A variety of methods are described, equipment, and the system for collecting breathing from a kind of main body are calculated. In one aspect, a kind of method for collecting breathing from a main body includes capturing a target sample from an exhaled gas of a main body, the target concentration with a target volatile organic compounds (VOC). The target sample of target VOC is captured from the alveolar volume score of exhaled gas, and exhaled gas indicates the lung capacity of main body. The target concentration of one target VOC may, for example, be a raised or low concentration for the target sample of the exhaled gas of the remaining score relative to exhaled gas, can find in dependent on the particular fraction for aiming at the special compound exhaled gas collected or analyzed.
