Patent ID: 6527726
Filing Date: 2003-03-04
Classification: A61B

Abstract:
A blood pressure monitor comprising:an inflatable cuff which is adapted to be wound around a body portion of a living subject to press said body portion through which an artery of the subject extends; a blood pressure measuring device which measures a blood pressure of the subject by changing a pressure in said cuff; a cuff pulse wave sensor which detects a cuff pulse wave which is a pressure oscillation produced in said cuff; a distal pulse wave sensor which detects a distal pulse wave from a distal section of said artery located on a distal side of said cuff wound around said body portion; cuff-pressure increasing means for increasing said pressure of said cuff at a predetermined rate; first peak-interval determining means for determining a first interval between an upper-peak point and a lower-peak point of each of first heartbeat-synchronous pulses of said distal pulse wave which are detected by said distal pulse wave sensor when said pressure of said cuff is increased at said predetermined rate by said cuff-pressure increasing means; second peak-interval determining means for determining a second interval between an upper-peak point and a lower-peak point of each of second heartbeat-synchronous pulses of said cuff pulse wave which are detected by said cuff pulse wave sensor when said pressure of said cuff is increased at said predetermined rate by said cuff-pressure increasing means; difference determining means for determining a difference between the first interval of said each of said first heartbeat-synchronous pulses and the second interval of a corresponding one of said second heartbeat-synchronous pulses; and blood pressure determining means for determining, as a diastolic blood pressure of the subject, a pressure of said cuff corresponding to a time when the differences determined by said difference determining means significantly largely change.