Deconvolution of High Rate Flicker Electroretinograms

Thesis

Alokaily, Ahmad O . 2014

• نوع عمل المنشور: Master Thesis
• مدينة النشر: Miami
• الوسوم: CLAD,RAD,DECONVOLUTION,HIGH RATE, FLICKER,ERG,FREG
• نوع الإطروحة: Master Thesis
• المدرسة: University of Miami

مستخلص المنشور

Flicker electroretinograms are steady-state electroretinograms (ERGs)
generated by high rate flash stimuli that produce overlapping periodic responses. When
a flash stimulus is delivered at low rates, a transient response named flash ERG
(FERG) representing the activation of neural structures within the outer retina is
obtained. Although FERGs and flicker ERGs are used in the diagnosis of many retinal 
diseases, their waveform relationships have not been investigated in detail. This study
examines this relationship by extracting transient FERGs from specially generated
quasi steady state, random ERGs at stimulation rates above 10 Hz and similarly
generated conventional flicker ERGs. The ability to extract the transient FERG
responses by deconvolving flicker responses to temporally jittered stimuli at high
rates is investigated at varying rates. FERGs were obtained from seven normal
subjects stimulated with LED-based displays, delivering steady state, low jittered quasi
steady state and low jittered random responses at five stimulation rates of 10, 15, 32, 50,
68 Hz. The two deconvolution methods (CLAD and RAD) enabled a successful
extraction of “per stimulus” unit transient ERG responses for all high stimulation
rates. The deconvolved FERGs were used successfully to synthesize flicker ERGs
obtained at the same high stimulation rates. The experimental results showed that, as thestimulation rate increased, the a-wave and b-wave amplitudes decreased significantly
between the 10 and 15 Hz and 15 and 32 Hz. Furthermore, the implicit time of a-wave 
increased between 2 and 10 Hz and decreased between 15 and 32 Hz. Moreover, b-wave 
decreased significantly as the stimulation rate increased up to 32 Hz.