The Multifocal Erg In Detecting System Research And Design

The multifocal electroretinogram (mERG) can be used to record many focal electroretinogram responses across the test field in a relatively short period of time. Although this technique is relatively new, it has already provided insights into the mechanisms of retinal disease. It can be used in the early diagnosis and prognosis of some retinal diseases, and can be used to objectively and sensitively observe the curative effect of medicine or surgery.With the development of society and the improvement of the science technology, mERG measure instrument are widely demanded and their capabilities are required better. The author of the paper design an integrated measure system based on computer. The first part describes the biomedical signal detection and how the mERG is recorded. In the second part, signal-processing method in analog technology are illustrated and its circuitry are designed which include signal preamplifier, shielding and interference restraint. In the study of weak signal detection, some key techniques about mERG have been discussed. The digitized techniques, about signal processing, realization are also described in the third part. Digital filter is one of the most important parts of digital signal processing. The Infinite Response digital filter (IIR) can be achieved through three steps: the design of prototype of analog low-pass filter, analog-to digital filter conversion and the conversion of filter frequency band. To extract the local responses is the key part in mERG. The hexagonal array stimulated different regions of retina simultaneously. The Fast Walsh transform algorithm and the cross-correlation technique, which utilized the pseudorandom features of m-sequence, extracted the single local response from each element.This paper will help to the teaching, researching and producing process. It is fresh air to the biomedical electronics, medical instrument.