Hitachi, Ltd.

Okayama University

Hitachi-high-technologies Corporation

Keiji Tsukada

Akihiko Kandori

Tsuyoshi Miyashita

Hiroyuki Suzuki

Hitoshi Sasabuchi

Daisuke Suzuki

Kazuhisa Machida

Shoji Kondo

Koichi Yokosawa

Takafumi Kawasaki

Yuji Miyahara

Yasuaki Komiyama

Yoshio Watanabe

Kenichi Okajima

Yasuhisa Shibata

Kuniomi Ogata

Toshihiko Kiwa

Minoru Sakairi

Kenko Uchida

Hiroyuki Miyagi

Akira Tsukamoto

Hideo Kawaguchi

Kenji Teshigawara

Masahiro Murakami

Atsushi Ninomiya

Ryuichi Shinomura

Junkichi Miura

Yusuke Seki

Andreas Manz

Provided is a magnetic field measuring device which has good temperature stability and which enables an improvement by making it possible for the sensitivity of a Hall element, a magnetic impedance (MI) element or a magnetic resistance (MR) element, which are conventionally used extensively, to be set freely. This magnetic field measuring device comprises: a temperature maintaining means for maintaining an extremely low temperature state in which a superconductor adopts a superconducting state; a magnetic sensor which is provided inside the temperature maintaining means to detect a magnetic field; and a magnetic field space forming means for forming a magnetic field space specific to the superconducting state, by adopting a superconducting state inside the temperature maintaining means; wherein the magnetic sensor is disposed in the magnetic field space.

Magnetic field measuring device

A magnetic flux leakage inspection method generates a magnetic flux parallel to a surface of an inspected object, and detects a magnetic flux that leaks from the surface of the inspected object with a magnetic sensor. The method includes exciting coils that generate an alternating magnetic field having a variable frequency, an exciting coil power source, a magnetic sensor, a lock-in detector, and a signal analyzer that analyzes changes of a signal intensity and a phase of the output of the magnetic sensor with output signals of the lock-in detector. The method obtains cosine or sine as a trigonometric function of a phase obtained by adding to the phase at each measurement point of multipoint measurement, an adjustment phase common to all the measurement points, and displays an analytical value obtained by multiplying the signal intensity and the sine or cosine at each measurement point with any adjustment phase.

Leakage magnetic flux flaw inspection method and device

Provided are a measuring device and a measuring method that use terahertz light, by which a substance to be detected can be detected with high sensitivity and high accuracy. A measuring device using a pulsed electromagnetic wave is provided with a substance detection plate, a means for generating the pulsed electromagnetic wave having amplitude intensity dependent on the amount of a substance to be detected at an irradiation position by irradiating the substance detection plate with a pulsed laser beam, and a detection means for detecting the amplitude intensity of the pulsed electromagnetic wave, and measures the change of the state of a solution containing the substance to be detected on the basis of the amplitude intensity.

Measuring device and measuring method that use pulsed electromagnetic wave

Provided is an ion sensor with which the concentration of ions in a solution can be determined without any reference electrode. The ion sensor is equipped with: a first electrode plate; a second electrode plate which has been disposed opposite the first electrode plate and has one or multiple openings; an ion-sensitive film continuously formed so that the film is interposed between the first electrode plate and the second electrode plate, blocks up one side of each opening of the second electrode plate, and extends from the end of that side of the opening to the outer surface of the second electrode plate through the inner wall surface of the opening; and a sensor support which supports the second electrode plate so that when the ion concentration of a test solution to be examined is determined, the ion-sensitive film comes into contact with the test solution only in the portions thereof that have been formed in each opening and on the outer surface of the second electrode plate. The ion sensor is configured so that the thickness of the ion-sensitive film interposed between the first electrode plate and the second electrode plate is different from the thickness of the ion-sensitive film formed on the outer surface of the second electrode plate. A difference in potential between the first electrode plate and the second electrode plate is measured.

Ion sensor

A material distribution measuring device () for measuring a reaction distribution or a concentration distribution of a material contained in a solution. The material distribution measuring device () comprises a material detecting plate () comprising a material-sensitive film () provided on an insulator () provided on a semiconductor (), a flow passage forming part () forming a solution flow passage () on the material detecting plate (), means for stabilizing the potential of the solution, means for applying a pulsed laser beam () from the semiconductor () side to the flow passage () side, means for scanning the material detecting plate () two-dimensionally with use of the pulsed laser beam (), means for measuring the amplitude strength of pulsed electromagnetic waves generated upon the application of the pulsed laser beam () to the material detecting plate (), and means for obtaining a reaction distribution or a concentration distribution of the material contained in the solution within the flow passage by qualitatively or quantitatively measuring the material to be detected from the amplitude strength.

Measurement device for the distribution of chemical concentration

A gas sensor () includes two field-effect transistors and gate electrodes on gate insulation films () of the two field-effect transistors to detect gas using the gate electrodes. The gas sensor () includes a first gate electrode (), a second gate electrode (), and voltage applying means. The first gate electrode () is provided on one of the field-effect transistors. The second gate electrode () is provided on another one of the field-effect transistors. The voltage applying means is for, with the first gate electrode () and the second gate electrode () coupled to one another by wiring, applying thereto one of a direct-current voltage and an alternating-current voltage having a same potential or a constant voltage difference. The first gate electrode () and the second gate electrode () are made of different metals. The one field-effect transistor and the other field-effect transistor have approximately the same structures.

