[Validating a 7-channel ambulatory polygraphy unit. 1: Operating instructions for the physician and patient].

Purpose: For some time, the ambulatory diagnosis of sleep-related breathing disorders has included the use of seven-channel recording units. One such unit is the POLY-MESAM (MAP, Martinsried, FRG). The first part of the present study prospectively investigated the handling of the system for physicians and patients, its technical reliability, reliability of the software used and the results in comparison to handscoring.

Methods: In all, 104 patients (95 males, 9 females) were studied for different severities of obstructive sleep-related breathing disorders. The first 51 patients were connected to the POLY-MESAM in the evening within the clinic. The patients then slept at home and returned the next day. Another 53 patients received only a short briefing in the clinic and connected themselves at home to the POLY-MESAM System. Each patient's status was monitored by means of a visual analogue scale. Automatic evaluation of the data was compared with the results of manual scoring.

Results: From the data recorded only 6% of the results were not usable. Patients acceptances of the system were very high (94.3%). On average each patient required 21 minutes for attaching and detaching the device. Scoring and instructing the patients required an average of 23 min. Regarding the apnea-hypopnea index (AHI), the correlation between automatic (AHI = 11.1) and manual (AHI = 11.3) evaluations was high. Analysis of snoring turned out to be insufficient.

Conclusions: The POLY-MESAM proved to be reliable and user-friendly. Our findings show that the system can be recommended for outpatient screening of sleep-related breathing disorders, with patients able to manage the system without help. Validation by using simultaneous polysomnography is the subject of part two of the study.