Stepping into the Future

Assistive robotics in and out of the lab

by Kathy Wechsler on September 1, 2006 - 3:41pm

QUEST Vol. 13, No. 5
MIT's leg exoskeleton
MIT’s leg exoskeleton enhances the strength of healthy individuals and may eventually allow many with disabilities to walk.

Who doesn’t want a Rosie, the household robot from “The Jetsons”? People with disabilities, especially those who have issues with strength, fine motor control or dexterity, would value a Rosie that could assist them with tasks of daily living to make them more independent.

Thus the field of assistive robotics was born. While many of these robotic devices, both in the United States and abroad, never make it out of the research phase, a number of assistive robotic products are available.

Robotics is the science or technology dealing with the design, construction and operation of robots, which are machines that can be programmed to perform certain tasks. Widely used in industry, robotics seems fertile ground for developing devices to assist people with disabilities.

“I think the possibilities these days are really endless because the ability to put together electronics and control systems has become a lot easier as both the hardware and the software available to designers have improved dramatically in the past 10 years,” said Allen Hoffman, a professor of mechanical engineering at Worcester Polytechnic Institute in Massachusetts. “The challenge here is to design devices that have enough of a market so that they can be commercialized and then made available to wide numbers of people.”

Arms of steel

One robotic device, developed in 2005 by three WPI students advised by Hoffman, who’s also the co-founder of the institute’s Assistive Technology Resource Center, was created to help young men with Duchenne muscular dystrophy (DMD) who still have hand function but whose arms are weak. The powered orthosis is a wearable brace designed to restore arm function, making it possible to complete everyday tasks such as brushing their teeth, combing their hair and feeding themselves.

The brace fits over the arm and extends from halfway between the elbow and shoulder to about wrist level. It’s run by a joystick, which controls two electric motors that operate through a set of gears to flex the elbow and rotate the arm.

Still a laboratory device being tested by teens with DMD, the powered orthosis won Hoffman and his team WPI’s first Kalenian Award for entrepreneurship. This competitive award includes $25,000 to further develop the brace into a commercialized product.

Hoffman’s goal is to have the brace finished by April. The team has applied for a provisional patent and hopes to market the device by early 2008.

WPI powered orthosis
WPI’s powered orthosis is run by a joystick to operate motors that flex the elbow and rotate the forearm. Photo by Patrick O’Connor

The Raptor Wheelchair Robot System from Phybotics, a division of Applied Resources in Fairfield, N.J., is already on the market. This robotic arm mounts behind the wheelchair so it doesn’t add any width, and was designed for people with limited function of their upper extremities, including the hands and fingers.

Controlled by a keypad or joystick, the Raptor is configured like a human arm with four joints and a gripper that acts like a hand. It can be programmed for many tasks to help the user live independently, including retrieving items from the floor and assisting in operating the computer. The rotating wrist on the robotic arm helps the user eat, drink and pour.

The Raptor costs $14,000; some users have received funding from private insurance, Vocational Rehabilitation and the Veterans Administration. A more sophisticated version will reach the market next year.

On your feet

Robotics engineers also are addressing the lower extremities. Several are exploring exoskeletons for both the arms and legs, said Hugh Herr, professor of media arts and sciences at Massachusetts Institute of Technology in Cambridge. Herr is director of the Biomechatronics Group, a research team within the MIT Media Laboratory.

Two years ago, Herr and the Biomechatronics Group, began work on a leg exoskeleton to augment the strength of healthy people by increasing their carrying capacity while not adding fatigue.

Phybotics technician Jamie Mendel
Phybotics technician Jamie Mendel tests the Raptor system before delivery to the customer.

The group is now modifying the leg exoskeleton to enable it to help a person who has poor ankle and knee control to use a walker. The user needs to have some control in the hips and torso.

The motor-driven exoskeleton covers the length of each leg and has artificial ankles, knees, hips and spine. It attaches to the waist, thighs and back and is configured so that when the user’s right leg moves forward, motors at the hips push the left leg back, helping to establish the rhythm of walking.

Similar to Herr’s leg exoskeleton is the Berkeley Lower-Extremity Exoskeleton, which is being developed at the Human Engineering & Robotics Lab at the University of California at Berkeley. Both exoskeletons transfer weight from the torso to the ground so that the weight isn’t on the user, Herr said.

The Hybrid Assistive Limb (HAL-5) is available in Japan for yearly rental. Developed by researchers at the University of Tsukuba in Japan, this “robot suit” helps the hip and knee generate torque or force to help a user with muscle loss walk, climb stairs, etc. The HAL-5 also gives a healthy human superhuman strength, the creators say.


Freedom Sciences
Automated transport and retrieval system
(215) 341-1754

Independence Technology
iBOT 4000
(866) 813-0761

Massachusetts Institute of Technology Biomechatronics Group
Leg exoskeleton; active ankle-foot orthosis

(973) 575-0650

University of California at Berkeley Robotics Laboratory
Berkeley lower-extremity exoskeleton

University of Tsukuba
hybrid assistive limb (HAL)

Worcester Polytechnic Institute Assistive Technology Resource Center
powered orthosis

(513) 731-2863

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