Patent classifications
G01R33/0213
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 scaled 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.
Noninvasive measuring method for rapid temperature variation under DC excitation magnetic field
Provided is a noninvasive measuring method for rapid temperature variation under a DC excitation magnetic field, comprising: (1) positioning ferromagnetic particles at a measured object; (2) applying a DC magnetic field to area of the ferromagnetic particles enabling the ferromagnetic particles to reach saturation magnetization state; (3) obtaining steady temperature T.sub.1 of the measured object at room temperature, and calculating initial spontaneous magnetization M.sub.1, of the ferromagnetic particles according to the steady temperature T.sub.1; (4) detecting amplitude A of a magnetization variation signal of the ferromagnetic particles after temperature of the measured object varies, and calculating temperature T.sub.2 after change according to the amplitude A of the magnetization variation signal; and (5) calculating temperature variation T=T.sub.2-T.sub.1 according to the temperature T.sub.2 after change and the steady temperature T.sub.1. The present invention can realize noninvasive temperature measurement with high speed and high accuracy so as to resolve technical problems of low speed and low precision.
PARTICLE THERAPY APPARATUS COMPRISING AN MRI
The present disclosure relates to a particle therapy apparatus for irradiating a target with a charged particle beam and having a particle accelerator and an isocentric gantry rotatable about an axis. The gantry includes a sequence of bending magnets to successively bend and direct the particle beam towards the isocentre of the gantry. A last bending magnet of the sequence is configured to bend the particle beam in a first plane including the isocentre and making a large angle with the axis. The gantry further includes a first scanning magnet arranged upstream of the last bending magnet and configured to scan the particle beam over the target. The apparatus also includes a magnetic resonance imaging (MRI) system having two main magnet units arranged on both sides of the isocentre and configured to generate a main magnetic field parallel to or coaxial with the axis.
Apparatus for measuring properties of an object with acoustically induced electromagnetic waves
A measuring method and apparatus in which a measurable object (23) is irradiated with acoustic waves to measure a change in property value of charged particles in the object from electromagnetic waves induced thereby. A part (2) of the measurable object irradiated with an acoustic focused beam (1) is in a charge distribution state in which positive charged particles (3) are greater in number in the part (2) where electromagnetic waves induced by positive charged particles (3) are not canceled by those induced by negative charged particles (4) and where net electromagnetic waves (6) are induced. Since a change in concentration of positive charged particles (3) and/or negative charged particles (4) changes the intensity of electromagnetic waves (6), it is possible to know such a change in concentration of the charged particles from a change in intensity of electromagnetic waves (6).
Method of measuring properties of an object with acoustically induced electromagnetic waves
A measuring method and apparatus in which a measurable object (23) is irradiated with acoustic waves to measure a change in property value of charged particles in the object from electromagnetic waves induced thereby. A part (2) of the measurable object irradiated with an acoustic focused beam (1) is in a charge distribution state in which positive charged particles (3) are greater in number in the part (2) where electromagnetic waves induced by positive charged particles (3) are not canceled by those induced by negative charged particles (4) and where net electromagnetic waves (6) are induced. Since a change in concentration of positive charged particles (3) and/or negative charged particles (4) changes the intensity of electromagnetic waves (6), it is possible to know such a change in concentration of the charged particles from a change in intensity of electromagnetic waves (6).
MAGNETIC PARTICLE IMAGING
A Magnetic Particle Imaging (MPI) system with a magnet configured to generate a magnetic field with a field free line, the magnet integrated with a flux return designed so that a flux path at approximately the center of the field-free line has a first reluctance and a second flux path distal from the center of the field-free line has a second reluctance, and the second reluctance is lower than the first reluctance to facilitate a high fidelity magnetic field and high fidelity field free line.
MAGNETIC PARTICLE IMAGING
A Magnetic Particle Imaging (MPI) system with a magnet configured to generate a magnetic field having a field free line, the system including at least one shim magnet configured to modify the magnetic field in a manner to maintain desired magnetic flux distributions during imaging.
MAGNETIC PARTICLE IMAGING
A Magnetic Particle Imaging (MPI) system including a mechanically-rotatable magnet generating a field-free line, where the system is capable of acquiring a plurality of projections at a plurality of rotation angles, and where the projection acquisition includes positioning the field free line at a plurality of positions at the plurality of angles.
MAGNETIC SENSOR INCLUDING A LORENTZ FORCE TRANSDUCER DRIVEN AT A FREQUENCY DIFFERENT FROM THE RESONANCE FREQUENCY, AND METHOD FOR DRIVING A LORENTZ FORCE TRANSDUCER
A magnetic field sensor includes a die and a current generator in the die. The current generator generates a driving current. A Lorentz force transducer is also formed in the die and coupled to the current generator to obtain measurements of a magnetic field based upon the Lorentz force. The magnetic field has a resonance frequency and the current generator drives the Lorentz force sensor with the driving current having a non-zero frequency different from the resonance frequency.
Apparatus for magnetic particle imaging
An apparatus for magnetic particle imaging, the apparatus comprising: a sensing unit configured to detect linear sample signals, which represent the mixed electromagnetic fields, generated from magnetic particles in a sample; a driving unit configured to move the sensing unit in a direction of X-axis, Y-axis, or Z-axis; and a data processing unit configured to rearrange in a matrix linear sample signals detected by the sensing unit that is moved by the driving unit.