Patent ID: 7566307

Claim:
A blood pressure monitoring apparatus comprising: a blood pressure measuring unit adapted to measure a blood pressure by a predetermined method; an electrocardiogram measuring unit adapted to measure an electrocardiogram; a pulse wave acquiring unit adapted to acquire a pulse wave in a predetermined location of a living body; a pulse wave propagation time calculating unit adapted to calculate a pulse wave propagation time from the pulse wave and, one of the electrocardiogram and a pulse wave acquired from a location different from the predetermined location; an estimated blood pressure calculating unit adapted to calculate an estimated blood pressure by using the pulse wave propagation time; an interval calculating unit adapted to calculate an interval between feature points contained in two consecutive heart beat waveforms of the electrocardiogram; a monitoring unit adapted to monitor one of a first correlation which is a correlation between a change of the pulse wave propagation time and a change of the interval between the feature points, and a second correlation which is a correlation between a change of the estimated blood pressure and a change of the interval between the feature points; and a control unit adapted to perform the measurement by said blood pressure measuring unit if said monitoring unit detects that the first correlation has become a negative correlation or the second correlation has become a positive correlation, and controlling said estimated blood pressure calculating unit to correct the estimated blood pressure on the basis of a difference between the measurement result and the estimated blood pressure.