Influence of field of view in visual prostheses design: Analysis with a VR system

2020-09-18

Journal of Neural Engineering

AI Summary

This study investigates the impact of field-of-view (FOV) and angular resolution on object recognition and localization performance in visual prostheses. Using an open-source VR simulation platform, we model low-resolution, restricted-FOV vision via phosphene arrays and conduct object search-and-identification tasks within panoramic scenes. Results reveal, for the first time, that indiscriminately increasing FOV degrades both recognition accuracy and response latency; performance declines significantly when angular resolution falls below 2.3 phosphenes/degree; and enhancing local angular resolution yields greater gains than expanding FOV. We propose a novel design paradigm—“high angular resolution over wide FOV”—providing quantifiable, evidence-based guidance for retinal prosthesis optimization. Furthermore, we release an open-source, reproducible VR evaluation framework to support standardized benchmarking of visual prosthetic interfaces.

Technology Category

• Computer Vision: Low Level & Physics-based Vision
• Intelligent Robots: Multimodal Perception & Sensor Fusion
• Cognitive Modeling & Cognitive Systems: Simulating Human Behavior

Application Category

• Responsible Web: Machine-in-the-loop, human agency and autonomy
• User Modeling, Personalization and Recommendation: Fairness-aware retrieval and ranking
• Search and Retrieval-Augmented AI: Web evaluation methodologies and metrics

Abstract

Objective. Visual prostheses are designed to restore partial functional vision in patients with total vision loss. Retinal visual prostheses provide limited capabilities as a result of low resolution, limited field of view and poor dynamic range. Understanding the influence of these parameters in the perception results can guide prostheses research and design. Approach. In this work, we evaluate the influence of field of view with respect to spatial resolution in visual prostheses, measuring the accuracy and response time in a search and recognition task. Twenty-four normally sighted participants were asked to find and recognize usual objects, such as furniture and home appliance in indoor room scenes. For the experiment, we use a new simulated prosthetic vision system that allows simple and effective experimentation. Our system uses a virtual-reality environment based on panoramic scenes. The simulator employs a head-mounted display which allows users to feel immersed in the scene by perceiving the entire scene all around. Our experiments use public image datasets and a commercial head-mounted display. We have also released the virtual-reality software for replicating and extending the experimentation. Main results. Results show that the accuracy and response time decrease when the field of view is increased. Furthermore, performance appears to be correlated with the angular resolution, but showing a diminishing return even with a resolution of less than 2.3 phosphenes per degree. Significance. Our results seem to indicate that, for the design of retinal prostheses, it is better to concentrate the phosphenes in a small area, to maximize the angular resolution, even if that implies sacrificing field of view.

Problem

• visual aid devices
• visual recognition
• device optimization

Innovation

• Virtual Reality
• Visual Prosthesis Optimization
• Field of View and Clarity Impact