Research Database

Association Between Objectively-Measured Physical Activity and Sleep, NHANES 2005–2006

  • Added on December 1, 2011

Statement of Problem Epidemiological studies examining the association between physical activity and sleep have relied on self-report measures of physical activity and have primarily been conducted in older adults. Therefore, to address these gaps in the literature, the purpose of the present study was to examine the association between objectively-measured ...


Usefulness of a Tri-Axis Accelerometer for Sleep-Wake Scoring

  • Added on November 7, 2011

Introduction A tri-axis accelerometer has been extensively used in recent years. We report our recent evaluation of the usefulness of a three-axis accelerometer for sleep-wake scoring of healthy individuals and patients with sleep-disordered breathing (SDB). Methods Subjects Seven healthy university students 4 men, 3 women, mean age of 21.1±0.7 Seven SDB patients 6 men, 1 ...


Automatic Sleep/Wake Identification From Wrist Activity

  • Published on 06/01/1992

The following fundamental research was not performed explicitly using an ActiGraph device. However, the theories developed in this paper are used extensively in ActiGraph's ActiLife software. The purpose of this study was to develop and validate automatic scoring methods to distinguish sleep from wakefulness based on wrist activity. Forty-one subjects (18 ...


Activity Based Sleep-Wake Identification: An Empirical Test of Methodological Issues

  • Published on 01/01/1994

The following fundamental research was not performed explicitly using an ActiGraph device. However, the theories developed in this paper are used extensively in ActiGraph's ActiLife software. Abstract The effects of actigraph placement and device sensitivity on actigraphic automatic sleep-wake scoring were assessed using concomitant polysomnographic and wrist actigraphic data from ...


Monitoring Sleep-Wake Rhythm with Actigraphy in Patients on Continuous Positive Airway Pressure Therapy

  • Published on 12/08/2010

Background Continuous positive airway pressure (CPAP) therapy has been shown to be effective in alleviating the underlying obstruction as well as reducing patients’ excessive sleepiness and improving their functioning and health-related quality of life. However, residual excessive sleepiness is observed in some patients even though CPAP therapy eliminates sleep apnea ...


Sleep Behaviour of Old People in Hong Kong

  • Published on 1999

Complaints of poor sleep and changes in sleep-wake patterns are common among old people. An understanding of the common 24-hour sleep-wake patterns and sleep satisfaction among old people is essential for effective sleep management. To this end, an exploratory study was conducted to examine the phenomenon. A set of valid ...


Sleep Changes Predict The Onset Of Physical Changes Associated With Puberty

  • Published on 12/03/2009

A study in the Dec.1 issue of the journal Sleep suggests that changes in children’s sleep patterns that typically occur between the ages of 11 and 12 years are evident before the physical changes associated with the onset of puberty. Results show that over the two-year course of the study, sleep ...


Nutritional Status, Growth and Sleep Habits Among Senegalese Adolescent Girls

  • Published on 2004

Objective To study the relation between sleep habits, nutritional status, growth and maturation in a group of African adolescent girls. The main hypothesis to be tested was that sleep length could be an effective way to spare energy, and thus malnourished girls sleep longer than normal girls. Design Three repeated ...


Nocturnal Activity and Sleep Assessment

  • Added on November 4, 2010

Sleep occupies approximately one third of our lives yet its modem study has largely been restricted to the use of the polygraph and to self-report via sleep logs. Actigraphy is a method for obtaining objective behavioral samples of nocturnal as well as diurnal activity. Activity is continuously measured and recorded ...


Issues of Validity in Actigraphic Sleep Assessment

  • Published on 2004

Objectives The Standards of Practice Committee of the American Sleep Disorders Association has supported the use of actigraphy in the assessment of sleep disorders. Pollak et al disagree. The objective of this paper is to identify and critically evaluate several theoretic and methodological issues that are central to these divergent ...