Abstract: In some embodiments, a device to measure a shape of cyclic variation of heart rate (CVHR) comprises a processor to detect CVHR from time series data of cardiac or pulse wave inter-beat interval, heart rate, or pulse rate; acquire at least one shape property index with respect to a waveform of the detected CVHR; and evaluate health risk based on the at least one shape property index. The CVHR appears periodically in the time series data. The at least one shape property index is selected from the group consisting of an amplitude of the CVHR (ACV), a slope, a ratio of the ACV to a duration, and an area. The health risk is inversely correlated with an intensity of a heart rate response determined from the at least one shape property index.

Abstract: Vascular endothelial function in terms of flow-mediated dilation (FMD) of peripheral arteries can be assessed reliably by measuring beat-to-beat pulse-wave conduction time (PCT) simultaneously for two symmetric segments of arteries locating on the right and left sides of body. When reactive hyperemia is induced in the peripheral tissues on one side, the time dependent changes in PCT caused by FMD on that side can be detected as the beat-to-beat differences in PCT between two sides (?PCT). ?PCT would provide a sensitive and specific assessment of the FMD response, because the influences of the systemic changes in hemodynamic and neurohumoral factors common to both sides are subtracted out. In addition, measurement of PCT requires no skillful technique and is advantageous in that the apparatus is inexpensive.

Abstract: Vascular endothelial function in terms of flow-mediated dilation (FMD) of peripheral arteries can be assessed reliably by measuring beat-to-beat pulse-wave conduction time (PCT) simultaneously for two symmetric segments of arteries locating on the right and left sides of body. When reactive hyperemia is induced in the peripheral tissues on one side, the time dependent changes in PCT caused by FMD on that side can be detected as the beat-to-beat differences in PCT between two sides (?PCT). ?PCT would provide a sensitive and specific assessment of the FMD response, because the influences of the systemic changes in hemodynamic and neurohumoral factors common to both sides are subtracted out. In addition, measurement of PCT requires no skillful technique and is advantageous in that the apparatus is inexpensive.

Abstract: Vascular endothelial function in terms of flow-mediated dilation (FMD) of peripheral arteries can be assessed reliably by measuring beat-to-beat pulse-wave conduction time (PCT) simultaneously for two symmetric segments of arteries locating on the right and left sides of body. When reactive hyperemia is induced in the peripheral tissues on one side, the time dependent changes in PCT caused by FMD on that side can be detected as the beat-to-beat differences in PCT between two sides (?PCT). ?PCT would provide a sensitive and specific assessment of the FMD response, because the influences of the systemic changes in hemodynamic and neurohumoral factors common to both sides are subtracted out. In addition, measurement of PCT requires no skillful technique and is advantageous in that the apparatus is inexpensive.

Abstract: Vascular endothelial function in terms of flow-mediated dilation (FMD) of peripheral arteries can be assessed reliably by measuring beat-to-beat pulse-wave conduction time (PCT) simultaneously for two symmetric segments of arteries locating on the right and left sides of body. When reactive hyperemia is induced in the peripheral tissues on one side, the time dependent changes in PCT caused by FMD on that side can be detected as the beat-to-beat differences in PCT between two sides (?PCT). ?PCT would provide a sensitive and specific assessment of the FMD response, because the influences of the systemic changes in hemodynamic and neurohumoral factors common to both sides are subtracted out. In addition, measurement of PCT requires no skillful technique and is advantageous in that the apparatus is inexpensive.

Abstract: In a clinical and physiological abnormality monitoring apparatus, and blood pressure monitoring apparatus detects a blood pressure abnormality and the like of a body by employing a pulse wave signal. A frequency analysis is carried out with respect to a pulse wave signal, while this pulse wave signal corresponds to time sequential data of pulse waves. As a result, both a C-frequency component indicative of a fluctuation component of a base line of the pulse wave signal, and also an A-frequency component representative of the respective pulse waves are acquired. A ratio C/A of power of a peak contained in the C-frequency component with respect to power of a peak contained in the A-frequency component is calculated to determine abnormality of the blood pressure.

Abstract: A physiological condition detecting method detects pulse waves from the body of a patient, and creates the envelope of the pulse waves by connecting every peak of the pulse waves. It determines that the patient is in non-REM sleep, if the envelope fluctuates regularly. It determines that the patient is in REM sleep, if the envelope fluctuates irregularly. Further the method calculates and normalizes the amplitude and period of the envelope. It determines whether the patient has obstructive sleep apnea syndrome based on the normalized amplitude. It determines whether the patient has central sleep apnea syndrome based on the normalized period. It determines that the patient has mixed sleep apnea syndrome based on the normalized amplitude and the normalized period.

Abstract: In a clinical and physiological abnormality monitoring apparatus, and blood pressure monitoring apparatus detects a blood pressure abnormality and the like of a body by employing a pulse wave signal. A frequency analysis is carried out with respect to a pulse wave signal, while this pulse wave signal corresponds to time sequential data of pulse waves. As a result, both a C-frequency component indicative of a fluctuation component of a base line of the pulse wave signal, and also an A-frequency component representative of the respective pulse waves are acquired. A ratio C/A of power of a peak contained in the C-frequency component with respect to power of a peak contained in the A-frequency component is calculated to determine abnormality of the blood pressure.

Abstract: A physiological condition detecting method detects pulse waves from the body of a patient, and creates the envelope of the pulse waves by connecting every peak of the pulse waves. It determines that the patient is in non-REM sleep, if the envelope fluctuates regularly. It determines that the patient is in REM sleep, if the envelope fluctuates irregularly. Further the method calculates and normalizes the amplitude and period of the envelope. It determines whether the patient has obstructive sleep apnea syndrome based on the normalized amplitude. It determines whether the patient has central sleep apnea syndrome based on the normalized period. It determines that the patient has mixed sleep apnea syndrome based on the normalized amplitude and the normalized period.