There are many reports on the clinical effect of acupuncture. We considered the quality of the needle is an important factor to improve the clinical effect and researches.
We did the following test on stainless steel needles.
1. Elasticity test. Bend the needle up to 90 degree position from original place and keep 90 degree position for a second, then release and check the restoration ability. (indicate in angle.)
2. Bending durability test.
Repeat the bending 30 degree angle to the both right anb left (total 60 degrees), until the needle fractured. (indicating the times of bending).
3. Sharpness of needle tip and smoothness of needle body. Penetrate the polyethylene film (thickness of film is 0.1mm), and measure the pressure required to penetration and resistance force at the time of insertion.
Summary of the results:
1. Elasticity test
The thinner needle indicates a bigger restorability which shows as follows;
0.152mm (thin)-78.1°, 0.179mm-69.5°, 0.215mm-67.4°, and 0.327mm (thick)-54.2° 2. Thin needle (0.152mm) was fractured at 491st bending, 0.179mm-440th bend, 0.215mm at 314th and the thick needle (0.327mm) at 98th bend. This test indicates fact that a thinner needle is stronger against bending.
3. The burden of penetraion of the thinnest needle (0.152mm) was 6.90g, the insertion resistance was 3.70g, 0.179mm needle-8.13g and 3.50g, 0.215mm needle-9.20g and 4.00g; the thick needle (0.327mm)-11.45g and 5.70g respectively.
According to these tests, the thinner needle has higher restorability, durability and sharpness than the thick one. Through the tests, we showed the needle standard by numbers, and we feel the necessity of consistency of needle quality for the research of acupuncture effect.
