Cardiovascular Monitoring Using Earphones and a Mobile Device the Social Factor

F requent and noninvasive cardiovascular monitoring is important in surveillance for cardiovascular catastrophes and treatment therapies of chronic disease. Resting heart rate, one of the simplest cardiovascular parameters, is an independent risk factor for cardiovascular disease (comparable with smoking, high blood cholesterol, or hypertension).1 In particular, the association between accelerated resting heart rate and mortality has been observed in general populations, elderly subjects, and patients with hypertension, with coronary artery disease, or who have survived a heart attack. As such, long-term monitoring of resting heart rate has important prognostic implications and provides an index of efficiency of therapy. Furthermore, regularly assessing bilateral circulation could help detect or monitor the progression of carotid artery disease (CAD), which is associated with increased risk of heart attack, ischemic stroke, and death from vascular causes. In particular, carotid artery stenosis often has no symptoms and is unknown to both the patient and doctor until it disrupts blood flow to the brain.2 Therefore, the development of wearable biosensors suitable for comfortable and continuous cardiovascular assessment could change the future of medicine by producing exquisitely detailed individual physiological data.3 Despite significant advances in wearable technology in the past few years, wearable computers still struggle for social acceptance.4,5 To help address this issue, we developed Heartphones, a comfortable and socially acceptable system for measuring the bilateral blood volume pulse (BVP). The system fits inside ordinary earbuds to provide measurements such as heart rate and beat-to-beat changes in heart rate variability (HRV).