Tanita Corporation

Masato Nakada

Koji Oguma

Toshiaki Sasaki

An AD conversion apparatus includes a shift signal generating portion configured to generate n shift signals (n is a natural number greater than one) of which amplitudes are different from each other; a shift signal controlling portion configured to control the shift signal generating portion; a compounding portion configured to compound input analog signal and the n shift signals sequentially into n first signals; an AD converting portion configured to execute AD conversion to convert the n first signals into n second signals; and a signal processing portion configured to calculate an average of the n second signals to generate output digital signal.

Analog-to-digital conversion apparatus, analog-to-digital conversion method, and electronic device

An activity information meter is provided which is capable of stable transmission between a measuring device and an output device and is highly convenient. In a measuring deviceorand an output deviceor, a selector is placed between a current output section and each electrode and between a voltage detection section and at least one electrode and a transmission route is selected as appropriate, thereby making possible bidirectional transmission using a body as a medium, a change in potential is detected based on a reference potential at the time of reception without using the earth as a reference potential or a voltage generated based on a body part impedance is detected without using the earth as a reference potential. As a result, the activity information meter is hardly influenced by the environment.

Activity information meter

A fatigue-degree evaluation device is provided for easily evaluating a degree of fatigue of a living body. Embodiments include a device wherein fluorescent light generated via a liquid excreted from a body is measured; the temperature of the liquid excreted from the body is measured; a pH is calculated based on the fluorescent light and the temperature of the liquid excreted from the body; and a fatigue degree is evaluated based on this pH.

Fatigue-degree evaluation device

There is provided an apparatus capable of carrying out an accurate bioelectrical impedance measurement by determining whether contact of a living body with electrodes used at the time of the bioelectrical impedance measurement is normal or not more accurately. The apparatus uses a parameter associated with a phase difference in determining the contact condition of the living body with the electrodes. As the parameter associated with a phase difference, the apparatus uses a value represented by X/R wherein R is a resistance component in a bioelectrical impedance to be measured and X is a reactance component in the bioelectrical impedance and determines that contact of the living body with the electrodes is not normal when the value of X/R is out of a determination range such as a&#x3c;X/R&#x3c;b (a and b are real numbers).

Bioelectric impedance measuring apparatus

A phase-sensitivity detector detects a phase sensitivity of an AC signal with a known frequency, output by an input amplifier, and an integrator double-integrates an output of (X-Y) of which the phase sensitivity is detected, thereby obtaining vector detecting information &#x3b1;(tend&#x2212;tst)/tm=A cos &#x3b8; and &#x3b1;(tend&#x2212;tst)/tm=A sin &#x3b8; of the AC signal with the known frequency.

Vector detecting device and living-body complex impedance measuring apparatus having the vector detecting device

A stress evaluation apparatus includes an impedance measuring unit for measuring an impedance of a fluid discharged from a living body; a temperature measuring unit for measuring a temperature of the fluid discharged from the living body; a pH calculating unit for calculating a pH value based on the impedance and temperature of the fluid discharged from the living body; and a stress evaluating unit for evaluating a stress based on the pH value calculated by the pH calculating unit.

Stress evaluation apparatus

Muscle fatigue measuring equipment is provided by which one can know muscle fatigue status objectively and easily. Embodiments include equipment for performing the steps of substituting a myoelectric value based on a measured myoelectric potential and a stored myoelectric value into an arithmetic expression for determining a myoelectric change; and substituting an extracellular fluid measured using biological impedance and a stored extracellular fluid value into an arithmetic expression for determining a change in extracellular fluid. The presence or absence of muscle fatigue, the equilibrium state of muscle fatigue, and the progress of muscle fatigue is determined using the determined myoelectric change and extracellular fluid change.

Muscle fatigue measuring equipment

A living body impedance measurement apparatus is provided which measures a voltage attributed to the impedance of a living body, and separates it into a voltage attributed to a resistance component and a voltage attributed to a reactance component. Then, the voltage attributed to the resistance component, the voltage attributed to the reactance component, and resistance and reactance components of an impedance of an external reference unit are substituted into an impedance calculation formula that accounts for impedance fluctuation. A fluctuation constant is thereby calculated that is a constant for a fluctuation variable representing fluctuation caused by impedance change factors. The resistance component and the reactance component of a true impedance of the living body are then calculated based on the fluctuation constant and the measured living body impedance.

Living body impedance measurement apparatus

A muscle fatigue level measuring device is provided which estimates muscle fatigue without being influenced by distances between electrodes. The muscle fatigue level measuring device measures a resistance component and a reactance component in a body part as impedance in the body part by impedance component measuring means, measures a muscular tissue effective length in the body part by muscular tissue effective length measuring means, computes biologically equivalent model parameters including extracellular fluid resistivity and distribution membrane capacitance based on these resistance component, reactance component and muscular tissue effective length by biologically equivalent model parameter computation means, and determines a muscle fatigue level based on the ratio of the extracellular fluid resistivity to the distribution membrane capacitance by muscle fatigue level determination means

Muscle fatigue level measuring device

The apparatus receives a load by a load receiving board, selects and switches a combination of a first sensor and a second sensor, a combination of the second sensor and a third sensor, a combination of the third sensor and a fourth sensor and a combination of the fourth sensor and the first sensor in turn by selection switching means, obtains output differences of all these combinations selected and switched in turn by the selection switching means in output difference conversion means, stores in a memory the output differences obtained in the output difference conversion means, determines in a barycentric position computation section a first directional position (position Gy with respect to the y coordinate axis) and a second directional position (position Gx with respect to the x coordinate axis) based on comparisons of the output differences stored in the memory, and outputs the positions in output means.

Barycentric position measuring apparatus

Disclosed is an apparatus for measuring an activity of autonomic nerve, comprising: a sympathetic nerve activity measuring unit; a parasympathetic nerve activity measuring unit; a memory unit; and an evaluation unit. According to the present invention the sympathetic nerve activity measuring unit measures an activity of the sympathetic nerve and the parasympathetic nerve activity measuring unit measures an activity of the parasympathetic nerve antagonistically functioning with the sympathetic nerve. The memory unit stores reference data acting as the criterion for comparing with relation between psychosomatic conditions based on the activity of the sympathetic nerve and the activity of the parasympathetic nerve. The evaluation unit compares measurement data representing the activity of the sympathetic nerve measured by said sympathetic nerve activity measuring unit and the activity of the parasympathetic nerve measured by said parasympathetic nerve activity measuring unit with said reference data stored in said memory unit for evaluating the relation between psychosomatic conditions.

Growing community of inventors

Asaka, Japan

Masato Nakada