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Grum
Grum Ngatu, Gaithersburg, MD US
| Patent application number | Description | Published |
|---|---|---|
| 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
| Patent application number | Description | Published |
|---|---|---|
| 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
| Patent application number | Description | Published |
|---|---|---|
| 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 |
Grum Telemariam, Washington, DC US
| Patent application number | Description | Published |
|---|---|---|
| 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 |