AR headset is aimed at keeping visually-impaired users on a collision-free course
When someone is afflicted with retinitis pigmentosa, they have poor peripheral vision, plus they have difficulty identifying obstacles in low light. In recently-conducted tests, however, it has been shown that a depth perception-boosting headset could help them to avoid collisions – and to grasp objects.
Led by Prof. Anastasios N. Angelopoulos, a team at the University of Southern California started with an ordinary Microsoft Hololens 1 AR (augmented reality) headset, which came equipped with depth-sensing cameras. The scientists then developed custom SLAM (simultaneous location and mapping) software for the device, which caused it to overlay a colored wire-frame grid upon the wearer's view of their surroundings.
Depending on how far away an object is from the headset's cameras, the translucent grid that overlays that object appears in one of four colors.
In the "mobility" mode, for instance – which is intended to keep wearers from running into things – objects less than 3 feet away (0.9 m) are white, object 3 to 4 feet away (1.2 m) are green, objects 4 to 5 feet away (1.5 m) are blue, and objects 5 to 6 feet away (1.8 m) are red. In order to avoid information-overload, items farther away than 6 feet aren't colored.
And in the "grasp" mode – designed appropriately enough to help users grasp objects – items 0 to 6 inches away (15.2 cm) are white, they're green at 6 to 12 inches (30.5 cm), blue at 12 to 18 inches (45.7 cm), and red at 18 to 24 inches (61 cm).
The system was trialled on 10 retinitis pigmentosa patients who had received little training, as they made their way through an obstacle course based on a US Food and Drug Administration-validated functional test. Based on subsequent video analysis, it was found that the test subjects averaged 50 percent fewer collisions when wearing the headset.
The participants were also tasked with grasping a wooden peg that was placed against a black background and behind four other pegs, without touching those front pegs. In that case, use of the headset resulted in a 70-percent boost in performance.
Once developed further, it is hoped that the technology could be applied to a wide range of already-available high-tech eyewear.
"Through the use of AR, we aim to improve the quality of life for low-vision patients by increasing their confidence in performing basic tasks, ultimately allowing them to live more independent lives," says Angelopoulos.
The research, which was performed in the lab of Dr. Mark Humayun, is described in a paper that was recently published in the journal Scientific Reports.