28 results about "Magnetocardiography" patented technology

The invention relates to a double-pump light semi-transparent and semi-reflective miniaturized triaxial SERF atom magnetometer device, which is characterized in that single pump light is guided into a probe by a polarization maintaining optical fiber; and then one beam of pump light is divided into two beams of circular polarization pump light with the same light intensity by using a half-wave plate, a polarization splitting prism, a right-angle reflector and a quarter-wave plate, and then the two beams of circular polarization pump light vertically pass through the same alkali metal gas chamber. After the pump light penetrating through the air chamber passes through the semi-transparent and semi-reflective flat beam splitter, one half of the pump light is detected by the photoelectric detector and used for extracting magnetic field information, and the other half of the pump light returns to the original path and passes through the alkali metal air chamber for the second time. According to the invention, high-sensitivity simultaneous measurement of a three-axis magnetic field of the miniaturized three-axis SERF atom magnetometer is realized, the atomic spin polarizability is enhanced, the uniformity of the atomic spin polarizability in the air chamber is improved, and the technical problem of spin polarizability uniformity in miniaturized application of the SERF atom magnetometer is solved; and the application of the array type triaxial SERF atom magnetometer in the fields of magnetocardiography, brain magnetism and the like is facilitated.

The present disclosure relates to methods, systems, and apparatus, including computer programs encoded on computer storage media, for denoising magnetic measurements. An example method includes obtaining, using a plurality of magnetometers of a magnetically unshielded device, noisy magnetic measurement data of a magnetic field at least partially caused by an organ of a subject; obtaining, using one or more inertial measurement units (IMUs) of the magnetically unshielded device, a motional measurement of the plurality of magnetometers; determining cleaned magnetic field data based at least in part on the noisy magnetic measurement data and the motional measurement data; and taking an action based at least in part on the cleaned magnetic field data.

The application belongs to the technical field of magnetocardiogram signal processing, and particularly relates to a method, device and medium for removing impact noise of multi-channel magnetocardiogram signals, comprising the following steps: S10, acquiring multi-channel magnetocardiogram signals collected by a magnetocardiograph; S20, based on the multi-channel magnetocardiogram signals, modeling the spatial relationship between channels by using a graph method, fitting the spatial distribution of the multi-channel magnetocardiogram signals containing noise signals by using a symmetric alpha stable distribution model, and obtaining a graph signal representation of the noisy magnetocardiogram signals; S30, constructing an lp regularization target function based on the graph signal representation, optimizing and solving the target function by using an iteratively reweighted least squares method, and obtaining the denoised magnetocardiogram signals. The method can remove the impact noise of individual channels in the multi-channel magnetocardiogram signals, and improve the signal-to-noise ratio of the magnetocardiogram signals; and the spatial denoising is helpful to improve the signal-to-noise ratio while completely retaining the time domain characteristics of the signals, and has no requirement for the number of time domain samples, and the detection efficiency is higher.

A method for determining positional information of a target organ of a human subject during a biomagnetic field scan comprises detecting, by a plurality of magnetometers, first biomagnetic field signals from at least a portion of the human subject's organ and second magnetic field signals from an electromagnetic transmitter positioned on a predetermined position of the human subject. The plurality of magnetometers have a known position during the biomagnetic field scan. The method includes determining a time-varying spatial relationship between the electromagnetic transmitter and the plurality of magnetometers based on the detected second magnetic field signals. The method further includes correcting artifacts in the detected first biomagnetic signals in accordance with the determined spatial relationship.

The application discloses a kind of based on electrocardiogram and cardiac magnetic multi-scale fusion cardiac electrophysiological signal classification method and system, comprising: obtaining electrocardiogram signal and cardiac magnetic signal, and the original ECG, MCG signal is respectively filtered and denoised pretreatment, and through R wave positioning division heartbeat, after Fourier transform, obtain two-dimensional spectrogram, after feature extraction, respectively establish multi-domain cardiac function signal dataset;Convolutional recurrent neural network is constructed, and the synchronous processing of two different forms of cardiac electrophysiological signals is realized by double input model, shallow signal feature extracted by convolutional neural network is input into the time sequence feature extraction module formed by recurrent neural network, fusion ECG, MCG signal local saliency feature and time sequence feature, form the final ECG, MCG signal feature used for classification.Combined with cross-entropy loss function, the feature after fusion is input into nonlinear classification layer, using Softmax carries out model training, and outputs classification result.

