Tuesday, January 4, 2011

Haptics offer sensation of touch without touching

From The Philadelphia Inquirer:

Using a cane, a blind person can easily detect obstacles at ground level. But what about something at waist height or above, such as the caution tape surrounding a construction site?

"It's insidious," said Suzanne Erb, a blind resident of Center City. "By the time you've reached it with your cane, it's way too late."

Unless you happen to be wielding a one-of-a-kind electronically enhanced cane, the work of University of Pennsylvania engineering students who consulted with Erb. The cane is equipped with a device that projects a cone of ultrasonic waves in front of the user, allowing it to detect obstructions and then warn the person by making the cane vibrate.

It was just one of eight student projects on display last month in a fast-growing field called haptics: generally, technology that provides the user with the mysterious sensation of touching something without actually doing so.

At an open house in the lab of assistant professor Katherine J. Kuchenbecker, visitors kicked an imaginary soccer ball and felt a computer-generated twhack on their feet. They palpated an artificial prostate by remotely manipulating a robotic arm. When they wielded a wooden drumstick in midair, they felt (and heard) it tap, ethereally, against a "drum" that existed only in the brain of a computer several feet away.

If you think there's something video-gamish about all this, ding-ding-ding! - award yourself 100 bonus points. Video games have had simple haptic features for years - say, making a joystick vibrate when you drive a car off the road - and game-makers are expected to roll out far more sophisticated versions in the near future, with tiny internal motors that push back in some way to replicate the experience of feeling.

The really big market will be in smartphones, said Charlie Anderson, a senior research analyst for the investment firm Dougherty & Co. L.L.C. in Minneapolis.

Phones already vibrate, and certain models are programmed to do so in response to touching the screen. Anderson projected that California-based Immersion Corp. would sell 125 million such units by the end of 2010, up from 30 million in 2008. On the horizon are pressure-sensitive "piezo" electronics, he said. You'll be able to push a picture of a button on the screen, and feel a click in a very precise location.

"I think the everyday person is going to have a haptic experience, more than likely, in the next couple of years," the analyst said.

Kuchenbecker, the Penn professor, said the field had its beginnings in the mid-20th century as scientists looked for safe ways to handle nuclear material from a distance. One early device allowed a person to manipulate objects with a mechanical arm and "feel" them at the same time, with no computer involved. Interacting with the virtual world came decades later.

With the advent of smaller devices and computing power, researchers now have their eye on a new frontier: inside the human body. Kuchenbecker, for one, has modified robotic medical devices to give surgeons the illusion of feel as they cut through tissue. Doctors, including urologist David Lee at Penn Presbyterian Medical Center, tried it out on pigs last summer.

Kuchenbecker also has started discussions with the military. Recently, she went to Orlando to meet with U.S. troops who use robots to defuse roadside bombs, a process that currently relies solely on what the soldiers can see. They urged her to develop a device that would add the sense of feel, Kuchenbecker said, pushing back when they pick something up.

"You want the operators to feel as if they're inhabiting the robot's body," she said.

The eight student projects at the Penn open house were not quite on that level of sophistication; the young engineers had done the bulk of their work in little more than a month. Still, they got a good reception from visitors, including several dozen elementary students from the Downingtown Area School District's Lego robotics club.

Erb, the blind woman who advised the students on their cane, pronounced that project a success. The components that enabled the detection of obstacles cost about $40, and were housed in a small box attached to the cane.

"If I didn't have a [guide] dog, I'd use it," said Erb, the chair of Mayor Nutter's Commission on People With Disabilities. "It really does everything you'd want it to do."

While the cane relied on ultrasound to locate obstacles, the other projects used different technologies. Students rigged a camera to capture infrared beams emanating from the drumstick, for example, while the soccer-ball game had a magnetic sensor to determine when the kicker's foot swung through the location of the imaginary ball.

At that moment, a nearby computer delivered voltage to a device strapped onto the kicker's calf called a solenoid, causing it to tug on a bicycle cable that ran to the foot. The cable, in turn, activated a pivot on a little plastic disk, causing it to strike the person's instep, explained Jacob Levinson, who is working toward a master's in mechanical engineering.

Meanwhile, up on the computer screen, a cartoon of a soccer ball flew through the air in response. Gooooaalll!

Then there was the lower-tech, yet elegant, approach used in a golf-putting demo. The head of the putter was attached to four motorized cables. Whenever a player failed to hold the club straight, he or she felt a gentle corrective tug in the appropriate direction.

It may not save lives, but it did seem like the kind of thing a weekend duffer might purchase. One of the gadget's developers, graduate student Jordan Brindza, acknowledged his own golf game could use some help. He joked:

"We envision having one of these in every executive office in America."

Just imagine the gift card: Haptic Holidays!