What sensors are in a smart cane? Pt 1

Blind or visually impaired individuals have to rely on other senses and typically have heightened capability – especially for hearing and touch. Using a white cane provides feedback in both of these areas. World Health Organization (WHO) data says that there are more than 253 million visually impaired people worldwide. Many of these individuals rely on a white cane for safer mobility. However, to make walking even safer, several inventors have created the next step enhancement to the cane.

In 2011, a teenager from India invented a smart stick for blind individuals, which can provide an early warning of an obstacle. Using infrared (IR) sensors connected to a motor, when reflected IR rays are detected, the stick vibrates, signaling a warning about obstacles ahead. Although it was intended to attach to a conventional walking stick and won an innovation award, it is not obvious that this invention resulted in an actual product.

In contrast, the Ray Electronic Mobility Aid for the Blind is a commercially available product. The compact (4.72-in. long by 1.1-in wide and only ¾-in. thick) aid is a handheld device that weighs 2.1 oz designed to complement a traditional canes for the blind. It uses an ultrasonic sensor to recognize obstacles up to a distance of 9.35 feet (2.85 meters) away and alert the user through an audible or vibrating signal. In its Escape mode, the user can locate small gaps such as door entrances or passageways through a crowd of people with audible or tactile feedback.

Based on an idea generated in the MIT Media Lab with product launch in 2017, the torch-it Saarthi is a sonar-based assistive mobility device for obstacle detection that mounts on the user’s cane. With three ranges, the Saarthi boasts accurate (99.7%) obstacle detection indoors (within 2 ft.), outdoors (within 4 ft.) and in open areas (within 8 ft.).