563 results about "Magnetic susceptibility" patented technology

A method and apparatus is provided for magnetic source magnetic resonance imaging. The method includes collecting energy signals from an object, providing additional information of characteristics of the object, and generating the image of the object from the energy signals and from the additional information such that the image includes a representation of a quantitative estimation of the characteristics, e.g a quantitative estimation of magnetic susceptibility. The additional information may comprise predetermined characteristics of the object, a magnitude image generated from the object, or magnetic signals collected from different relative orientations between the object and the imaging system. The image is generated by an inversion operation based on the collected signals and the additional information. The inversion operation minimizes a cost function obtained by combining the data extracted from the collected signals and the additional information of the object. Additionally, the image is used to detect a number of diagnostic features including microbleeds, contract agents and the like.

The subject invention pertains to a method and apparatus for placing a minimally-invasive access with respect to a patient's bone or other non-soft tissue. The subject invention can use a drilling machine incorporating an ultrasound motor. The subject drilling machine can be applied to sample, for example, bone biopsies under MRI control. In a specific embodiment, the subject ultrasound motor can be completely manufactured of non-magnetic materials, such as plastics, titanium, and titanium alloy, or ceramics and piezoceramics. The subject drilling apparatus can be placed into an MRI near field without influencing the image quality, and without the drilling apparatus itself being disturbed by the MRI magnet, gradient, or high-frequency field. The subject invention can incorporate good shielding with the subject drilling apparatus use of these materials, and can achieve minimal, if any, image distortions or so-called artifacts. Thus, the subject invention can involve the problem by use of non-magnetic materials of low magnetic susceptibility for the design of an actuation unit.

An assembly with a substrate, nanomagnetic material and magetoresistive material. The nanomagnetic material has a saturation magentization of from about 2 to about 3000 electromagnetic units per cubic centimeter; and it contains nanomagnetic particles with an average particle size of less than about 100 nanometers. The average coherence length between adjacent nanomagnetic particles is less than 100 nanometers.

A method and apparatus is provided for magnetic source magnetic resonance imaging. The method includes collecting energy signals from an object, providing additional information of characteristics of the object, and generating the image of the object from the energy signals and from the additional information such that the image includes a representation of a quantitative estimation of the characteristics, e.g a quantitative estimation of magnetic susceptibility. The additional information may comprise predetermined characteristics of the object, a magnitude image generated from the object, or magnetic signals collected from different relative orientations between the object and the imaging system. The image is generated by an inversion operation based on the collected signals and the additional information. The inversion operation minimizes a cost function obtained by combining the data extracted from the collected signals and the additional information of the object. Additionally, the image is used to detect a number of diagnostic features including microbleeds, contract agents and the like.

A probe instrument using room-temperature sensor(s) that can measure variations in magnetic susceptibilities. The instrument has sufficient resolution to monitor paramagnetic materials in a human body, such as iron in a human liver, by noninvasively examining patients with iron-overload diseases. The instrument includes room temperature magnetic sensors, and detects the sample, that is, the tissue response to an alternating current field applied by an applied field coil. The applied field coil dimensions are chosen so that the applied field is optimized for maximum response from the liver while minimizing the effects due to the overlying abdominal tissue and at the same time not unduly increasing the sensitivity of the instrument to the lung. To overcome variations in the sensor output due to fluctuations in the applied field, change in the ambient temperature and mechanical relaxation of the instrument, the sensor-sample distance is modulated. The detector assembly is oscillated while the examined patient remains stationary. An improved water-bag technique is employed to eliminate background tissue response. The detector assembly forms part of a probe instrument for performing noninvasively the paramagnetic concentration of a patient.

A microfluidic device for manipulating particles in a fluid has a device body that defines a main channel therein, in which the main channel has an inlet and an outlet. The device body further defines a particulate diverting channel therein, the particulate diverting channel being in fluid connection with the main channel between the inlet and the outlet of the main channel and having a particulate outlet. The microfluidic device also has a plurality of microparticles arranged proximate or in the main channel between the inlet of the main channel and the fluid connection of the particulate diverting channel to the main channel. The plurality of microparticles each comprises a material in a composition thereof having a magnetic susceptibility suitable to cause concentration of magnetic field lines of an applied magnetic field while in operation. A microfluidic particle-manipulation system has a microfluidic particle-manipulation device and a magnet disposed proximate the microfluidic particle-manipulation device.