A system includes a magnetocardiography (MCG) subsystem having a plurality of magnetometers. The system measures, via the MCG subsystem using the plurality of magnetometers, MCG data comprising biomagnetic field signals from a human subject. the system receives, from one or more ECG electrodes that are physically coupled to the human subject, ECG data comprising cardiac electrical activity of a heart of the human subject. The system determines location information of the one or more electrodes that are mounted on the human subject. In some embodiments, the system enhances the measured MCG data and / or the received ECG data according to determined location information of the one or more electrodes.

The present disclosure relates to methods, systems, and apparatus, including computer programs encoded on computer storage media, for simulating magnetic data. An example method includes obtaining electrical data of an organ of a subject. The method further includes generating current data corresponding to a current source based on the electrical data of the organ of the subject. The method further includes generating simulated magnetic data of the organ of the subject based on the current data corresponding to the current source. The method further includes taking an action based on the simulated magnetic data.

The application provides a kind of fusion heart magnetism and electrocardiogram cardiac source localization method, comprising: obtaining the individualized heart-lung-trunk model of subject based on medical image, obtaining volume conductor conduction model by using boundary element method, calculating simulation signal by using source model and conduction model, then solving to obtain simulation source, solving to obtain actual source by using measured signal, comparing the similarity between actual source and simulation source, and then fusing the source localization results of heart magnetism and electrocardiogram by weighted average method.The application fuses heart magnetism signal and electrocardiogram signal to locate the cardiac source of subject, and determines the confidence of electrocardiogram source localization result and heart magnetism source localization result according to the similarity between actual source and simulation source, so as to determine the weighted coefficient of the two, improve the accuracy of cardiac source localization, and can be applied to clinical diagnosis and treatment.

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 present disclosure relates to methods, systems, and apparatus, including computer programs encoded on computer storage media, for denoising magnetic measurements. An example method includes obtaining, using a plurality of magnetometers of a magnetically unshielded device, noisy magnetic measurement data of a magnetic field at least partially caused by an organ of a subject; obtaining, using one or more inertial measurement units (IMUs) of the magnetically unshielded device, a motional measurement of the plurality of magnetometers; determining cleaned magnetic field data based at least in part on the noisy magnetic measurement data and the motional measurement data; and taking an action based at least in part on the cleaned magnetic field data.

This invention relates to a three-dimensional adjustable support device for a sensor based on an optically pumped magnetometer and its measurement method. Aimed at solving the problems of poor sensor fit and adaptability in existing magnetocardiography (MCC) detection systems, it provides a scalable, adjustable, and precise three-dimensional positioning solution. The support panel adopts a modular design and includes a three-dimensional positioning system that can adapt to the anterior chest curve of subjects of different body types, from adolescents to adults. The optically pumped magnetometer is installed in an independently adjustable insert that can slide along the normal direction within the support frame and is precisely locked by a self-locking mechanism. This design ensures the stability and repeatability of sensor positioning and minimizes mechanical errors, thereby ensuring the acquisition of high-quality magnetocardiographic signals.

The application relates to a mouse heart magnetocardiography and magnetoencephalography testing device and method based on a zero-field atomic magnetometer, and relates to the field of heart magnetocardiography and magnetoencephalography testing. The application solves the problems that the existing mouse heart magnetocardiography and magnetoencephalography testing device has a large volume, and the magnetic field signal is distorted due to the movement or struggle of the mouse, and motion artifacts are generated. A plurality of groups of tool fixing hole positions (1-1) are formed in pairs on the upper end face of a platform (1), a plurality of heart magnetometer mounting holes (1-2) are formed in the middle of the length direction of the lower end face of the platform (1), a heart magnetometer is mounted in the heart magnetometer mounting hole (1-2), one insert (2) is inserted in each group of tool fixing hole positions (1-1), the insert (2) is provided with a magnetoencephalography mounting hole (2-1) and a head mounting hole (2-2). The mouse heart magnetic signal and the magnetoencephalography signal are tested at the same time, and the error introduced by the environmental magnetic field change in the experiment process is reduced to the maximum extent. The application is used for mouse heart magnetocardiography and magnetoencephalography testing.

