WITH ON-LINE SUPERVISION

Anita Jain, Rolf Weiß, Leonie Fricke, Mario Köhn, Marie-Luise Krohm, Andrea Steinhausen, Gerhard Mutz & Egon Stephan
Psychological Department, Cologne University
Herbert-Lewin-Straße 2, 50996 Köln, Germany

INTRODUCTION As beds in sleep laboratories are scarce and costly, other methods for high quality sleep recordings are needed. An alternative to time consuming and costly laboratory research is ambulatory monitoring, especially if an expert has online access to current data from any place.

METHODS A small, high quality 24 channel digital recorder (Koelner Vitaport System, device type 2) was developed in order to measure all variables relevant to normal and pathological sleep as well as additional physiological signals and environmental conditions (light, temperature). Our standard setting, that can be changed according to demands, consists of two channels of EOG, EMG, three EEGs, excursion of thorax and abdomen, airflow, O2-Saturation, ECG, puls wave, skin conductance, skin temperature, leg movement, body position, snoring sound and ambient light.

Digital data is stored on a 170 MB hard disk on the device and power is supplied by batteries, thus allowing for unrestricted movement of patients or subjects. The device can also be connected via a high speed modem and a normal telephone line by ISDN or the Internet with TCP/IP to the hospital, doctor's room or research laboratory. By this means, constant or occasional high resolution online supervision of signal quality and the patient's state is possible by an expert from any place.

In order to compare sleep under natural and laboratory conditions, polysomnographic recordings were carried out with this setting in 12 students on two consecutive nights in the laboratory and two nights at their homes.

RESULTS The measurement device was well tolerated by the subjects and high quality signals could be obtained under laboratory as well as under ambulatory conditions. Subjects could even remove recording equipment by themselves in the morning.

DISCUSSION The device offers cost effective means for high quality polysomnography in research as well as in the clinical field, because constant supervision during the night is not needed and no special room is required. The sleep of people, who would not visit a sleep laboratory, can be assessed. The possibility to connect the ambulatory device via the telephone line to the investigator ensures supervision when needed.