Fourier transformed steady-state flash evoked potentials for continuous monitoring of visual pathway function
| Autor: | K. Rüther, R. Bergholz, G. Fritz, T. N. Lehmann |
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| Rok vydání: | 2007 |
| Předmět: |
Adult
Male Steady state (electronics) Phase (waves) Somatosensory system Signal Discrete Fourier transform symbols.namesake Physiology (medical) Meningeal Neoplasms Humans Computer vision Visual Pathways Visual Cortex Physics Epilepsy Fourier Analysis business.industry Continuous monitoring Middle Aged Sensory Systems Ophthalmology Amplitude Fourier transform symbols Evoked Potentials Visual Visual Field Tests Female Artificial intelligence Visual Fields business Meningioma Photic Stimulation Biomedical engineering |
| Zdroj: | Documenta ophthalmologica. Advances in ophthalmology. 116(3) |
| ISSN: | 0012-4486 |
| Popis: | Monitoring of somatosensory, motor and auditory pathway function by evoked potentials is routine in surgery placing these pathways at risk. However, visual pathway function remains yet inaccessible to a reliable monitoring. For this study, a method of continuous recordings was developed and tested. Steady-state visual evoked potentials were elicited by flash stimulation at 16 Hz and analysed using discrete Fourier transform. Amplitude and phase of the fundamental response were dynamically averaged and continuously plotted in a trend graph. The method was applied on awake individuals with normal vision and on patients undergoing neurosurgery. In most individuals it was possible to continuously record significant responses. Surprisingly, characteristic time-courses of amplitude and phase were observed in several subjects. These findings were attributed mainly to flicker-adaptation. During anesthesia, amplitude and signal-to-noise ratio were markedly smaller. Signal recognition was facilitated when potentials were recorded with a subdural electrode placed directly at the occipital pole. The anesthetic agent propofol had a major impact on the recordings. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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