Runners pounding the pavement are often tuned into two very different kinds of beats: the music from their earbuds and the thumps of their hearts.

Valencell keeps runners on top of both of them and more. The Raleigh startup has developed technology that tracks the wearer’s biometric performance. Blood flow, heart rate, even VO2 max – the maximum amount of oxygen the body can use during exercise – can be measured through an earbud that looks no different than conventional audio earbuds. Conceptually, it sounds easy. But until Valencell, no company has been able to pull off a wearable monitor that works on a moving body.

“It’s an incredibly hard thing to do,” said Valencell President Steven LeBoeuf. “The marketplace has not figured out how to measure vital signs in people when they live their everyday lives.”

Valencell is establishing a niche in fitness but the underlying technology, which the company calls PerformTek, comes from medicine. Wearable monitors tracking vital signs have been used in hospitals for decades. While these devices work on a stationary patient, efforts to develop the technology for applications outside of a hospital have failed. Throughout the 1990s several companies tried without success to develop monitors that would work on a moving person. Valencell started developing and testing its technology in 2007. The company has been awarded 10 patents for its technology so far; more than 30 additional patents are pending.

Valencell had trouble raising money in the company’s early days. LeBoeuf, who led the optoelectronic biosensor program at GE Global Research prior to founding Valencell, said his company had a prototype but investors wanted to see market traction. So LeBoeuf started talking to big companies for funding, which helped the company move the technology beyond a prototype. In 2011 Best Buy Capital, the venture arm of consumer electronics retailer Best Buy, led a $5.5 million series B round. LeBoeuf said that funding was used to scale the technology into product form.

Many wearable fitness monitors are already commercially available. According to research from Berg Insight, wearable smart devices are projected to reach 64 million units by 2017. Berg says that smart device shipments – smart glasses, watches and wearable fitness trackers – leaped from 3.1 million units to 8.3 million from 2011 to 2012, representing nearly 168 percent growth. These fitness trackers include devices featuring an electrode fastened to the body by chest straps. While those products can get accurate heart rate readings, heart rate is the only vital sign those devices measure, LeBoeuf said. Perhaps more important from a retail standpoint, most runners don’t like to wear the chest straps.

Valencell doesn’t sell directly to consumers. Instead, the company’s strategy is to find partners that can integrate PerformTek into their own products. The first licensing partner, announced in July, was irriver. The South Korean consumer electronics company incorporated PerformTek technology into a stereo headset now commercially available in Asia and Europe. Valencell announced its Scosche Industries as its second licensing partner last month. At the Consumer Electronics Show next month in Las Vegas, Scosche will launch a new armband integrated with Valencell’s technology.

“It made sense because they already had distribution and a product in that space,” LeBoeuf said. “We had the technology. It’s their armband with our technology.”

LeBoeuf won’t rule out raising additional funds but he said Valencell is still assessing its capital needs. The company already has revenue. For each device sold or shipped with the PerformTek technology, Valencell collects a royalty. The company is also paid other fees associated with the licensing agreements so Valencell brings in money even before a product launches.

For now, Valencell is chatting up more potential partners. Those discussions go beyond fitness. LeBoeuf said he’s also talking with with companies that support first responders and the military. He declined to disclose any of those companies, citing non-disclosure agreements. But he explained that the same technology that measures vital signs of a long distance runner could be used to monitor a firefighter, a paramedic or a soldier. Those measures could be sent to a secure network.

In a nod to PerformTek’s health care origins, Valencell also has an eye on bringing the technology into new medical monitoring applications. PerformTek was validated through clinical tests at Duke University in 2010, testing LeBoeuf said was done with future health care applications in mind. The Duke studies should be sufficient to show equivalence to existing medical monitoring technologies, the threshold for securing Food and Drug Administration clearance on the technology as a medical device. Someday elderly people could continuously wear Valencell’s technology to monitor their vital signs. But LeBoeuf concedes that such health care applications of the technology are still years away.

“The marketplace for consumer wearable vital signs and monitors on a long term basis is one that people have been hoping for quite some time and it still hasn’t happened,” LeBoeuf said. “But the market for fitness is here and now.”

So in the near term, Valencell is focusing on commercialization through sports and fitness partners. Companies that already make armband and headset products are interested in Valencell’s technology as a differentiator in the crowded fitness space. Iriver and Scosche are the only two publicly announced partners – so far.

“There are a number of announcement to be made for CES,” LeBoeuf said.