By 2030, 71 million Americans will be over age 65, according to the U.S. Census. Currently, 30 percent of elderly Americans who are not in assisted living live alone, and 90 percent say they want to grow old in their homes, according to AARP. Home health care, much of it for the elderly, is one of the fastest-growing segments in the country's fastest-growing industry.

The Inspiration: In 1993, Charles Hillman, an engineering consultant, was living on a farm in Wisconsin. His great-aunt Clara, then in her late 80s, occupied a cottage 100 yards from the main house. One day, Aunt Clara called to complain she was cold. Arriving at the cottage, Hillman found all the windows flung wide; his aunt said she had opened them because the room was smoky. "I went down into the crawlspace and saw her furnace was on fire," recalls Hillman. After extinguishing the blaze, Hillman asked his aunt why she hadn't mentioned the erratic temperatures and strange noises that had been emanating from beneath the house for days. Says Hillman: "She gave the answer that boomers caring for aging parents hear all the time: 'I know you're busy and didn't want to bother you.' "

The Business: GrandCare Systems, based in West Bend, Wisconsin, makes technology that helps seniors live independently. Sensors installed around the home monitor motion (tracking, for example, if the resident appears to be wandering or fails to rise from a chair or bed and how often doors open and close); check room temperature; and allow remote reporting of blood pressure, pulse, weight, and other health indicators. A communications base, accessed through an ordinary television, delivers content that includes weather and spiritual offerings and enables communication with family, friends, and caregivers.

How It Got Started: After rescuing Aunt Clara, Hillman had to wait for the technology to catch up to his idea for a system to help seniors and their caregivers avoid similar situations. He bided his time by studying the market. He joined the boards of a local long-term-care organization and the American Association of Homes and Services for the Aging. "As we would discuss finances and state reimbursement, it was pretty clear that institutional long-term care was not a sustainable model," says Hillman. "Also, the view of nursing homes has really changed. People fear them more than death."

As he prepared to launch the business in 2004, Hillman joined a consortium of companies developing technology for the aged. The consortium's large corporate members -- including Intel and Philips -- were generous with their survey data. That research helped Hillman determine how to price his offerings, market simultaneously to seniors and their personal and professional caregivers, and design products that wouldn't simply be unplugged or ignored. "People are used to getting information from their television and their telephone, so that's where we started," says Hillman, who purchased sensors and other hardware components from GE and hired programmers to develop software linking it all together.

The company launched in 2005 and spent several years testing the system in the independent-living units of long-term-care facilities. Those facilities may become his customers as well, Hillman says.

The Result: GrandCare released its new core system, HomeBase, last summer, and had sold several hundred units by mid-August, after the product was featured on CBS's The Early Show. The company, which expects to become profitable this year, has seven employees -- chiefly programmers -- and markets through a network of almost 200 independent dealers. It has sold systems in every U.S. state, the United Kingdom, Canada, and Australia.