Researchers Use Electrodes for “Human Cruise Control”

Sure, you can get directions by looking at a map on your phone or listening to turn-by-turn navigation. But what if you could just walk from point A to point B in a new place without having to look at a device or even think about whether you’re on the right course?

A group of researchers from three German universities is working on just that. In a study, they electrically stimulated a leg muscle to nudge subjects to turn left or right along twisty routes in a park. The work, which researchers refer to as “human cruise control,” will be presented next week in a paper at the CHI 2015 human-computer interaction conference in Seoul, South Korea.

Max Pfeiffer, a coauthor of the paper and graduate student at the University of Hannover, says the idea is to eliminate the distraction of having to constantly pay attention to your phone while finding your way. If the researchers can figure out how to make the technology reliable enough and get people comfortable using it, it could also be helpful for exercise workouts or guiding emergency responders in situations where they can’t see well.

The researchers placed electrodes on participants’ sartorius muscles, which run diagonally across the thighs. These connected to a commercially available electrical muscle stimulation device and a Bluetooth-equipped control board that were worn at the waist.

First, researchers blindfolded participants and used the system to navigate them indoors to learn about controlling walking with electrical muscle stimulation. A couple of participants didn’t feel anything when their muscles were actuated by researchers, but researchers were able to control 11 participants well enough to steer them.

After that, the experiment went outside. The researchers made four participants turn along park trails and across lawns by using a smartphone app to send electrical current to the subjects’ right or left legs. A video from the researchers shows what this kind of electric zap looks like: a subtle twitching that turns the leg outward, only strong enough to affect you if you’re walking (if you’re standing still, it wouldn’t be enough of a jolt to turn your leg, researchers say). The feeling, Pfeiffer says, is like a tingle that lessens over time.

Now the researchers are working on improving the precision of their system and automating it so subjects can follow a route without a human directing them.

One problem with the idea is that people would need a great reason to wear electrodes, which for the study were bulky and noticeable, especially when combined with the electrical muscle stimulation control unit. Simpler technologies for less disruptive navigation are already emerging. The Apple Watch, for instance, gives you the sensation of a tap on the wrist when you need to make a left or right turn.

“I don’t see myself putting these electrodes on in the morning,” says Juan David Hincapié-Ramos, a postdoctoral researcher at the University of Manitoba’s human-computer interaction lab. He worked on a somewhat similar project in 2013 that used a depth-sensing camera to give smartphone users on-screen alerts about upcoming obstacles (see “Safe Texting While Walking? Soon, There May be an App for That”).

In the paper, researchers suggest one solution that may make wearing electrodes less of a chore: add them to underwear.