Using a Home Sleep Testing Devices to Verify the Smart Watch Sensor for Measuring Nocturnal Respiratory Rate

Abstract:
As sensors improve, smartwatch-based respiratory rate measurement becomes available. However, the accuracy of smartwatches in measuring nocturnal respiratory rate (NRR) remains controversial. This study aimed to evaluate the accuracy of smartwatches in NRR measurement based on a comparative analysis of home sleep testing (HST) devices. We recruited 35 participants who were preparing for home sleep apnea screening. They were all required to wear the S7 smartwatches and HST devices overnight. The S7 watch is equipped with a three-axis accelerometer for NRR estimation. We compared the S7 estimated NRR with reference NRR obtained from nasal airflow, abdominal motion, and chest motion signals. For all participants, the root mean square errors of the continuous NRR and overnight average NRR measurements were 1.48 and 0.40 bpm, respectively, and the small deviations were -0.22 and -0.23 bpm, respectively. This study demonstrates the ability of the S7 smartwatch to accurately estimate NRR at night.