Hitachi, Ltd.

Hitachi High-Tech Fine Systems Corporation

Hitachi-High-Technologies Corporation

Hitachi Computer Peripherals Co., Ltd.

Hitachi High-Tech Solutions Corporation

Ryuzo Kawabata

Akihiko Kandori

Takako Mizoguchi

Yuko Sano

Seiichi Suzuki

Taro Osabe

Kuniomi Ogata

Kenji Yamamoto

Yudai Kamada

Tsuyoshi Miyashita

Hiroshi Suzuki

Tsukasa Funane

Yusuke Seki

Noritake Shizawa

Yuudai Kamada

Mitsuru Onuma

Hiroyuki Kanda

To perform respiratory monitoring and cardiac-output measurement on general patients, an aspect of a biological measurement apparatus includes: at least two electrodes that are attached to a living body; a power supply that causes an AC current to flow between the two electrodes; at least two coils that are placed so as to sandwich a line linking the two electrodes, and detect a magnetic field related to a change in the AC current accompanying a change in impedance of the living body; and a detection circuit that performs addition or subtraction of signals related to the magnetic field detected with the two coils, and outputs the signals as a change in the impedance.

Biological measurement method

Provided is a rail inspection system capable of accurately detecting a defect of a railroad rail. The system includes: a sensor part group that has a plurality of sensor parts having receiver coils, and first oscillator coils and second oscillator coils corresponding to the receiver coils being arranged in a line parallel in a width direction of a railroad rail to be inspected; an oscillation part that supplies an oscillation signal to each of the first oscillator coils and the second oscillator coils; and a detection part group that has a plurality of detection parts to detect, with respect to an output signal from each of the receiver coils when the sensor part group moves in a laying direction of the railroad rail, a first inspection signal corresponding to a first phase of the output signal and a second inspection signal corresponding to a second phase of the output signal.

Rail inspection system

In a rail inspection system, a positional deviation can be detected with accuracy. The rail inspection system includes a first sensor unit which is disposed to face a rail for a vehicle, and includes at least one receiver coil and at least one oscillation coil which are arranged in an arrangement direction intersecting with a layout direction of the rail, an AC voltage source which applies AC voltage to the oscillation coil, and a displacement detection unit which detects a displacement between the rail and the first sensor unit based on an induced voltage of the receiver coil. The first sensor unit is configured such that, when the displacement is a first displacement, a first maximum value appears in the induced voltage, and when the displacement is a second displacement, a second maximum value of which a phase is reversed against the first maximum value appears in the induced voltage.

The present invention addresses the problem of checking defects of a rail for a vehicle with a high SN ratio. A detection device () for generating check data related to the defects of a railway rail RR (rail for a vehicle) is provided with an oscillating coil C() and an oscillating coil C() that are disposed on the surface opposite the railway rail RR and generate AC magnetic fields whose directions are opposite to each other, and a receiving coil () that is positioned between or in the vicinity the oscillation coils and that outputs a magnetic field waveform based on the magnetic fields received from the oscillating coils as the check data.

Rail check device and rail check system

An object of the invention is to reduce 1/f noise and white noise at the same time by integrally reducing noise of an MR sensor and noise of an operation circuit part. A magnetoresistive sensor according to the invention includes a plurality of magnetoresistive sensor parts each having a bridge circuit in which four magnetoresistive elements are connected, and outputs of the respective magnetoresistive sensor parts are connected in parallel to one another to an input of an amplifier circuit (see FIG.).

Magnetoresistive sensor and gradiometer

The present invention addresses the problem of stabilizing signals in magnetic field measurement using optical pumping. In order to solve the problem, disclosed is a light source apparatus () that is characterized in having: a light intensity fluctuation detection circuit () that detects intensity fluctuation of light outputted from a laser output unit (); and an acousto-optic modulator () that corrects light intensity on the basis of light intensity fluctuation detected by means of the light intensity fluctuation detection circuit () such that the light intensity is constant Furthermore, a magnetic field measuring apparatus of the present invention is characterized in having: one sensor unit that passes therethrough light outputted from a light source unit: and a signal control processor that eliminates the light intensity fluctuation on the basis of two lights passed through the sensor unit.

