11 results about "Magnetoencephalography" patented technology

The present application is drawn to a system and method, as well as method for manufacture of a device and system for determining the position and orientation of at least one magnetic field sensor comprising: a rigid structure comprising an array of at least five electromagnetic coils; at least one wire that connects to and powers the electromagnetic coils; wherein the placement and orientation of the electromagnetic coils on the rigid structure are predetermined; wherein the electromagnetic coils, each having a predefined magnetic moment per unit current, are constructed with a printed circuit board (PCB) comprising at least one conductive layer; and wherein the system is configured such that a stray magnetic field emanating from the at least one, as measured at the location of the at least one magnetic field sensor, generates substantially lower magnetic field intensity than that produced by each of the at least five electromagnetic coils.

This invention discloses a magnetoencephalogram (MEG) compatible preamplifier method and device, which allows the MEG preamplifier to be placed within a magnetically shielded device. This invention achieves weak magnetism in the preamplifier circuit through the design of component selection and distribution; improves anti-interference capability and transmission stability by designing the MEG amplification factor and signal conditioning process; implements secondary amplification, power supply, and acquisition outside the magnetically shielded device, placing strongly magnetic components away from the weak magnetic environment to complete the entire acquisition process; and adopts a modular design, reducing the number of channels on each circuit board by distributing electrode channels, thereby reducing the size and facilitating the arrangement of the preamplifier system within the limited magnetically shielded space. This invention achieves weak magnetism in the preamplifier circuit, enabling high-quality brain-computer magnetic synchronous acquisition when placed within a magnetically shielded space.

This invention relates to a miniaturized triaxial SERF atomic magnetometer device with dual-pump light semi-transparent and semi-reflective beams. A single pump light is guided into the probe by a polarization-maintaining fiber. Then, using a half-wave plate, a polarization beam splitter, a right-angle mirror, and a quarter-wave plate, the pump light is split into two circularly polarized pump lights of equal intensity, which then pass perpendicularly through the same alkali metal gas cell. The pump light passing through the gas cell is then split by a semi-transparent and semi-reflective planar beam splitter; half of the pump light is detected by a photodetector to extract magnetic field information, while the other half returns along the same path and passes through the alkali metal gas cell a second time. This invention achieves high-sensitivity simultaneous measurement of triaxial magnetic fields in a miniaturized triaxial SERF atomic magnetometer, enhances atomic spin polarizability, and improves the uniformity of atomic spin polarizability within the gas cell. It addresses the technical challenge of achieving uniform spin polarizability in miniaturized SERF atomic magnetometer applications, and is beneficial for applications of array-type triaxial SERF atomic magnetometers in fields such as magnetocardiography and magnetoencephalography.

The invention discloses a self-adaptive subspace projection suppression method based on optical pump magnetometer external noise, and belongs to the technical field of neural magnetic imaging (MEG) signal processing.The method comprises the steps that brain magnetic signals are collected through a wearable optical pump magnetometer array and preprocessed, and a signal and noise subspace decomposition model is established; integrating a model-driven noise modeling method and a data-driven noise modeling method, and constructing a noise subspace base vector; constructing a signal subspace basis vector in combination with a guide field matrix and event correlation analysis; identifying residual noise components based on event correlation analysis, and perfecting noise subspace modeling; signal noise separation is realized by adopting a hierarchical projection strategy; and analyzing the time correlation of internal and external space signals, and constructing a time projection matrix to remove residual interference to obtain a clean MEG signal. According to the invention, various types of external noise interferences can be effectively suppressed, the signal-to-noise ratio and the reliability of brain magnetic signals are remarkably improved, and the method is particularly suitable for practical application of a wearable optical pump magnetometer system.

The application relates to a magnetoencephalography device and a method for registering the magnetoencephalography device and MRI, and belongs to the field of magnetoencephalography research. The method comprises the following steps: acquiring a head image of a subject wearing a magnetoencephalography device; point cloudizing the head image of the subject to obtain a scene point cloud; performing corresponding point clustering processing on the scene point cloud and a marker module model point cloud, identifying the marker module, and determining the position coordinates of the marker module; determining the sensor probe position according to the position coordinates and the relative position relationship between the marker module and the sensor array; acquiring a three-dimensional MRI image of the head of the subject, and separating the three-dimensional MRI image into a scalp three-dimensional image and a cerebral cortex anatomical structure; extracting an MRI facial image according to the scalp three-dimensional image; and registering the MRI facial image and the head image of the subject based on the sensor probe position, so that the sensor array and the cerebral cortex anatomical structure are in a unified coordinate system. The method improves the accuracy of registration.