A light emitter drive circuit for an oximeter which utilizes a single inductor for driving multiple light emitters. The inductor is connected to a switching circuit to multiple energy storage circuits, such as capacitors. These are alternately charged up, using the same inductor. Subsequently, the capacitors are alternately discharged for their corresponding light emitters through the same inductor. Also, the magnetic susceptibility of the LED drive circuit is reduced by using magnetic flux canceling in the inductor. In one embodiment, a toroidal inductor is used with geometric symmetry and its magnetic flux. In another embodiment, a dual core closed bobbin shielded inductor is used.

Featured are methods for magnetic resonance imaging of a volume, such a volume having susceptibility-generating objects or interfaces having susceptibility mismatches therein. Such a method includes selectively visualizing one of susceptibility-generating objects or interfaces having susceptibility mismatches as hyperintense signals, where such visualizing includes controlling variable imaging parameters so as to control a geometric extent of a signal enhancing effect, m more particular aspects of the present invention, such selectively visualizing includes attenuating or essentially suppressing signals from fat and / or water, namely on-resonant water protons, so as to thereby enhance a signal(s) associated with magnetic susceptibility gradient(s). Also featured are MRI systems, apparatuses and / or applications programs for execution on a computer system controlling the MRI data acquisition process embodying such methods.

A medical device suitable for use with magnetic resonance imaging techniques includes a component that is formed from a refractory metal, a precious metal, an alloy comprising a refractory metal, an alloy comprising a precious metal, and / or alloy comprising at least one refractory metal and at least one precious metal. The component has a magnetic susceptibility less than about 300×10−6 cgs, and has a low radiopacity such that the component can be visualized under fluoroscopy.

A transverse rf saddle coil (30) for use in NMR is affixed in intimate thermal conract on one surface of a ceramic coilform (23) of high thermal conductivity. The probe is mostly for use with solid samples at high fields where the axis of the coilform is not alignedwith the main field. An orthogonal rf coil (1) is mounted in intimate thermal contact to the first saddle coil (30) via a ceramic spacer or coilform (2). The coilform is cooled by high-velocity gas flow and is also often associated with bearing exhaust gas from a high speed sample spinner. The two coils are tuned to different rf frequencies with circuits capable of supporting high rf currents. The rf coils (30, 1) may be magnetically compensated and expansion controlled, and passive geometric compensation of magnetic susceptibility effects from a sample spinner stator may also be incorporated. Novel coil mounting techniques, including metallurgical bonds to ceramics and capturing by dielectric clam-shells, are also disclosed.

A method of producing three-dimensional particle structures with enhanced magnetic susceptibility in three dimensions by applying a triaxial energetic field to a magnetic particle suspension and subsequently stabilizing said particle structure. Combinations of direct current and alternating current fields in three dimensions produce particle gel structures, honeycomb structures, and foam-like structures.

Exemplary quantitative susceptibility mapping methods, systems and computer-accessible medium can be provided to generate images of tissue magnetism property from complex magnetic resonance imaging data using the Bayesian inference approach, which minimizes a cost function consisting of a data fidelity term and two regularization terms. The data fidelity term is constructed directly from the complex magnetic resonance imaging data. The first prior is constructed from matching structures or information content in known morphology. The second prior is constructed from a region having an approximately homogenous and known susceptibility value and a characteristic feature on anatomic images. The quantitative susceptibility map can be determined by minimizing the cost function. Thus, according to the exemplary embodiment, system, method and computer-accessible medium can he provided for determining magnetic susceptibility information associated with at least one structure.

A high magnetic susceptibility nanomagnetic material that may be attached to recognition molecules and other therapeutic biological materials so as to be targeted to specific biologic tissues, thereby enabling the presence of the targeted tissue to be detected under magnetic resonance imaging with much greater sensitivity. Also a stent coated with such nanomagnetic material to enable artifact free imaging of such stent under magnetic resonance imaging.

A wireless headset capable of receiving audio signals transmitted wirelessly and compatible for use in an MRI scanner is disclosed. The headset includes a first wireless module connected to the first earphone and a second wireless module connected to the second earphone. Each wireless module is electrically connected to a speaker in the respective earphone. The first wireless module receives the audio signal from a remote source and coordinates transmission of the audio signal to each of the speakers. The compact nature of each earphone minimizes the length of wire runs. In addition, the headset is made of materials having low magnetic susceptibility such that they will not be affected by the magnetic field from the MRI scanner.

