While tipping their hats to the scores of breakthroughs that have emerged from corporate labs, inventors also say they are concerned that bottom-line pressures at many companies may cause pure research to be eclipsed by innovation tied to rapid commercialization -- leading to routine refinements of existing products rather than to breathtaking advances.

A tug of war has emerged between individual inventors and corporations over proposed legislative changes in patent laws, with the inventors arguing that possible revisions would benefit the business giants. Corporations have argued that the system is equitable but flawed. Dean Kamen, an inventor whose creations include the wearable insulin pump and the Segway transporter, recently testified before Congress, calling for changes in the patent system that also preserve protections for individual inventors.

Despite those tussles, Mr. Stross says he believes that recent technological advancements have helped to move innovation out of the corporate sphere and to "give the lone inventor access to inexpensive tools and resources to once again be master of one's own lab."

Robert S. Langer, a research scientist at the Massachusetts Institute of Technology and a biotechnology pioneer, says that he shares the concerns raised in the National Academy of Sciences report but that he remains confident about the country's prospects. "While I think we can always do better, I am optimistic about the spirit of innovation in this country," he said. "I think we hold a lead, but no lead is unassailable."

For Mr. West, whose career has spanned stretches in creative havens like Bell Labs, inventing has meant brainstorming sessions with fellow tinkerers and long hours walking the corridors of his own mind. "I spend a great deal of the hours that I'm awake within myself," he said. "You never want to stop doing it, especially when it's a pleasure. It's vital to my existence and I couldn't live if I wasn't an inventor."

Ilene Busch-Vishniac, a Johns Hopkins professor and inventor who has collaborated with Mr. West for more than two decades, most recently on acoustical research, called him the quintessential explorer. "For an inventor to be successful they have to think outside of the box and propose things that are wildly different," she said. "Secondly, you need to be able to figure out how to do the tests that evaluate whether something is plausible. Jim is great at both of those things, but especially at figuring out the tests."

Mr. West began testing his limits at an early age, defying his family's wishes that he become a dentist and setting his sights on a doctorate in physics. To dissuade him, his father introduced him to other African-American friends with doctorates -- all of whom had failed to land university posts and held blue-collar jobs instead. Still, Mr. West pressed on, coached by a series of mentors, memorizing text and numbers to mask his reading problems, building on his mathematical gifts and eventually enrolling as an undergraduate in physics at Temple University.