VitalEar: An Earable Heartbeat and Respiratory Rate Monitoring System Under Aerobic Exercises

Heart rate (HR) and respiratory rate (RR) are essential physiological indicators of people's physical function and exercise performance. Advancement in sensor technology has rendered earable devices with in-ear microphones feasible for vital sign monitoring. However, it is rather challenging to monitor heart rate and respiration simultaneously with a single earable device especially when a person is doing exercises. This is because intense physical activities can lead to significant noise interference which can easily obscure physiological signals. To address this challenge, this paper presents VitalEar, an exercise physiological monitoring system based on in-ear microphones, designed to estimate HR and RR while addressing complex motion interference and variability in users and activities. VitalEar employs Empirical Wavelet Transform (EWT) to decompose heartbeats into periodic and harmonic coefficients, enhancing noise reduction in the ECG spectrogram reconstruction model. Additionally, VitalEar incorporates a DCN-LSTM-based breathing curve reconstruction model to mitigate background noise and variability in user and activity. The experiments show that VitalEar achieves an average MAE of 5.61 BPM and 2.31 RPM, MAPE of 4.16% and 10.58% for HR and RR estimation, respectively. Compared to related work, our approach offers significant advantages in robustness against intense physical activities