Plasma-Processed Puncture Needle Surface Smoothing

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Solution Overview

Problem

Current puncture needles, such as insulin injection needles, cause significant pain due to their diameter and surface roughness, leading to discomfort for patients, and existing methods to reduce pain are insufficient.

Innovation Solution

A method of manufacturing puncture needles involving plasma processing of metallic base materials in a mixed gas atmosphere with argon as the main gas and oxygen/nitrogen as the reaction gas, reducing surface roughness and pain during use.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If the outer diameter of the needle is reduced to decrease piercing pain, then the piercing pain is reduced, but the needle tip size becomes too small to secure the required infusion volume

Engineering Contradiction:
Improvepiercing painVSAvoidneedle tip size
Core Design Contradiction:
Object-affected harmful factorsVSVolume of moving object

Solution Approach 1:

The needle is designed with different diameters at different locations: a small diameter at the tip portion to reduce piercing pain and a larger diameter at the base end portion to secure infusion volume. This local variation in dimensions allows the needle to simultaneously satisfy both requirements of minimizing pain and maintaining adequate flow capacity.

Inventive Principle:
Principle #3Local quality

2Object-affected harmful factors

If the surface of the needle tube is polished to reduce surface roughness, then the frictional resistance against the living body is reduced, but the manufacturing complexity and time increase

Engineering Contradiction:
Improvefrictional resistanceVSAvoidmanufacturing time
Core Design Contradiction:
Object-affected harmful factorsVSLoss of time

Solution Approach 1:

The mechanical polishing process is replaced with plasma processing, which uses plasma chemistry to smooth the needle surface. This substitution achieves the desired surface roughness (Ra ≤ 0.8 μm) while significantly reducing manufacturing time and complexity compared to traditional mechanical polishing methods.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Manufacturing precision

If conventional plasma processing is used to smooth the needle surface, then the surface roughness is reduced, but the surface becomes too smooth causing the needle to stick to the living body

Engineering Contradiction:
Improvesurface roughnessVSAvoidsticking to living body
Core Design Contradiction:
Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The plasma processing parameters are precisely controlled to achieve an optimal surface roughness range (Ra ≤ 0.8 μm). By adjusting parameters such as gas composition (He/O2 mixture), power, and processing time, the surface is smoothed enough to reduce friction but not so smooth that it causes sticking, thereby resolving the contradiction between surface smoothness and anti-sticking properties.

Inventive Principle:
Principle #35Parameter changes

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

The method significantly reduces piercing pain by smoothing the needle surface, resulting in a puncture needle that causes minimal discomfort during use.

Implementation Method 1

processing a needle-like metallic base material, having at an end a machined surface obtained by machining, with plasma generated in an atmosphere filled with a mixed gas mainly including a main gas and a reaction gas

Methodology Applied
Scientific EffectPlasma: Plasma

Data Source

PatentEP2818580B1Method for producing a puncture needle
Publication Date: 2016.06.01 SHINMAYWA INDUSTRIES LTD
  • EP2818580B1 patent drawingFigure 1(a)~1(b)
  • EP2818580B1 patent drawingFigure 2
  • EP2818580B1 patent drawingFigure 3(a)~3(c)

AI summary

Provided is a method for producing a puncture needle, which causes no significant pain during use such as when pierced. The method for producing the puncture needle includes the step of processing a pipe-like metallic base material having at one end a grinding surface obtained by machine work with plasma generated in an atmosphere filled with a mixed gas mainly including a main gas and a reaction gas.