Abstract: A radiation light, containing a plurality of rays of light with wavelengths, is irradiated on a predetermined part of a human body, and the intensity of each of the plurality of rays of light with wavelengths contained in the radiation light is measured by a spectroscope when the radiation light is reflected by or transmits through the predetermined part of the human body. A measured ratio of a pulsatile component absorbance at each of the wavelengths except for a reference wavelength to that at the reference wavelength is calculated based on an intensity Id and an intensity Is of the each of the plurality of rays of light, where the intensity Is is defined as an intensity obtained when an optical path length is maximized in systole while the intensity Id is defined as an intensity obtained when the optical path length is minimized in diastole.

Abstract: A blood pressure measurement apparatus includes a derivation control unit that performs derivation control to derive a blood pressure of a measured person. The derivation control unit includes an envelope extracting unit to extract an envelope of a volume pulse wave based on an arterial volume signal, a differential processing unit to differentiate the envelope with respect to a cuff pressure, a maximum value extracting unit to extract a maximum value of a differential value of the envelope, and a blood pressure decision unit that decides the cuff pressure used for the differential of the maximum value as a blood pressure.

Abstract: A blood pressure information measurement device includes light emitting elements and light receiving elements as a plurality of pairs of first and second sensors in a cuff. While the cuff pressure is increased, combinations of the plurality of pairs of the light emitting elements and the light receiving elements are switched, and volume pulse waves are obtained from each of the combinations. After increasing the cuff pressure, for each of the volume pulse waves corresponding to the combinations, a specific volume value at a point where the amount of volume change becomes maximal is extracted. Thereafter, based on values corresponding to the maximum and minimum blood pressure and the specific volume value, the sensors for measurement are determined.

Abstract: A blood pressure measurement apparatus includes a derivation control unit that performs derivation control to derive a blood pressure of a measured person. The derivation control unit includes an envelope extracting unit to extract an envelope of a volume pulse wave based on an arterial volume signal, a differential processing unit to differentiate the envelope with respect to a cuff pressure, a maximum value extracting unit to extract a maximum value of a differential value of the envelope, and a blood pressure decision unit that decides the cuff pressure used for the differential of the maximum value as a blood pressure.

Abstract: An electronic manometer detects pressure within a cuff at which an amplitude of change in a volume of an artery of a measurement subject becomes a maximum by detecting volume of an artery of a measurement subject while superimposing a vibration of high frequency during a period of raising the pressure to apply on the cuff or during a period of lowering after raising to greater than or equal to a systolic blood pressure of the measurement subject. The electronic manometer controls the pressure to apply on the cuff so that the volume of the artery of the measurement subject becomes constant, and measures the blood pressure of the measurement subject from an increased or decreased value of the pressure to apply.

Abstract: A small and inexpensive, noninvasive bone density measuring device is provided. A measuring part of the bone density measuring device is constituted by a light emitter 120, which emits near-infrared light, and a light receiver 130, which receives light via a bone of a measuring subject, arranged in a holder 110. Bone density is measured by inserting an arm, for example, in the holder 110 and measuring light absorption (absorbance) by the arm bone. The light emitter 120 and the light receiver 130 are connected to a control unit 140. The control unit 140 controls the light emitter 120 to emit light, inputs a measured value from the light receiver 130, and displays it as bone density. In order to remove the influence of light from the background or difference in bone thickness, ratio of absorbance between two wavelengths is preferably employed.