Orientation and mobility outcome measures

Despite orientation and mobility (O&M) being a significant factor determining quality of life of people with low vision or blindness, there are no gold standard measures or agreement on how to measure O&M performance. In the first part of this systematic review, an inventory of O&M outcome measures used by recent studies to assess the performance of orientation and/or mobility of adults with vision impairment (low vision and blindness) is presented. A wide variety of O&M outcome measures have been implemented in different fields of study, such as epidemiologic research and interventional studies evaluating training, assistive technology, vision rehabilitation and vision restoration. The most frequent aspect of outcome measures is efficiency such as time, distance, speed and percentage of preferred walking speed, followed by obstacle contacts and avoidance, and dis/orientation and veering. Other less commonly used aspects are target identification, safety and social interaction and self-reported outcome measures. Some studies employ sophisticated equipment to capture and analyse O&M performance in a laboratory setting, while others carry out their assessment in real-world indoor or outdoor environments. In the second part of this review, the appropriateness of implementing the identified outcome measures to assess O&M performance in clinical and functional O&M practice is evaluated. Nearly a half of these outcome measures meet all four criteria of face validity (either clinical or functional), responsiveness, reliability and feasibility and have the potential to be implemented in clinical or functional O&M practice. The findings of this review confirm the complicated and dynamic nature of O&M. Multiple measures are required in any evaluation of O&M performance to facilitate holistic assessment of O&M abilities and limitations of each individual.     

Impact of the COVID-19 lockdown on digital device-related ocular health

Purpose:Since the declaration of the lockdown due to COVID-19, the usage of digital devices has gone up across the globe, resulting in a challenge for the visual systems of all ages. The purpose of this study is to assess the impact of the lockdown on digital device usage, and consequently, the ocular surface health implications and circadian rhythm abnormalities related to digital eye strain.Methods:An open online survey was sent through various social media platforms and was open for a period of 2 weeks.Results:A total of 407 usable responses were obtained; the average age of respondents was 27.4 years. Typically, 93.6% of respondents reported an increase in their screen time since the lockdown was declared. The average increase in digital device usage was calculated at about 4.8 ± 2.8 h per day. The total usage per day was found to be 8.65 ± 3.74 hours. Sleep disturbances have been reported by 62.4% of people. Typically, 95.8% of respondents had experienced at least one symptom related to digital device usage, and 56.5% said that the frequency and intensity of these symptoms increased since the lockdown was declared.Conclusion:The study highlighted the drastic increase in use of digital devices after the initiation of the COVID-19 lockdown, and along with it, the slow deterioration of ocular health across all age groups. Awareness about prevention of digital eye strain should be stressed, and going forward, measures to bring these adverse effects to a minimum should be explored.     

An electronic travel guide for visually impaired – vehicle board recognition system through computer vision techniques

Abstract

Purpose: In the context of assistive technology, mobility takes the meaning of “moving safely, gracefully, and comfortably”.The aim of this article is to provide a system which will be a convenient means of navigation for the Visually Impaired people, in the public transport system.

Method: A blind regular commuter who travels by public transport facility finds difficulty in identifying the vehicle that is nearing the stop. Hence, a real-time system that dynamically identifies the nearing vehicle and informs the commuters is necessary. This paper proposes such a system namely the “Vehicle Board Recognition System” (VBRS). Computer Vision techniques such as segmentation, object recognition, text detection and optical character recognition are utilized to build the system, which will detect, analyze, derive and communicate the information to the passengers.

Results: Thanks to the rapid development in technology, there are several navigation systems both hand held and wearable, available to help visually impaired (VI) people move comfortably both indoor and outdoor. Many blind people are not comfortable in using these devices or they are not affordable for them. Thus the proposed system gives them the comfort of navigation.

Conclusion: This system can be installed in the bus stop to assist the Visually Impaired, from externally rather than their hand held or wearable assistive devices.

• Implications for rehabilitation

• This proposed system will help the visually impaired to

• ensure secure navigation

• be independent of the others

• develop self confidence.

• overcome the training, affordability of wearable/ handheld devices.

