7月14日，一位视力残疾人（左一）在辅导员的指导下练习使用电子导盲仪上下楼。当日，北京市西城区残疾人活动中心举行2012年盲人定向行走培训课，培训视力残疾人借助电子导盲仪行走。据介绍，该电子导盲仪由中科院声学研究所研发，采用超声波回声定位原理，与盲杖搭配使用，可探测到10米范围内的障碍物，帮助视力残疾人安全出行。新华社记者 张宇 摄     July 14,，A eyesight disabled（Left a）In under the guidance of the practice using electronic guide instrument fluctuation building。On that day，The west city of Beijing, the disabled activity center held 2012 years the blind walk directional training course，Training with electronic vision disabled guide instrument to walk。According to introducing，The electronic guide instrument by the Chinese academy of sciences research institute of acoustics，The ultrasonic echo positioning principle，And blind rod collocation is used，Can detect to 10 m range of obstacles，Help vision disabled safety travel。The xinhua news agency zhangyu perturbation