By designing the circuit structure of preamplifier and selecting new elements such as ultra low noise operational amplifier and linear opto-coupler,some difficulties in EEG acquisition is overcome and the Common Mode Rejection Ratio(CMRR) of preamplifier is highly increased.So EEG can be amplified and detected well.

Objective To assess retinal arteriole stenosis in cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) and to evaluate the relationship between retinal arteriole stenosis with cranial MRI changes and clinical features. Methods Sixteen CADASIL patients (mean age was (43.4±8.1)years, mean duration was(4.7±3.4)years)and sixteen age matched healthy individuals were enrolled. Mini-Mental State Examination (MMSE) and modified Rankin scale scoring were performed in 16 patients. Cranial MRl with Coulthard scores was assessed on CADASIL patients as well. Retinal examinations for arteriole stenosis were done for each subject. Bivariate correlations (Kendall's tau-b) were used to assess the relationship among the grade of retinal stenosis, MMSE, modified Rankin seale, cranial MRI with Coulthard scores and age. Results Retinal arteriole stenosis presented in 15 cases. in whom 4 cases showed mild arterio-venous nicking. while it only presented in 2 controls. Grade 0.Ⅰ, and Ⅲ of retinal arteriole stenosis are noted in 1/16,4/16,7/16 and 4/16cases respectively. Coulthard scores of cerebral MRl were 6.0.19.0.25.1 and 29.8 respectively from Grade 0 toⅢ of retinal arteriole stenosis. The correlation coefficient of retinal arteriole stenosis and cranial MRI scores was 0.743(P＜0.001＝,MMSE-0.429(P＜0.05＝,modified Rankin scale 0.437(P＞0.05).and age 0.299(P＞0.05).Conclusion Retinal arteriole stenosis is significantly correlated with lesion in cranial MRI and dementia.