A method and apparatus for indirect, quantitative estimation of beat-to-beat arterial blood pressure utilizing the individualized rectifying technique. A function TK=H(P) that describes the relationship between Korotkoffs sound delay time Tk and cuff pressure P is obtained by measuring the different cuff pressure P and corresponding Tk in the Korotkoffs sound sensor that is distal to the cuff. Keep the cuff pressure at a constant value Pm, the blood pressure variance can be calculated using the Korotkoffs sound delay time Tkm, according to the function Tk=H(P). The invention can measure the beat-to-beat artery blood pressure indirectly. The technique can be applied to obtain individual coefficient of regress equation for continuous arterial blood pressure measurement by the instantaneous blood pressure fluctuation, which make the rectifying technique more safe, effective and less erroneous. The technique makes the operation of noninvasive continuous blood pressure measurement for long time more practical.
