Harmless near-infrared light is projected from vein finder to the skin and then absorbed by the Deoxyhemoglobin in veins so there is a reduced amount of light reflection from the veins, but the light will be totally reflected by surrounding tissue. Then Vein Illuminator will detect the reflected near infrared light information and analysis it in processor therefore identify the veins.
It's all about Precision
After processing, Vein finder will project the vein image on the surface of skin at the exact position.The precision is crucial for vein finder since there is almost no room for deviation. The accuracy of VeinSight Vein Finder is less than 0.5mm.
Other Kind of Vein Finder
There are surely other kind of Vein Finder, the common principle is that the Deoxyhemoglobin in veins can absorb lights that the surrounding tissue only reflect. And the differentiation is different vein finder uses different light.For example, Accuvein uses Laser, and VEINLITE uses LED light. But most vein finder in the market uses Near infrared light, because it's more safe and has a good perfermance.Read more about VeinSigth Vein Finder VS500