15 research outputs found
Brain spirography in acute ischemic stroke - a pilot study
Wst臋p. Istot膮 udaru niedokrwiennego m贸zgu, podobnie jak wie艅cowej niedomogi
serca, jest ostry deficyt energetyczny, kt贸ry doprowadza do wyst膮pienia ogniskowego
deficytu neurologicznego, a cz臋sto - r贸wnie偶 do uog贸lnionych zaburze艅 czynno艣ci
m贸zgu. Niedokrwienie i niedotlenienie m贸zgu powoduj膮 zmiany czynno艣ci oddechowej.
Materia艂 i metody. W badaniach pos艂u偶ono si臋 oryginalnym urz膮dzeniem -
spirografem m贸zgowym (SGM). Pozwala ono na uzyskanie zapisu krzywej oddechowej
dzi臋ki zastosowaniu czujnika przep艂ywowego. Przebadano 50 chorych we wczesnym
okresie udaru niedokrwiennego m贸zgu oraz grup臋 kontroln膮 z艂o偶on膮 z 40 zdrowych
ochotnik贸w. Rozleg艂o艣膰 niedokrwienia m贸zgu oceniano szacunkowo wed艂ug klinicznych
grup motoryki og贸lnej cia艂a (KG MOC).
Wyniki. Dotychczasowe wyniki bada艅 wskazuj膮 na zale偶no艣膰 mi臋dzy rozleg艂o艣ci膮
niedokrwienia a zapisem krzywej spirograficznej m贸zgu.
Wnioski. Spirografia m贸zgowa jest prostym, nieinwazyjnym badaniem, znajduj膮cym
zastosowanie w ocenie nasilenia niedomogi kr膮偶enia w przebiegu udaru niedokrwiennego
m贸zgu. Mo偶e pos艂u偶y膰 jako narz臋dzie do monitorowania wczesnej fazy udaru niedokrwiennego
m贸zgu.Background. The main issue of stroke is an acute energy deficit which causes brain focal neurological deficits. The same
situation is observed in heart circulation insufficiency. Brain ischemia and hypoxia leads to changes in breathing rhythm.
Material and methods. The original device called brain spirograph was used during research. Thanks to usage of a flow
sensor, brain spirograph allows to registrate a breathing curve. Fifty patients in an acute phase of ischemic stroke and 40
volunteers were examined. The size of brain circulation insufficiency was assessed according to Clinical Groups of Whole
Body Motorics Method.
Results. Our results indicate the connection between the size of brain circulation insufficiency and the shape of breathing curve.
Conclusions. Brain spirography is a simple, non-invasive method of assessment of the size of brain circulation insufficiency.
This method could be used in monitoring of an acute phase of stroke
Estimation of parameters of ferromagnetic objects
Ferromagnetic object placed in the earthly magnetic field causes additional disturbance of the distribution of this field all around itself. The determination of the position and the value of the extremes of the magnetic field of the object allows to calculate the approximate localization and identification of the object. This paper presents the results of analysis of the position and the value of the extremes of the magnetic field and new method of localization and calculation of magnetic moment of the object. The numerical calculations have been made on the basis of MatLab
Ship鈥檚 de-perming process using coils lying on seabed
A ship built from ferromagnetic steel disturbs the uniformity of the Earth鈥檚 magnetic field. Changes of ship鈥檚 signature are due to the magneto-mechanical interaction of the hull with the Earth鈥檚 magnetic field. The ship鈥檚 magnetic field can be detected by a magnetic naval mine. For this reason, the vessel has to be demagnetized. There are several methods of ship鈥檚 de-perming. The results of experimental and computer simulations of the ship鈥檚 de-perming process using coils lying on the seabed are presented in this paper. The simulation of the de-perming process with a hysteresis model of ship鈥檚 steel was carried out in Opera-3d 18R2. The laboratory experiments were carried out using a physical ship鈥檚 model, several Helmholtz coils, magneto-resistive sensors, etc. The experiments and computer simulations have shown that ship鈥檚 de-perming with coils lying on the seabed is possible. The values of coil currents are over dozen times greater than those used in the standard method
Study of the influence of flux compression generator winding parameters on current amplification factor
W pracy przedstawiono wyniki bada艅 wp艂ywu zmian parametr贸w konstrukcyjnych
cewki roboczej generatora magneto kumulacyjnego (FCG) na jego mo偶liwo艣ci generacyjne,
a zw艂aszcza na wsp贸艂czynnik wzmocnienia pr膮du przy obci膮偶eniu o charakterze
indukcyjno-rezystancyjnym. W trakcie dzia艂ania FCG jego indukcyjno艣膰 i rezystancja
malej膮 w wyniku zwierania uzwojenia przez rozszerzaj膮cy si臋 twornik. W wyniku tego
