Near infrared light penetration ability is stronger than visible light,
and the hemoglobin in the blood has better absorption towards NIR than other tissues.
Visible light
Visible light can penetrate into the skin 1~2mm depth only, and most of it is reflected and scattered.
Infrared light
Epidermis
Dermis
Superficial vein
Subcutaneous tissue
Infrared radiation value ≤0.6mW/cm
Dual light source
World’s First Depth Detection Mode