瞳孔孔径动态变化测量分析装置

本文介绍了我们研制的瞳孔孔径动态变化测量分析装置，主要介绍其设计原理、分析测量方法和初步的测量结果。     

眼睛动态检测系统在神经疾病定位诊断中的初步应用

目的:探讨光反射传导径路出现异常引起眼睛变化的特点,研究眼睛的动态检测对光反射传导径路出现异常的神经性病变定位诊断的价值。方法:观察分析病例,在暗视条件下,应用本课题组设计的眼睛动态检测系统检测病例的瞳孔及其对光反射。瞳孔对光反射检查是在左右两侧分别给予光刺激时,定量检测双侧眼的瞳孔变化情况。检测的特征值包括瞳孔初始直径(D0)、瞳孔收缩速度(V)等。根据其眼睛的动态变化情况,作出传导径路出现神经病变的定位分析。结果:病例的瞳孔大小和瞳孔对光反射都出现了异常现象,但各自有不同的特点。病例C的左侧瞳孔明显小于右侧,左眼的直接对光反射消失、间接对光反射也消失;右眼直接对光反射存在、间接对光反射也存在。病例D的右侧瞳孔明显小于左侧,右眼直接对光反射消失,间接对光反射虽然幅度小,但存在;左眼直接对光反射存在,间接对光反射消失。结论:眼睛动态检测可起到对光反射传导径路异常的神经疾病定位分析和鉴别诊断的重要作用。     

常染色体显性遗传性白内障伴小瞳孔一家系

先证者（Ⅳ2）男，19岁，学生，智力、发育正常。自幼左眼晶状体混浊，灰白色；白天注视远处物体时，瞳孔直径小于2mm；瞳孔对光反射甚微；瞳孔放大时呈卵圆形；视力偏低，且随年龄增长，视力逐步下降；全身其他情况正常。诊断为遗传性白内障伴小瞳孔。家系调查见图1。Ⅰ1、Ⅱ2、Ⅲ2、Ⅳ1、Ⅳ2均有同样病症。家系中无近亲通婚史。     

新型数字化视神经功能客观检测仪

正近日,中国科学院苏州生物医学工程技术研究所医学影像室、医用机器视觉实验室研制成功用于视神经疾病诊断的数字化定量检测相对性瞳孔传入障碍(RAPD)仪器。它可独立、定量地检测双眼瞳孔对光反射的全过程,用于与视神经通路相关疾病的临床定量诊断。数字化RAPD检测仪采用数字化瞳孔成像和独立光路单眼刺激技术,可分别对左右眼进行独立的光刺     

重症颅脑损伤患者术后NIHSS评分的影响因素分析

目的：分析重症颅脑损伤患者术后NIHSS评分的影响因素。方法：以2013年3月至2015年6月在我院治疗的100例重型颅脑损伤患者为观察对象,采用单因素方差分析、t检验及多重逐步回归分析探讨影响重症颅脑损伤患者术后NIHSS评分的因素。结果：100例患者中轻型神经功能缺损者38例,中型神经功能损伤者46例,重型神经功能缺损者16例;年龄较大、存在呼吸异常、低血压、复合伤、瞳孔散大、瞳孔对光反射消失、颅内血肿量较大、有消化道出血、出现脑积水的患者术后NIHSS评分较高,差异有统计学意义;将单因素分析有意义的因素：年龄、呼吸异常、低血压、复合伤、瞳孔散大、瞳孔对光反射、颅内血肿量、消化道出血、脑积水作为自变量,以患者术后NIHSS评分作为因变量,进行多重逐步回归分析,年龄、颅内血肿量、脑积水进入回归方程。结论：重症颅脑损伤患者术后NIHSS评分受年龄、颅内血肿量和脑积水有密切关系。     

