Segmented Inner Needle for Puncture Device Stability
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Solution Overview
Problem
Existing puncture devices face issues with the outer needle collapsing or rising during puncture, leading to increased puncture resistance and difficulty in accurately accessing deep blood vessels, which can result in injury to the vessel or surrounding tissues.
Innovation Solution
A puncture device design featuring a hollow outer needle with a uniform diameter portion and a tapered portion, combined with an inner needle having a small diameter portion and a larger diameter portion, where the inner needle is inserted such that its needlepoint is most projected from the outer needle's distal opening, ensuring the outer needle follows the inner needle without collapsing and reducing puncture resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the inner needle and outer needle are made thin to reduce damage to blood vessel and facilitate puncture, then puncture performance is improved, but the needle tube becomes yielding and cannot reach deep targeted blood vessels
Solution Approach 1:
The inner needle is divided into multiple diameter sections: a small diameter portion (0.2-0.8mm) at the tip for puncture, a large diameter portion (1.0-2.0mm) at the proximal end for strength, and an intermediate portion connecting them. This segmentation allows the needle to be thin at the puncture tip while maintaining strength at the proximal end, resolving the contradiction between puncture performance and structural strength.
Solution Approach 2:
Different portions of the inner needle are given different diameters to serve different functions: the tip portion is thin for minimal tissue damage and easy puncture, while the proximal portion is thick for structural strength and flexibility. This local quality variation allows the needle to simultaneously achieve both puncture performance and strength requirements.
2Object-affected harmful factors
If the inner needle is made thin to reduce inner diameter, then puncture damage is minimized, but the time difference between actual puncture and flashback confirmation increases
Solution Approach 1:
The inner needle has a small diameter portion at the tip for minimal puncture damage, but a large diameter portion at the proximal end that accelerates blood flow and enhances flashback visibility. This local quality variation allows the needle to minimize damage at the puncture site while providing rapid feedback at the proximal end.
Solution Approach 2:
The large diameter portion acts as an intermediary structure that receives blood flow from the puncture site and accelerates it toward the proximal end, reducing the time difference between actual puncture and flashback confirmation while maintaining minimal damage at the thin-tipped puncture site.
3Ease of operation
If the inner needle is made thin, then puncture resistance is reduced, but the outer needle may collapse and rise during insertion
Solution Approach 1:
The inner needle is segmented into different diameter portions: a small diameter portion that reduces puncture resistance and allows the outer needle to follow smoothly, and a large diameter portion that provides structural support and prevents collapse during insertion. This segmentation resolves the contradiction between low puncture resistance and outer needle stability.
Solution Approach 2:
The inner needle has local quality variations with a thin portion at the tip for low puncture resistance and a thick portion at the proximal end for structural stability. This allows the needle assembly to maintain both easy puncture and stable insertion without outer needle collapse.
4Ease of operation
If the outer needle is made thin, then puncture resistance is reduced, but the needle tube becomes yielding and cannot access deep blood vessels
Solution Approach 1:
The inner needle is segmented with a small diameter portion for low puncture resistance and a large diameter portion for structural strength and flexibility. This segmentation enables the needle to penetrate deep tissues with minimal resistance while maintaining the strength needed to reach deep blood vessels without bending or collapsing.
Solution Approach 2:
The inner needle exhibits local quality variations where the tip portion is thin for low puncture resistance and deep tissue penetration, while the proximal portion is thick for structural strength. This local quality differentiation allows the needle to simultaneously achieve easy puncture and deep reach without yielding.
Data Source
AI summary
A puncture device is provided that does not allow an outer needle to collapse or rise at the time of puncture and exhibits small puncture resistance.A puncture device 1 includes: a hollow outer needle 2; an outer needle hub 3 provided at a proximal end portion of the outer needle 2; a hollow inner needle 4 inserted into the outer needle 2 for use; and an inner needle hub 5 provided at a proximal end portion of the inner needle 4. The inner needle 4 includes, from the distal side, a sharp needlepoint 41, a small diameter portion 42 having an almost uniform outer diameter; an intermediate portion 43 formed as a tapered portion which is progressively increased in outer diameter as it goes toward the proximal end; and a larger diameter portion 44 having inner and outer diameters larger than inner and outer diameters, respectively, of the small diameter portion 42. If the puncture device 1 is assembled, the needlepoint 41 is most projected from the distal opening 24 of the outer needle 2 and the proximal end of the small diameter portion 42 and the distal end of the large diameter portion 4 are located inside the outer needle 2. The inner diameter of the outer needle 2 at a portion L1 where the outer needle 2 covers the small diameter portion 42 of the inner needle 4 is smaller than the large diameter portion 44 of the inner needle 4.