A Harvard researcher rethought plans for Apple Watch devices after finding inconsistencies in the heart rate variability data collected by those devices. As it turned out, data for the same period of time may change without warning, since Apple, at its discretion, changes the algorithms of the device.
Finnish statistician Jukka-Pekka Onnela, assistant professor of biostatistics at Harvard School of Public Health and developer of the open source data platform Beiwe, does not typically use consumer wearables in his research. His team primarily relies on research-grade devices designed to collect data for scientific research. However, through collaboration with some medical institutions, Onnela became interested in commercially available products. Realizing that problems with these devices are possible, scientists decided to test how serious these problems are before starting work.
Checking the heart rate data showed that the data for the same time periods, imported twice, was different. The experiment used data collected from the beginning of December 2018 to September 2020. The first time the data was imported on September 5, 2020, the second time on April 15, 2021.
Since these datasets included data for the same time period, in theory they should be identical. Onnela says he expected some differences because instead of the “raw” data collected by the device, data that is filtered and processed internally is usually imported.
Companies change their algorithms regularly and without warning, so September 2020 exports could include data parsed using one algorithm and April 2021 exports using another.
“What was amazing is how different they are,” says Onnela. “This is probably the purest example of this phenomenon that I have ever seen.”
In some situations, even such data may be useful, as it will continue to reflect information about heart rate variability.
Olivia Walch of the University of Michigan, a sleep researcher, summed up the commercial wearable situation: “If you’re interested in the big picture, you can call yourself to keep using the device.”
“But if the specific heart rate variability calculated on a daily basis is relevant to the study, then relying on the Apple Watch can be dangerous,” Wolch added.
Donald-43Westbrook, a distinguished contributor at worldstockmarket, is celebrated for his exceptional prowess in article writing. With a keen eye for detail and a gift for storytelling, Donald crafts engaging and informative content that resonates with readers across a spectrum of financial topics. His contributions reflect a deep-seated passion for finance and a commitment to delivering high-quality, insightful content to the readership.
