Denso Corporation

Toyota Jidosha Kabushiki Kaisha

Nippon Medical School Foundation

Taiji Kawachi

Tsuyoshi Nakagawa

Teiyuu Kimura

Hideki Seki

Mitsuyuki Kobayashi

Takeshi Yoshinori

Kenichi Yanai

Shinji Nanba

Takuya Kataoka

Masaru Kakizaki

Kouki Futatsuyama

Kazuhiro Sakai

Yoshitaka Fuwamoto

Rie Ohsaki

Takao Katoh

Shingo Imura

Akiko Ito

Hiroshi Yamakita

Takashi Matsuoka

Koki Futatsuyama

Yuuki Shimizu

A heating and cooling stimulation device includes a stimulation supply unit configured to supply hot stimulation and cold stimulation to a subject; an estimation unit configured to estimate a fatigue level of the subject; and a control unit configured to control an operation of the stimulation supply unit so as to supply the hot stimulation and the cold stimulation alternately to the subject in accordance with the fatigue level estimated by the estimation unit. The control unit controls the operation of the stimulation supply unit such that an amount of the cold stimulation received by the subject increases as the fatigue level estimated by the estimation unit becomes higher.

Heating and cooling stimulation device

A pulse wave measuring device checks whether amplitude of a pulse signal satisfies a gain changing condition and, when the gain changing condition is satisfied, changes a gain. The pulse wave measuring device includes an amplitude storing unit and a mode progressing unit. The amplitude storing unit stores plural gain changing conditions, to which a series of order are assigned, respectively. A mode progressing unitchanges the gain changing condition to the next-ordered gain changing condition upon determination that the mode progress condition is satisfied. The gain changing condition is satisfied in case that Yor more number of pieces of Xamplitudes are larger than an upper limit value Uor smaller than a lower limit value L. Xis increased as the order of the set gain changing condition is higher.

Pulse wave measuring device

In a pulse wave signal processor, a first filter attenuates a frequency component in an acquired pulse wave signal or in a differentiated pulse wave signal, and the attenuated frequency component is more than or equal to a first frequency. A second filter attenuates a frequency component in the acquired pulse wave signal, and the attenuated frequency component is less than the first frequency and more than or equal to a second frequency. A characteristic-point extractor extracts a characteristic point that exists in each single pulse of the pulse wave signal filtered by the second filter, and a signal separator partitioning the pulse wave signal or the differentiated signal filtered by the first filter into sections such that each section includes one of the extracted characteristic points. The partitioned sections are overlapped such that the characteristic points are coincident with each other, and arithmetically averaged.

Pulse wave signal processor

An heart rhythm monitoring device for a vehicle, which determines whether a driver has an arrhythmia includes a vehicle state determining portion that determines whether the vehicle is stopped; an electrode arranged on a steering wheel in a position where the driver grips the steering wheel; an electrocardiogram waveform obtaining portion that obtains a first electrocardiogram waveform from the electrode; and a signal processing and calculating portion that determines whether the heart rhythm of the driver is erratic based on the first electrocardiogram waveform. When the vehicle is in motion, the signal processing and calculating portion determines whether the heart rhythm of the driver is erratic based on the waveform component that is strong with respect to noise in the first electrocardiogram waveform.

Method and device for monitoring heart rhythm in a vehicle

A signal-to-noise ratio and measurement precision is increased in electrode units disposed on the left and right sides of a steering wheel. A plurality of electrode units is disposed in the left and right handholds of a steering wheel. The contact impedances of all the electrode units are measured. A pair of left and right electrode units to be used to measure an electrocardiographic signal is designated from among the electrode units whose measured contact impedances are less than or equal to a first threshold. The results of measurement of an electrocardiographic signal by the designated electrode units are added in order to minimize noise. An electrode unit with high contact impedance is used to measure induction noise and remove the induction noise component from the electrocardiographic signal measurement result.

Biosignal measuring equipment

In an apparatus for measuring a biological condition of a living body, a light emitting unit emits individually first and second lights to a measurement portion of the living body. The first and second lights have first and second wavelengths, respectively. The first and second wavelengths are different from each other. A light receiving unit receives first and second reflection lights to generate first and second detection signals based on the first and second reflection lights, respectively. The first and second reflection lights are based on the first light reflected from the measurement portion and the second light reflected therefrom, respectively. The first and second detection signals have different characteristics from each other due to the difference between the first and second wavelengths. A measuring unit measures the biological condition based on the different characteristics of the first and second detection signals.

Method and apparatus for measuring biological condition

A sleepiness level detection device detects a heartbeat signal when a time equal to or longer than Tand equal to or shorter than Thas elapsed since the start of driving. The heartbeat signal is subjected to FFT processing to obtain a spectrum signal. By use of a peak frequency of the spectrum signal, a driver conscious-state peak frequency is estimated. A consciousness level index band &#x3b1; is set with respect to the conscious-state peak frequency. A sleepiness level index band &#x3b2; is set with respect to a frequency, which is calculated by multiplying the conscious-state peak frequency by a predetermined ratio (65 to 90%). A sleepiness level evaluation parameter Sp (=&#x3b2;p/(&#x3b1;p+&#x3b2;p)) for indicating the sleepiness level of the driver is calculated with the use of the strength &#x3b1;p and &#x3b2;p of spectrum signals.

Sleepiness level detection device

A method of obtaining information that corresponds to the R&mdash;R interval of electrocardiogram from the pulse-wave of a human body. The method is comprised of steps of detecting the pulse-wave of a human body in a predetermined period, differentiating the detected pulse-wave to provide a speed-pulse-wave, measuring intervals of peaks of the speed-pulse-wave, and substituting the intervals of peaks of the speed-pulse-wave for the R&mdash;R interval of the electrocardiogram.

Method of obtaining information that corresponds to electrocardiogram of human body from pulse wave thereof

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Kariya, Japan

Taiji Kawachi