There is provided a semiconductor package capable of protecting a passive element, a semiconductor chip, or the like included in the package from external force and having enhanced Electro Magnetic Interference (EMI) and Electro Magnetic Susceptibility (EMS) characteristics and a manufacturing method thereof. The semiconductor package includes a substrate having at least one cavity formed in a side surface thereof and an electrode provided within the cavity; at least one electronic component mounted on a surface of the substrate; a mold part sealing the electronic component and having insulating properties; and a shield part attached to the mold part to cover an outer surface of the mold part, electrically connected to the electrode provided within the cavity, and having conductive properties.

A magnetic field probe comprises a sample (4) that exhibits magnetic resonance at an operating frequency, an electrically conductive structure (8) surrounding the sample for receiving a magnetic resonance signal therefrom, and a solid jacket (12) encasing the sample and the conductive structure. The jacket is made of a hardened two-component epoxy system containing a paramagnetic dopant dissolved therein, with the concentration of the dopant being chosen such that the jacket has a magnetic susceptibility that is substantially identical to the magnetic susceptibility of the conductive structure.

A pearlescent pigment and a process for enhancing the magnetic properties of a pearlescent pigment. The pearlescent pigment has a layer with regions of γ-Fe2O3 and regions of α-Fe2O3. The magnetic properties of a pearlescent pigment may be enhanced by the steps of: providing a platelet pigment with a layer of Fe2O3, with a magnetic susceptibility less than 0.1×10−5 m3 / kg; reducing some or all of the Fe2O3 to Fe3O4; and oxidizing some or all of the Fe3O4 to γ-Fe2O3. The color difference (ΔE*) between the provided pigment and the resultant pigment is not more than about 5.

A system and method for using hyperpolarized noble gases together with an appropriately designed and optimized magnetic resonance imaging pulse sequence to rapidly acquire static or dynamic magnetic resonance images. The strong magnetic resonance signal from hyperpolarized gases, combined with the present magnetic resonance imaging technique, presents the opportunity for the imaging of gases with both high spatial and high temporal resolution. One potential application for such a method is the direct, dynamic visualization of gas flow, which would be extremely useful for characterizing a variety of fluid systems. In the medical field, one such system of substantial importance is the lung. The system and method provides for visualizing regional ventilatory patterns throughout the respiratory cycle with high temporal and high spatial resolution. The low sensitivity to susceptibility artifacts permits good image quality to be obtained in various orientations. Depending on the application, temporal resolution can be traded for anatomical coverage. Such application of dynamic imaging of the lung using hyperpolarized gases will provide unique information on the physiology and pathophysiology of the lung, and has the potential for many clinically-relevant applications.

An R-T-B system rare earth permanent is provided, which comprises a sintered body comprising: an R2T14B phase (wherein R represents one or more rare earth elements (providing that the rare earth elements include Y) and T represents one or more transition metal elements essentially containing Fe, or Fe and Co) as a main phase; and a grain boundary phase containing a higher amount of R than the above main phase, wherein, when Pc (permeance coefficient) is 2, if a total flux is defined as f1 under the application of an effective magnetic field of 240 kA / m (providing that an effective magnetic field = an applied magnetic field - a demagnetizing field, and each value of them is absolute value), if a total flux is defined as f2 under the application of an effective magnetic field of 800 kA / m, and if a total flux is defined as f3 under the application of an effective magnetic field of 2, 000 kA / m, a magnetization rate a (= f1 / f3 x 100) is 40% or more, and a magnetization rate b (= f2 / f3 x 100) is 90% or more.

There are provided a semiconductor package including an electromagnetic shielding structure having excellent electromagnetic interference (EMI) and electromagnetic susceptibility (EMS) characteristics, while protecting individual elements in an inner portion thereof from impacts, and a manufacturing method thereof. The semiconductor package includes: a substrate having ground electrodes formed on an upper surface thereof; at least one electronic component mounted on the upper surface of the substrate; an insulating molding part including an internal space in which the electronic component is accommodated, and fixed to the substrate such that at least a portion of the ground electrode is externally exposed; and a conductive shield part closely adhered to the molding part to cover an outer surface of the molding part and electrically connected to the externally exposed ground electrodes.