The present disclosure relates to methods, systems, and apparatus, including computer programs encoded on computer storage media, for denoising magnetic measurements. An example method includes obtaining, using a plurality of magnetometers of a magnetically unshielded device, noisy magnetic measurement data of a magnetic field at least partially caused by an organ of a subject; obtaining, using one or more inertial measurement units (IMUs) of the magnetically unshielded device, a motional measurement of the plurality of magnetometers; determining cleaned magnetic field data based at least in part on the noisy magnetic measurement data and the motional measurement data; and taking an action based at least in part on the cleaned magnetic field data.

This invention discloses a method for assessing the degree of coronary artery occlusion based on magnetocardiography (MCG), comprising: acquiring a MCG dataset, divided into a training set and a test set; assigning labels to each MCG data point; training different classification models using the training set and labels, with different degrees of coronary angiography occlusion as boundaries, to obtain trained classification models; testing the test set using the trained classification models to obtain the positive probability of each MCG data point under different classification models and degrees of coronary angiography occlusion; weighting the positive probability of each classification model under different degrees of coronary angiography occlusion to obtain a score for each classification model; weighting the scores of each MCG data point under different classification models to obtain a final score for each MCG data point; assessing the percentage of coronary artery occlusion based on the final score; and a system for assessing the degree of coronary artery occlusion based on magnetocardiography. This invention can provide a more accurate, objective, and detailed assessment of coronary artery occlusion.

The invention relates to a method of localisation of vector magnetometers arranged in a network, comprising the following steps:generation (EMi), by a magnetic field source (S), of m reference magnetic fields with known amplitudes and known and distinct directions;measurement (MESj) of the m reference magnetic fields along n axes of magnetometers in the network, m and n being such that m*n≥6;determination (LOCj) of the position and orientation of magnetometers of the network from said measurements, relative to the magnetic field source.The invention also includes a magnetic field measurement instrument that includes a network of vector magnetometers and is capable of implementing the localisation method.Application to the imagery of biomagnetic fields, for example in magnetocardiography or in magnetoencephalography.

A magnetic field measuring apparatus according to an example embodiment includes: an external container; an internal container storing a liquid refrigerant, disposed inside the external container, and including a neck portion having a first diameter and a body portion having a second diameter greater than the first diameter, wherein a space between the internal container and the external container is maintained in a vacuum state; a SQUID sensor module mounting plate disposed below the internal container; a plurality of SQUID sensor modules mounted below the SQUID sensor module mounting plate; and a 4K heat shielding portion formed of a conductive mesh disposed to surround the SQUID sensor module mounting plate and the plurality of SQUID sensor modules.

A kind of multi-channel joint space-time filtering method of magnetocardiogram signal belongs to magnetocardiogram signal processing field, first, multi-channel magnetocardiogram signal is collected, all channels are fitted to obtain the Hermite parameter of each channel at each time using Hermite fitting method;Magnetocardiogram image is divided into several blocks from space, and the magnetocardiogram image at each time is expressed using the Hermite parameter of corresponding channel;All magnetocardiogram image blocks at all times are clustered using clustering method to construct different characteristic waveform magnetocardiogram image block set;Within the range of this set, the magnetocardiogram signal is weighted and averaged to obtain the denoised magnetocardiogram signal.The present application utilizes the characteristics of high synchronism and high repeatability of multi-channel magnetocardiogram signal, denoises magnetocardiogram image in time domain and space domain, improves the non-Gaussian noise suppression effect of spectral overlap and the quality of two-dimensional magnetocardiogram image data, while retaining the time domain characteristics of magnetocardiogram signal, improves the signal-to-noise ratio of magnetocardiogram signal.

