Boundary Element Method-Based Cortical Potential Imaging of Somatosensory Evoked Potentials Using Subjects' Magnetic Resonance Images

NeuroImage ◽  
2002 ◽  
Vol 16 (3) ◽  
pp. 564-576 ◽  
Author(s):  
B. He ◽  
X. Zhang ◽  
J. Lian ◽  
H. Sasaki ◽  
D. Wu ◽  
...  
Keyword(s):  
Boundary Element Method ◽  
Magnetic Resonance ◽  
Evoked Potentials ◽  
Boundary Element ◽  
Somatosensory Evoked Potentials ◽  
Magnetic Resonance Images ◽  
Cortical Potential ◽  
Cortical Potential Imaging ◽  
Element Method

scholarly journals Functional Magnetic Resonance Imaging and Somatosensory Evoked Potentials in Rats with a Neonatally Induced Freeze Lesion of the Somatosensory Cortex

2004 ◽  
Vol 24 (12) ◽  
pp. 1409-1418 ◽  
Author(s):  
Wolfram Schwindt ◽  
Michael Burke ◽  
Frank Pillekamp ◽  
Heiko J. Luhmann ◽  
Mathias Hoehn
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Functional Magnetic Resonance Imaging ◽  
Evoked Potentials ◽  
Somatosensory Cortex ◽  
Somatosensory Evoked Potentials ◽  
Magnetic Resonance Images ◽  
Projection Area ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging

Brain plasticity is an important mechanism for functional recovery from a cerebral lesion. The authors aimed to visualize plasticity in adult rats with a neonatal freeze lesion in the somatosensory cortex using functional magnetic resonance imaging (fMRI), and hypothesized activation outside the primary projection area. A freeze lesion was induced in the right somatosensory cortex of newborn Wistar rats (n = 12). Sham-operated animals (n = 7) served as controls. After 6 or 7 months, a neurologic examination was followed by recording of somatosensory evoked potentials (SSEPs) and magnetic resonance experiments (anatomical images, fMRI with blood oxygen level–dependent contrast and perfusion-weighted imaging) with electrical forepaw stimulation under α-chloralose anesthesia. Lesioned animals had no obvious neurologic deficits. Anatomical magnetic resonance images showed a malformed cortex or hyperintense areas (cysts) in the lesioned hemisphere. SSEPs were distorted and smaller in amplitude, and fMRI activation was significantly weaker in the lesioned hemisphere. Only in a few animals were cortical areas outside the primary sensory cortex activated. The results are discussed in respect to an apparent absence of plasticity, loss of excitable tissue, the excitability of the lesioned hemisphere, altered connectivity, and a disturbed coupling of increased neuronal activity to the hemodynamic response.

A BOUNDARY-ELEMENT METHOD FOR ATOMIZATION OF A FINITE LIQUID JET

1995 ◽  
Vol 5 (6) ◽  
pp. 621-638 ◽  
Author(s):  
J. H. Hilbing ◽  
Stephen D. Heister ◽  
C. A. Spangler
Keyword(s):  
Boundary Element Method ◽  
Boundary Element ◽  
Liquid Jet ◽  
Element Method

Application of the Boundary Element Method and Modal Analysis to Tire Acoustics Problems

1993 ◽  
Vol 21 (2) ◽  
pp. 66-90 ◽  
Author(s):  
Y. Nakajima ◽  
Y. Inoue ◽  
H. Ogawa
Keyword(s):  
Finite Element ◽  
Boundary Element Method ◽  
Boundary Element ◽  
Acoustic Radiation ◽  
Traffic Noise ◽  
Noise Prediction ◽  
Prediction System ◽  
Tire Noise ◽  
Acoustic Contribution ◽  
Element Method

Abstract Road traffic noise needs to be reduced, because traffic volume is increasing every year. The noise generated from a tire is becoming one of the dominant sources in the total traffic noise because the engine noise is constantly being reduced by the vehicle manufacturers. Although the acoustic intensity measurement technology has been enhanced by the recent developments in digital measurement techniques, repetitive measurements are necessary to find effective ways for noise control. Hence, a simulation method to predict generated noise is required to replace the time-consuming experiments. The boundary element method (BEM) is applied to predict the acoustic radiation caused by the vibration of a tire sidewall and a tire noise prediction system is developed. The BEM requires the geometry and the modal characteristics of a tire which are provided by an experiment or the finite element method (FEM). Since the finite element procedure is applied to the prediction of modal characteristics in a tire noise prediction system, the acoustic pressure can be predicted without any measurements. Furthermore, the acoustic contribution analysis obtained from the post-processing of the predicted results is very helpful to know where and how the design change affects the acoustic radiation. The predictability of this system is verified by measurements and the acoustic contribution analysis is applied to tire noise control.

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