Quantitative effects of mattress types (comfortable vs. uncomfortable) on sleep quality through polysomnography and skin temperature

Information concerning the stages of sleep is one of the most important clues for determining the quality of a particular mattress. The purpose of this study was to determine the effects of mattress type on sleep quality by measuring skin temperature, by using a subjective mattress rating system, and through the use of Polysomnogram. Polysomnography involved the recording of brain waves through electroencephalography (EEG) and the generation of a video graphic record of eye movement (EOG), chin movements (EMG) and heart rhythm (ECG). Sixteen subjects were used in this study, which was a test of mattress comfort. Subjects spent 6 days and nights in the laboratory. Data was recorded for a period of 7 h for each of 3 nights. It was found that mean skin temperature, deep sleep (stage III and stage IV), sleep efficiency, wake after sleep onset (WASO), stage 1 and subjective ratings of mattress comfort were significantly affected according to mattress type. When subjects slept on "comfortable" mattresses, mean skin temperature was higher than for "uncomfortable" mattresses. Lower body skin temperature, sleep efficiency and percentage of deep sleep were higher as well. The percentages of WASO and stage 1 were lower when subjects slept on "comfortable" mattresses. Subjective ratings of sleep quality paralleled recorded sleep data.