Heart-sound detecting apparatus and heart-sound detecting method

1. An apparatus for obtaining information relating to a velocity at which a pulse wave propagates through an artery of a body portion of a living subject, the apparatus comprising:

a heart-sound detecting apparatus comprising

a pressure-pulse-wave sensor which is adapted to be worn on the body portion of the subject that is distant from a chest of the subject, detects a pressure pulse wave produced by the artery of the body portion, and generates a pressure-pulse-wave signal representing the detected pressure pulse wave, and

a heart-sound extracting means for extracting, from the pressure-pulse-wave signal generated by the pressure-pulse-wave sensor, a heart-sound component representing a heart sound of the subject; and

an information obtaining means for obtaining said information based on a first timing at which the pressure-pulse-wave sensor of the heart-sound detecting apparatus detects a prescribed periodic portion of the heart sound, and a second timing at which the pressure-pulse-wave sensor detects a prescribed periodic portion of the pressure pulse wave;

wherein the information obtaining means comprises means for obtaining, as said information, a time difference between the first and second timings.

2. An apparatus according to claim 1 , wherein the information obtaining means comprises means for obtaining, as said information, said velocity by dividing, by said time difference, a distance between a heart of the subject and the body portion thereof distant from the chest thereof.