Sensor technology has become smaller, lighter and more powerful. At the same time, more attention is being paid to preventive health and personal fitness as an answer to the nation’s rising medical bills.

A result, for sensor companies like BodyMedia, is an opportunity to marry body sensors to smartphones to create full-body monitors. Last week, BodyMedia announced that its armband sensors would be able to communicate with smartphones, wirelessly, using Bluetooth. Its health sensors will be one of the first devices, other than ear buds, that link to smartphones with Bluetooth short-range communications.

John Stivoric, chief technology officer, says the company has been working closely with Apple and Google, to develop its smartphone application. It opens the door to allowing a person to monitor a collection of the 9,000 variables — physical activity, calories burned, body heat, sleep efficiency and others — collected by the sensors in a BodyMedia armband in real-time, as the day goes on.

In the past, BodyMedia users had to consult personal data downloaded to a Web site or observe a few measurements on special watchband display, sold for $100.

The smartphone, though, is full-fledged computer in hand. “It’s a dashboard for the human body, a great viewer into what your body is doing on the fly,” said Mr. Stivoric, the last of the four founders with a day-to-day role at BodyMedia.

BodyMedia, based in Pittsburgh, has long been a cool yet ahead-of-its-time company. It was founded in 1999 by four researchers at Carnegie Mellon University. Three were affiliated with the Mobile and Wearable Computing Lab at the university, and the fourth was an artificial intelligence expert.

The start-up came out with body-monitoring products when the state of the art — in the consumer marketplace at least — wasn’t much more than pedometers. BodyMedia was a darling at health and technology conferences, held up as a glimpse of the future. But it struggled as a business, since its offerings seemed a bit too big and a bit too costly for the mainstream consumer.

But things may be changing for BodyMedia and similar companies, according to analysts.

The Bluetooth-enabled armband costs $249 and the BodyMedia data service costs $7 a month, when purchased in an annual subscription. The new offerings go on sale next month, at the company’s Web site, www.BodyMedia.com and at Amazon.

To date, BodyMedia has sold mostly to consumers in the United States, including as an offering through health clubs. In Europe, it has been used for clinical applications.

Potential new markets, analysts say, include diabetes management and corporate wellness programs, where a number of health service companies have sprung up, including RedBrick Health, Virgin HealthMiles and Tangerine Wellness.

“BodyMedia has been at it a long time, learned a lot and has accumulated a lot of intellectual property,” said Rob McCray, chief executive of the Wireless-Life Sciences Alliance, a trade organization for mobile health companies. “And this market is real now.”

Body sensor computing holds its original appeal for the computer scientist on the founding team. The body is a data source, to be collected and analyzed. “Artificial intelligence is about digging through big data sets to find meaning,” said Astro Teller, who later founded a hedge fund management company, which uses AI techniques, and recently joined Google.

In health care, that means using data to make “better personal and policy choices,” said Mr. Teller, who is chairman of BodyMedia.