They’re calling it “the world’s first smart heart wearable.” A big claim from the health-tech company Fourth Frontier for its Frontier X2 device, which takes the idea of ECG sensors found in smartwatches such as the Apple Watch and the Google Pixel Watch close to heart. Literally. The Frontier X2 gets strapped around the chest to sit close to the wearer’s ticker. Fourth Frontier says their wearable, targeted at the fitness market, can monitor the user’s breathing rate, heart rate, heart strain, heart rhythm, and the all-important heart rate variability (HRV) — the fluctuations that can indicate health problems.
In measuring heart rate, wrist-worn ECG devices can’t take continuous readings during physical activity because they typically require the wearer to use both hands to get a measurement. They also tend not to be that accurate when the wearer is moving. For example, research on the Apple Watch published in the Cardiology Journal found that the accuracy of the device’s ECG feature is comparable to that of a standard 12-lead ECG while the wearer is at rest or engaged in low to moderate activity. But the accuracy decreases as the level of physical activity increases. While Fourth Frontier is careful to note that the Frontier X2 is a health and fitness product — not intended for medical diagnosis or treatment — they say their device’s accuracy is comparable to that of the medical-grade GE Holter Monitor.
So what can the Frontier X2 do? Its makers say the device can accurately record a continuous ECG for up to 24 hours. Using what Fourth Frontier calls “AI generated Cardiac Rhythm markers,” the X2 can detect changes in the user’s heart rhythm. But the majority of its features focus on fitness; the device offers real-time personalized assistance during workouts, while AI-enabled algorithms offer post-training insights with recommendations and weekly goals. And the Frontier X2 can serve as a heart rate monitor when synched via Bluetooth to a host of other devices including Garmin watches, the Apple Watch, and Peloton exercise equipment.
So will there come a day when it’s common for people to walk around with wearables strapped to their chests? It may not be as far-fetched as it sounds. If you were sporting a heart-rate monitor on a chest strap in the early 80s, chances are you were a hardcore athlete engaged in the then-popular practice of “intensity training.” And your device might have raised some eyebrows. Today, nobody looks twice at someone with heart-monitoring tech on their wrist. As history has shown, trends that start with fitness enthusiasts can spread to the general market, and so a heart monitor positioned near the heart could very well become the norm.
