The present invention relates to a field-sensor device comprising a reference field sensor providing a reference sensor signal in response to a field, a calibrated field sensor providing a calibrated sensor signal in response to the field, a reference circuit connected to the reference field sensor and adapted to receive a reference signal, and an adjustable circuit connected to the calibrated field sensor and adapted to receive a calibrated signal. When the adjustable circuit is adjusted with the calibrated signal, said calibrated signal being different from the reference signal, the calibrated field sensor provides a calibrated sensor signal substantially equal to the reference sensor signal. The field sensor device is arranged to be exposed, when in a calibration mode, to a uniform calibration field and, when in operational mode, to an operational field being a field gradient.

A method includes measuring a first property of a magnetic field using a bridge circuit with spatially separated bridge branches, and measuring a second property of the magnetic field using a magnetic field sensor located between the spatially separated bridge branches.

Embodiments relate to a method including obtaining m measured values for each field sensor by measuring with respect to a first sensor group including first type of field sensors and a second sensor group including different second type of field sensors, which are attached to the rigid body, at m time steps; and calibrating a sensor frame of the first type of field sensor and a sensor frame of the second type of field sensor by using a correlation between the first type of field sensor and the second type of field sensor based on measured values of at least some of the m time steps, wherein the multiple field sensors include different field sensors of a magnetic field sensor, an acceleration sensor, and a force sensor, and a system therefor.

A multichannel magnetic field sensor including a plurality of magnetic field sensing elements includes a multiplexed signal path. A front end amplifier is coupled to receive a first magnetic field signal during a first time interval and a second magnetic field signal during a second time interval. A first low pass filter processes the amplified signal during the first time interval and a second low pass filter processes the amplified signal during the second time interval. A sinc filter is coupled to receive the first low pass filtered signal during the first time interval and the second low pass filtered signal during the second time interval. A Schmitt trigger circuit includes a comparator to process the sinc filter output signal and to generate a first comparator output signal during the first time interval and a second comparator output signal is provided during the second time interval.

A system and method that can automatically select a frequency of a magnetic field in a magnetic tracking system. A magnetic tracking system emits an alternating magnetic field using a set of three frequencies. In the present approach, a transmitter is capable of generating multiple sets of three frequencies. A processor selects a first set of frequencies to use and causes the receiver to measure the amplitude of the magnetic field at those frequencies. In one embodiment, the frequency set having the lowest energy is selected. The processor then compares an estimated jitter at those frequencies to the actual jitter experienced using the frequencies. If the actual jitter exceeds the estimated jitter by a predetermined amount, the processor switches to a different set of frequencies and causes the receiver to measure the magnetic field at the new set of frequencies. The process may repeat using the additional sets of frequencies.

Disclosed is a multi-channel atomic magnetic detector (100), including at least one detection assembly, with each detection assembly including a plurality of detection air chambers (130) in the same plane and a light-splitting member (110) for allocating polarized beams from a light source (180) to each detection air chamber (130) in the detection assembly, wherein the plurality of detection air chambers (130) of each detection assembly are arranged in a centrally symmetric manner or an axially symmetric manner relative to the light-splitting member (110). The multi-channel atomic magnetic detector (100) has a high detection density and is beneficial for noise reduction.

Methods, computer-readable storage devices, and systems are described for reducing movement of a patient undergoing a magnetic resonance imaging (MRI) scan by aligning MRI data, the method implemented on a Framewise Integrated Real-time MRI Monitoring (“FIRMM”) computing device including at least one processor in communication with at least one memory device. Aspects of the method comprise receiving a data frame from the MRI system, aligning the received data frame to a preceding data frame, calculating motion of a body part between the received data frame and the preceding data frame, calculating total frame displacement, and excluding data frames with a cutoff above a pre-identified threshold of the total frame displacement.

The present invention discloses a method and apparatus for simulating and designing structural parameters of an air-core coil. The method for simulating and designing structural parameters of the air-core coil includes: building an impedance function of the air-core coil according to a structural parameter variable, the air-core coil being of a differential structure and being wound in a completely parallel winding fashion; building an index function of the air-core coil by calculating an equivalent bandwidth, sensitivity and an equivalent noise power spectrum by means of the impedance function. The method is intuitive, and makes calculation of the optimized technological and structural parameters easier and more convenient, thus reducing the amount of calculation and shortening the calculation time.

Provided is a magnetic field measurement device which includes a magnetic sensor array that is composed of a plurality of magnetic sensor cells, each of which has a magnetic sensor and an output unit for outputting an output signal, arranged at lattice points between two curved surfaces, each of which is bent in one direction, so as to be three-dimensionally arranged, and is capable of detecting an input magnetic field in three-axial directions, a measurement data acquisition unit configured to acquire measurement data measured by the magnetic sensor array, and a magnetic field reconstruction unit configured to reconstruct a magnetic field of a component orthogonal to a virtual sensor array plane with respect to one or more positions on the virtual sensor array plane, which is a plane specified in a three-dimensional space, using the measurement data.

A sensor comprising: a first magnetoresistive (MR) bridge having a first stray field sensitivity; a second MR bridge having a second stray field sensitivity; and a driver circuitry configured to: (i) supply a first voltage to the first MR bridge, and (ii) supply a second voltage to the second MR bridge that is different from the first voltage, wherein supplying the first voltage and the second voltage to the first MR bridge and the second MR bridge, respectively, causes the first stray field sensitivity to match the second stray field sensitivity.