Murata Manufacturing Co., Ltd.

Murata Manufacturingco., Ltd.

Yasushi Sato

Takanori Hayashi

A biological information measurement device includes a photoplethysmographic sensor that detects a photoplethysmographic signal, an envelope detection processor that generates an envelope of the photoplethysmographic signal, and an amplitude normalization processor that normalizes amplitude of the photoplethysmographic signal to a desired amplitude value based on amplitude of the envelope. The device further includes an adaptive line spectrum enhancer that is capable of varying a filter coefficient, suppressing an aperiodic component contained in the normalized photoplethysmographic signal, and outputting a periodic component. A biological information obtainment unit is provided to obtain biological information such as a pulse rate based on an output signal from the adaptive line spectrum enhancer.

Biological information measurement device

A biological information measurement apparatus includes a phase/frequency comparison unit that outputs a deviation signal based on a phase difference between a biological signal and an oscillation signal; a loop filter; and a voltage controlled oscillation unit that generates the oscillation signal in accordance with the deviation signal that has passed through the loop filter. The apparatus further includes a CPU that estimates a SN ratio of the biological signal and analyzes a phase difference/frequency difference between the biological signal and the oscillation signal. A variable low pass filter is provided that selectively blocks a signal of a predetermined frequency band contained in the deviation signal that has passed through the loop filter and the CPU changes a cutoff frequency of the variable low pass filter based on the SN ratio and the phase difference/frequency difference.

Biological information measurement method and apparatus with variable cutoff frequency low pass filter

A biological information measurement apparatus includes a phase/frequency comparison unit that outputs a deviation signal based on a phase difference between a biological signal and an oscillation signal; a variable loop filter that varies a cutoff frequency and a phase margin and that selectively blocks a signal of a predetermined frequency band contained in the deviation signal; and a voltage controlled oscillation unit that generates the oscillation signal in accordance with the deviation signal that has passed through the variable loop filter. The apparatus further includes a CPU that estimates a SN ratio of the biological signal and analyzes a phase difference/frequency difference between the biological signal outputted from the comparison unit and the oscillation signal. The CPU further changes a constant of the variable loop filter based on the SN ratio and the phase difference/frequency difference.

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Nagaokakyo, Japan

Yasushi Sato