Endoscope Puncture Needle Inner Sheath Gap Coverage
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Solution Overview
Problem
Existing puncture needles for endoscopes face difficulties in moving the needle tube within a sheath when the sheath is largely bent, due to deformation and the risk of the needle tip entering gaps between coil loops, which interferes with the needle's movement.
Innovation Solution
A puncture needle design featuring a coil sheath with an inner sheath that covers the gaps between coil loops, allowing the needle tube to move freely even in a bent state, utilizing a manipulation section with a needle slider and engaging section to control the needle's advancement and retraction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a coil sheath is used to allow large bending, then the sheath can be largely bent, but gaps occur between wire loops and the needle tip may enter the gaps interfering with movement
Solution Approach 1:
An inner sheath is introduced as an intermediary component between the needle tube and the coil sheath. The inner sheath covers the gaps between the wire loops of the coil sheath, preventing the needle tip from entering these gaps. This mediator allows the coil sheath to maintain its bending capability while eliminating the harmful gap formation that interferes with needle tube movement.
2Device complexity
If a resin tube is used as sheath, then the structure is simple, but the tube may be flattened and it is difficult to largely bend
Solution Approach 1:
The sheath is constructed as a composite structure combining a coil-shaped outer sheath made of wire with an inner sheath. The coil structure provides excellent bending capability and flexibility, while the inner sheath maintains structural integrity. This composite design overcomes the limitation of simple resin tubes that flatten and resist bending.
3Productivity
If the needle tube is moved in a bent sheath, then tissue sampling can be performed in deep organs, but frictional resistance increases and movement becomes difficult
Solution Approach 1:
The inner sheath serves as a mediator that provides a smooth, continuous surface for the needle tube to slide against. This eliminates the irregular gaps between coil loops that create friction and resistance. The inner sheath ensures that the needle tube can move freely even when the outer coil sheath is bent, enabling easy operation during tissue sampling in deep organs.
Data Source
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AI summary
In a puncture needle for an endoscope, in a state in which a distal end of an outer sheath (71) is located in an observation field of an observation optical system of an endoscope and a needle slider (23) is retracted to abut a needle slider engaging section (9b), a distal end of an inner sheath (74) is located closer to a distal side than a proximal end (108b) of a raising base (108) in the outer sheath (71), and a proximal end of the inner sheath (74) is located closer to a proximal side than a needle tip (3a) of a needle tube (3) in the outer sheath (71).