Hand Veins

Abstract

In the human hand there is a complex structure of veins and blood vessels, many of which are just a few millimeters below the skin surface. Using noninvasive and safe imaging techniques it is possible to capture an image of the larger veins and blood vessels near the skin surface in various parts of the hand. These images are most readily obtained from the back of the hand and the palm of the hand. This vein structure, which is mostly invisible to the human eye, forms a pattern of interconnecting lines which is different from one individual to another and can be used as a physiological biometric. Two imaging methods can be used for safe, noninvasive imaging of veins near the skin surface: (1) Far infrared thermography, and (2) near infrared imaging. Far infrared imaging detects heat radiated from the hand and veins. Near infrared imaging detects infrared light reflected from a hand illuminated by near infrared light.