The activity and fitness tracking wearable devices market has been growing in recent years thanks to competition between innovative companies like Jawbone and Fitbit. Now the market is in the process of evolving as technology improves and manufactures with significantly more research and development capacity, namely Microsoft and Apple, have stepped in over the past nine months with their latest hardware, The Microsoft Band and the Apple Watch.
This led Rachel Metz of MIT's Technology Review to wonder if these sensors' "technology [is] really accurate enough to turn wearable devices into digital medical tools?"
In her research Metz interviewed cardiologist and genomics professor of the Scrips Research Institute Eric Topol, who said:
"We’re at an inflection point, or transition, from lifestyle health stuff to medical metrics."
Metz then conducted a review to see how close the Microsoft Band and Apple Watch came to providing accurate medical metrics that could be useful for providing more than just general activity levels, and maybe provide something that doctors and health professionals could rely on for the care. For this test she spent several days wearing the Apple Watch and the Microsoft Band during her normal bike commute to work. While biking with either device she also wore a Polar H7 Bluetooth chest strap, which is described as "one of the most accurate consumer devices for measuring heart rate."
While results varied, and as she says "sometimes they varied a lot," Metz found that the Band's average measurements were consistently closer to the chest strap's measurements than the Apple Watch. She notes that while the Band could be as many as 13 beats per minute off from the Polar device, the Apple Watch could be off by as much as 77 beats per minute. She also added that the Microsoft Band was sometimes within a beat or two per minute.
Overall her review showed that all of these devices still show inconsistencies that most likely prohibits the current generation of wearables from serving as professional grade medical monitors that give profoundly insightful and actionable metrics to everyone. Notably, some of the issues arise from taking measurements at the wrist themselves since everyone's wrist and body type is different, as well as that the measurements are being taken from across the skin.
But none of this is to say she didn't find a significant amount of hope for wearable devices providing more helpful health monitoring and that there is a great deal of innovative research continuing for new types of sensors and refining the current technology that is making its way into consumers' hands.
In the meantime, while research continues to improve for better sensors to provide more medical grade measurements, it appears that the Microsoft Band is the best option for accurate heart rate monitoring from an activity tracker by a fair degree.