Search Results - "Nyenhuis, J.A."

Peripheral nerve stimulation by gradient switching fields in magnetic resonance imaging by So, P.P.M., Stuchly, M.A., Nyenhuis, J.A.

“…A heterogeneous model of the human body and the scalar potential finite difference method are used to compute electric fields induced in tissue by magnetic…”
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Power deposition inside a phantom for testing of MRI heating by Amjad, A., Kamondetdacha, R., Kildishev, A.V., Park, S.M., Nyenhuis, J.A.

“…A patient in MRI is exposed to the time varying gradient and radio-frequency (RF) fields. Measurements of RF-induced temperature rise in implant in phantoms…”
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MRI safety: RF-induced heating near straight wires by Park, S.M., Kamondetdacha, R., Amjad, A., Nyenhuis, J.A.

“…One of the most crucial magnetic resonance (MR) safety concerns is related to excessive heating of metallic implants by the radio frequency (RF) magnetic…”
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Gelled versus nongelled phantom material for measurement of MRI-induced temperature increases with bioimplants by Park, S.M., Nyenhuis, J.A., Smith, C.D., Lim, E.J., Foster, K.S., Baker, K.B., Hrdlicka, G., Rezai, A.R., Ruggieri, P., Sharan, A., Shellock, F.G., Stypulkowski, P.H., Tkach, J.

“…Measurements in phantoms are used to predict temperature changes that would occur in vivo for medical implants due to the radio frequency (RF) field in…”
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Simulation of human respiration in fMRI with a mechanical model by Brosch, J.R., Talavage, T.M., Ulmer, J.L., Nyenhuis, J.A.

“…Obtaining functional magnetic resonance images of the brain is a challenging measurement process having a low characteristic signal-to-noise ratio. Images…”
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Multipole characterization of a magnetic source using a truncated SVD by Kamondetdacha, R., Kildishev, A.V., Nyenhuis, J.A.

“…This paper presents a new technique for characterizing a magnetic source using truncated singular value decomposition (TSVD). It shows how the smallest…”
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Multipole analysis of an elongated magnetic source by a cylindrical sensor array by Kildishev, A.V., Nyenhuis, J.A., Morgan, M.A.

“…This paper covers basics of the magnetic characterization of an elongated source. The core element of the work is to obtain a magnetic multipole image (MI) of…”
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Multipole imaging of an elongated magnetic source by Kildishev, A.V., Nyenhuis, J.A.

“…This paper describes a mathematical method for modeling the magnetic field from an elongated source, a method that is relevant to the reduction of the magnetic…”
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Method for detection of broken bars in induction motors by Dobrodeyev, P.N., Volokhov, S.A., Kildishev, A.V., Nyenhuis, J.A.

“…A method and apparatus for detection of broken bars in the rotor of a squirrel cage induction motor are described. The test method is easy to implement, no…”
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Investigation of the magnetization process of domain walls in an iron-garnet film by direct optical observation of vertical Bloch lines by Fedyunin, Y., Friedlaender, F.J., Nyenhuis, J.A.

“…Vertical Bloch lines (VBL) were observed in a (YLuBi)/sub 3/(FeGa)/sub 5/O/sub 12/ magnetic garnet film from the light diffracted from the stripe domains…”
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MRI and implanted medical devices: basic interactions with an emphasis on heating by Nyenhuis, J.A., Sung-Min Park, Kamondetdacha, R., Amjad, A., Shellock, F.G., Rezai, A.R.

“…There are three principal magnetic fields in magnetic resonance imaging (MRI) that may interact with medical implants. The static field will induce force and…”
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Heating near implanted medical devices by the MRI RF-magnetic field by Nyenhuis, J.A., Kildishev, A.V., Bourland, J.D., Foster, K.S., Graber, G., Athey, T.W.

“…The temperature rise in the vicinity of a medical implant due to the RF field in Magnetic Resonance Imaging (MRI) was evaluated. For the calculations, the…”
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Interactions of medical implants with the magnetic fields in MRI by Nyenhuis, J.A.

“…Interactions of the static, gradient and radio frequency (RF) magnetic fields in a magnetic resonance (MR) imager with implanted medical devices are…”
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Comparison of rectangular and damped sinusoidal dB/dt waveforms in magnetic stimulation by Havel, W.J., Nyenhuis, J.A., Bourland, J.D., Foster, K.S., Geddes, L.A., Graber, G.P., Waninger, M.S., Schaefer, D.J.

“…In magnetic (eddy-current) stimulation, sensory and motor nerve are stimulated by a time-varying magnetic field (dB/dt) produced in an appropriate coil. In…”
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Deperming technology in large ferromagnetic pipes by Kildishev, A.V., Nyenhuis, J.A., Dobrodeyev, P.N., Volokhov, S.A.

“…This report describes a deperming technique for reducing the arc blow effect in DC welding of ferromagnetic pipelines. The technique is based on compensation…”
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Multipole imaging of an elongated magnetic source by Kildishev, A.V., Nyenhuis, J.A.

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Magnetic stimulation of excitable tissue: calculation of induced eddy-currents with a three-dimensional finite-element model by Mouchawar, G.A., Nyenhuis, J.A., Bourland, J.D., Geddes, L.A., Schaefer, D.J., Riehl, M.E.

“…The eddy-current distribution in a 3-D inhomogeneous model of a dog's thorax due to time varying fields in magnetic resonance imaging (MRI) x, y, and…”
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Prediction of the magnetic field below an axisymmetrical planar sensor array with a magnetic source located above the measurement plane by Kildishev, A.V., Kamondetdacha, R., Nyenhuis, J.A.

“…Summary form only given. Rapid advancements in magnetic sensor technology are creating opportunities for solving traditional problems of ship magnetism. Both…”
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Multipole imaging source by a cylindrical sensor array by Kildishev, A.V., Nyenhuis, J.A., Morgan, M.A.

“…Summary form only given. In magnetic multipole imaging, the spheroidal expansions coefficients (c," , snm ) characterizing the magnetostatic potential are…”
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A comparison of phantom materials used in evaluation of radiofrequency heating of implanted medical devices during MRI by Smith, C.D., Nyenhuis, J.A., Foster, K.S.

“…The safety of implanted medical devices within the magnetic resonance imaging (MRI) environment is an issue that must be continually addressed. All magnetic…”
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