Artikel
Navigation and Obstacle Avoidance with the Bionic Vision Australia Suprachoroidal Retinal Prosthesis
Suche in Medline nach
Autoren
Veröffentlicht: | 7. März 2016 |
---|
Gliederung
Text
Objective: We have recently completed a pilot trial to show device safety and efficacy for a novel 24-channel suprachoroidal device. This study investigated the performance of the device using a simple obstacle avoidance task.
Methods: Two participants with a prototype suprachoroidal retinal implant participated: a 53-year-old female (P1) and a 50-year-old male (P2). Both had pre-implant visual acuity of bare light perception from retinitis pigmentosa. The task was to walk a straight course (27m long x 2.6m wide) and avoid randomly located ground obstacles that varied in size (small, medium and large) and contrast (white, grey and black). The device setting (on vs. off) was randomised. Data collected included number of contacts with obstacles, total task time and number of hesitations. No mobility aid was used.
Results: P1 completed 78 trials of this task, and P2 completed 54 trials. With the device on, the percentage of objects that were contacted by the participant decreased significantly for P1 (on: 24% vs off: 38%, p=0.007), and trended towards significance for P2 (on: 40% vs off: 52%, p=0.06). Participants were significantly slower with the device on (P1= mean time 37 seconds (off) to 109s (on), and P2= mean 56s (off) to 150s (on); p<0.0001 for both). Participants were more likely to hesitate when approaching obstacles with the device on (P1= mean 6.3 hesitations (on) vs 0.5 (off) and P2= mean 6.7 (on) vs 0.4 (off); p<0.0001 for both).
Discussion: This study provides evidence that the prototype device can provide sufficient vision to improve obstacle avoidance on a standardized simple travel task. The additional visual input increased the number of hesitations and overall task time, but increased visual certainty resulting in fewer contacts with obstacles. Future work is needed to investigate the impact of rehabilitation training in prosthetic trials.