High-tech walking stick for advanced navigation
250 million people worldwide are affected by a visual impairment. The aim is to make everyday life easier for these people with a high-tech long cane.
A technically upgraded long cane should guide visually impaired people to their destination more quickly and safely. That's what U.S. scientists report after testing the device extensively with blind and visually impaired people who had experience using a long cane. In the trials, visually impaired people walked 18 percent faster than with an ordinary long cane. For sighted people who were blindfolded, it was as much as 35 percent, the group led by Patrick Slade of Stanford University in California wrote in the journal Science Robotics.
"More than 250 million people worldwide have visual impairments and face challenges when moving outside their homes," the researchers write. "This affects their independence and their mental as well as physical health." To improve orientation, the researchers fitted the long cane for the blind with a camera, global positioning system (GPS) antenna and a laser system to detect the surroundings (LIDAR), among other features. They also attached a motor-driven wheel to the tip of the cane, which can turn in different directions through a combination of several rollers.
Acoustic signals, vibration and motive force
Slade and colleagues tested three concepts of user guidance that have been used on similar devices: In these, obstacles and avoidance routes are indicated either by acoustic signals, by vibration, or by a motion force. In the latter case, the user feels a force while walking that steers the cane in a certain direction. This mechanism is based on the information from the sensors being fed to a microcontroller, which then steers the motor-driven omni-directional wheel in a specific direction.
This principle of motion force worked best for feedback because, according to the researchers, users can grasp it intuitively. In addition, they receive supplementary acoustic information through a small pair of headphones. A program that continuously locates the long stick while recording the environment navigates the visually impaired people to their destination. The system also recognizes certain symbols such as a stop sign or the sign of a bus stop. Once such a sign is recognized as a destination, the program guides the user there. Less contact with obstacles - but too heavy
"The extended long cane reduced the number of times participants contacted the environment in all experiments," Slade's team writes. With an ordinary long cane, the visually impaired participants touched an average of 36 obstacles with their canes; with the new device, the average was about nine. But not all participants were faster with the electronic long cane. Also, many of the twelve visually impaired participants found the 1.2-kilogram device too heavy.
The researchers still want to improve their enhanced long stick. For example, an ultrasonic sensor could register changes in terrain slope and obstacles at head level, which they say has proven effective in other devices. Incidentally, their device is quite inexpensive at 400 U.S. dollars (about 346 euros) and is operated with open-source software, the scientists emphasize.
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More information: https://wewalk.io/en/