Breathing rate is critical for the user's respiratory health and is hard to track outside the clinical context, requiring specialized devices. Earables could provide a convenient solution to track the breathing rate anywhere by leveraging the user's breathing-related motion and sound captured through the earables' motion sensors and microphones. However, small non-breathing head movements or background noises during the assessment affect the estimation accuracy. While noise filtering improves accuracy, it can discard valid measurements. This paper presents a multimodal approach to tracking the user's breathing rate using a signal-processing-based algorithm on motion sensors and a lightweight machine-learning algorithm on acoustic sensors from the earables that balances the accuracy and data retention. A user study with 30 participants shows that the system can accurately calculate breathing rate (Mean Absolute Error < 2 breaths per minute) while retaining most breathing sessions (75\%) performed in real-world settings. This work provides an essential direction for remote breathing rate monitoring.
https://doi.org/10.1145/3544548.3581265
The ACM CHI Conference on Human Factors in Computing Systems (https://chi2023.acm.org/)