Abstract: A system that accurately evaluates a living subject's circulatory system, even if the living subject is taking high blood pressure medication includes a time-difference determining device that determines a time difference between predetermined periodic points on a subject's electrocardiographic waveform and predetermined periodic points on corresponding oscillatory pressure-pulse waves of the living subject. A strain application device applies a physical strain to the subject's body for a predetermined period of time so that the subject' blood pressure changes. A blood-pressure measurement device measures the subject's blood pressure while the subject's blood pressure is changing. A circulatory-system evaluation device determines a relationship between changes in the subject's blood pressure and corresponding time differences determined by the time-difference determining. The circulatory-system evaluation device evaluates the subject's circulatory system based on the hysteresis present in the relationship.

Abstract: An apparatus that detects both the blood pressure and the electrocardiographic waveform of a living subject and that can be quickly and easily fitted to the living subject includes a cuff that is wrapped around a portion of the living subject for detecting the subject's blood pressure, and a flexible electrocardio electrode on the inner surface of the cuff for detecting the electrocardiographic waveform generated by the living subject's cardiac muscle. When the cuff is wrapped around a portion of the living subject, the electrocardiographic electrode is automatically fitted and correctly positioned on the living subject. Because the electrocardio electrode does not have to be separately fitted and attached to the living subject, the "set up" time is significantly reduced. Thus, the apparatus of this invention is especially useful in emergency medical situations, where rapid measurements are required.

Abstract: A system and method for evaluating the degree of elasticity of a subject's arteries includes an inflatable cuff that is wrapped around a portion of the living subject. A cuff pressure regulating circuit changes the constriction pressure applied by the inflatable cuff to the subject. A time-difference determining circuit determines a time difference between predetermined periodic points on an electrocardiographic waveform of the living subject and predetermined periodic points on corresponding pressure pulse waves of the living subject. An arterial elasticity evaluation circuit determines the degree of elasticity of the subject's arteries based on the relationship between changes in the time difference determined by the time-difference determining circuit and changes in the constriction pressure applied by the inflatable cuff.

Abstract: A system and method evaluates the autonomic nervous system of a living subject based on the high frequency components present in the fluctuations of the living subject's pulse cycle and on the low frequency components present in the fluctuations of the living subject's blood pressure. The autonomic nervous system evaluation system includes an electrocardiographic waveform determiner that detects an electrocardiographic waveform of the living subject. A pulse cycle determining circuit determines a pulse cycle of the living subject based on the electrocardiographic waveform. A blood pressure estimating circuit estimates the living subject's blood pressure based on time differences between predetermined periodic points on the electrocardiographic waveform and predetermined periodic points on corresponding pulse waves.

Abstract: A system for reliably and accurately measuring the electrocardiographic waveform generated by a subject's cardiac muscle includes electrocardio electrodes that have multiple openings on their surfaces, a body contact determination circuit for determining if a subject is in physical contact with the electrocardio electrodes, a blow control circuit for causing air to flow out of the multiple openings of the electrocardio electrode when the subject is not in physical contact with the electrocardio electrodes and a suction control circuit for causing air to be sucked through the multiple openings of the electrocardio electrodes when the subject is in physical contact with the electrocardio electrodes. In a preferred embodiment, a pulse wave propagation velocity determining circuit is used to determine the propagation velocity of a subject's pulse wave.