pierwotny pr膮d zasilaj膮cy uzwojenie generatora ulega wzmocnieniu. Zmieniaj膮c parametry
konstrukcyjne cewki roboczej mo偶na wp艂ywa膰 na warto艣膰 wsp贸艂czynnika wzmocnienia
pr膮du generatora. Przebieg zmian indukcyjno艣ci generatora w trakcie dzia艂ania wyznaczono
metod膮 numeryczn膮.In the paper the results of research on the flux compression generator (FCG) parameters
influence on its generation factor have been presented. During the operation of the
FCG, its inductance and resistance decrease as a result of the winding being short-circuited
by the expanding armature. As a result, the primary current supplying the generator is
amplified. By the change of the coil parameters, the value of the generator current amplification
factor can be influenced. The change of the generator inductance during the operation
has been determined with the numerical methods
Comparative analysis of coaxial magnetocumulative generators
This paper presents the results of a computer simulation of coaxial magnetocumulative current generators (MCGs). The simulation tests were carried out for different values of the internal diameter, length and speed of the deformation of the MGP element
The analysis of resonance-based high power electromagnetic pulses emission system
W literaturze przedmiotu s膮 opisane w艂a艣ciwo艣ci emiter贸w impuls贸w pola elektromagnetycznego
w postaci uk艂ad贸w bazuj膮cych na antenach wysokonapi臋ciowych HVR
(ang. High Voltage Radiator) [2, 5]. W celu podniesienia skuteczno艣ci emisji poprzez
wyd艂u偶enie czasu trwania impulsu oraz zwi臋kszenie jego amplitudy mo偶liwe jest zastosowanie
system贸w rezonansowych dostrojonych do parametr贸w sygna艂u kszta艂towanego
w uk艂adzie formowania impulsu wysokiego napi臋cia [2, 3]. W pracy dokonano syntezy
modelu symulacyjnego systemu emisji impuls贸w pola elektromagnetycznego du偶ej
mocy oraz zweryfikowano jego skuteczno艣膰 w ramach bada艅 eksperymentalnych przeprowadzonych
na uk艂adzie fizycznym.In the literature, the emission properties of the electromagnetic field pulse systems
based on high voltage antennas (HVR) have been widely described. In order to increase
the emission efficiency by extending duration and increasing amplitude of the impulse it
is possible to use a resonance system tuned to the parameters of the signal shaped in the
pulse forming circuit. The synthesis of a time-domain simulation model of a complex
high-power electromagnetic pulses emission system and its verification by experimental
research has been presented in this paper
Load parameters optimization of the flux compression generator
W pracy przedstawiono wyniki symulacji komputerowej generatora magnetokumulacyjnego
(GM) obci膮偶onego cewk膮 indukcyjn膮. Badania symulacyjne przeprowadzono
w celu optymalizacji parametr贸w cewki obci膮偶enia generatora dla wybranej konstrukcji
modelu GM. Badano wp艂yw indukcyjno艣ci i rezystancji obci膮偶enia na wsp贸艂czynnik
wzmocnienia pr膮du w uk艂adzie oraz na energi臋 pola magnetycznego zgromadzon膮
w obci膮偶eniu.Computer simulation results of the flux compression generator (FCG) loaded with an
inductor has been presented in this paper. Simulation research has been performed in
order to optimize the load parameters of the selected model of FCG coil. The influence
of the load inductance and resistance on the current gain factor and the load accumulated
magnetic field energy has been investigated
The flux compression generator load parameters selection
Computer simulation results of the flux compression generator (FCG) loaded with an inductor has been presented in this paper. Simulation research has been performed in order to select the parameters of FCG load coil properly. The influence of the load inductance and resistance on the current gain factor and the magnetic field energy accumulated in a load coil has been investigated
Time domain model of the resonance-based electromagnetic pulses emission system
In the literature, the emission properties of the electromagnetic field pulse systems based on high voltage antennas (HVR) have been widely described. In order to increase the emission efficiency by extending duration and increasing amplitude of the impulse it is possible to use a resonance system tuned to the parameters of the signal shaped in the pulse forming circuit. The synthesis of a time-domain simulation model of a complex electromagnetic pulses emission system and its verification by experimental research has been presented in this paper