This invention relates to the field of cardiac electrophysiological diagnostic technology, and discloses a method and system for extracting pulmonary hypertension features based on magnetocardiography. The method includes: acquiring the cardiac magnetic field strength distribution matrix of the subject and calculating the magnetic field gradient direction vector; extracting the zero-position feature trajectory of the magnetic field gradient direction vector to determine the respiratory displacement compensation value and correct the spatial coordinates of the magnetic field distribution; analyzing the distribution symmetry of the magnetic field gradient direction vector to establish a rotation axis reference; calculating the angular displacement offset of the magnetic field gradient direction vector relative to the rotation axis reference and generating gradient rotation feature parameters; determining the angular distribution consistency index of the magnetic field gradient direction vector and establishing the phase-locked characteristic time, and calibrating the gradient rotation feature parameters. This invention, by constructing a geometric reference for the topological evolution of the magnetic field, eliminates the influence of anatomical position deviations of the subject, captures the rotational distortion of the right ventricular electrical conduction path, and improves the accuracy of pathological feature extraction.

The invention discloses a design method and system for a biplane disc coil of a magnetocardiography measuring device, and the method comprises the steps: predetermining an internal uniform region according to the size of an existing miniaturized magnetocardiography barrel, and giving a current density form of surface current continuously distributed on the surface of a disc; determining a magnetic field expression corresponding to the discrete target field points in the space target area; solving an undetermined coefficient in the current density to obtain the surface current density distribution of the double-plane disc-shaped coil; the method comprises the following steps: discretizing current density, and calculating initial coil current routing by using a stream function; parameters influencing the multi-dimensional coil are optimized by adding an intelligent bionic optimization algorithm; and determining final parameters, re-dispersing the current density, and substituting the current density into a current function to obtain a specific winding diagram of the coil. According to the method, the space utilization rate of the magnetocardiogram device can be improved, the area of the end cover of the barrel can be better utilized, and meanwhile, a new thought is provided for guiding the design of the magnetic shielding barrel with the small length-diameter ratio through the small distance between the double-plane disc coils.

The invention provides a magnetocardiogram detection method and device based on QRS magnetocardiogram vector ring development parameters and a medium. The method comprises the following steps: determining a vector parameter based on a QRS magnetocardiogram vector loop; determining a time parameter and a speed parameter based on the QRS magnetocardiogram vector loop; determining direction parameters based on the QRS magnetocardiogram vector loop; determining an area parameter based on the QRS magnetocardiogram vector loop; comprehensive parameters are determined based on the vector parameters, the time parameters, the speed parameters, the direction parameters and the area parameters, and the magnetocardiogram state is determined based on the comprehensive parameters. According to the method, important characteristics which cannot be reflected by existing magnetic map parameters are supplemented, and the method has important significance on detection of myocardial ischemia and bundle branch block by researchers; the comprehensive parameters are obtained by performing a series of data processing on the vector parameters, the time parameters, the speed parameters, the direction parameters and the area parameters, and the magnetocardiogram state is determined based on the comprehensive parameters instead of subjective judgment, so that the preciseness and accuracy of determining the magnetocardiogram state are improved.

The invention discloses a physiological signal quality evaluation method and system for magnetocardiogram. The physiological signal quality evaluation method comprises the following steps of 1, obtaining a plurality of cardiac cycle segments; 2, constructing a multi-view sample set; step 3, inputting the multi-view sample set into the improved BYOL network, including sharing an encoder and a multi-scale path, the multi-scale path corresponding to the input of different time windows, configuring differentiated projection heads and predictors, and outputting an encoding representation vector and a prediction vector; step 4, generating a cross-scale alignment error signal; 5, forming joint comparison loss; step 6, based on a DENCLUE clustering algorithm, dynamically adjusting a density weight through combined comparison loss, and generating a clustering feature center set; and 7, carrying out distance matching analysis on the prediction vector and the clustering feature center set to generate a quality evaluation result. According to the method, the improved BYOL network and the DENCLUE clustering algorithm are fused, and unsupervised magnetocardiogram quality evaluation is achieved.

