Article
Evaluation of reaching movement and mobility with a prosthetic vision simulator
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Published: | November 30, 2017 |
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Outline
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Objective: To evaluate reaching movement and mobility with a prosthetic vision simulator (PVS).
Methods: Study 1 aimed to evaluate reaching movement. 10 healthy subjects wore a PVS and performed a localization test with and without a gaze feedback system. In the localization test, a white square target (visual angle, 5°) was randomly displayed on a PC monitor (black background) and subjects were asked to touch the target. The distance between the touched position and center of the target was automatically calculated. We compared the average deviation with or without gaze feedback. Study 2 aimed to evaluate mobility. 12 healthy subjects wore a PVS and walked without stepping on white circles (obstacles) on a black carpet (6 m long × 2.2 m wide). In addition to the central residual visual field, 3 types of artificial visual fields which imitated phosphenes obtained by a single (5 × 5 electrodes; visual angle, 15°; upper visual field) or dual (two 5× 5 electrodes; visual angle, 30°; upper or lower visual field) electrode array were displayed on the head-mount display. We compared the number of times a subject stepped on the obstacles among the 3 types of visual fields.
Results: In study 1, the deviation was smaller with gaze feedback than without it. In study 2, the dual electrode array with a large upper visual field, resulted in better mobility than the single electrode array with a small upper visual field or dual electrode array with a large lower visual field.
Discussion: By PVS, we may identify the optimized conditions of retinal prosthesis system for reaching and mobility.