Gas sensor

A living body inspection apparatus including an oscillation coil which passes an AC current, a detection coil which detects an AC magnetic field generated from the detection coil, an amplification circuit which amplifies a voltage generated by the magnetic field induced by the detection coil, a detecting unit for detecting the output signal of the amplification circuit, a low pass filter to which the output signal of the detecting unit is input, a unit for setting the oscillation coil and detection coil in first and second regions of the living body, a recording unit for recording the output of the low pass filter while the first region and the second region of the living body are moving and a displaying unit for displaying the data recorded in the recording unit or results of analysis of the recorded data.

Living body inspection apparatus

The present invention relates to a magnetic impedance measurement device comprising an apply coil for generating an alternate magnetic field of variable frequency, a power source for the apply coil, at least one magnetic sensor means comprising a pair of magnetic sensors for detecting orthogonal vector components of a magnetic field generated from a test object, the vector components being parallel to the face of the apply coil, a measurement means for the magnetic sensor for measuring a detected signal from said magnetic sensor mean, the measurement means being located at a distance from the face of the apply coil and facing the test object, a lock-in amplifier circuit for detecting from an output of the measurement means a signal having the same frequency as the frequency of the apply coil and an analysis means for analyzing intensity and phase changes of an output of the magnetic sensor means with the use of an output signal of the lock-in amplifier circuit.

Device for measuring magnetic impedance

The present invention discloses a magnetic detecting device comprising an apply coilfor generating an alternate magnetic field of variable frequency and a power sourcefor the apply coil; a magnetic sensorfor detecting a change in the magnetic field induced by a test objectplaced at a distance from a surface of said apply coil and toward said test object, said magnetic sensor being provided with a cancel coilfor canceling a magnetic field generated at the position of the magnetic sensor by a direct magnetic field and/or said apply coil; a measurement circuitfor the magnetic sensor for measuring a detection signal of said magnetic sensor; a lock-in amplifier circuitfor detecting an output of said measurement circuit for the magnetic sensor into two signals having the same frequency as that of said apply coil and phases different from each other by 90 degrees; and an analysis meansfor analyzing a phase change of the output of said magnetic sensorusing an output signal from said lock-in amplifier circuit

Magnetic detecting device and material identifying device

There is provided a magnetic shield which can shield external magnetic fields in the direction of an axis of a tubular magnetic shield and in the direction vertical to the axis. A magnetic shield has a cylindrical ferromagnetic substance-having openings on both ends and two superconducting loops housed in the respective insides of superconducting loop containers-,-. The superconducting loops are constructed of high critical temperature superconducting wire. The two superconducting loops have semicircle shapes and are arranged in x-direction so as to be symmetrical with respect to an axis of the cylindrical ferromagnetic substance-. The superconducting loop containers-,-are arranged in the insides near both open ends of the cylindrical ferromagnetic substance-with supports. The superconducting loops are arranged to be vertical to the axis of the cylindrical ferromagnetic substance-. The superconducting loops are cooled by liquid nitrogen or a refrigerator. A lightweight, small magnetic shield having high operability can be realized.

Magnetic shields and instruments for measuring biomagnetic fields

A display method for a magnetic field measuring apparatus which includes detecting a magnetic field generated from a biotest sample by a plurality of magnetic sensors and displaying measurement data obtained on the basis of the detected magnetic field in any display mode, which further comprises displaying an operating information display screen, the operating information display screen having a processing function display section selecting an operation menu including a biotest sample list, data measurement or data analysis; a biotest information display section; and a data display area.

Method of measuring a biomagnetic field, method of analyzing a measured biomagnetic field, method of displaying biomagnetic field data, and an apparatus therefor

A biomagnetic field measuring apparatus has a plurality of fluxmeters disposed externally of a living body and each including a superconducting quantum interference device (SQUID) for detecting a biomagnetic field generated from the living body, the plurality of fluxmeters being operative to detect a temporal change of a component of the biomagnetic field in a first direction which is vertical to the surface of the living body, an operation processor for performing computation for determining a temporal change of a value proportional to a root of square sum of differential value of the first-direction magnetic field component in second and third directions which cross the first direction and computation for integrating the temporal change of the value over a predetermined interval to determine an integral value, and a display for displaying the determined integral value. Distribution of magnetic fields generated from the heart is determined with a small number of fluxmeters.

Biomagnetic field measuring method and apparatus

A biomagnetic measurement technique which can obtain a potential waveform corresponding to a ventricular muscle cell action potential in a non-invasive manner. The biomagnetic measurement apparatus including an operating circuit for magnetometer. The output data of the operating circuit for the magnetometer is collected and a current vector at time t is calculated. Further, an absolute value Ixy of the current vector, a potential waveform V (t) in time corresponding to depolarization of a heart from the absolute value of the current vector, and a potential waveform V (t) in a refractory period of the heart to a period corresponding to repolarization from the absolute value of the current vector are calculated.

Biomagnetic measurement apparatus

Disclosed herein is a biomagnetic measurement apparatus capable of visualizing cardiac electrical current distributions with information on the cardiac morphology of a subject. A magnetic field component in the z direction, vertical to the chest surface of a subject, is measured from two directions, front and back of the chest, and then to calculate the current distributions in the two directions and the distributions of the amplitudes of those current distributions. A three-dimensional standard heart model is created from average data on the cardiac morphology obtained from plural healthy subjects. An optimal position of the model is determined using the coordinates of the sinus node and the coordinates of the left ventricle. Then, a weight coefficient is obtained by front and back current distributions and front and back the distributions of the amplitudes of those current distributions on a set boundary of the model.

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Okayama, Japan

Keiji Tsukada