Automatic detection of sleep-disordered breathing from a single channel airflow record

¹ Dept of Pulmonology, Fukuoka National Hospital, Fukuoka, Japan
² Dept of Public Health Medicine, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, Japan

^* To whom correspondence should be addressed. E-mail: nakano_h{at}palette.plala.or.jp.

	Abstract

Single channel airflow monitors developed for screening for sleep-disordered breathing (SDB) have conflicting results for their accuracy. We hypothesized that the analytic algorithm is crucial for the performance and tried to develop a novel computer algorithm.

We employed 399 polysomnography records including a thermal sensor signal. The first 100 records were used in the development of the algorithm and the remainder for validation. In addition, 119 polysomnography records including a thermocouple signal and a nasal pressure signal were used for the validation. The algorithm was designed to obtain a time series (flow-power) using power spectral analysis that expresses fluctuation in the airflow signal amplitude. From the time series the algorithm detects transient falls of the flow-power and calculates flow-RDI defined as the number of the falls per hour.

In the validation group, the areas under receiver operating characteristic curves for diagnosis of SDB (apnea-hypopnea index 5) were 0.96, 0.95, and 0.95, for the records of the thermal sensor, thermocouple, and nasal pressure system, respectively. The diagnostic sensitivity/specificity of the flow-RDI were 96%/76%, 88%/80%, and 97%/77%, respectively.

These results suggest that a single channel airflow monitor can be used to detect SDB automatically if the analytic algorithm is optimized.

This article has been cited by other articles:

				H. Nakano, T. Tanigawa, Y. Ohnishi, H. Uemori, K. Senzaki, T. Furukawa, and S. Nishima Validation of a single-channel airflow monitor for screening of sleep-disordered breathing Eur. Respir. J., October 1, 2008; 32(4): 1060 - 1067. [Abstract] [Full Text] [PDF]