A new multichannel system is presented which records and analyzes polysomnographic data. The reasonably priced hardware and software makes the diagnosis and therapy of sleep apnea syndrome possible even in smaller internal departments. By using this system, adjustments to the nCPAP therapy can be undertaken. A newly developed analog-digital converter and software functions record simultaneously up to 24 channels. It performs the functions of commercially available instruments for induction plethysmography. The system has a modular setup. It is also possible to record special parameters, such as transcranial Doppler signals. Without any difficulty, instruments already used in the sleep laboratory can be included into this multichannel system. For instance, the screening device for the sleep apnea syndrome MESAM IV can be easily integrated. With this combination, it is possible to adjust sleep apnea patients to the nCPAP therapy by using the MESAM IV device. The software also enables analysis of breathing parameters and algorithmic revision of channels. In this way, filters can be integrated and amplitude calculations can be conducted.