Many years ago, IBM researcher James Levine watched an elderly uncle try to manipulate a mouse as he used a personal computer.
"He discovered that he had a hand tremor," Levine said. "He really couldn't control it at all. It was really sad to watch."
Levine, a staff member at the Thomas J. Watson Research Center in Yorktown Heights, N.Y., later attended an IBM workshop on making computers easier to use for senior citizens. There was a lot of software written for seniors who are visually impaired but no products for people who suffered from tremors or Parkinson's disease.
So Levine, a 43-year veteran of IBM, decided to develop an adapter for a standard computer mouse to help people with tremors use a PC.
Levine created a prototype of a mouse adapter in a year. The device, which looks a bit like a guitar effects box, is a small device with two on-and-off switches. It plugs in between the PC and the mouse, and it can easily be switched off when someone else wants to use the mouse.
The device, called the Assistive Mouse Adapter, can be adjusted for tremor severity and to filter out unintended multiple clicks on the mouse, caused by trembling fingers.
The adapter uses an algorithm to filter out high-frequency motion. Another algorithm helps people who have trouble double-clicking.
"It recognizes a sloppy double-click and sends a perfect one to the computer," Levine said.
There's a large number of potential customers for such a mouse. There are nearly 10 million people in the United States who have what is called Essential Tremor, the most common form of hand tremors, according to the International Essential Tremor Foundation, a nonprofit organization in Lenexa, Kan.
Essential Tremor is seen frequently among the elderly and can be inherited genetically at birth. It causes abnormal involuntary shaking and often affects hands, arms, the head and the voice box. Most people are able to live normal lives with the condition, but everyday activities such as eating, dressing or writing can be difficult.
"Over 60 percent of the people we know work on computers," said Catherine Rice, executive director of the Essential Tremor Foundation. "It is a constant complaint among our members that they can't find a mouse that they can maneuver easily."
While the average age of onset is about 45, Essential Tremor also can affect children. Rice said a mouse adapter such as Levine's invention also could be used by schoolchildren.
"We are very excited about this and hopeful that it is going to help our members," she said. Parkinson's disease also is associated with tremors and afflicts as many as 1 million Americans, according to the Parkinson's Disease Foundation.
IBM worked with researchers at the University of Colorado, who gave Levine's prototype adapter to 12 people with Essential Tremor. Levine said at the end of their testing "everyone wanted to buy one."
The company recently signed an agreement with Montrose Secam, a small British electronics company, which will begin making the adapter and selling it online for under $100. The company will pay IBM an undisclosed amount of royalties on any sales.
Montrose founder James Cosgrave has a personal interest in the mouse adapter. Cosgrave, who started his career as a bush pilot, has suffered from Essential Tremor since his youth.
Cosgrove, 67, first heard about the adapter in 2004. IBM provided him with a prototype, and he was so impressed with it that he signed an agreement to market the product.
"Using the Assistive Mouse Adapter makes it possible for me to use a PC normally," Cosgrave wrote in an e-mail. "Its use has been truly life-changing for me."