Blood pressure estimation apparatus and blood pressure estimation method

A blood pressure estimation apparatus which estimates blood pressure of a subject using a standardization mode and an estimation mode, comprising:

• blood flow sound power waveform calculation means for determining a blood flow sound power waveform from blood flow sound of the subject in the standardization mode;
• blood pressure measuring means for measuring reference systolic blood pressure and reference diastolic blood pressure of the subject in the standardization mode;
• standard pulse curve storing means for storing a standard pulse curve whose time axis and pulse pressure axis have been standardized such that times and pulse pressures at a start point and an end point of a rising phase of a pulse wave measured in advance will be constant, in the standardization mode;
• first computing means for determining a correspondence curve which represents a relationship between blood flow sound power and estimated blood pressure from relationships among the blood flow sound power waveform, the reference systolic blood pressure, the reference diastolic blood pressure, and the standard pulse curve, in the standardization mode;
• blood flow sound power measuring means for continuously measuring the blood flow sound of the subject and the blood flow sound power in the estimation mode;
• and
• second computing means for continuously estimating blood pressure from the blood flow sound power measured continuously, using the correspondence curve in the estimation mode.