Nihon Kohden Corporation

Masaru Yarita

Kazumasa Ito

Naoki Kobayashi

Kenji Miyata

Tetsuya Shibasaki

A method of processing first and second signals obtained by measuring a medium, to obtain a pulse wave signal and an artifact signal which are separated, includes: separating vectors of the first and second signals by using a separation matrix into a vector of the pulse wave signal and a vector of the artifact signal, the separation matrix including a norm ratio of a stable zone of the pulse wave signal and a compensated norm ratio of an artifact zone.

Signal processing method, signal processing apparatus, and pulse photometer using the same

In an apparatus for measuring an oxygen saturation in blood, a plurality of light emitters irradiate a living tissue with a plurality of light beams having different wavelengths. A light receiver receives the light beams reflected from or transmitted through the living tissue to generate pulse wave signals in accordance with pulsations of the blood in the living tissue. A separator separates each of the pulse wave signals into a plurality of amplitude signals each of which is associated with one frequency, thereby generating pairs of amplitude signals each of which is associated with one of a plurality of frequencies. A first processor calculates a ratio between the amplitude signals in each of the pairs of the amplitude signals. A selector selects one of the pairs of the amplitude signals. A second processor calculates the oxygen saturation from the ratio of the selected pair of the amplitude signals.

Apparatus and method for measuring oxygen saturation in blood

At least an electroencephalogram (EEG) detected by a sensor is input from a signal input section as a vital sign signal. The vital sign signal is stored in a storage as vital sign data. A display includes a first display area, a second display area and a third display area. A controller reads out the vital sign data from the storage to display the vital sign signal on the display. The controller includes a first display processor, which displays the EEG in a real time manner, on the first display area, a second display processor, which displays the EEG at a time point in past, on the second display area, and a third display processor, which displays a time-varying trend of a parameter of the EEG, on the third display area. A designator designates a time point in past in the trend displayed in the third display area, so that the EEG at the designated time point is displayed on the second display area.

Vital sign display monitor

A living body is irradiated with a first light beam having a first wavelength and a second light beam having a second wavelength which is different from the first wavelength. The first light beam and the second light beam, which have been reflected or transmitted from the living body, are converted into a first electric signal corresponding to the first wavelength and a second electric signal corresponding to the second wavelength, as the observed pulse data. A light absorbance ratio obtained from the first electric signal and the second electric signal is computed, for each one of frequency ranges dividing an observed frequency band. It is determined that noise is not mixed into the observed pulse wave data in a case where a substantial match exists among light absorbance ratios computed for the respective frequency ranges.

Method for reducing noise, and pulse photometer using the method

A first signal and a second signal are provided as two continuous signals having an identical fundamental frequency. A first spectrum which is either one of a frequency spectrum or a frequency power spectrum of the first signal in a predetermined time period is obtained. A second spectrum which is either one of a frequency spectrum or a frequency power spectrum of the second signal in the predetermined time period is obtained. A normalized value which corresponds a ratio of a difference between the first spectrum and the second spectrum and a sum of the first spectrum and the second spectrum at the fundamental frequency is obtained. A ratio of an amplitude of a signal component of the first signal and an amplitude of a signal component of the second signal is obtained based on the normalized value.

Signal processing method and pulse wave signal processing method

An electrode for measuring a biomedical signal has: thin foil electrodes,to,which are formed into a square shape; lead wires,to,which are connected to the electrodes,to,respectively; and a support section,which is made of a flexible material such as rubber or plastic, formed into a slender thin plate-like shape, and supports the electrodes,to,in a straight line and at constant intervals. The lead wires,to,are twisted.

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Tokyo, Japan

Masaru Yarita