[A simple procedure for quantitative and time coded detection of snoring sounds in apnea and snoring patients].

Abstract

A simple technique for time-encoded recording of snoring sounds is presented. An electronic circuit connected to a stereo cassette recorder via cord remote control will start the recorder when the sound pressure of the snoring sound surpasses a preset level. The snoring sound is recorded on one track of the cassette recorder. The other track is used for the time code. Every 120 seconds the tape recorder is switched on by the electronic circuit and a short high level signal is recorded. The time interval between two time coding signals equals the snoring time. Analysis of the time coding signals is performed by an A/D converter installed in a Personal Computer. The converter amd accompanying software are used to calculate the duration of the intervals between the coding signals. The results are displayed graphically where sleeping time is plotted against snoring time (Fig.2). The length of each bar equals the snoring time in seconds for each 120 second interval. Snoring periods can be recognised at a glance and the snoring pattern can be evaluated. Three cases studies are presented demonstrating the performance of the technique. A 39-year-old female with nonpathological snoring (Fig.2), a 45-year-old male with heavy and regular snoring (Fig. 3) and a 36-year-old male with a full-blown Pickwickian Syndrome (Fig. 4). This patient's response to nasal cPAP is demonstrated in Fig. 5.