A diagnosis method and apparatus for measuring blood hemoglobin concentration,
oxygen saturation, pulse rate, respiration rate, or degree of aging of blood vessels
using light includes an input/output unit for receiving a command for measurement
from a user and for providing information on the result of a measurement to the
user; a control unit for receiving the command for measurement from the input/output
unit and for generating a control signal; a light generating unit for generating
at least two light beams for measurement according to the control signal; a light
receiving unit for receiving the light beams transmitted through an object that
is subject to measurement and for converting the received light beams into electrical
signals; and a data processing unit for processing the electrical signals received
from the light receiving unit and for outputting information on the result of a
predetermined measurement.