A system and method for determining the state of health of a battery. In particular, the present invention is related to a system and method for determining the state of health of an electrochemical battery cell by obtaining state of charge measurements for the battery cell, and using the state of charge measurements to calculate the state of health of the battery cell, wherein the state of charge measurements are based on the magnetic susceptibility of the battery cell. The system includes a sensing device for measuring the magnetic susceptibility of the battery cell, and a computing device for performing the steps of the disclosed method.

Subterranean hydrocarbon reservoirs are analyzed by characterizing the relative presence and character of microfractures in rock samples from the reservoirs. Core samples are saturated with a suspension of magnetite particles of known concentration. The samples are then subjected to an applied magnetic field of known strength. The anisotropy of magnetic susceptibility, or AMS, of the samples is then observed, providing a measure of grain orientation in the samples. The characteristics of the microfractures in the samples are thus available to characterize the reservoirs, and in particular the contribution of the microfractures to the porosity and permeability of formations in the reservoirs.

The invention provides a geophysical prospecting technical method for recognizing the lithology of petrosilex by using the combined characteristics of gravity-magnetic-electronic anomaly, which comprises the following steps of collecting and recording the physical characteristics of drill core; carrying out cluster analysis on the density, magnetic susceptibility and resistivity of rock by using k-means clustering and obtaining the clustering code of the drill core; carrying out gravity and magnetic anomaly stripping to the gravity and magnetic prospecting result for obtaining the anomaly and adopting the same clustering to conduct three-dimensional anomaly coding; and combining the clustering code of the physical characteristics of rock with gravity-magnetic-electronic anomaly code for reflecting the lithology of each petrosilex in an exploratory area. By developing the method for recognizing the lithology of petrosilex by using integral gravity-magnetic-electronic from qualitative speculation to quantitative statistics, the invention reduces human subjective factors from experience, avoids the situation that different geological interpreters obtain different results and improves the recognition effect of petrosilex.

The MRI apparatus of the present invention performs a pulse sequence for applying successively 180° pulses 102, 103 . . . after application of a 90° pulse 101 at constant intervals and applying readout magnetic fields 111 during the interval between pairs of 180° pulses while the polarity of the magnetic field 111 is inverted several times to collect a plurality of gradient echo signals that are phase encoded differently. Here, the application of the readout gradient magnetic field is controlled such that generation of the gradient echo signals does ot coincide with generation of the spin echo signal. The image reconstruction is performed by using only T2* weighted gradient echo signals to obtain images reflecting difference in magnetic susceptibility and inhomogeneities in local magnetic fields.

Disclosed is a new propeller EPI pulse sequence with reduced sensitivity to field inhomogeneities is proposed. Image artifacts such as blurring due to Nyquist ghosting and susceptibility gradients are investigated and compared with those obtained in previous propeller EPI studies. The proposed propeller EPI sequence uses a readout that is played out along the short axis of the propeller blade, orthogonal to the readout used in previous propeller methods. In contrast to long-axis readout propeller EPI, this causes the echo spacing between two consecutive phase-encoding (PE) lines to decrease, which in turn increases the k-space velocity in this direction and hence the pseudo-bandwidth.

The invention relates to a ground-penetrating-radar-based active fault shallow ground surface spatial distribution detection method, and belongs to the field of geological survey. The method mainly comprises the following steps of primary election of an active fault passing region, ground-penetrating radar line layout and field data collection, ground-penetrating radar image processing and image anomaly region extraction and recognition and ground-penetrating radar image three-dimensional rebuilding and slice analysis. Accordingly, the detects that for an existing active fault shallow ground surface spatial structure detection method, the data collecting efficiency of a trial trench, an electrical prospecting apparatus, a magnetic susceptibility meter and the like is low, the resolution ratio is low, and the surface environment is destroyed are overcome, active fault detection under the complex environment can be achieved continuously in a large area, the method is easy to implement, the detection efficiency and precision are high, and the result is visual.

Hydrophobic paramagnetic nanoparticles can be injected with the enhanced oil recovery injection water by incorporating them inside of surfactant micelles to serve as an oil tracer. A variety of paramagnetic nanoparticles that show different susceptibility and magnetization responses to applied magnetic oscillation can be injected at different injectors, so that the origin of the oil from the different enhanced oil recovery patterns could be quantitatively identified. The concentrations of the nanoparticles in the produced crude oil and brine can be easily and instantly measured individually, employing the magnetic susceptibility meter without contacting the fluids directly.