基于改进图割的超声瞳孔图像分割与直径测量

传统的瞳孔直径测量是通过医生手工标定,对于眼外伤和丧失意识的患者测量不方便。针对瞳孔直径测量的人工交互量大且测量鲁棒性不强的问题,采用图割算法分割瞳孔超声图像并测量瞳孔直径。对传统图割算法进行两个方面的改进,采用自适应阈值的区域生长代替人为种子点选取,在保证分割效果的基础上减少了图割的交互量;在能量函数的数据项部分增加图像的梯度信息,减少了原始算法分割结果中出现的小区域,增强了对弱边缘的分割。最后,对采集到的超声瞳孔图像进行自动分割、自动测量瞳孔直径,可以得到患者瞳孔的直径动态变化,给临床诊断提供依据。为了验证算法的有效性,对10位患者的动态瞳孔超声图像进行基于改进图割的瞳孔直径测量,并与医生的手动测量结果对比。结果表明,本方法的结果与医生手动测量结果的绝对误差小于0.2 mm,相关系数不小于0.83。通过改进图割算法,改善了分割效果,实现了超声瞳孔动态图像的自动直径测量,并可有效代替瞳孔直径的人工测量,减少人工交互量。     

昏迷病人的护理

昏迷是意识完全丧失的一种严重情况。病人对语言无反映,各种反射(如吞咽反射、角膜反射、瞳孔对光反射等)呈不同程度的丧失。     

全身麻醉前后患者年龄、性别与瞳孔变化临床研究

目的：探讨全身麻醉前后患者年龄、性别与瞳孔直径及反应速率变化的关系。方法：选取2015年7月至2015年10月在兰州军区兰州总医院行全麻手术的患者90例(180眼),以年龄分为低年龄组(3~40岁)、中年龄组(41~60岁)和高年龄组(61岁以上),其中低年龄组30例(60眼),男16例(32眼),女14例(28眼),平均年龄(22.60±10.36)岁;中年龄组30例(60只眼),男13例(26眼),女17例(34眼),平均年龄(48.73±5.82)岁;高年龄组30例(60只眼),男20例(40眼),女10例(20眼),平均年龄(66.63±4.88)岁。结果：麻醉前后各组左、右眼之间差别具有显著性(P<0.05);麻醉前各组男、女性别之间差别无显著性;麻醉后各组男、女性别之间差别无显著性;低年龄组、中年龄组、高年龄组两两比较,发现随着年龄增高,患者瞳孔直径、反应速率具有统计学意义(P<0.05)。结论：全身麻醉患者瞳孔直径变化与年龄、性别相关,密切观察患者瞳孔及反应速率变化对麻醉效果、麻醉深度、术中患者病情的变化具有指导性意义。     

学龄前儿童瞳孔水平位的对称性研究

采用摄影测量方法对６１５名汉族学龄前儿童瞳孔水平位对性进行了研究。结果表明：瞳孔正中点距和瞳孔外紫点距，两项测距的非对称率均小于３．９％，呈现高度对称性；两项测距两侧差值的均数５岁以前均小于２ｍｍ，５岁以后均小于１ｍｍ，两项测距的差值均有６０％以上的个体小于１ｍｍ，有明显的年龄变化特点，但在５岁以后趋于稳定。     

一种快速精确的瞳孔和角膜反射光斑中心定位算法的研究

眼动追踪系统在临床医学中有着重要应用,为提高系统中眼图特征值的识别率,创新性地提出一种双层过滤的瞳孔中心和角膜反射光斑中心的定位算法。瞳孔中心定位算法首先对获取的眼睛图像二值化处理,然后以100～300为阈值设定轮廓点数,进行第一次瞳孔过滤,最后用最小二乘法椭圆拟合瞳孔轮廓,并将最接近圆的轮廓作为瞳孔轮廓,继而得到瞳孔中心。在此基础上,进一步对瞳孔中心一定范围内的眼图进行边缘检测,求其轮廓,并找出轮廓的外接矩形中心,然后以瞳孔中心为基点进行坐标转换,最终求出角膜反射光斑中心。算法在一定程度上缩小图像处理的区域,提高实时性和反射光斑的识别率。实验结果表明,所设计的算法能够实时地对不同情况下的瞳孔和角膜反射光斑中心进行准确定位,瞳孔-角膜反射向量坐标最大均方差低于0.74像素,平均误差低于0.53像素。算法运行速度达到12.8 ms/帧。算法满足精确性的同时具有很强的鲁棒性,为后续眼动设备的开发提供重要的参考价值。     

Tropicamide effects on pupil size and pupillary light reflexes in Alzheimer's and Parkinson's disease.