Magnetic field measuring apparatus

A magnetic measurement device has a magnetic sensor including a glass cell having alkali metal gas encapsulated therein that is configured to detect a magnetic field using a magneto-optical characteristic of spin-polarized alkali metal. A laser light source is configured to generate pump light introduced into the magnetic sensor and a coil provided in the same magnetically shielded space as the magnetic sensor is configured to apply a static magnetic field and a RF magnetic field to the magnetic sensor. A signal processor is configured to perform lock-in detection of a light detection signal transmitted through the glass cell of the magnetic sensor, control an intensity of the static magnetic field and a frequency of the RF magnetic field generated by the coil according to a lock-in detection output, and obtain a measurement signal reflecting a magnetic field intensity of an object to be measured in the magnetically shielded space.

Magnetic field measurement device

A compression depth calculation system is configured to calculate the compression depth which is a magnitude of depression of the compressed object generated by the compression and includes a measuring apparatus to be mounted on the object, and a compression depth calculating apparatus is configured to calculate the compression depth on the basis of information from the measuring apparatus. The compression depth calculation apparatus calculates a coefficient of transformation on the basis of a second-order differential waveform created for the information acquired from a magnetic sensor and acceleration information acquired from an acceleration sensor, creates a displacement waveform of a compressed portion by multiplying the acquired information by the coefficient of transformation, and calculates the compression depth on the basis of the displacement waveform.

Compression depth calculation system and compression depth calculation method

In a magnetic immunoassay using AC magnetic susceptibility measurement, a signal from non-coupled magnetic particles is prevented to mix with a desired measurement signal from magnetic particles coupled with an object to be measured. A sample vessel in which a mixed solution of an inspection objective sample and the magnetic particles are included is carried by a sample support, such that a precipitation of the magnetic particle coupled with the object to be measured dispersed in the solution by a magnetic field from a dissociating coil is promoted. Next, the sample vessel is carried to the magnetizing coil and the magnetic signal from the non-coupled magnetic particle remaining in a supernatant in the vessel is peculiarly measured by an MR sensor to perform AC magnetic susceptibility measurement with high precision.

Magnetic immunoassay using AC susceptibility measurement

Stable magnetic field measurement is enabled without collapse of polarization or fluctuation of intensity of a laser beam incident on a glass cell of an optical pumping magnetic sensor. Excitation light generated with a light source, having optimized light intensity and polarized wave, through frequency stabilization, intensity control and polarized-wave control, is introduced via a polarized wave holding optical fiber to a magnetic sensor provided in a magnetic shield, and magnetic field measurement is performed by optical pumping using magneto-optical properties of spin-polarized alkali metal. The magnetic sensor has a structure where a lens, a polarization optical device, the glass cell and a photodetector, are integrally accommodated in a non-magnetic case.

Optical pumping magnetometer

In order to provide a magnetic field measuring apparatus facilitating the pressure control in a gas cell, or capable of inspecting the internal pressure of the gas cell without using any special process, the magnetic field measuring apparatus is configured such that a process layer of the magnetic field measuring apparatus has such a structure that includes a first hollow portion and a second hollow portion provided opposed to first hollow portion with a first isolation wall interposed therebetween. Alternatively, a method for manufacturing the magnetic field measuring apparatus includes breaking the first isolation wall after generating alkali metal (FIG.and FIG.).

Magnetic field measuring apparatus and method for manufacturing same

For measuring hardness of an object, a measurement apparatus is pushed against the object and a degree of hardness calculation system calculates hardness based on information from the measurement apparatus. The measurement apparatus includes an acceleration sensor which outputs first information of acceleration of a contact area of the measurement apparatus, and a second sensor, such as a magnetic sensor or a pressure sensor, which outputs second information based on pressure applied to the contact area. The degree of hardness calculation system generates a second-derivative waveform by twice differentiating a waveform based on the output of the second sensor, compares the second-derivative waveform and the information of acceleration from the acceleration sensor, and calculates hardness of the object based on the comparison result.

Degree of hardness measurement system and degree of hardness measurement method

A living body inspection apparatus includes: a first detecting unit detecting a displacement of two positions in a lateral direction of a subject's larynx; a second detecting unit detecting a swallowing sound of the subject; a displaying unit displaying a waveform regarding the displacement of the two positions formed using information from the first detecting unit and a waveform regarding the swallowing sound formed using information from the second detecting unit; a processor instructing the displaying unit; and a flexible holding member including a pair of sensor holding members having flexibility and provided with the first and second detecting units at one ends, and a mounting member integrally formed with the pair of sensor holding members at other ends to hold the sensor holding members, the other ends being made open so that the mounting member is mounted on and held by the subject's larynx.

Growing community of inventors

Tokyo, Japan

Ryuzo Kawabata