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Wheelchairs

Wheelchairs Photo Credit: Clipart.com

Generally, the developed countries export new technology to poorer, developing ones. But when it comes to wheelchairs, it can work the other way around. This story looks at an organization that counts on some of the world's poorest countries to develop some of the most innovative new ideas.


Transcript

Wheelchairs for rough neighborhoods. I'm Bob Hirshon and this is Science Update.

When a motorcycle accident left Ralf Hotchkiss reliant on a wheelchair, he felt truly helpless. Not because of his injury, but because the chair the hospital gave him fell apart before he'd gone half a block. Ever since, Hotchkiss has worked toward making wheelchairs tougher, faster and cheaper. As an engineer at San Francisco State University, he started a program called Whirlwind Wheelchair International.

Hotchkiss:
We work with people who ride wheelchairs or need wheelchairs in developing countries who build their own. And we exchange technology with them.

Why developing countries? Well, first off because many people there literally crawl to get around, and desperately need chairs. But also because they come up with the best ideas.

Hotchkiss:
Necessity is the mother of invention, and there they have far greater need for good wheelchairs than we do. We have cars and paved sidewalks. They have neither.

The result is ingenious improvements to make wheelchairs that roll over rocks and along hillsides. And they're built from cheap hardware and spare bike parts. Through these efforts, Hotchkiss hopes to provide wheelchairs to the twenty million people in the world who need them.

For the American Association for the Advancement of Science, I'm Bob Hirshon.


Making Sense of the Research

American wheelchairs exported to developing nations are usually outdated models that break easily and are difficult to repair because replacement parts aren't available. To resolve this problem, some countries are constructing their own wheelchairs out of ordinary hardware and bicycle parts that are very inexpensive and locally available. They test the chairs over time to find and fix the weak points, and eliminate any unnecessary, costly features. This process of design and testing results in chairs that are more practical, both economically and structurally. The final products are strong enough to stand up to much greater mileage, over much rougher roads.

As you learned in this Science Update, engineers solve problems by applying scientific principles to practical ends. Also, in any design project, limitations imposed by time, money, and available materials must be considered. Designs that are best in one respect may be inferior in other ways; some features must be sacrificed to get others.

Now try to answer these questions:

  1. What is the strength of the design of wheelchairs in developing countries?
  2. What kinds of design constraints do all engineers need to take into account?
  3. Which design constraints do you think would be of greatest priority to engineers in developing countries? Which would be most important in your country?
  4. What unique strengths do engineers in developing countries bring to the design process?
  5. What challenge would developing technology in developed countries and sending it to other countries present?
  6. Listen to another Science Update entitled Jean Engineering. What similarities do you see between the two stories? What constraints or limitations existed in that situation? What was the priority for that engineer and community? Why?

For Educators

To better understand how engineering affects lives, visit A Sightseer’s Guide to Engineering from the National Society of Professional Engineers. The site, designed for grades 3-5, highlights various places around the United States that tell the story of engineering.


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