 34, at least a part of the distal portion is positioned further on the radially outside than the inner surface of the sheath when viewed from an axial direction of the needle tube 35.