Sleep disorder is a major health problem. 10% of the population of the U.S. is affected by sleep apneas, and 1 billion people worldwide experience some kind of chronic nasal congestion during sleep. IMEC's wireless sleep staging system which is light weight, wearable and miniaturized can drastically increase the comfort of sleep disorders tests. The system consists of a head band with three sensor nodes measuring 2 EEG-channels (electroencephalogram) to monitor the brain activity, 2 EOG-channels (electro-oculogram) to monitor the eye activity and 1 EMG-channel (electromyogram) to monitor the chin muscle activity. These 5 signals provide the required information for sleep staging according to the Rechtschaffen and Kales standard. The sensor nodes integrate IMEC's proprietary ultra-low power biopotential read-out ASIC (application-specific integrated circuit) to amplify and filter the 5 different ExG signals. The measured ExG signals are wirelessly transmitted to the recording computer. No additional wires from the head to the body or from the head to the recording device are needed, making the system comfortable to wear. The system is optimized for low power resulting in 12 hours autonomy.