Biomaterial Database

Time and frequency analysis of simultaneously recorded corneal and non-corneal electroretinogram. 1979

M Gur, and I Gath

Electroretinograms (ERGs) were simultaneously recorded with corneal and non-corneal (lower or upper eye lid) electrodes in four healthy subjects. 64 traces of the non-corneal ERG were averaged. The two signals were compared in both time and frequency domains. The power spectrum of both signals was computed by the fast Fourier (FFT) and linear prediction (LP) algorithms. Except for amplitude differences, the two signals had almost identical time domain (a- and b-wave latencies) and frequency domain (dominant power spectrum peaks) parameters. It is concluded that non-corneal ERG does not differ significantly from corneal ERG, and that its clinical interpretation can be based on existing corneal ERG data.

UI	MeSH Term	Description	Entries
D011336	Probability	The study of chance processes or the relative frequency characterizing a chance process.	Probabilities
D003201	Computers	Programmable electronic devices designed to accept data, perform prescribed mathematical and logical operations at high speed, and display the results of these operations.	Calculators, Programmable,Computer Hardware,Computers, Digital,Hardware, Computer,Calculator, Programmable,Computer,Computer, Digital,Digital Computer,Digital Computers,Programmable Calculator,Programmable Calculators
D003315	Cornea	The transparent anterior portion of the fibrous coat of the eye consisting of five layers: stratified squamous CORNEAL EPITHELIUM; BOWMAN MEMBRANE; CORNEAL STROMA; DESCEMET MEMBRANE; and mesenchymal CORNEAL ENDOTHELIUM. It serves as the first refracting medium of the eye. It is structurally continuous with the SCLERA, avascular, receiving its nourishment by permeation through spaces between the lamellae, and is innervated by the ophthalmic division of the TRIGEMINAL NERVE via the ciliary nerves and those of the surrounding conjunctiva which together form plexuses. (Cline et al., Dictionary of Visual Science, 4th ed)	Corneas
D004596	Electroretinography	Recording of electric potentials in the retina after stimulation by light.	Electroretinographies
D005143	Eyelids	Each of the upper and lower folds of SKIN which cover the EYE when closed.	Eyelid
D005583	Fourier Analysis	Analysis based on the mathematical function first formulated by Jean-Baptiste-Joseph Fourier in 1807. The function, known as the Fourier transform, describes the sinusoidal pattern of any fluctuating pattern in the physical world in terms of its amplitude and its phase. It has broad applications in biomedicine, e.g., analysis of the x-ray crystallography data pivotal in identifying the double helical nature of DNA and in analysis of other molecules, including viruses, and the modified back-projection algorithm universally used in computerized tomography imaging, etc. (From Segen, The Dictionary of Modern Medicine, 1992)	Fourier Series,Fourier Transform,Analysis, Cyclic,Analysis, Fourier,Cyclic Analysis,Analyses, Cyclic,Cyclic Analyses,Series, Fourier,Transform, Fourier
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000328	Adult	A person having attained full growth or maturity. Adults are of 19 through 44 years of age. For a person between 19 and 24 years of age, YOUNG ADULT is available.	Adults
D013997	Time Factors	Elements of limited time intervals, contributing to particular results or situations.	Time Series,Factor, Time,Time Factor