G01R33/1276

Sensor array for reading a magnetic PUF

A magnetic sensor array device is described that is constructed with multiple single sensor die, diced out of a wafer individually and packaged in a multi-chip module (MCM). The device comprises an array of multi-axis magnetic sensors that can measure the multi-dimensional magnetic field of an arbitrary sized two-dimensional region with high spatial resolution, reduced sensing distance, higher measurement throughput, tolerance to motion, improved temperature measurement, and improved yield when placed on a circuit card comprises part of an authentication system including a physical unclonable function (“PUF”), a substrate, a plurality of magnetized particles randomly dispersed in the substrate, and a PUF reader constructed using one or more of the magnetic sensor array devices wherein the PUF reader measures the magnetic field at multiple locations in close proximity to the magnetized particles. The measured magnetic field data may be compared to previously enrolled data to assess authenticity.

Magnetic particle imaging method based on non-ideal field free point

A magnetic particle imaging method based on a non-ideal Field Free Point (FFP), including the following steps: setting external magnetic field conditions of a non-ideal FFP and an ideal FFP, and obtaining a magnetization vector M of Superparamagnetic Iron Oxide Nanoparticles (SPIOs) and a Point Spread Function (PSF) in combination with a Langevin function; obtaining a signal feature on basis of a voltage signal of a detection coil of a Magnetic Particle Imaging (MPI) instrument; performing integral transformation on the voltage signal collected by the detection coil of the MPI instrument to obtain a voltage signal of an equivalent ideal FFP; averaging the moving speed of an FFP of the MPI instrument to obtain a moving speed of the equivalent ideal FFP; obtaining an equivalent Three-Dimensional concentration reconstruction image on basis of the voltage signal of the equivalent ideal FFP and a moving speed of the equivalent ideal FFP.

MAGNET ARRANGEMENT FOR GENERATING A SELECTION MAGNETIC FIELD, APPARATUS WITH A MAGNET ARRANGEMENT AND METHOD FOR GENERATING A SELECTION MAGNETIC FIELD
20220091199 · 2022-03-24 ·

A magnet arrangement for generating a selection magnetic field with a gradient and a field-free region in a sample volume includes: a Maxwell magnet system with two ring magnets, which are arranged in coaxial fashion and at a distance from one another on a common Z-axis extending through the sample volume, a focus field coil arrangement with at least one focus field coil pair for displacing the field-free region within the sample volume, and a drive coil for generating an MPI drive field. The magnet arrangement comprises a quadrupole magnet system with at least one quadrupole ring for generating a quadrupole magnetic field, the quadrupole magnet system being arranged coaxially with respect to the Maxwell magnet system. Using the magnet arrangement according to the invention, it is possible to switch between a selection magnet field with a field-free point and a field-free line without undesirably increasing the field gradient.

Magnetic particle imaging (MPI) reconstruction method based on RecNet model

An MPI reconstruction method, device, and system based on a RecNet model include obtaining a one-dimensional (1D) MPI signal on which imaging reconstruction is to be performed, taking the 1D MPI signal as an input signal, and inputting the input signal and a velocity signal of an FFP corresponding to the input signal into a trained magnetic particle reconstruction model RecNet for image reconstruction to obtain a two-dimensional (2D) MPI image, where the magnetic particle reconstruction model RecNet is constructed based on a domain conversion network and an improved UNet network. The MPI reconstruction method, device, and system obtain a high-quality and clear magnetic particle distribution image without obtaining the system matrix.

ANALYZING APPARATUS, MAGNETIC FIELD GENERATING APPARATUS FOR ANALYZING APPARATUS, AND ANALYZING METHOD

An analyzing apparatus according to the present embodiment comprising: a sample placer where a cartridge is placed, the cartridge being capable of storing a sample containing a magnetic substance; an imager configured to be placed on an opposite surface side of a surface where the cartridge is placed on the sample placer and configured to image the sample by imaging from the opposite surface side; and a first magnetic field generator configured to be placed on the opposite surface side and to form a communicating port on a position corresponding to the imager and configured to generate a first magnetic field by forming a first magnetic pole around the communicating port.

Methods and apparatuses related to magnetic relaxometry measurements in the presence of environmental response to magnetic excitation

Example embodiments of the present invention provide a magnetic relaxometry measurement apparatus, comprising: a magnetizing system configured to supply a pulsed magnetic fields to a sample; a sensor system configured to detect magnetic fields produced by induced magnetization of the sample after a magnetic field pulse from the magnetizing system; one or more compensating coils configured to suppress generation of eddy currents in an environment surrounding the apparatus due to the pulsed magnetic fields.

Magnetic field generation device, measurement cell, analysis apparatus, and particle separation device
11105771 · 2021-08-31 · ·

A magnetic field generation device (100) includes a first magnet (1), a second magnet (2), and a position adjustment mechanism (5). The second magnet (2), together with the first magnet (1), generates a magnetic field. The position adjustment mechanism (5) adjusts a position of the first magnet (1). The magnetic field generation device (100) controls the value of the product of a magnetic flux density and a magnetic flux density gradient in the magnetic field through the adjustment of the position of the first magnet (1) by the position adjustment mechanism (5).

Techniques for magnetic particle imaging

A magnetic particle imaging apparatus includes magnets [106,107] that produce a gradient magnetic field having a field free region (FFR), excitation field electromagnets [102,114] that produce a radiofrequency magnetic field within the field free region, high-Q receiving coils [112] that detect a response of magnetic particles in the field free region to the excitation field. Field translation electromagnets create a homogeneous magnetic field displacing the field-free region through the field of view (FOV) allowing the imaging region to be scamled to optimize scan time, scanning power, amplifier heating, SAR, dB/dt, and/or slew rate. Efficient multi-resolution scanning techniques are also provided. Intermodulated low and radio-frequency excitation signals are processed to produce an image of a distribution of the magnetic nanoparticles within the imaging region. A single composite image is computed using deconvolution of multiple signals at different harmonics.

FERROMAGNETIC PARTICLES AS ULTRA-SENSITIVE NON-LINEAR RESPONSE LABELS FOR MAGNETIC PARTICLES IMAGING (MPI) AND SENSING APPLICATIONS

A significant enhancement of detection capabilities of the room temperature MPQ is seen using optical lithography-defined, ferromagnetic iron-nickel alloy microdisks. Irreversible transitions between strongly non-collinear (vortex) and a collinear single domain states, driven by an ac magnetic field, translate into a nonlinear magnetic response that enables ultrasensitive detection of material at relatively small magnetic fields.

METHOD OF CALIBRATING MAGNETIC PARTICLE IMAGING SYSTEM

A method of calibrating a magnetic particle imaging system including a magnetic field generator and a measurement device by proposing a coded calibration scene, wherein the coded calibration scene contains multiple nanoparticle samples distributed inside a volume of the coded calibration scene, larger than a field of view, wherein the coded calibration scene is moved linearly in one or more directions and/or rotated at one or more axes on the magnetic imaging system, and further, a mechanical system for moving the coded calibration scene.