| 摘要 |
PROBLEM TO BE SOLVED: To provide a cardiac sound detector that detects a cardiac sound in a site far away from the thorax. SOLUTION: The cardiac sound detector detects the vibration of the skin of the wrist by pressing a flexible piezoelectric sheet 32 against the radius from the outer skin in the wrist. Since the vibration contains a cardiac sound component transmitted to the wrist through the bone, a cardiac sound detection means 60 extracts a frequency component of 30 to 600 Hz as a frequency of the cardiac sound from a vibration signal SV outputted from the piezoelectric sheet 32. Since the piezoelectric sheet 32 simultaneously presses also the radial artery, the vibration signal SV contains a radial arterial wave. A noise filter means 62 filters out a frequency component that causes a noise to the radial artery and determines the radial arterial wave. Since a pulse wave velocity PWV can be determined from the radial arterial wave and the cardiac sound, the pulse wave velocity PWV can be determined from a signal obtained by one sensor alone. COPYRIGHT: (C)2005,JPO&NCIPI
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