Low-Cost Open Source Ultrasound-Sensing Based Navigational Support for Visually Impaired

Abstract

Nineteen million Americans have significant vision loss. Over 70% of these are not employed full-time, and more than a quarter live below the poverty line. Globally, there are 36 million blind people, but less than half use white canes or more costly commercial sensory substitutions. The quality of life for visually impaired people is hampered by the resultant lack of independence. To help alleviate these challenges this study reports on the development of a low-cost (<$24), open-source navigational support system to allow people with the lost vision to navigate, orient themselves in their surroundings and avoid obstacles when moving. The system can be largely made with digitally distributed manufacturing using low-cost 3-D printing/milling. It conveys point-distance information by utilizing the natural active sensing approach and modulates measurements into haptic feedback with various vibration patterns within the distance range of 3 m. The developed system allows people with lost vision to solve the primary tasks of navigation, orientation, and obstacle detection (>20 cm stationary, moving up to 0.5 m/s) to ensure their safety and mobility. Sighted blindfolded participants successfully demonstrated the device for eight primary everyday navigation and guidance tasks including indoor and outdoor navigation and avoiding collisions with other pedestrians.

Low-Cost Assistive Technologies for Disabled People Using Open-Source Hardware and Software: A Systematic Literature Review

“…Concerning the walking assistants, the studies [16], [100], [102], [134], [135], [137], [143], [144], [161] report smart sticks or white canes for disabled people using sensors and computer vision techniques according to the convention pointed out in the review about walking assistants in reference [29]. It is important to notice that the authors interchange the terms smart stick or white cane in their works.…”

“…As conclusions of the study, the authors remarked that new additional trials and the incorporation of GPS are needed in the project. In [16] a low-cost ultrasound-sensing based device is presented with a cost less than USD 24. The device was tested with n=5 non-blind users.…”

“…While the studies in the SLR show that OSHW and OSS can contribute to the accessibility and reduce the barriers of cost and implementation of the ATs, that otherwise would require an expensive traditional process of design and fabrication, several challenges outlined in Fig. (16) were detected. Each one of these with some suggestions to overcome them are described below: 1) Improvement of the technical factors: In several studies in the SLR, in special, those related to computer vision, the researchers and developers have manifested the need to improve the latency and accuracy of object detection in the algorithms and libraries employed.…”

“…Besides, Table (15) describes the software, some of them open source, for several disabilities identified. For wearable and portable ATs, recommend to review the works [16],…”

“…These low-cost devices have enough performance to enable an enormous range of applications array of scientific and medical applications [14], [15]. For example, they can be used for everything from making low-cost ultrasound-based navigational aids for the visually impaired [16] to controlling manufacturing equipment like low-cost 3-D printers through the RepRap project (self Replicating Rapid proto-typers that literally fabricated their own components) [17]- [19]. OSHW developers contribute by building and freely distributing the files containing software source codes, which are readable by 3-D printers [20].…”