A Sensing Framework for Indoor Spatial Awareness for Blind and Visually Impaired Users.

In this paper, we present Bluetooth low energy (BLE)-based sensing framework that provides real time spatial awareness for blind and visually impaired (BVI) users while navigating independently through large public venues. The proposed framework includes the following functionalities using only the received signal strength indicator obtained from the BLE sensors: 1) determining the location of the user, 2) estimating the user's moving direction, and 3) detecting the proximity of landmarks next to the user. We evaluate these functionalities individually. Moreover, we incorporate the proposed framework in PERCEPT indoor navigation system and test it with BVI users in a large public venue. Testing results show that the location, moving direction, and landmark proximity computed by the framework, although not very accurate, provide sufficient information to enable BVI users to independently navigate in large indoor venues. This conclusion aligns with Nobel Prize winning findings that confirm the spatial nature of the entorhinal-hippocampal system and the existence of a positioning system in the brain.