JMIR Publications

ABSTRACT

Background:

Respiratory inductance plethysmography (RIP) belts are the standard for measuring thoracoabdominal movements in home sleep apnea test (HSAT), but are often cumbersome and power-intensive.

Objective:

This study aims to characterize the abdominal movement signals measured by a wireless, single-point, abdomen-worn sensor to evaluate its suitability for sleep apnea (SA) screening.

Methods:

Overnight recordings were obtained from 37 participants using a wireless abdomen-worn sensor and a thoracic RIP belt during HSAT. The abdominal movement signal was analyzed for breath detection, respiratory rate (RR) estimation, and waveform similarity relative to the RIP signal. The factor influencing the agreement between two signals was also investigated.

Results:

Data from 34 participants were analyzed. The abdominal movement signal showed moderate agreement with the thoracic RIP signal, achieving a sensitivity of 82.44%, a positive predictive value of 76.22%, and an F1-score of 78.99% for breath cycle detection. RR estimation yielded a mean absolute percentage error of 5.42% and limits of agreement of ± 3 bpm. Morphological similarity was moderate, with an average distance correlation of 0.73 and a mean square error of 0.64. The agreement between the two signals declined with increasing respiratory event severity.

Conclusions:

The abdominal movement signals recorded by the wireless abdomen-worn sensor demonstrated moderate accuracy for basic respiratory metrics. These results support the sensor’s potential as a promising candidate for preliminary AI-based SA screening.