A method and apparatus for measuring the
biological condition of an animal by acquiring and analyzing its biological signals are provided. The biological signals from
skin temperature, a photoplenthysmogram (PPG), an electrocardiogram (ECG), electrodermal activity (EDA), an electromyogram (EMG), and an electrogastrogram (EGG) are detected using a biological
signal detection unit which is attached to the animal's
skin. Feature vectors, including the mean
heart rate of the photoplenthysmogram and its standard deviation, the
very low frequency,
low frequency, and
high frequency components of
heart rate variability, the frequency and mean amplitude of
skin conductance responses, and the mean and maximum skin temperatures, are extracted from the detected biological signals. The
biological condition, including needs and emotions, of the animal as to whether or not the animal feels hunger or fear, how much the animal is stressed, or whether or not the animal needs to have a bowel movement, is determined using a pattern classifier which has learned reference vectors, which reflect the behaviors, needs, and emotions of different kinds of animals for various biological conditions and are stored in a predetermined
database. Therefore, the
biological condition of the animal can be determined through instrumental communication, not through human languages, and the breeding of pets can be efficiently managed.