Patent ID: 8491490

Claim:
An analyzing method of analyzing a load signal corresponding to changes in loads of a subject applied to a bed, the load signal including a first alternating current (AC) signal having first amplitudes contained in a first width and a second AC signal having second amplitudes contained in a second width larger than the first width, the analyzing method comprising: a first operation, performed by a first counter, including extracting a respiratory disorder pattern in which the first AC signal is followed by the second AC signal, extracting as a respiratory signal individual amplitude data of the amplitude values of individual crests in the respiratory disorder pattern, selecting, in succession, each of the crests forming the respiratory disorder pattern, and determining, for each selected crest, an average of amplitude values of a plurality of crests from the individual amplitude data, the selected plurality of crests including the selected crest and one or more neighboring crests, creating an averaged amplitude pattern of the determined averages, and counting a number of average values of the averaged amplitude pattern that exceed a first reference value used to evaluate a sleep apnea syndrome per unit time as an initial number of respiratory disorders; and a second operation, performed by a second counter, including determining whether the amplitudes of the crests of the respiratory disorder pattern that are above the first reference value appear successively in the individual amplitude data when the number of respiratory disorders counted in the first step group is a number that indicates the presence of the sleep apnea syndrome, and reducing the first reference value to a second reference value when the maximum amplitudes of the crests of the respiratory disorder pattern that are above the first reference value appear successively, and counting a number of crests that exceed the second reference value as a new number of respiratory disorders.