Analysis of pattern electroretinogram signals of early primary open-angle glaucoma in discrete wavelet transform coefficients domain
| Autor: | Ebrahim Jafarzadehpour, Shahin Yazdani, Homa Hassankarimi, Seyed Mohammad Reza Noori, Fatemeh Radinmehr |
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| Rok vydání: | 2017 |
| Předmět: |
Discrete wavelet transform
Adult Male Wavelet Analysis Glaucoma Standard deviation Correlation 03 medical and health sciences Young Adult 0302 clinical medicine Wavelet medicine Electroretinography Humans Time domain Symlet business.industry Pattern recognition Middle Aged medicine.disease Ophthalmology Coiflet Case-Control Studies 030221 ophthalmology & optometry Visual Field Tests Female Artificial intelligence Visual Fields business 030217 neurology & neurosurgery Glaucoma Open-Angle |
| Zdroj: | International ophthalmology. 39(10) |
| ISSN: | 1573-2630 |
| Popis: | To evaluate discrete wavelet transform coefficients and identify descriptors of pattern electroretinogram (PERG) waveforms in order to determine PERG characteristics for optimizing the diagnosis of early primary open-angle glaucoma (POAG). Pattern electroretinogram was performed in 30 normal eyes and 30 eyes with primary open-angle glaucoma according to the ISCEV protocol. The check size was 0.8° and 16°, and the color was black/white in both groups. The results were analyzed in time domain (TD) and discrete wavelet transform (DWT) using the MATLAB software. The mean value, standard deviation, and relative energy of level 6 and 7 detail coefficients (d6, d7) and level 7 approximation coefficients (a7) of Daubechies 4 (db4), Daubechies 8 (db8), Symlet 5 (sym5), Symlet 7 (sym7), and Coiflet 5 (coif5) wavelets were calculated. In all the mentioned wavelets, DWT descriptors were extracted. Signals were reconstructed by inverse DWT. All data obtained by TD and DWT analyses were compared between the two groups. In both check sizes, a significant attenuation of N95 amplitude was seen in the patient group. The relative energy of a7 of db8 increased significantly in the POAG group in the 0.8° check size. In larger check stimuli, the relative energy of d7 of coif5 decreased significantly and the standard deviation of d7 of sym7 increased markedly in glaucomatous patients (P |
| Databáze: | OpenAIRE |
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