Abstract: A heart-sound detecting apparatus, including a heart-sound microphone which detects at least one heart sound produced by the heart of a living subject and outputs a heart-sound signal representing the detected heart sound, a time-frequency analyzing device for analyzing, with respect to time and frequency, at least a portion of the heart-sound signal that includes a first heart sound I, and an aortic-valve-opening-timing determining device for determining a timing when the aortic valve of the heart opens, based on a time when a magnitude of the analyzed signal at a frequency higher than a frequency range of a main component present in an initial portion of the first heart-sound I is greater than a prescribed threshold value.

Abstract: An apparatus for estimating an intraarterial blood pressure of a living subject, based on information non-invasively obtained from a circulatory organ of the subject, including: a first device for obtaining first information which relates to velocity of propagation of a pulse wave; a second device for obtaining at least one of second information which relates to heart rate and third information which relates to an area defined by a volume pulse wave; a third device for estimating, according to a predetermined relationship to between (A) blood pressure, and (B1) first information and (B2) at least one of (B21) second information and (B22) third information, the blood pressure, based on the first information and the at least one of the second information and the third information, the predetermined relationship being defined by a numerical expression including a plurality of predetermined coefficients; and a fourth device for selecting, from a plurality of groups of predetermined coefficients which correspond t

Abstract: An apparatus for successively estimating an intraarterial blood pressure of a living subject, based on information non-invasively obtained from a circulatory organ of the subject, including: a first device for non-invasively obtaining, from the circulatory organ of the subject, first information which relates to velocity of propagation of a pulse wave which propagates through an artery of the subject; a second device for non-invasively obtaining, from the circulatory organ of the subject, at least one of second information which relates to heart rate of the subject and third information which relates to an area defined by a volume pulse wave from a peripheral portion of the subject; and a third device for estimating, according to a predetermined relationship between (A) blood pressure, and (B1) first information and (B2) at least one of (B21) second information and (B22) third information, the intraarterial blood pressure of the subject, based on the first information obtained by the first device and the at l

Abstract: An apparatus for estimating an intraarterial blood pressure of a living subject, based on information of the subject, including: a first device for obtaining first information which relates to velocity of propagation of a pulse wave; a second device for obtaining at least one of second information which relates to heart rate and third information which relates to an area defined by a volume pulse wave; a third device for estimating, according to a predetermined relationship between (A) blood pressure, and (B1) first information and (B2) at least one of (B21) second information and (B22) third information, the blood pressure of the subject, based on the first information and the at least one of the second and the third information, the relationship being defined by a numerical expression including a plurality of coefficients; a fourth device for determining an activity of an autonomic nerve system, based on at least one of fourth information which relates to fluctuations of the blood pressure and fifth informa