Design and implementation of a modularized polysomnography system

In recent years, an increasing number of people suffer from sleep disorders. Polysomnography (PSG) is commonly used in hospitals or sleep centers to diagnose sleep disorders because it continuously and simultaneously records multiple physiological signals during sleep. However, the excessive number of wired connections for conventional PSG is often a problem that leads to sleep disturbance. Due to the high cost and bulky body, traditional PSG systems are not suitable for sleep recording at home. This paper proposes the design and implementation of a modularized and distributed PSG system that is more convenient and has potential for recording at home. It is composed of multiple, tiny, low-cost, and wireless-synchronized signal acquisition nodes, and each node acquires specific physiological signals within a small body region to reduce sleep disturbance as a result of recording wires. To evaluate accuracy, the system and a commercial PSG system were mounted on subjects to simultaneously perform overnight recording, and the recorded data were compared. A two-phase sleep experiment was also performed to compare the comfortableness of these two systems. The results show that, in addition to high consistency (> 93%) with the reference system, due to the reduction of the disturbance from recording wires, the proposed system has better comfortableness performance in terms of several objective and subjective sleep indices.