Improved mobility performance with an artificial vision therapy system using a thermal sensor

Abstract

Objective. To evaluate the benefit of integrating thermal imaging into an artificial vision therapy system, the Argus II retinal prosthesis, in simplifying a complex scene and improving mobility performance in the presence of other persons. Approach. Four Argus II retinal implant users were evaluated on two tasks: to locate and approach target persons in a booth, and to navigate a hallway while avoiding people. They completed the tasks using both the original Argus II system (the ‘Argus II camera’) and a thermal-integrated Argus II system (the ‘thermal camera’). The safety and efficiency of their navigation were evaluated by their walking speed, navigation errors, and the number of collisions. Main results. Navigation performance was significantly superior when using the thermal camera compared to using the Argus II camera, including 75% smaller angle of deviation (p < 0.001), 48% smaller error of distance (p < 0.05), and 30% fewer collisions (p < 0.05). The thermal camera also brought the additional benefit of allowing the participants to perform the task in the dark as efficiently as in the light. More importantly, these benefits did not come at a cost of reduced walking speed. Significance. Using the thermal camera in the Argus II system, compared to a visible-light camera, could improve the wearers’ navigation performance by helping them better approach or avoid other persons. Adding the thermal camera to future artificial vision therapy systems may complement the visible-light camera and improve the users’ mobility safety and efficiency, enhancing their quality of life.