Digital Signal Processing in Ophthalmic Images for Overall Structure in Clinical VEP Signals

Abstract

VEPs can provide important diagnostic information regarding the functional integrity of the visual systems. Several types of VEPs are routinely used in a clinical setting. These primarily differ in a mode of stimulus presentation. Four standard stimulus protocols are defined. The standard VEP protocols are defined for a single recording channel with a midline occipital active electrode. By limiting this standard to four protocols, the intention is that standard VEPs will be incorporated universally into clinical VEP testing along with additional tests and extended protocols that a laboratory may chose to use. This work presents a technique for reliable extraction P-100 latency and amplitude using a wavelet based technique. The standard does not require that all four protocols should be used for every investigation on every patient. In many circumstances, a single stimulus protocol will be appropriate. Four standard stimulus protocols are defined. These are Pattern reversal VEPs elicited by checker board stimuli, Pattern Onset/Offset Flash VEPs elicited by similar checkerboard stimuli, Pattern reversal VEPs elicited by LED Goggles stimuli and Pattern Onset/Offset Flash VEPs elicited by similar LED Goggles stimuli. The analysis of P-100 latency and amplitude measurement variability based on visual pathway conduction in VEP has been shown to have clinical utility. The reliable measurement of VEP techniques to do is less well developed. This work presents a technique for reliable extraction P-100 latency and amplitude using a wavelet based technique. The VEP is still one of the most main tools to access to one of the most unknown and complex systems is nature. There are no doubts that due to its complexity and ability to reflect underlying processes in the visual of the VEP signal are theoretically the best physiological signal for extraction and comprehension of human behavior. The basic algorithms for VEP signal are presented. The overall structure of clinical VEP signal is treated here. The gathered examples are based on the laboratory experiments realized during the subject cognitive processes.