Bio-metric technology is mainly refers to the identity authentication by human biological characteristics of a kind of technology, the biological characteristics of usually has a unique (different) with others, can be measured or can automatic identification and verification, genetic or lifelong, etc.The so-called bio-metric core is how to obtain these traits, and convert it to digital information, stored in a computer, use reliable matching algorithm to complete the verification and recognition process of personal identity.

Physical characteristics include: fingerprints, vein, palm, retina, iris, body odor, face and even blood vessels, such as DNA, bone;Behavior characteristics include: signatures, voice, walking gait, etc. Bio-metric system is carried out on the biological characteristics of sampling, extract its unique feature is converted into digital code, and further to the code of feature template, when people interaction with recognition system authentication, the recognition system by capturing the characteristics and compare the features in the database template, in order to determine whether the two match, thus decided to accept or reject the mentally incapacitated person.