"IEEE Transactions on Biomedical Engineering." (2007) Vol. 52. no. 2. p. 225-233 

Bruce O'Hara and his co-author colleagues describe their first successful system for monitoring sleep and wake in mice in "Pattern recognition of sleep in rodents using piezoelectric signals generated by gross body movements." In their findings, the researchers noted that they still didn't know the basic functions of sleep, and finding the genes that influence sleep in mice (as the dominant model organism among mammals) is one of the most likely avenues to discover these functions and better understand both normal sleep and sleep disorders. For most physiological functions, humans and mice use the same genes. 

O'Hara emphasized one major obstacle to such studies in mice -- the difficulty of performing EEG analysis (the gold standard for sleep) on mice.  The article describes a more efficient way to monitor sleep and wake accurately using a piezoelectric surface attached to the floor of the mouse cage that functions as an extremely sensitive motion detector, which can be used to distinguish sleep versus wake. With its success, the piezoelectric system will provide a means to perform the desired genetic studies.  

Bruce O'Hara is an associate professor of biology in the College of Arts and Sciences at the University of Kentucky. He earned his doctorate degree from Johns Hopkins University in 1988. His articles have appeared in various publications and his research interest focuses on sleep and circadian rhythms.