The Fitbit Flex is a Bluetooth 4.0- enabled activity tracker.

Bluetooth 4.0. or Bluetooth Smart, is emerging as the leading connectivity protocol for fitness devices, and the medical market is likely to follow soon, according to industry analysts in statements released by the Bluetooth SIG. Bluetooth SIG announced that since 2008 it has qualified 142 medical products and 56 fitness products.

In addition, IMS Research, now part of IHS Inc., projected that by 2016 more consumer medical devices would use Bluetooth Smart for wireless than any other technology, covering more than 50 percent of the wireless-enabled consumer medical device market with 5.7 million shipments. As for sports and fitness devices, ABI Research projects 120 million annual shipments in 2017, over 75 percent of the total market.

According to Bluetooth SIG chief marketing officer Suke Jawanda, the original Bluetooth BDR/EDR technology was optimized for sending continuous streams of data -- like audio. Bluetooth Smart sends data in very short bursts, so the radio only has to be on for about three milliseconds at a time. As a result, it has much lower power use. Classic Bluetooth technology was fairly widespread in medical and fitness devices, but the power requirements made it less practical for continuously worn tracking and monitoring devices.

"When we take a look at the innovation in the plumbing layer, now it makes more sense to why Bluetooth Smart is, frankly, the de facto standard in sports and fitness and its becoming the de facto standard in health and medical," Jawanda told MobiHealthNews. "Polar created a Bluetooth heart rate monitor. Under normal use cases, the coin cell battery that was powering that heart rate monitor would only last a few months. That same chest rate strap now, with Bluetooth Smart, is going to last a couple of years."

Bluetooth SIG highlighted smart inhaler Asthmapolis and back-end patient monitoring software Swissmed Mobile as examples of consumer medical devices leveraging the technology as well.

"Fitness has been fantastic for us," Jawanda told MobiHealthNews. "For Bluetooth Smart, that's the first vertical that's really popped where scale has begun to shift. I think medical is even a bigger opportunity and over the next two years could shift also." He said the uncertainty of FDA regulation is likely keeping medical developers away from Bluetooth, which has smartphone app integration as a major selling point.

Jawanda said that as well as the low power usage and near-instantaneous communication, the big advantage to companies using Bluetooth is its widespread penetration, which allows a range of peripheral devices to easily communicate with each other, as well as with consumer smartphones, tablets and laptops.