Diagnostic tests for Alzheimer's disease (AD) involving tropicamide blockade of cholinergic oculomotor functions were examined in AD patients (n=15), Parkinson's disease (PD) patients (n=15), and non-clinical control (NC) participants (n=15). Pupillographic methods were used to measure pupil diameter and pupillary light reflexes after double-blind ocular administration of dilute tropicamide (0.01%) in one eye and saline in the other eye. Changes in pupil size were measured in bright background light and near-darkness. Tropicamide increased pupil diameter to a similar extent in all three groups in light and darkness. Tropicamide also reduced the amplitude and latency of the pupillary light reflex to a similar extent for all three groups. Tropicamide pupillary response tests, therefore, were not sensitive or specific diagnostic tests for AD. Peak constriction amplitude of the pupillary light reflex was significantly reduced in both eyes in AD and PD groups relative to non-clinical controls, but AD and PD groups did not differ significantly. The pupillary light reflex test, therefore, was sensitive to AD, but lacked adequate specificity. Finally, peak constriction amplitude correlated significantly with dementia severity and donepezil treatment may have partially normalized pupillary light reflex abnormalities in AD patients. The pupillary light reflex test, therefore, may index central cholinergic dysfunction associated with disease progression and improvement in cholinergic function associated with pharmacologic treatment response in AD.     

The fear-inhibited light reflex: importance of the anticipation of an aversive event.

RATIONALE: It has been shown previously that the amplitude of the pupillary light reflex response decreases when subjects anticipate an aversive stimulus (i.e. electric shock), compared to periods when subjects are resting ('fear-inhibited light reflex'). OBJECTIVE: To compare the effects of the anticipation of an electric shock (putative aversive event) and of an acoustic stimulus (putative neutral event) on the light reflex. METHODS: Twelve healthy volunteers participated in a training session and an experimental session. Pupil diameter was monitored with infra-red binocular television pupillometry. The experimental session consisted of 14 blocks of 3 light stimuli. 'Relaxation' (no anticipation) and 'anticipation' (electrical or acoustic stimulus) blocks alternated. Mood and feelings were self-rated on visual analogue scales. RESULTS: The anticipation of the electrical stimulus was associated with increases in initial pupil diameter and subjectively rated 'anxiety' and 'alertness', and a decrease in the amplitude of the pupillary light reflex response, whereas anticipation of the acoustic stimulus was associated with increases in initial pupil diameter and subjective 'alertness' only. CONCLUSIONS: The increase in initial pupil diameter is related to the anticipation of any stimulus, whereas the decrease in the amplitude of the light reflex response is associated with the aversiveness of the anticipated stimulus.     

Pupillometric assessment of excessive daytime sleepiness in narcolepsy-cataplexy.

Ten untreated patients with narcolepsy-cataplexy and age- and sex-matched normals between the ages of 20 and 71 years underwent pupillometric analyses immediately prior to each of five multiple sleep latency test sessions. Although narcoleptics were sleepier as indicated both by their Stanford Sleepiness Scale ratings and by their latencies to sleep onset, the baseline pupil diameter, pupillary light reflex, and pupillary orienting response did not differentiate between groups. Narcoleptics did, however, exhibit a significantly greater frequency of spontaneous oscillations in the dark-adapted state than did controls. These findings indicate that pupillary stability may serve as a supplementary diagnostic tool for narcolepsy-cataplexy. The results are discussed with the view that psychosensory restoration of alertness, among other extraneous variables, must be controlled when utilizing pupillometric techniques. A review of the literature indicates a variety of methodological and statistical shortcomings that must be amended. Suggestions are made for improving the reliability and validity of the pupillometric approach.     

