Imagine if the activities you enjoy and perhaps take for granted—such as cooking a meal and eating it with your family, or exploring the outdoors—became difficult or even impossible because you had a physical or cognitive disability.
Two IEEE members are working on assistive robotics to let people with disabilities maintain a sense of independence while accomplishing everyday tasks they no longer can do on their own.
HELP AT HOME
Senior Member Siddhartha Srinivasa is founder of the Personal Robotics Lab at Carnegie Mellon University, in Pittsburgh. He’s leaving CMU this month to join the University of Washington, Seattle, where he will continue to build devices to help people with mobility issues because of spinal cord injuries or aging.
When caregivers aren’t available to help someone with limited mobility 24 hours a day, technology can step in. But Srinivasa doesn’t want his robots only doing things for people; he wants them to work with humans, he says, to achieve a goal, like preparing a meal.
He and other researchers at CMU started working on HERB (home-exploring research butler) more than a decade ago. The two-armed, three-wheeled robot stands about 2 meters high and helps people with paralysis perform simple tasks around the home. It can, for example, unload a dishwasher or prepare simple meals.
With an object-detecting Kinect camera for a head, HERB relies on image-analysis software to find things, such as a piece of fruit or a microwaveable meal. It then grasps the object (each of its hands has three multijointed fingers). RGBD sensors process red, green, and blue color information as well as depth—so HERB can figure out the distance to an object.
In the process, the robot can determine the optimal way to move its limbs without accidentally bumping into something. For now, HERB is used only for research; it won’t be in homes anytime soon.
Another of Srinivasa’s projects is the Assistive Dexterous Arm (ADA—an acronym chosen to honor computing pioneer Ada Lovelace). The portable, flexible arm, with two mechanical fingers, weighs less than 10 kilograms. Clipped to a wheelchair or table, it can help feed people unable to grasp utensils on their own.
Srinivasa says the ADA is learning several more things: how to ladle hot soup, for example, twirl spaghetti on a fork, and cut meat. And timing is important, he notes: The ADA needs to read social cues to determine when to dole out the next bite of food. A person eating with a friend doesn’t necessarily take a bite right after swallowing the last one. The next bite might come only after she has stopped speaking, or when her companion briefly looks away. The team is still working on algorithms to determine the right time to serve up the next spoonful or forkful of food.
Living independently at home is great, but people with disabilities don’t necessarily want to be inside all day. IEEE Fellow Rory Cooper has been working for decades on designing autonomous wheelchairs and attachments to help people explore the world in ways previously thought impossible.
Cooper is director of the Human Engineering Research Laboratories (HERL), a joint effort of the University of Pittsburgh and the U.S. Department of Veterans Affairs. Thirty percent of the faculty and student researchers at HERL have a disability. In 1980 while serving as a U.S. Army sergeant in Worms, Germany, he sustained a spinal-cord injury in a bicycle accident that left him partially paralyzed.
He and other HERL researchers recently developed the Mobility Enhancement Robotic Wheelchair (MEBot), which can handle rugged terrain yet is narrow enough to cruise through doorways and down hallways. The researchers were challenged to build the chair by the U.S. Marine Corps Wounded Warrior Regiment.
The MEBot has six wheels—two large drive wheels (about 35 centimeters in diameter) in the middle and four caster wheels: two in front and two in back. When the wheelchair senses a curb, the front casters lift onto it, followed by the drive wheels. It’s a smooth climb that doesn’t jostle the passenger. When the wheelchair goes up a ramp, sensors detect the incline and adjust the seat to keep it level. The chair can navigate slippery surfaces, where traditional power wheelchairs sometimes get stuck or spin their wheels. The ultimate goal is for the MEBot to climb a flight of stairs, Cooper says.
Cooper also invented the PARA (patient assist robotic arm), and he is working with RE2 Robotics, a Pittsburgh startup, to bring it to market. The PARA attaches to the edge of a standard power wheelchair’s seat and can help people transfer from the chair to a car, toilet, or couch. People who use wheelchairs can have trouble transferring out of them unless the destination is near the same height and only a few centimeters away.
The PARA can lift a person who weighs up to 113 kilograms and handle the transfer over greater distances.Hooks on the arm attach to a sling, which supports the person being lifted. The team recently was awarded a US $75,000 grant from the U.S. National Institutes of Health to develop a commercial prototype, which is still a few years away from completion.
“We are working to give people with severe disabilities from spinal cord injuries or ALS [amyotrophic lateral sclerosis] a level of mobility that is simply unprecedented,” Cooper says.
This article is part of our June 2017 special issue on assistive tech.