The white cane used by some visually impaired people now has a new high-tech variant that can help users navigate and increase their walking speed in the future. Old assistive technologies on the cane actually slowed the walking speed.
This updated version, the Augmented Cane, steers users in the right direction by moving the stick left and right based on data from the environment. The researchers, led by Patrick Slade of Stanford University, published the results this Wednesday in the magazine Science Robotics.
More than 250 million people worldwide have some form of visual impairment. The white cane and guide dog are now often used to help them navigate. Dogs guide people around obstacles and other persons, but their deployability is limited by their high training costs. The white cane helps the user to explore the environment by touching the surface the user is walking on and objects in the environment. In a familiar environment, the user can follow the line of a recognizable wall or lawn in order to find the way to, for example, home.
Both dogs and canes have their limitations. The user of the standard stick cannot perceive obstacles beyond the length of the stick, and neither the stick nor the dog can help navigate unfamiliar territory.
The researchers designed a variant of the white cane, a research prototype, which now allows this without slowing down the walking speed. Techniques already existed to help users navigate through an unfamiliar environment and to warn people of distant obstacles. GPS has already been used for navigation and laser technology, mounted on a stick or on the body, warns of nearby objects. Cameras were already able to recognize certain objects in traffic with the help of artificial intelligence. Only: those techniques significantly reduced the walking speed. It takes the user time to interpret the different types of data that come in via audio or vibration in the stick. The physical load is also often high. The walking speed of people with a cane and laser technology is on average 36 percent lower than that of people with a standard cane. This was shown in an earlier experiment conducted by other researchers in a lab with obstacles. The walking speed of people with a visual impairment is important, according to the researchers, because it influences mobility.
A motorized wheel steers the user in the right direction
The new prototype actually speeds up walking speed, compared to the standard cane, by not only communicating via audio and vibration, but mainly by literally directing the user. The walking stick collects data about the environment, including a camera, GPS and distance technology. A portable microcontroller in the stick receives the data and maps out a navigation plan. A motorized wheel at the end of the stick guides the user in the right direction. This way, the user does not have to interpret all kinds of different types of data first. The user can switch off the control and determine the walking speed himself. The stick weighs one kilogram.
The researchers had twelve blindfolded subjects navigate through corridors past obstacles. They compared their walking behavior when they used a standard cane with when they had the high-tech variant in their hands. With the new high-tech cane they walked on average 18 percent faster than test subjects with a traditional cane. Those with the high-tech stick also had significantly fewer collisions and navigation was more accurate. Users also walked more smoothly around obstacles with the high-tech stick. Technical improvements and more extensive experiments with a diverse group of people with impaired vision are still needed before the technology can be used for everyday use.