Screen-Free Haptic Breathwork with HRV-Adaptive Control, Pilot Outcomes and System Design

Vayu is a mobile breathwork system consisting of an iOS app and Apple Watch application that uses screen-free haptic cues and HRV-adaptive pacing to guide slow, resonant breathing. A pilot study lasting 4 to 6 weeks involved 199 adults aged 22 to 65 from Canada, the United States, and India who completed daily sessions of 5 to 10 minutes. Average adherence was 4.1 ± 2.3 sessions per week, with 71% of active users completing at least 3 sessions weekly. After four weeks, perceived stress decreased by 2.5 points, resting heart rate declined by 7.4 beats per minute, and HRV increased by a median of 28.6% compared to baseline. Mood improvements were also observed. No adverse events were reported during the study. The results suggest that the Vayu system is effective and well-tolerated with strong user engagement.