In addition to one’s physical health, heart rate variability is also being investigated as an indicator of mental health. But in addition to looking at the heart, some wearables, such as the Spire, also measure breathing patterns to help users calm down. One head-worn device, the Muse
, actually measures electrical signals from the brain and responds with personalized sessions on a mobile device to help relieve stress. Poor mental health is a major concern, as it is a risk factor for weight gain, heart disease, and other chronic physical conditions. Apple has even included a breathing app in the upcoming Apple Watch software update.