Sales of once novel wearable wireless healthcare devices are trending toward $6 billion in projected revenue by 2018, according to a forecast from ABI Research.

The London-based consultancy looked at sports, fitness, and wellness devices, as well as gear intended for home and remote patient monitoring.

“Fitness activity trackers are quickly gaining popularity in the market. Different from other more single-use or event-centric devices, activity trackers monitor multiple characteristics of the human body including movement, calories burned, body temperature, and sleep tracking,” says ABI senior analyst, Adarsh Krishnan.

Shipments of activity trackers are expected to grow at a rate of 40 percent year-over-year and overtake the 2013 shipment leader, heart rate monitors, in 2017.

ABI projects home monitoring devices, the second largest market, will also see strong growth over the next five years, with overall device revenue growing at year-over-year rate of more than 39 percent. Part of that growth will be driven by the development of what ABI calls “cross-over devices” such as personal emergency response devices with added activity tracker features.

ABI categorized the wearable remote patient monitoring devices and the professional healthcare markets as being unique due to relatively fewer suppliers and high device costs, such as electrocardiography and continuous glucose monitors. It says that blood pressure monitors and pulse oximeters remain the most popular devices in the patient monitoring and professional category.

“A perfect storm of innovation within low power wireless connectivity, sensor technology, big data, cloud services, voice user interfaces and mobile computing power is coming together and paves the way for connected wearable technology,” says Johan Svanberg, a senior analyst with the Swedish consultancy Berg Insight.

Berg recorded sales of smart glasses, smart watches and wearable fitness trackers at 8.3 million units worldwide in 2012, up from 3.1 million devices in the previous year and it expects total shipments of wearable technology devices to reach 64 million units in 2017. The market won’t get there without further advances and refinement, says Svanberg.

“Today’s devices need to evolve,” he says, “into something more than single purpose fitness trackers or external smartphone notification centers in order to be truly successful.”