Ultradian rhythms in alertness - a pupillometric study

Pupillary size, pupillary light reflex and pupillary motility were measured every 15 min, for 10 continuous hours, in eight young adults. Time series constructed from the range of pupillary motility revealed 75 to 125 min rhythms; these were significantly out of phase with rhythms of similar periodicity in pupillary diameter and in the magnitude of the pupillary light reflex. There was no consistent correspondence between Stanford Sleepiness Scores and pupillary activity. It is suggested that the rhythms in pupillary activity reflect underlying rhythms in CNS arousal that also modulate perceptual, cognitive and electroencephalographic processes, a conclusion which supports Kleitman's BRAC model.     

Neurological pupillary noise in narcolepsy

SUMMARY Pupillometry has a long but inconclusive history as a means of measuring human alertness. Spontaneous pupillary oscillations in narcoleptics and the sleep deprived are a recognized but quantitatively elusive indication of alertness. Stimulation of the pupillary light reflex (PLR) has provided contradictory or confusing indications of alertness levels. Results from 10 diagnosed narcoleptics and 10 control subjects in which the PLR system was stimulated and a reliable (90%) discriminator derived for classifying narcoleptics and controls was reported. Random pupillary oscillations, which is called pupillary noise to distinguish these oscillations from spontaneous ones, were estimated from continuous pupil diameter recordings using a recursive least squares method applied to a subject–specific PLR system model. Pupillary noise sum of squares indicate that narcoleptics have significantly (P < 0.005) less PLR noise than controls. This difference was attributed to supranuclear inhibition of randomly active Edinger-Westphal neurons long hypothesized to be the source of random papillary oscillations. This inhibition also has been suggested as a cause of PLR sensitivity to nocturnal sleep quality so it may be that these findings apply to the sleep deprived and not just specifically to narcoleptics.     

A Faster and More Accurate Instrument for Digital Measurement of Pupil Diameter

This low cost device enables the experimenter In make a faster and more accurate measurement of pupil diameter registered on a TV recorder. Instead of a direct external measurement on the TV screen with a scale, two black or dark areas with sharp vertical edges are electronically superimposed on (he pupil projection on the monitor, These dark areas can easily he moved independently in both horizontal directions, so that the pupil becomes confined at its edges. The time required by the cathode ray to pass the field between these areas is a linear index of pupillary diameter. This time can be registered with a frequency counter.     

The pupillary light reflex cannot be used to measure sleepiness

The pupillary light reflex (PLR) has been considered by some researchers to be responsive to changes in levels of sleepiness. However, no previous studies have tested this hypothesis with the dramatic variation of sleepiness across a complete circadian cycle. In this experiment, 20 normal individuals (age: 18–48 years) underwent a 27-hr constant routine, during which they were kept awake except for a 15-min nap opportunity every hour. Sleepiness was assessed both subjectively, by the Stanford Sleepiness Scale, and objectively, by a modified version of the Multiple Sleep Latency Test. The PLR in response to a flash of light was recorded every 2 hr, immediately before a nap period. Results showed that baseline pupil diameter became smaller with progressive sleep restriction, but there were no changes in any of the parameters of the PLR despite significant fluctuations in sleepiness. Some of the changes in the PLR were significantly related to changes in baseline pupil diameter. When baseline diameter was partialled out, there was still no effect of sleepiness on the PLR. The results suggest that the PLR cannot be used as a measure of sleepiness.     

