Denso Corporation

Toyota Jidosha Kabushiki Kaisha

Nippon Medical School Foundation

Nippondenso Co., Ltd.

Tsuyoshi Nakagawa

Kouki Futatsuyama

Taiji Kawachi

Takeshi Yoshinori

Harutsugu Fukumoto

Hajime Inuzuka

Takao Katoh

Hiroshi Hayashi

Ichiro Yoshida

Kunihiko Hara

Teiyuu Kimura

Shinji Nanba

Hiroshige Murata

Yoshitaka Fuwamoto

Satomi Yoshioka

Rie Ohsaki

Tatsuya Ikegami

Shinya Matsunaga

Minoru Makiguchi

Akiko Ito

Naoki Mitsumoto

Motohisa Osaka

Yoshiaki Nakatsugawa

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

In a pulse wave analyzer, an ECG signal and a pulse wave signal are detected from an object to be analyzed. A plurality of feature points are extracting from the acquired ECG signal, the feature points appearing in a waveform of the ECG signal. The acquired pulse wave signal is segmented into a plurality of pulse wave signal pieces based on times at which the feature points appear. Each of the pulse wave signal pieces is segmented every heart beat. A reference pulse wave is calculated based on the plurality of pulse wave signal pieces, by multiplying the pulse wave signal pieces by coefficients and averaging the pulse wave signal pieces multiplied by the coefficients. The reference pulse wave is used to estimate the blood pressure of the object.

Pulse wave analyzer and blood pressure estimator using the same

An electrocardiograph includes first and second induction electrodes, a signal difference generation section, an electrocardiographic detection section, a signal applying section, and a contact detection section. The signal difference generation section generates a potential difference between a signal from the first induction electrode and a signal from the second induction electrode as a signal difference. The electrocardiographic detection section detects an electrocardiographic complex of a subject based on the signal difference. The signal applying section applies a first signal to the first induction electrode and a second signal to the second induction electrode. The first signal has a property different from the electrocardiographic complex. The second signal has a property different from the electrocardiographic complex and the first signal. The contact detection section detects a contact state of the subject to the first and second induction electrodes based on the signal difference.

Electrocardiograph with subject contact detection based on signal difference

A living body state monitor apparatus includes: a living body information acquisition device to acquire living body information containing an electrocardiography waveform and a pulse waveform from a user; an irregular heartbeat detection section to detect an irregular heartbeat from the electrocardiography waveform; and a pulse wave feature quantity extraction section to extract a pulse wave feature quantity from a pulse wave corresponding to the irregular heartbeat. Further, a living body state determination section is included to determine a danger degree on user's living body state using both of (A) information on kind and/or continued time period of an irregular heartbeat detected by the irregular heartbeat detection section, and (B) a pulse wave feature quantity extracted by the pulse wave feature quantity extraction section, and/or a variation of the extracted pulse wave feature quantity.

Living body state monitor apparatus

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 physical response record system includes a main unit and various sensors for recording driver's conditions and vehicle operations by a driver. The driver's conditions in combination with the vehicle operations are used to determine a risky situation of the vehicle based on an averaged driver's condition and the like. The risky situation is further analyzed for detecting a risky object and stored as a record for later use.

System and method for recording physical response

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 vehicle tiredness alleviating system provided with at least one of a vehicle air-conditioning system for controlling a temperature in a passenger compartment, a seat heating system for heating the surface of a seat, and a seat vibration system for repeatedly vibrating a seat for a predetermined time, further provided with a means for judging the tiredness degree of a passenger seated on a seat in the passenger compartment and a means for performing at least one of temperature control of the vehicle air-conditioning system, temperature control of the seat heating system, and control of the vibration strength or vibration time of the seat vibration system.

Vehicle tiredness alleviating system

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

To prevent leakage of light from a waveguide path to an isolation film in a photocoupler, isolation films are formed so that end portions thereof face a substrate, and a photodiode and phototransistor are formed on islands surrounded by these isolation films. Accordingly, a waveguide path optically coupling the photodiode and photocoupler is formed on a silicon oxide film and on the end portions of the isolation films. The isolation films are formed by alternatingly laminating silicon oxide films having a refractive index smaller than the waveguide path and silicon nitride films having a refractive index equal to or greater than the waveguide path. Accordingly, the several film thicknesses of the silicon nitride films are established to be smaller than the wavelength of light within the silicon nitride films. Because of this, leakage of light from the waveguide path to the silicon nitride films of the isolation films can be prevented.

Photocoupler having element isolation layers for low cross-talk low

A semiconductor strain sensor includes a silicon substrate, a strain resistive element and electrodes. The silicon substrate has a deformable portion which is deformed when stress is applied to it. The strain resistive element is formed on the deformable portion and has an at least a first layer and a second layer which form a heterojunction between them. The first layer is doped with impurities so that a two-dimensional carrier gas layer is formed in the second layer near the heterojunction. The two-dimensional carrier gas layer has carriers originating from the impurities. The electrodes electrically contact the two dimensional carrier gas layer. Change of resistance of the strain resistive element in accordance with the stress is detected through the electrodes.

Growing community of inventors

Aichi-gun, Japan

Tsuyoshi Nakagawa