A miniature actigraph worn about the wrist (Mini Motionlogger, Ambulatory Checking, Inc. Ardsley, NY) was applied To judge sleep quality objectively, making it feasible to watch sleep beneath normal situation with minimal distortions. The actigraph measures wrist action using a piezoelectric aspect and interprets wrist actions into an electrical https://www.youtube.com/watch?v=PgNzdZr0_hg