The application relates to a kind of based on magnetoencephalography stimulation combination electroencephalogram analysis method, method is by carrying out real stimulation and pseudo-stimulation control experiment, respectively obtains original mixed signal matrix and reference sensory artifact signal matrix;Then, the convolution kernel to be solved is introduced to construct convolution mixed mathematical model, and the modulation mechanism of sensory artifact is described in a mathematical way;Subsequently, two matrixes are input into the model, and the pure direct neural response signal matrix and individualized modulation convolution kernel matrix are separated out by applying joint iterative inversion calculation with space-time constraints;Finally, based on pure signal extraction multidimensional neurophysiological characteristics and combined with modulation mode analysis, generate comprehensive report.The method can effectively separate sensory artifact, and provide a new analysis approach for obtaining more reliable and direct cortical neuroelectrophysiological response.

The invention discloses a brain magnetic compatible near-infrared channel arrangement and modulation frequency distribution method, and belongs to the technical field of multi-mode brain function imaging. In order to solve the problems that in the prior art, personalized optrode arrangement optimization is difficult, standardized meta-information files are tedious to generate, and brain magnetic compatible frequency distribution efficiency is low, optrode coordinates are constructed based on individual head three-dimensional information, the positions of a light source and a detector are optimized through a greedy algorithm, and optrode two-dimensional coordinates are adjusted through dimension reduction and nonlinear optimization; and an automatic scheme is generated by using a method for carrying out brain magnetic compatible frequency allocation by using a graph coloring algorithm. According to the method, the experimental channel scheme of the whole brain or the region of interest can be quickly generated, the standard file and the channel visualization graph can be automatically generated, the brain magnetic compatibility and the high frequency utilization rate are considered at the same time, and the method is suitable for multi-mode brain imaging experiment preparation and personalized helmet or flexible cap optrode design.

This invention provides a method, apparatus, and device for issuing brain-computer interface commands related to language-motor co-imagination. The method includes: acquiring a user's magnetoencephalography (MEG) data during a language-motor co-imagination task, inputting this data into a language-motor co-decoding model to obtain motor intention results, and then issuing brain-computer interface commands. The adaptive position encoding module in the language-motor co-decoding model identifies the cognitive state in the MEG data and extracts motor imagination soft boundary features, semantic cue soft boundary features, and combined soft boundary features. These features provide the model with accurate boundary information, helping to distinguish different imagination tasks. The motor imagination decoding module in the model extracts time-frequency features using the motor imagination soft boundary features; the semantic decoding module in the model extracts discrete semantic encoded sequences based on the semantic cue soft boundary features. The combined decoding module integrates these features for intention decoding, significantly improving the discriminative power of different imagination tasks and the accuracy of intention decoding.

The application discloses a magnetoencephalography compatible multi-channel near-infrared high sampling rate modulation method and system, and belongs to the field of multi-modal brain function imaging research.The method comprises the following steps: modulating a driving signal of an fNIRS light source to a high-frequency carrier; adopting a multi-channel frequency division multiplexing strategy, transmitting the modulated driving signal to each fNIRS light source, so that each fNIRS light source emits infrared light rays for detecting a target; and demodulating the detected infrared light rays to obtain the amplitude of the detected infrared light rays.The application can realize non-contact sensing of the target.The application can reduce electromagnetic interference in the process of MEG and fNIRS synchronous imaging, utilize specific frequency modulation technology to realize synchronous acquisition of magnetoencephalography signals and multi-channel high sampling rate near-infrared signals, and accurately and quickly demodulate the near-infrared signals.

Various embodiments disclosed herein comprise systems and methods to locate magnetic field sensors. In some examples, a system comprises a controller, a sensor mount, a coil set comprising one or more coils, and a magnetic field sensor. The sensor mount mounts the magnetic field sensor and constrains at least one degree of freedom of the magnetic field sensor in position or orientation. The controller supplies electric current to the coil set. The coil set generates magnetic waves that form at least one coil magnetic field in response to receiving the current. The magnetic field sensor measures the strength of the coil magnetic field. The controller locates the magnetic field sensor based on the constraint and the measured strength of the coil magnetic field.

The application discloses a kind of biological magnetic imaging systems with adjustable spatial resolution, including detection unit, stimulation unit, optical pumping atomic magnetic field measurement unit and data acquisition processing device;Optical pumping atomic magnetic field measurement unit is set in magnetic shield room;Optical pumping atomic magnetic field measurement unit includes atomic gas chamber;Detection unit includes laser, diffractive optical element, collimating lens, imaging zoom lens group and multiple fixed pitch photodetector;Diffractive optical element and collimating lens are set along laser exit light path;Imaging zoom lens group is set behind the exit light path of atomic gas chamber;Photodetector receives signal light emitted by imaging zoom lens group;Data acquisition processing device is electrically connected with each photodetector.The application can save time and cost under the premise, adjust the spatial resolution of system conveniently and quickly, has wide application scene, can adapt to magnetocardiography, magnetoencephalography, muscle magnetism and different application needs, and is suitable for constructing atomic magnetometer array with adjustable pitch.