“Consumer health wearables—commercially available health tracking devices such as
smartwatches and other wearable sensors coupled to smartphones—have become
broadly adopted in the United States. A 2024 study found that 44.5% of Americans
reported using a wearable on a regular basis. These devices are designed to
passively and continuously collect physiological data, offering users a convenient,
data-driven, and readily available means of engaging with indicators of their health.
Biometrics tracked by consumer wearables with demonstrated links to health status
include heart rate, heart rate variability, blood oxygen saturation, electrodermal activity, blood pressure, and indices of sleep quantity and quality, among others.”