Apparatus for measuring pulse-wave propagation velocity

An apparatus for measuring a propagation velocity of a pulse wave which is propagated through an artery of a living subject, the apparatus comprising:

• a first and a second heartbeat-synchronous-wave sensor which detect, as the pulse wave, a first and a second heartbeat-synchronous wave, respectively, each of which is produced from the artery of the subject in synchronism with a heartbeat of the subject;
• maximum-slope-line determining means for determining, with respect to at least one of said first and second waves, a maximum-slope line which passes through a maximum-slope point where a heartbeat-synchronous pulse of said one wave takes a maximum slope, such that said maximum-slope line has the maximum slope;
• maximum-point-line determining means for determining, with respect to said one wave, a maximum-point line which passes through a maximum point where said heartbeat-synchronous pulse of said one wave takes a maximum amplitude, such that said maximum-point line is parallel to a base line which passes through respective minimum points on both sides of the maximum point of said heartbeat-synchronous pulse of said one wave;
• reference-point determining means for determining a reference point from a point of intersection of said one wave and a line which passes through a point of intersection of said maximum-slope line and said maximum-point line and is perpendicular to the maximum-point line;
• and
• propagation-velocity determining means for determining the propagation velocity of the pulse wave based on a time difference between said reference point determined with respect to said heartbeat-synchronous pulse of said one wave and a corresponding heartbeat-synchronous pulse of the other of said first and second waves.

An apparatus for measuring a propagation velocity of a pulse wave which is propagated through an artery of a living subject, the apparatus comprising:

• a first and a second heartbeat-synchronous-wave sensor which detect, as the pulse wave, a first and a second heartbeat-synchronous wave, respectively, each of which is produced from the artery of the subject in synchronism with a heartbeat of the subject;
• reference-point determining means for determining, with respect to at least one of said first and second waves, a maximum-slope point where a heartbeat-synchronous pulse of said one wave takes a maximum slope, and determining the determined maximum-slope point as a reference point;
• and
• propagation-velocity determining means for determining the propagation velocity of the pulse wave based on a time difference between said reference point determined with respect to said heartbeat-synchronous pulse of said one wave and a corresponding heartbeat-synchronous pulse of the other of said first and second waves.