The present disclosure relates to methods, systems, and apparatus, including computer programs encoded on computer storage media, for simulating magnetic data. An example method includes obtaining electrical data of an organ of a subject. The method further includes generating current data corresponding to a current source based on the electrical data of the organ of the subject. The method further includes generating simulated magnetic data of the organ of the subject based on the current data corresponding to the current source. The method further includes taking an action based on the simulated magnetic data.

The invention discloses a magnetic compatible atomic magnetometer load state magnetocardiogram detection system and method, and belongs to the technical field of biomedical engineering and weak magnetic field measurement. The system comprises a magnetic shielding device, an SERF atom magnetometer array, a magnetic compatible load applying device and a data acquisition and magnetocardiogram generation module. According to the magnetic compatible load applying device, a fluid pressure remote transmission structure is formed by a non-magnetic elastic bag body, a non-metal pressure guide pipeline and an external pressure detection unit, and grip strength of a subject is conducted to the outside of the shielding device in a non-magnetic mode. The method comprises the following steps: firstly, measuring the maximum grip strength of a subject and setting a target load interval; after a subject enters the shielding device, a resting-state magnetocardiogram base line is collected, and the subject continuously holds and presses the non-magnetic elastic bag body to perform equal-length contraction movement; and when the pressure is stabilized in the target load interval, automatically triggering to acquire a load state magnetocardiogram signal. Real-time load state magnetocardiography completely compatible with a high-sensitivity atom magnetometer is achieved for the first time.

The present disclosure relates to methods, systems, and apparatus, including computer programs encoded on computer storage media, for denoising magnetic measurements. An example method includes obtaining, using a plurality of magnetometers of a magnetically unshielded device, noisy magnetic measurement data of a magnetic field at least partially caused by an organ of a subject; obtaining, using one or more inertial measurement units (IMUs) of the magnetically unshielded device, a motional measurement of the plurality of magnetometers; determining cleaned magnetic field data based at least in part on the noisy magnetic measurement data and the motional measurement data; and taking an action based at least in part on the cleaned magnetic field data.

A method for determining positional information of a target organ of a human subject during a biomagnetic field scan comprises detecting, by a plurality of magnetometers, first biomagnetic field signals from at least a portion of the human subject's organ and second magnetic field signals from an electromagnetic transmitter positioned on a predetermined position of the human subject. The plurality of magnetometers have a known position during the biomagnetic field scan. The method includes determining a time-varying spatial relationship between the electromagnetic transmitter and the plurality of magnetometers based on the detected second magnetic field signals. The method further includes correcting artifacts in the detected first biomagnetic signals in accordance with the determined spatial relationship.

A single-beam dual-channel atomic magnetometer system, through a combined polarization beam splitter set in a dual-channel meter head with a single-beam input interface, can split a single beam into a first pump beam and a second pump beam to act on the first alkali metal gas cell and the second alkali metal gas cell respectively. It can simultaneously obtain dual-channel magnetic field information, and has the characteristics of high sensitivity and high integration. It is conducive to forming a high-density magnetometer array and serving fields such as magnetoencephalography and magnetocardiography.

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.

The invention provides a heart magnetic field simulation device based on a current dipole and a control method thereof. The device comprises a trunk simulation container; a support; the heart simulation shell is supported in the internal space of the trunk simulation container by a supporting piece, and a plurality of through holes are distributed in the surface of the heart simulation shell; the conductive solution is located in the trunk simulation container; the current dipole simulator is located in the conductive solution and fixed to any through hole in the surface of the heart simulation shell, and the positive electrode and the negative electrode of the current dipole simulator are connected to the electrocardiosignal generator; the electrocardiosignal generator is configured to generate a simulation electrocardiosignal, the electrocardiosignal generator, the positive electrode of the current dipole simulator, the conductive solution and the negative electrode of the current dipole simulator form a conductive path, and the conductive path generates a heart simulation magnetic field; when the current dipole simulator is fixed at different through hole positions of the heart simulation shell, the conductive path has different magnetic field expressions. According to the technical scheme, the cost of magnetocardiography simulation is reduced.