Patent classifications
G01R33/1276
Magnetic particle imaging system and magnetic particle imaging method
A magnetic particle imaging system includes a field free region generator and an excited magnetic field generator. The field free region generator generates a field free line with a direction of linear extension of a field free region as a direction of extension. The excited magnetic field generator generates an excited magnetic field in the field free line generated by the field free region generator. The excited magnetic field generator includes a first excited magnetic field generation unit and a second excited magnetic field generation unit. The first excited magnetic field generation unit and the second excited magnetic field generation unit are spaced from each other in the direction of extension of the field free line.
MPI imaging device, method for generating a magnetic field with a gradient and a field-free line by means of an MPI imaging device
An MPI imaging device for mapping an object to be examined in a sample volume, with a magnet arrangement which is designed to generate an MPI magnetic field with a gradient B1 and a field-free line in the sample volume, the magnet arrangement comprising a first pair of magnet rings with two magnet rings in a Halbach dipole configuration, which are arranged coaxially on a common Z axis that runs through the sample volume, wherein the magnet arrangement comprises a second pair of magnet rings with two further magnet rings in a Halbach dipole configuration, which is arranged coaxially in relation to the first pair of magnet rings, the magnet rings of both pairs being arranged rotatably with respect to one another about the Z axis. As a result, a variable MPI selection field can be generated by means of permanent magnets.
Magnet arrangement for generating a selection magnetic field, apparatus with a magnet arrangement and method for generating a selection magnetic field
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.
METHOD FOR ELECTRONIC CALIBRATION OF MAGNETIC PARTICLE IMAGING SYSTEM
A method for electronic calibration of a magnetic particle imaging system is provided by proposing a coded calibration scene that contains multiple nanoparticle samples distributed randomly or pseudo-randomly inside a volume of the coded calibration scene where nanoparticle positions are changed virtually multiple times to create different calibration scenes. Virtual effect is created with current carrying electromagnets surrounding the nanoparticle samples. The method comprises: placing a plurality of nanoparticle samples inside a calibration scene; surrounding the plurality of nanoparticle samples with one or more electromagnets; applying a current to the one or more electromagnets to cause a magnetic field offset at a desired amplitude to virtually move the plurality of nanoparticle samples to a desired position; generating a system matrix with compressed sensing methods by using measurements taken for different current excitations of the one or more electromagnets, wherein the plurality of nanoparticles samples are virtually in different positions.
Pulsed magnetic particle imaging systems and methods
A pulsed magnetic particle imaging system includes a magnetic field generating system that includes at least one magnet, the magnetic field generating system providing a spatially structured magnetic field within an observation region of the magnetic particle imaging system such that the spatially structured magnetic field will have a field-free region (FFR) for an object under observation having a magnetic nanoparticle tracer distribution therein. The pulsed magnetic particle imaging system also includes a pulsed excitation system arranged proximate the observation region, the pulsed excitation system includes an electromagnet and a pulse sequence generator electrically connected to the electromagnet to provide an excitation waveform to the electromagnet, wherein the electromagnet when provided with the excitation waveform generates an excitation magnetic field within the observation region to induce an excitation signal therefrom by at least one of shifting a location or condition of the FFR. The pulsed magnetic particle imaging system further includes a detection system arranged proximate the observation region, the detection system being configured to detect the excitation signal to provide a detection signal. The excitation waveform includes a transient portion and a substantially constant portion.
ARRANGEMENT ALLOWING THE PERFORMANCE OF BOTH MAGNETIC PARTICLE IMAGING AND MAGNETIC RESONANCE IMAGING AND A DEVICE COMPRISING THIS ARRANGEMENT
An arrangement that enables performing of both magnetic particle imaging and magnetic resonance imaging and a device including the arrangement are provided. The arrangement that enables performance of both magnetic particle imaging and magnetic resonance imaging includes: at least one primary magnetic element pair configured to generate a selection magnetic field (SMF1/SMF2) for magnetic particle imaging, at least one secondary magnetic element pair configured to generate a driving magnetic field, and at least one tertiary magnetic element pair configured to generate a focus magnetic field (FMF).
Method and apparatus for analyzing a sample volume comprising magnetic particles
The described embodiments relate to a method for analyzing a sample volume including magnetic particles. The method may include applying an electric excitation signal to a measuring coil so as to generate a magnetic field acting on the sample volume using the measuring coil. Furthermore, the method may include sensing an electric measurement signal dependent on the inductance of the measuring coil and analyzing magnetic permeability of the sample volume using the measurement signal.
Hysteresis effect-based field free point-magnetic particle imaging method
A hysteresis effect-based Field Free Point-Magnetic Particle Imaging (FFP-MPI) method includes the following steps: acquiring a hysteresis loop model of Superparamagnetic Iron Oxide Nanoparticles (SPIOs); calculating to obtain a Point Spread Function (PSF) of the SPIOs on the basis of a sinusoidal excitation magnetic field and the hysteresis loop model of the SPIOs; acquiring an original reconstructed image of FFP-MPI on the basis an FFP moving track and a voltage signal; performing deconvolution on the original image with respect to the PSF considering an hysteresis effect, so as to obtain a final reconstructed image; the artifacts and phase errors of image reconstruction caused by the hysteresis effect of the SPIOs with large particle sizes are reduced, the deficiency in reconstruction by the traditional reconstruction method that ignores the hysteresis effect is overcome, the reconstruction speed and the resolution are greatly improved, and the application range of the SPIOs is expanded.
Magnetic rolling bearing capable of reducing balance radial force of gear pump, and its life calculation method
The present invention discloses a magnetic rolling bearing capable of reducing the balance radial force of the gear pump, which includes a magnetized inner ring, a rolling body, a cage, and a magnetized outer ring assembly. The inner ring is magnetized to make the inner and outer ring surfaces of the magnetized inner ring have different magnetic properties; the magnetized outer ring assembly consists of four components, namely an upper ring surface of the magnetized outer ring assembly, a lower ring surface of the magnetized outer ring assembly, and two components in left and right. The left and right components are not magnetized, they are connected by recesses and are fixed with bolts, and the four components are alternately connected to form a complete ring.
Collectable Resale Protection
To better protect collectible cards, a better tamper evident case is needed, one that counterfeiters cannot replicate. Disclosed is a collectible card case where each edge is physical unclonable function (“PUF”) material that counterfeiters cannot replicate. Further disclosed is a thermally sealed bag with an integrated PUF material where each bag is unique and unclonable, and a device for sealing and measuring the magnetic and optical properties of the PUF material. Finally, a reusable hard case is disclosed with features that allow for a one-time use PUF security clip.