Sleep studies in the subject's home

Because the ambient environment affects sleep duration and sequence, sleep in the subject's home may be more valid than in a laboratory. Telephone polysomnogram transmission (TPSM) and portable electromagnetic tape recordings offer recordings in the subject's bedroom. Ten subjects were recorded in the laboratory and at home by TPSM and portable recording. Overall sleep patterns were similar with all three techniques, but sleep and REM latency were much shorter and REM duration much longer, and time awake after sleep onset was longer with laboratory recordings. These data show that sleep patterns in the home differ from recordings in the laboratory. Portable recordings provide the additional benefit of monitoring daytime cycles. TPSM affords seven or eight channels for more precise recording and sleep staging.