VISUALIZATION OF THREE-DIMENSIONAL DATA FIELD AND ITS APPLICATION IN MACHINE TESTING

In order to realize visualization of three-dimensional data field （TDDF） in instrument, two methods of visualization of TDDF and the usual manner of quick graphic and image processing are analyzed. And how to use OpenGL technique and the characteristic of analyzed data to construct a TDDF, the ways of reality processing and interactive processing are described. Then the medium geometric element and a related realistic model are constructed by means of the first algorithm. Models obtained for attaching the third dimension in three-dimensional data field are presented. An example for TDDF realization of machine measuring is provided. The analysis of resultant graphic indicates that the three-dimensional graphics built by the method developed is featured by good reality, fast processing and strong interaction

Applications of dynamic visual acuity test in clinical ophthalmology

Dynamic visual acuity test(DVAT)plays a key role in the assessment of vestibular function,the visual function of athletes,as well as various ocular diseases.As the visual pathways conducting dynamic and static signals are different,DVATs may have potential advantages over the traditional visual acuity tests commonly used,such as static visual acuity,contrast sensitivity,and static perimetry.Here,we provide a review of commonly applied DVATs and their several uses in clinical ophthalmology.These data indicate that the DVAT has its unique clinical significance in the evaluation of several ocular disorders.

THE SIGNIFICANCE OF TESTING PREOPERATIVE VISUAL FUNCTION IN CATARACT USING LASER INTERFEROMETRIC VISUAL ACUITY AND ERG

Tests of preoperative visual function and prediction of postoperative E chart visual acuity(ECVA) using laser interferometric visual acuity(LIVA) and electroretinogram(ERG) were performed in 16 cases(19 eyes) of cataract. The results showed that the coincident rate between preoperative LIVA and postoperative ECVA was 63.2%, and there was a parallel correlation between preoperative amplitude of photopic ERG b-wave and postoperative ECVA in 79.0% of the eyes. Comparing these two methods, the test of LIVA ...

Comparison of Snellen and Early Treatment Diabetic Retinopathy Study charts using a computer simulation

AIM：To compare accuracy,reproducibility and test duration for the Snellen and the Early Treatment Diabetic Retinopathy Study（ETDRS）charts,two main tools used to measure visual acuity（VA）.·M ETHODS：A computer simulation was programmed to run multiple virtual patients,each with a unique set of assigned parameters,including VA,false-positive and false-negative error values.For each virtual patient,assigned VA was randomly chosen along a continuous scale spanning the range between 1.0 to 0.0 log MAR units（equivalent to 20/200 to 20/20）.Each of 30 000virtual patients were run ten times on each of the two VA charts.·RESULTS：Average test duration（expressed as the total number of characters presented during the test±SD）was12.6±11.1 and 31.2±14.7 characters,for the Snellen and ETDRS,respectively.Accuracy,defined as the absolute difference（±SD）between the assigned VA and the measured VA,expressed in log MAR units,was superior in the ETDRS charts：0.12±0.14 and 0.08±0.08,for the Snellen and ETDRS charts,respectively.Reproducibility,expressed as test-retest variability,was superior in the ETDRS charts：0.23±0.17 and 0.11±0.09 log MAR units,for the Snellen and ETDRS charts,respectively.·CONCLUSION：A comparison of true（assigned）VA to measured VA,demonstrated,on average,better accuracy and reproducibility of the ETDRS chart,but at the penalty of significantly longer test duration.These differences were most pronounced in the low VA range.The reproducibility using a simulation approach is in line with reproducibility values found in several clinical studies.

Working Memory Function in Chinese Dyslexic Children:A Near-Infrared Spectroscopy Study

The deficiency theories of dyslexia are quite contradictory and the cross-cultural studies in recent years mainly focused on whether the dyslexics among cultures shared the same cognitive profile or just based on the language.This study used Near-Infrared Spectroscopy (NIRS) imaging to measure the regional cerebral blood volume (BV) and the changes of cerebral activation in the left prefrontal cortex of 12 Chinese dyslexic children and their 12 age-matched normal controls during the Paced Vis-ual Serial Addition Test (PVSAT).Results showed that the scores of PVSAT of dyslexic children were significantly lower than those of the normal children (t=3.33,P<0.01).The activations of the left pre-frontal cortex in the normal group were significantly greater than those of dyslexic children (all P<0.01).Our results indicated that Chinese dyslexia had a general deficiency in working memory and this may be caused by the abnormal metabolic activity of brain blood volume in the left prefrontal cortex and the deficits in brain function might be the basis of neuropathology of Chinese dyslexia.Present study sup-ports the difference on brain activation of dyslexics from different languages may be caused by the same cognitive system related to reading.

Neurofeedback Treatment Study for ADHD by Using the Brain-Computer Interface Neurofeedback System

Neurofeedback or electroencephalogram(EEG) biofeedback technology is widely used in clinical rehabilitation field. In this paper, we used a brain-computer interface(BCI) neurofeedback system for attention deficit hyperactivity disorder(ADHD) children treatment.After 20 training sessions, integrated visual and auditory-conhnuous performance test(IVA-CPT), DSM-IV and conner scale results suggested that the attention ofsubjectshad been strengthened, which showed that the BCI neurofeedback system could provide an effective therapyfor treating ADHDchildren.