125results about "Measurements of magnetic particles" patented technology

A system and method are provided to detect target analytes based on magnetic resonance measurements. Magnetic structures produce distinct magnetic field regions having a size comparable to the analyte. When the analyte is bound in those regions, magnetic resonance signals from the sample are changed, leading to detection of the analyte.

The present invention relates to method and device for detecting changes of a magnetic response of at least one magnetic particle in a carrier fluid. The method comprises: using a measuring procedure comprising measuring the characteristic rotation time of said magnetic particle, said measuring procedure further involving measuring Brownian relaxation in said carrier fluid under influence of an external pulsed excitation magnetic field, and based on said influence of said external pulsed excitation magnetic field measuring a hydrodynamic volume of a particle or a change in a hydrodynamic volume of the particle change upon modification of an effective volume of the particle or its interaction with said carrier fluid by detecting change of magnetization of the particle with time by monitoring change of an output signal in detection coil.

Superparamagnetic nanoparticle-based analytical method comprising providing a sample having analytes in a sample matrix, providing a point of care chip having analytical regions, each of which is a stationary phase having at least one or more sections, labeling each of the analytes with a superparamagnetic nanoparticle and immobilizing the labeled analytes in the stationary phase, providing an analytical device having a means for exciting the superparamagnetic nanoparticles in vitro and a means for sensing, receiving, and transmitting response of the excited superparamagnetic nanoparticles, placing the chip in the analytical device and exciting the superparamagnetic nanoparticles in vitro, sensing, receiving, and transmitting the response of the superparamagnetic nanoparticles, and analyzing the response and determining characteristic of the analytes, wherein the response of the superparamagnetic nanoparticles comprises harmonics. The present invention also provides the hybrid point of care chip and analyzer to be used in the analytical method.

A physical unclonable function (PUF) having magnetic and non-magnetic particles is disclosed. Measuring both magnetic field and image view makes the PUF difficult to counterfeit. PUF may be incorporated into a user-replaceable supply item for an imaging device. A PUF reader may be incorporated into an imaging device to read the PUF. Other systems are disclosed.

Magnetic material imaging (MMI) system including first and second sets of field-generating coils. Each of the field-generating coils of the first and second sets has an elongated segment that extends along an imaging axis of the medical imaging system. The imaging axis extends through a region-of-interest (ROI) of an object. The elongated segments of the first set of field-generating coils are positioned opposite the elongated segments of the second set of field-generating coils and the ROI is located between the first and second sets of field-generating coils. The MMI system also includes a coil-control module configured to control a flow of current through the first and second sets of field-generating coils to generate a selection field and to generate a drive field. The selection and drive fields combine to form a movable 1D field free region (FFR) that extends through the ROI.

A magnetic sensor device (300) for sensing magnetic particles (15), the magnetic sensor device (300) comprising a magnetic field generator unit (12) adapted for generating a magnetic field, an excitation signal source (302) adapted for supplying the magnetic field generator unit (12) with a static electric excitation signal, an excitation switch unit (303) adapted for switching between different modes of electrically coupling the excitation signal source (302) to the magnetic field generator unit (12), and a sensing unit (11) adapted for sensing a signal indicative of the presence of the magnetic particles (15) in the generated magnetic field.

The present invention can provide a method of determining the presence, location, quantity, or a combination thereof, of a biological substance, comprising: (a) exposing a sample to a plurality of targeted nanoparticles, where each targeted nanoparticle comprises a paramagnetic nanoparticle conjugated with one or more targeting agents that preferentially bind with the biological substance, under conditions that facilitate binding of the targeting agent to at least one of the one or more biological substances; (b) subjecting the sample to a magnetic field of sufficient strength to induce magnetization of the nanoparticles; (c) measuring a magnetic field of the sample after decreasing the magnetic field applied in step b below a threshold; (d) determining the presence, location, quantity, or a combination thereof, of the one or more biologic substances from the magnetic field measured in step (c).

