FIELD : medicine.SUBSTANCE : group of inventions relates to medicine. Method for determining respiratory signals of a subject is carried out using a device for determining respiratory signals. Using the receiving unit, the image data determined by the subject in the observation field are received. Processing unit evaluates image data by detecting motion patterns or detecting contours. Obtained images are divided into parts to detect motion vectors from different parts. Motion vectors are determined by detecting patterns in parts of an image or by detecting contours in sections of an image. Estimating unit is used to determine various periodic signals corresponding to the inhalation-exhalation frequency information of the subject from different observation field areas based on the motion pattern. Spectral parameter of periodic signals, such as a frequency spectrum or distribution of spectral energy of each of the signals, is determined using a frequency analysis unit. Using the selection unit, selecting different parts of the image based on the spectral parameter as different zones. Various respiratory signals are determined based on different periodic signals from different zones. Different respiratory signals are determined based on motion vectors from different regions of the subject. Weight coefficient is determined for each of the selected different parts of the image and various respiratory signals based on periodic signals of the selected image parts weighted with a weight coefficient.EFFECT : higher accuracy of breath detection.9 cl, 7 dwg