     

积极主动为贫困人口服务--上海市北站医院平价病房的案例调查

目的:对上海市一所国有民营医院的平价病房进行案例调查,了解运行状况、经验及存在问题。方法:相关人员访谈和现场观察。结果:该院设立了14张床位的平价病房,收治对象是低保户、特困户及经济困难的外来务工人员。对医保病人和自费病人设定不同的减免优惠方案,包括减免50.0%的床位费和10.0%的护理、检查、治疗及手术等劳务费用(药费除外)。以收治急性病为主,住院时间原则上不超过2周。出院病人总费用的实际减免率约为6.0%￣10.0%。结论:创办平价病房的方向应予肯定。是民营机构委托管理医院的一种公益性(非营利性)的表现,对其他公立医疗机构具有促进作用。     

Characterizing luminous efficiency functions for a simulated mesopic night driving task based on reaction time

The objective of this study is to test the luminous efficiency functions V(lambda), V'(lambda), V(10)(lambda) and their linear combinations on the basis of a data set gained from a simulated mesopic night-time driving experiment. Another aim is to provide 'real-world' data for the 'X framework' or 'linear combination model', and to find out its limits in a practical situation. Human performance was measured by the reaction time method. Results show that the single parameter of the linear combination of photopic and scotopic luminous efficiency functions can be determined analytically with little variation for a given mesopic background luminance level and a given visual target colour, but the computation leads to considerable deviations comparing all three target colours (red, green and blue) used in the experiment. The conclusion for the given experimental conditions is that the single parameter of the linear combination model has an increasing deviation for lower background luminance levels.     

New stand magnifiers do not meet rated levels of performance

A new range of stand magnifiers has been released by the COIL company in the United Kingdom. Examination of these magnifiers reveals that they fail to deliver the rated magnifications labelled prominently on the appliances, as a result of the manufacturer's conformance with the requirements of the German DIN standard and the use of back vertex power (F'_v) rather than equivalent dioptric power (F_m) of the magnifier. In this study we provide information on the optometric parameters of these new stand magnifiers that will assist the more accurate specification of improvements in vision expected from their use.     

体外受精-胚胎移植取消周期47例临床分析

目的 :探讨在体外受精 -胚胎移植周期中因卵巢反应不良而取消周期的病因及处理方法。方法 :对2 0 0 0年 1 1月至 2 0 0 1年 1 2月接受超促排卵周期因故而取消周期 47例进行分析 ,选择与取消周期者同日或最接近日进入周期接受超促排卵并完成移植周期的 75例作为对照组。结果 :在超促排卵周期中因卵巢反应不良而取消周期 34例 ,占 6 .9% ,反应不良组平均年龄及不孕年限均较对照组长 (P <0 .0 5) ,基础FSH >8IU/L和 /或E2 >50pg/ml反应不良组明显高于对照组 (P <0 .0 1 ) ,反应不良组Gn起始用量及每日用量均明显高于对照组 ,(P <0 .0 0 1 )。结论 :反应不良的原因为卵巢储备功能低下 ,体内存在Gn抗体 ,原因不明 ;加大Gn剂量、降低GnRH -a用量、合用生长激素为常用处理方法。     

Myelination of the corpus callosum in the cat: time course, topography, and functional implications

The parameters of myelin development were ascertained in two specific regions of the corpus callosum in a series of cats aged 12 postnatal days through adult. The posteriormost portion of the splenium and the anterior-most portion of the genu were examined in cross section by using the electron microscope. Measurements were made to determine the age at which myelin first appeared, the number and distribution of myelinated fibers, the number and distribution of myelin lamellae, and cross-sectional area of ensheathed axons during development. The results indicate that myelination begins and ends earlier in the anterior region of the callosum. Measurements of myelin lamellae indicate similarities between anterior and posterior regions of the callosum, although development occurs earlier in the genu than in the splenium. No evidence was found for a sequence in the size of axons acquiring myelin sheaths, except that extremely small fibers are the last to begin myelinating. Myelination of the splenium of the corpus callosum begins at the very end of the behavioral and physiological critical period for the corpus callosum's role in visual functional development (Elberger: Behav. Brain Res. 11:223-231, '84; Elberger and Smith: Exp. Brain Res. 57:213-223, '85). Since myelination of a pathway is used as an index of functional reliability, this indicates that the basis for the callosal role in developing visual functions is probably not based on its physiological input to visual cortex.