Grum
Grum Ngatu, Gaithersburg, MD US
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20100300819 | ROTARY VANE MAGNETORHEOLOGICAL (MR) ENERGY ABSORBER - A rotary vane magnetorheological energy absorber, which enables a longer stroke capability in a more compact configuration than conventional magnetorheological devices, is disclosed. This novel device design is attractive for applications where long stroking capability, high force dynamic range, device size, and device weight are important. The improved magnetorheological energy absorber comprises an internal or external flow valve and a hollow body enclosing fixed and rotary vanes as well as magnetorheological fluid. Fluid flow in the valve is restricted as a solenoid is activated, thus adjusting the capability of the device to react torque. Various flow valve configurations are disclosed, as well as various motion translation mechanisms for translating linear motion to rotary motion for use of the rotary vane magnetorheological energy absorber. The improved design minimizes the amount of magnetorheological fluid required as compared to conventional linear stroke energy absorbers, thus minimizing device weight. | 12-02-2010 |
Grum Teklemariam, Arlington, VA US
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20090085700 | Open MRI Magnetic Field Generator - A magnet primarily for use in MRI applications comprises a pair of poles oriented about a plane of symmetry parallel to each therebetween defining an air gap region, magnetic field sources secured on the surfaces of the poles opposite the air gap that have yokes disposed on them, the yokes connected to each other by returns so that the entire magnet assembly can form a closed magnetic flux circuit to substantially confine the magnetic fields generated by the apparatus in the air gap where an imaging region is formed to place subjects for the purposes of examination. The main assembly being cylindrical in geometry has permanent magnets for magnetic field sources that are composed of two regions, a central disk-like portion magnetized substantially along the axial direction and an outer ring-like region magnetized substantially along the radial direction extending axially to form part of the pole together producing a very efficient and even flux distribution throughout the entire magnet assembly with minimal flux leakage. A further means of reducing flux leakage is incorporated in the yokes which have two sections, a disk-like region and an ring-like section to enclose the permanent magnets. The poles are made of multiple sections with a central disk-like region and an outer ring-like region that is a combination of permanent magnets and high permeability materials. This magnet assembly can achieve 1.0 Tesla or greater magnetic fields for whole-body scanning without saturating the magnet pole and other structures. | 04-02-2009 |
20090206837 | INTERVENTIONAL MRI MAGNETIC FIELD GENERATOR BASED ON PERMANENT MAGNETS - A magnet assembly primarily for use in MRI Interventional applications having an array of four mam permanent magnets that are spaced-apart and arranged into a ring-like geometry with six easy-access openings The magnetization direction in each permanent magnet is anti-parallel to any other adjacent permanent magnet in the πng assembly while it is parallel to any other permanent magnet in the array that is oppositely located just as in a quadrupolar system Such an arrangement has the advantage of concentrating the magnetic field inside the nng enclosure while minimizing magnetic field generated outside Together, these four spatially spaced-apart permanent magnets create a very homogeneous and strong magnetic field in the central enclosure with two orthogonal access paths and one parallel access path to the enclosure Through one access pathway a patient can be inserted while through the other pathways a doctor can fully access the patient. | 08-20-2009 |
Grum Teklemariam, Washington, DC US
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20110241812 | MAGNETIC FIELD GENERATOR BASED ON DUAL PERMANENT MAGNET RINGS - A magnet assembly primarily for use in MRI applications is disclosed comprising two main permanent magnet rings that are spaced-apart and arranged to be coaxially aligned with two easy-access openings. The magnetization direction in each magnet ring is substantially radially oriented and maintains an anti-parallel orientation with respect to each other. Together, these two magnet rings create a homogeneous and strong magnetic field in the central enclosure between them with two orthogonal access paths to the enclosure. Through one access pathway a patient can be inserted while through the other pathway a doctor can fully access the patient and perform interventional procedures during a real-time MRI scan. Embodiments of the system also have poles and yokes that shape the field and minimize fringe fields. Embodiments of this magnet assembly can achieve high magnetic fields for whole-body scanning without saturating the magnet pole and other structures. | 10-06-2011 |
20120240385 | Cylindrical Bi-Planar Gradient Coil for MRI - Cylindrical bi-planar gradient coil assemblies for use in open magnetic resonance imaging, wherein each of the coil assemblies contains in sequential order (i) a circular primary coil set placed flat above a cylindrical planar substrate, (ii) cooling means, (iii) 0th and 2nd order shims, (iv) shield layers, and (v) 1st order shims. In use the gradient coil assemblies are disposed symmetrically to each other about a plane of symmetry parallel to each. | 09-27-2012 |
Grum Teklemariam, Kitchener CA
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20160061915 | Polarizing a Spin Ensemble for Magnetic Resonance Imaging - In some aspects, polarization of a spin ensemble can be increased using cavity-based techniques. A magnetic resonance imaging (MRI) system includes a cavity and a resonator. The cavity is adapted to interact with a spin ensemble in an imaging subject in a static magnetic field. The resonator is adapted to generate an interaction between the cavity and the spin ensemble that increases polarization of the spin ensemble. In some implementations, the spin ensemble achieves a polarization that is higher than its thermal equilibrium polarization. | 03-03-2016 |
20160077168 | TRANSFERRING SPIN POLARIZATION - In some aspects, polarization of a spin ensemble can be increased using cavity-based techniques. A sample contains a first spin ensemble and a second spin ensemble. A drive field couples the first spin ensemble with a cavity, and the coupling increases the polarization of the first spin ensemble. Polarization is transferred from the first spin ensemble to the second spin ensemble. In some examples, the polarization is transferred from a solvent or an abundant species to a solute or a dilute species in the sample. | 03-17-2016 |
20160077177 | Using a Thermally-Isolated Cavity to Polarize a Spin Ensemble - In some aspects, polarization of a spin ensemble can be increased using cavity-based techniques. A resonator applies a drive field to a spin ensemble in a sample in a static magnetic field. The drive field couples the spin ensemble with a cavity, and the coupling increases the polarization of the spin ensemble. In some cases, the sample is thermally insulated from the cavity, for example, to maintain the sample at a higher temperature than the cavity. In some implementations, the spin ensemble achieves a polarization that is higher than its thermal equilibrium polarization. | 03-17-2016 |
Grum Telemariam, Washington, DC US
Patent application number | Description | Published |
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20110248715 | Compact Inhomogeneous Permanent Magnetic Field Generator for Magnetic Resonance Imaging - A magnet assembly primarily for use in MRI applications is disclosed. The magnet assembly is composed of a single disk and ring permanent magnet set connected to a C-type magnet yoke and return fixture with asymmetrically arranged poles. Together, the permanent magnets create a strong magnetic field that has a large static gradient in the central enclosure. The magnet assembly is primarily designed for diffusion based MRI scanning but can perform routine MRI scanning as well. | 10-13-2011 |