A sensor device (50) for sensing magnetic particles (15), the sensor device (50) comprising a substrate (25) and a sensing unit (11, 20) provided on and/or in and/or near the substrate (25) and being adapted for sensing a detection signal indicative of the presence of the magnetic particles (15), and a magnetic field control unit (30 to 34) provided off the substrate (25) and being adapted for generating a time-dependent magnetic field for interaction with the magnetic particles (15).

A calibration method for an MPI (=magnetic particle imaging) apparatus for conducting an MPI experiment, wherein the calibration method comprises m calibration MPI measurements with a calibration test piece and uses these measurements to create an image reconstruction matrix with which the signal contributions of N voxels within an investigation volume of the MPI apparatus are determined, wherein compressed sensing steps are applied in the calibration method with a transformation matrix that sparsifies the image construction matrix, and wherein only a number M<N of calibration MPI measurements for M voxels are carried out, from which the image reconstruction matrix is created and stored. This specifies an efficient method for determination of the system matrix for the MPI imaging method, which does not require much time to determine an MPI system function and nevertheless achieves a high degree of precision.

SQUID imaging of a subject's head after the subject having been administered superparamagnetic nanoparticles comprising: an iron-containing core, a coating covering the core and a probe molecule conjugated to the coating wherein the probe molecule locates the superparamagnetic nanoparticle to a target in the brain that is characteristic of the neurodegenerative disease; magnetizing the superparamagnetic nanoparticles using external magnetic coils; and measuring the decaying remanence magnetic fields of the superparamagnetic nanoparticles attached to the target and not from unattached superparamagnetic nanoparticles to obtain magnetic field measurements.

Apparatus and method for detecting a nonlinear magnetic particle based on a single excitation coil. The apparatus includes a signal generation unit for generating an input composite signal by combining a high-frequency sine wave signal and a low-frequency sine wave signal, generated based on a fundamental frequency, with each other, a signal application unit for applying the input composite signal to a single excitation solenoid coil included in a measurement head, through which a sample passes, to generate a magnetic field in the measurement head so as to detect a nonlinear magnetic particle, and a detection unit for detecting an output signal emitted from the sample depending on the magnetic field by using at least one detection solenoid coil included in the measurement head, analyzing a frequency domain of the output signal, and detecting whether the nonlinear magnetic particle is present in the sample.

The invention concerns a device for the qualitative or quantitative measurement of a magnetically labelled analyte. The device includes a coil arrangement for measuring the analyte from a sample absorbed in a test base. The coil arrangement includes at least one measuring coil and a reference coil arranged in connection with it. From the signal of the coil arrangement a change in inductance correlating to the content of the magnetically labelled analyte is arranged to be detected. The change in inductance is arranged to be detected from a change (ΔA, Δφ) in amplitude and/or phase appearing in the output signal of the coil arrangement, which is arranged to be measured at the frequency of the input signal. In addition, the invention also relates to a corresponding method.

The invention relates to the field of biomedical imaging and particularly relates to an open type magnetic particle three-dimensional imaging system and method based on array type receiving coils, and aims to solve a problem of contradiction between imaging precision and imaging speed in the prior art. The system comprises a non-magnetic field line generation module, a non-magnetic field line driving module, a signal detection module, a current excitation module, a signal conditioning module and an image reconstruction module. The imaging method comprises the following steps that a non-magnetic field line is constructed; the spatial position of the non-magnetic field line is adjusted by adjusting the current; an array type receiving coil of the signal detection module is used for detecting an induced voltage signal, then the induced voltage signal is processed by the signal conditioning module to obtain a signal without a fundamental frequency component, a direct current component in the voltage signal is filtered out by a digital filtering technology, and then Fourier transform is carried out on the voltage signal to obtain a frequency spectrum sequence of the voltage signal; and a measurement matrix of the array type receiving coil is constructed, and magnetic particle concentration space distribution is calculated by using the frequency spectrum sequence and the measurement matrix to realize three-dimensional high-precision rapid imaging.