Characteristics of the pupillary light reflex in the alert rhesus monkey

This study investigated the static and dynamic characteristics of the pupillary light reflex (PLR) in the alert rhesus monkey. Temporal characteristics of the PLR were investigated with Maxwellian viewing during sinusoidal changes in illumination of a 36 degrees stimulus in both monkeys and humans. Bode plots of the PLR response were fitted by a linear model composed of a delay combined with a cascaded first- and second-order filter. The Bode magnitude plots conformed to this model with a sharp roll-off above 1.3 Hz for the human PLR and 1.9 Hz for the monkey PLR. Bode phase angle plots were fitted by this model with a delay of 280 ms for humans and 160 ms for monkeys. To investigate the influence of the sympathetic innervation of the iris on steady-state pupil diameter, dynamics of pupillary responses, and the latency of the PLR, we blocked this innervation pharmacologically with a selective alpha-1 adrenoreceptor antagonist. Although there was a resultant miosis (decrease in pupil diameter) from the relaxation of the pupil dilator muscle, no other measures of the PLR, including the dynamics and latency, were significantly affected by this treatment. We examined the pupillary responses evoked by visual stimuli presented either binocularly or monocularly at various locations on a 80 x 60 degrees tangent screen. These pupillomotor fields revealed that, as has been reported for humans, stimuli at the fovea and surrounding macular region of monkeys produce substantially larger pupillary responses than more peripheral stimuli and that binocular responses are substantially greater than can be accounted for by the linear summation of binocular retinal illuminance. In conclusion, we found that the spatial characteristics of the PLR of the rhesus monkey are very similar, in all important aspects, to those reported for humans and that the temporal responses of the PLR are comparable between the two species. The rhesus monkey thus provides an excellent model for experimental studies of the neural control of the pupil.     

Characteristics of the pupillary light reflex in the macaque monkey: metrics

To investigate whether the simian light reflex is a reasonable model for the human light reflex, we elicited pupillary responses in three behaving rhesus macaques. We measured the change in pupillary area in response to brief (100 ms), intermediate (1 s), and long (3-5 s) light flashes delivered by light-emitting diodes while the monkey fixated a stationary target. Individual responses in the same monkey to either 100-ms or 1-s stimuli of the same light intensity were quite variable. Nevertheless, in response to the 100-ms stimulus, average pupillary constriction and peak constriction velocity increased and latency decreased linearly with the log of stimulus luminance. The minimum average constriction latency across monkeys for the brightest flash was 136 ms. A linear decrease of constriction latency with stimulus luminance also occurs in humans, but their latencies are approximately 70 ms longer. In addition, peak constriction velocity was highly correlated with the decrease in pupillary area. Dilation metrics were not as well related to stimulus luminance as were constriction metrics. The latency from flash offset to the onset of dilation was relatively constant, averaging approximately 480 ms. Peak dilation velocity was also correlated, but less well, with the increase in pupillary area. Constriction generally was greater and of longer duration for 1-s light pulses than for 100-ms pulses of equal luminance. The initial time courses of the responses to the two stimuli of different durations were identical until approximately 150 ms after response onset. Human pupillary responses for long and short flashes also have identical initial time courses. For very long (3-5 s) and very bright constant-luminance stimuli, the simian pupil underwent oscillations at frequencies of 0.9-1.6 Hz. Similar oscillations, called hippus, occur in the human pupillary light reflex. Like humans, the monkeys also exhibited consensual and binocular pupillary responses. Except for response latency, the pupillary responses in the two primate species are otherwise quite similar. Therefore any knowledge we gain about the neuronal substrate of the simian light reflex can be expected to have considerable relevance when extrapolated to humans.     

Measuring the conditioned response: A comparison of pupillometry,skin conductance,and startle electromyography

In human fear conditioning studies, different physiological readouts can be used to track conditioned responding during fear learning. Commonly employed readouts such as skin conductance responses (SCR) or startle responses have in recent years been complemented by pupillary readouts, but to date it is unknown how pupillary readouts relate to other measures of the conditioned response. To examine differences and communalities among pupil responses, SCR, and startle responses, we simultaneously recorded pupil diameter, skin conductance, and startle electromyography in 47 healthy subjects during fear acquisition, extinction, and a recall test on 2 consecutive days. The different measures correlated only weakly, displaying most prominent differences in their response patterns during fear acquisition. Whereas SCR and startle responses habituated, pupillary measures did not. Instead, they increased in response to fear conditioned stimuli and most closely followed ratings of unconditioned stimulus (US) expectancy. Moreover, we observed that startle‐induced pupil responses showed stimulus discrimination during fear acquisition, suggesting a fear potentiation of the auditory pupil reflex. We conclude that different physiological outcome measures of the conditioned response inform about different cognitive‐affective processes during fear learning, with pupil responses being least affected by physiological habituation and most closely following US expectancy.