- Noninvasive identification of ischemic lesion and its reliability;
- Software for the measurement of spectral characteritics of the reflectivity and transmitivity of materials utilising Fourier infrared spektroscopy;
- Long-term changes of EEG during audiovisual stimulation training.
Result 1: Noninvasive identification of ischemic lesion and its reliability
Project: VEGA 2/4089/26 „Hodnotenie zmien repolarizácie srdca pomocou mnoho-zvodových meraní EKG“
Investigators: E. Hebláková, J. Švehlíková, .M. Turzová, M. Tyšler
Boli navrhnuté ukazovatele umožňujúce posúdiť použiteľnosť mnohozvodových EKG meraní na lokalizáciu ischémie pomocou dipólového modelu jej zdroja a odhadnúť spoľahlivosť získaného výsledku. Ukazovatele umožňujú posúdenie kvality nameraných údajov (zmeny v EKG nesmú byť prekryté rušením), charakteru lézie (musí byť primerane malá) a stability nájdeného riešenia (jednoznačný výsledok). Ako kritérium pre nájdenie dipólu reprezentujúceho patologické zmeny v EKG metóda používa minimálnu relatívnu rms diferenciu medzi nameranými a dipólu zodpovedajúcimi povrchovými integrálovými mapami. Na hodnotenie vplyvu rušenia vo vstupných dátach a „nedipólovosti" zdroja bola použitá strednekvadratická hodnota 2-rozmerného gradientu v rozdielovej mape resp. relatívny príspevok kvadrupólu k meranej mape. Na posúdenie dôveryhodnosti výsledku bol použitý koeficient neurčitosti, ktorý rastie, ak v bodoch vzdialených od nájdenej lézie stúpa počet hodnôt kriteriálnej funkcie blízkych k hodnote pre nájdené riešenie. Z výsledkov získaných na simulovaných aj experimentálnych dátach vyplýva, že uvedené ukazovatele môžu pomôcť pri hodnotení možnosti lokalizácia oblasti s ischemickým poškodením srdca a jej spoľahlivosť.
Publications:
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HEBLÁKOVÁ E. - ŠVEHLÍKOVÁ J. - TURZOVÁ M. - TYŠLER M.: Method for Noninvasive Detection of Ischemic Regions, Applicability and Limitations. Lékař a technika, 2006, Vol.36(2), 245-249. ISSN 0301-5491.
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HEBLÁKOVÁ E. - ŠVEHLÍKOVÁ J. - TURZOVÁ M. - TYŠLER M.: Applicability of Model Based Localization of Ischemic Lesions. In: Abstractband, 33rd International Congress on Electrocardiology, 2006, 27.
Result 2: Software for the measurement of spectral characteritics of the reflectivity and transmitivity of materials utilising Fourier infrared spektroscopy
Investigators: M. Hain, E.Kawate
Applicator: Nanoelectronics Reserch Institute, AIST, Japan.
In the frame of international cooperation with Nanoelectronics Research Institute, AIST, Japan a program for automated measurement of spectral characteristics od reflectivity and transmitivity of materials was developed. Software is responsible for setting of angle of incidence through two motorized rotational stages carrying two mirrors; it controls spectrometer Varian FTS 7000e and collects measured data - interferograms and spectra. Measured data are transferred to a MS Excel program, where the data are evaluated and visualised.
Advantage of the software is not only a reduction of measurement time, but also decreasing of measurement uncertainty by elimination of time and temperature drift.
Figure: Result of measurement of a spectral reflectance and transmittance of a 30 micrometer thick glass under the normal incidence of light (R – reflectance, T – transmittance, A – absorptance).
Result 3: Long-term changes of EEG during audiovisual stimulation training
Project: VEGA 2/4026/04
Investigators: M. Teplan, A. Krakovská, S. Štolc
Audio-visual stimulation (AVS) is a method for external influence of the brain by repetitive monotonous visual and sound stimuli. AVS was declared as a treatment tool with ability to correct certain neurological and psychical disorders. Exact study of AVS phenomenon may contribute to better understanding and enhancement of AVS phenomena and help in designing further clinical studies. The aim of the project was to research impact of AVS in direct, transient, and long-term time frame and to characterize EEG changes during long-term repetitive application of AVS. Statistically significant correlation between increased relaxation evaluated by subjective assessment of tested persons and increase of powers in lower frequency bands (4-10 Hz) was found, as well as between decrease of signal complexity and increase of synchronization between hemispheres in alpha range in some cortex locations. We have shown that in comparison with other methods for inducing relaxation e.g., regular listening to relaxation music, AVS training is more effective in evoking long-term changes in EEG. In order to characterize relaxation state of man application of certain methods was proposed and elaborated, namely traditional spectral measures (based on powers in various frequency bands) and modern nonlinear complexity measures (originated in theory of dynamical systems and chaos theory).
Publications:
- TEPLAN, M. - KRAKOVSKÁ, A. - ŠTOLC, S.: EEG responses to long-term audio-visual stimulation. International Journal of Psychophysiology, 2006, Vol. 59/2, 81-90.
- TEPLAN, M. - KRAKOVSKÁ, A. - ŠTOLC, S.: Measures of EEG in the context of long-term audio-visual stimulation. In: MEASUREMENT 2005. 5th International Conference on Measurement. Bratislava, Slovak Republic, Institute of Measurement Science, SAS, 2005, 225-228.
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