Luo Yvonne Hsu-Lin, Zhong Joe Jianjiang, da Cruz Lyndon
Biomedical Research Centre, National Institute of Health Research, Moorfields Eye Hospital NHS Foundation Trust, 162 City Road, London, EC1V 2PD, UK.
Institute of Ophthalmology, University College London, 11-43 Bath Street, London, EC1V 9EL, UK.
Graefes Arch Clin Exp Ophthalmol. 2015 Nov;253(11):1907-14. doi: 10.1007/s00417-014-2912-z. Epub 2014 Dec 31.
The Argus® II retinal prosthesis system has entered mainstream treatment for patients blind from Retinitis Pigmentosa (RP). We set out to evaluate the use of this system by blind subjects to achieve object localisation and prehension in 3-dimensional space.
This is a single-centre, prospective, internally-controlled case series involving 5 blind RP subjects who received the Argus® II implant. The subjects were instructed to visually locate, reach and grasp (i.e. prehension) a small white cuboid object placed at random locations on a black worktop. A flashing LED beacon was attached to the reaching index finger (as a finger marker) to assess the effect of enhanced finger visualisation on performance. Tasks were performed with the prosthesis switched "on" or "off" and with the finger marker switched "on" or "off". Forty-eight trials were performed per subject. Trajectory of each subject's hand movement during the task was recorded by a 3D motion-capture unit (Qualysis®, see supplementary video) and analysed using a MATLAB script.
Percentage of successful prehension±standard deviation was: 71.3 ± 27.1 % with prosthesis on and finger marker on; 77.5 ± 24.5 % with prosthesis on and finger marker off; 0.0 ± 0.0 % with prosthesis off and finger marker on, and 0.00 ± 0.00 % with prosthesis off and finger marker off. The finger marker did not have a significant effect on performance (P = 0.546 and 1, Wilcoxon Signed Rank test, with prosthesis on and off respectively). With prosthesis off, none of the subjects were able to visually locate the target object and no initiation of prehension was attempted. With prosthesis on, prehension was initiated on 82.5 % (range 59-100 %) of the trials with 89.0 % (range 66.7-100 %) achieving successful prehension.
Argus® II subjects were able to achieve object localisation and prehension better with their prosthesis switched on than off.
阿格斯®II视网膜假体系统已成为色素性视网膜炎（RP）致盲患者的主流治疗手段。我们旨在评估盲人受试者使用该系统在三维空间中实现物体定位和抓握的情况。
这是一项单中心、前瞻性、自身对照的病例系列研究，涉及5名接受阿格斯®II植入的RP盲人受试者。受试者需通过视觉定位、伸手并抓握（即抓持）一个随机放置在黑色工作台上的白色小长方体物体。一个闪烁的LED信标附着在伸手的食指上（作为手指标记），以评估增强手指可视化对操作表现的影响。任务在假体“开启”或“关闭”以及手指标记“开启”或“关闭”的情况下进行。每位受试者进行48次试验。任务过程中每位受试者手部运动的轨迹由三维运动捕捉单元（Qualysis®，见补充视频）记录，并使用MATLAB脚本进行分析。
成功抓握的百分比±标准差为：假体开启且手指标记开启时为71.3±27.1%；假体开启且手指标记关闭时为77.5±24.5%；假体关闭且手指标记开启时为0.0±0.0%，假体关闭且手指标记关闭时为0.00±0.00%。手指标记对操作表现没有显著影响（分别在假体开启和关闭时，Wilcoxon符号秩检验，P = 0.546和1）。假体关闭时，没有受试者能够通过视觉定位目标物体，也没有人尝试开始抓握。假体开启时，在82.5%（范围59 - 100%）的试验中开始抓握，其中89.0%（范围66.7 - 100%）实现了成功抓握。
与假体关闭相比，阿格斯®II受试者在假体开启时能够更好地实现物体定位和抓握。
