Pitt and India join forces to build wheelchair

By Keith Gillogly

Some people have trouble getting around on sidewalks. Others cannot get around at all in areas… Some people have trouble getting around on sidewalks. Others cannot get around at all in areas without them.

This is the world of many people bound to manual wheelchairs, unable to afford electric ones — especially in parts of rural India. Researchers in New Delhi, India, have been working with a team from Pitt for the past nine years to develop a low-cost electric wheelchair. It will be able to run on uneven ground throughout urban and rural areas and will cost a fraction of what similar chairs do.

Rory Cooper, who directs Pitt’s Human Engineering Research Laboratories, said that the chair his lab has helped develop could help many people who can’t get around on their own.

“The chair has the potential to change millions of lives. Most people in low-income countries have difficulty obtaining a manual wheelchair, and having their own power chair is a dream simply out of their reach in many cases.”

Jon Pearlman, who oversees the wheelchair’s design, is a visiting assistant professor in the Department of Rehabilitation Science and Technology, and said that the mobile electric wheelchair should be in final testing stages in six months.

Mobile electric wheelchairs that can handle rougher terrain already exist, but they can cost thousands — a very high-end model could be as much as $25,000, Pearlman said. The Single Motor Propelled Wheelchair, or SIMPL wheelchair, that Pearlman’s developing aims to provide the functionality of a higher-end model at a lower price. Pearlman projected they could provide the wheelchair to customers in India for about $650.

Four years ago, the developers in New Delhi tested the chair’s maneuverability on indoor and outdoor courses.

Some electric wheelchairs handle well in tight, indoor spaces with smooth ground, but Pearlman’s is built for more rigorous terrain. During the test, the SIMPL wheelchair was piloted up ramps, across gravel, steered around a figure-8 track and taken down small drops.

The durability and performance of Pearlman’s chair tested well, especially compared to several other lower-cost electric wheelchairs deemed insufficiently durable.

“Most of the people in India that could benefit from a power chair are using manual chairs,” Pearlman said. “They have family or some assistant pushing them around the whole day. What I’ve generally found is you put them in my chair and they just take off. They spend the whole day doing what they want to do.”

One of the wheelchair’s key features is a fifth wheel located under the seat that’s connected to the motor used for propulsion. The extra wheel increases stability, traction and maneuverability. As Pearlman pushes down on various parts of the chair, its suspension bends and absorbs the stress like a spring.

A suspension system, designed to absorb impact on rougher ground, is typically found only on more expensive electric wheelchairs. The front wheels are 12 inches in diameter and designed to climb obstacles.

“Especially in rural, semi-urban and [areas] outside of the urban cities, the streets and roads [in India] are not smooth and don’t have flat surfaces. There are not curb cuts,” Nekram Upadhyay said in an e-mail. Upadhyay is the head of the Department of Assistive Technology at the Indian Spinal Injuries Center.

“Those who live in rural parts of India, most of the people with disabilities find difficulties commuting small distances, like school, college and their work,” he said.

Developing the chair

Since 2004, Pearlman and other researchers at Pitt have worked with doctors at the Indian Spinal Injury Center in New Dehli to develop the chair. Two years before, the National Institutes on Disability and Rehabilitation Research contacted Pitt to begin planning the project. The University and the injury center then started collaborating to improve wheelchair quality.

The motor and control system are the most expensive parts of an electric wheelchair, Pearlman said. So he implemented a just-as-effective scooter controller on his chair instead, which only costs around $50.

Another way he cut costs was to reduce the chair to a single motor. Most chairs have two motors, one for each wheel.

The wheelchair is designed to accommodate all types of physically disabled individuals who cannot walk or have trouble walking, including those who are paralyzed or suffered a stroke. Polio victims in India are also potential users.

Standard control and steering comes from a handlebar with a twist throttle, but users can employ other steering methods. Paralyzed individuals with limited upper body function could use a sip-and-puff system that relies on the inhaling and exhaling on a sensor to control the wheelchair, Pearlman said.

Pearlman said in around six months, he’d like to do a longer-term test where a prototype chair is taken home for a couple weeks and field tested by potential users.

The wheelchair received a patent in February, but researchers are waiting for approval for a grant from the National Institutes of Health to begin commercialization. If approved, funding from the grant could begin within the next month.

“There is a global market for this wheelchair, and all countries are looking to provide high quality health care at reasonable costs,” Cooper said in an e-mail. “It was always intended to be useful in the United States, India and globally.”