A magnetic sensor is configured such that, even if noise is generated from a bus bar at ON-OFF switching of a voltage for controlling the current to be measured flowing through the bus bar, the influence of the noise on the result of measurement made by the magnetic sensor can be reduced. The magnetic sensor includes a main body having two opposing sides, the main body being capable of measuring a value of a current to be measured flowing through a bus bar by detecting a magnetic field induced by the current to be measured, wherein a signal terminal for outputting a detection signal and a supply terminal for supplying electrical power to the main body extend only from one of the two sides of the main body.

A magnetic sensor device includes a magnetic field converter that receives an input magnetic field input along a first direction and outputs an output magnetic field along a second direction, which is orthogonal to the first direction. A magnetic field detector is provided at a position where the output magnetic field can be applied. A magnetic shield that blocks an external magnetic field along the second direction. is provided. The magnetic field converter has a shape in which the length in a third direction, which is orthogonal to both the first direction and the second direction, is longer than the length in the second direction, when viewed along the first direction. The magnetic shield is provided at a position overlapping with the magnetic field converter and the magnetic field detector, when viewed along the first direction.

A Hall probe comprising a Hall effect sensing element. The probe is capable of precisely measuring the strength of a magnetic field in high-voltage and vacuum environments.

A magnetoencephalograph M1 includes: multiple optically pumped magnetometers 1A that measure a brain's magnetic field; multiple magnetic sensors for geomagnetic field cancellation 2 that measure a magnetic field; multiple magnetic sensors for active shield 3 that measure a fluctuating magnetic field; a geomagnetic field nulling coil; an active shield coil 9; a control device 5 that determines a current to generate a magnetic field for canceling the magnetic field based on measured values of the multiple magnetic sensors for geomagnetic field cancellation 2, determines a current to generate a magnetic field for canceling the fluctuating magnetic field based on measured values of the multiple magnetic sensors for active shield 3, and outputs a control signal corresponding to each of the determined currents; and a coil power supply 6 that outputs a current to each coil in response to the control signal.

A brain measurement apparatus includes: a magnetoencephalograph including optically pumped magnetometers, magnetic sensors for measuring a static magnetic field at positions of the optically pumped magnetometers, and a nulling coil for canceling the static magnetic field; an MRI apparatus including a permanent magnet, a gradient magnetic field coil, a transmission coil, and a receive coil for detecting a nuclear magnetic resonance signal; and a control device that, when measuring the brain's magnetic field, controls a current to be supplied to the nulling coil based on measured values of the magnetic sensors and operates so as to cancel a static magnetic field at the position of each of the optically pumped magnetometers and, when measuring an MR image, controls the gradient magnetic field by controlling a current to be supplied to the gradient magnetic field coil and generates an MR image based on an output of the receive coil.

A magnetic sensor capable of reducing noise caused by an interference magnetic field and capable of outputting a highly accurate signal in accordance with changes in a detected magnetic field includes a magnetic detection element, a first magnetic body having a first surface and a second surface, which is opposite to the first surface, and a second magnetic body positioned approximately in the center of the first magnetic body in the short direction on the first surface of the first magnetic body. The magnetic detection element is provided to be opposite to the second magnetic body with the first magnetic body interposed in between and positioned approximately in the center of the first magnetic body in the short direction. The magnetic sensing direction of the magnetic detection element is a direction approximately parallel to the short direction of the first magnetic body and the second magnetic body, and a width W1 of the first magnetic body is larger than a width W2 of the second magnetic body.

A sensor housing has a receiving recess at one end portion of the sensor housing located at one end of the sensor housing. The one end portion of the sensor housing faces first and second magnetic circuit portions. A circuit board is received in the receiving recess and has an opening, a front-side region and a rear-side region. The front-side region is located on a side of the opening where the one end of the sensor housing is placed. The rear-side region is located on an opposite side of the opening. A main body of a magnetic sensing device overlaps the opening such that terminals projecting from one of a pair of side walls of the main body are located at the front-side region, and terminals projecting from another one of the pair of side walls is located at the rear-side region.

A shielding arrangement for a magnetoencephalography (MEG) system includes a passively shielded enclosure having a plurality of walls defining the passively shielded enclosure, each of the plurality of walls including passive magnetic shielding material to reduce an ambient background magnetic field within the passively shielded enclosure; a vestibular wall extending from a first vertical wall to define, and at least partially separate, a vestibular area of the passively shielded enclosure adjacent the doorway and a user area of the passively shielded enclosure; and active shield coils distributed within the passively shielded enclosure and configured to further reduce the ambient background magnetic field within the user area of the passively shielded enclosure.

A magnetocardiography (MCG) system includes a passively shielded enclosure having walls defining the passively shielded enclosure, each of the walls including passive magnetic shielding material to reduce an ambient background magnetic field within the passively shielded enclosure; an MCG measurement device including optically pumped magnetometers (OPMs); and active shield coils within the passively shielded enclosure and stationary relative to the passively shielded enclosure and the MCG measurement device, wherein the active shield coils are configured to further reduce the ambient background magnetic field within a user area of the passively shielded enclosure.

A magnetic field recording system includes a headgear for a user; optically pumped magnetometers (OPMs) disposed in or on the headgear to detect magnetic fields and, in response to the detection, produce magnetic field data; at least one sensing modality including an optical sensing modality having at least one light source and at least one camera or light detector to receive light reflected or directed from the user and to produce an optical data stream; a tracking unit to receive the optical data stream and track a position or orientation of the headgear or user; a system controller to control operation of the OPMs and receive, from the tracking unit, the position or orientation of the headgear or user; and a processor to receive the optical data stream and the magnetic field data from the OPMs and analyze the magnetic field data using the optical data stream for validation.