Sleep (system call)

About: Sleep (system call) is a research topic. Over the lifetime, 2633 publications have been published within this topic receiving 27806 citations. The topic is also known as: Sleep() & sleep().

Sleep forms memory for finger skills

Abstract: Practicing a motor skill triggers a process of memory consolidation that continues for hours after practice has ended, and becomes manifest in an improved skill at later testing. We used a sequential motor task (finger-to-thumb opposition task) to show that, in humans, the formation of motor skill memories essentially benefits from sleep. Independent of whether placed during daytime or nighttime, sleep after practice enhanced speed of sequence performance on average by 33.5% and reduced error rate by 30.1% as compared with corresponding intervals of wakefulness. The effect of sleep after learning proved to be stable when retesting was postponed for another night, to exclude effects of sleep loss and to assure that all subjects had sufficient sleep before retrieval testing. Also, the consolidating effect of sleep was specific for the motor sequence learned. It did not generalize to a similar sequence containing identical movement segments in a different order. Retention periods of wakefulness improved performance only moderately and only if placed during daytime. The observations demonstrate a critical role of sleep for storing and optimizing motor skills.

A Novel, Open Access Method to Assess Sleep Duration Using a Wrist-Worn Accelerometer.

Abstract: Wrist-worn accelerometers are increasingly being used for the assessment of physical activity in population studies, but little is known about their value for sleep assessment. We developed a novel method of assessing sleep duration using data from 4,094 Whitehall II Study (United Kingdom, 2012–2013) participants aged 60–83 who wore the accelerometer for 9 consecutive days, filled in a sleep log and reported sleep duration via questionnaire. Our sleep detection algorithm defined (nocturnal) sleep as a period of sustained inactivity, itself detected as the absence of change in arm angle greater than 5 degrees for 5 minutes or more, during a period recorded as sleep by the participant in their sleep log. The resulting estimate of sleep duration had a moderate (but similar to previous findings) agreement with questionnaire based measures for time in bed, defined as the difference between sleep onset and waking time (kappa = 0.32, 95%CI:0.29,0.34) and total sleep duration (kappa = 0.39, 0.36,0.42). This estimate was lower for time in bed for women, depressed participants, those reporting more insomnia symptoms, and on weekend days. No such group differences were found for total sleep duration. Our algorithm was validated against data from a polysomnography study on 28 persons which found a longer time window and lower angle threshold to have better sensitivity to wakefulness, while the reverse was true for sensitivity to sleep. The novelty of our method is the use of a generic algorithm that will allow comparison between studies rather than a “count” based, device specific method.

Sleep apnea treatment apparatus

Abstract: Improved methodology and apparatus for the clinical study and treatment of sleep apnea which incorporates one or more of the following features: (1) application of mono-level, alternating high and low level, or variable positive airway pressure generally within the airway of the patient with the mono-level, high and low level, or variable airway pressure generally being coordinated with and/or responsive to the spontaneous respiration of the patient, (2) usage of adjustably programmable pressure ramp circuitry capable of producing multiple pressure ramp cycles of predetermined duration and pattern whereby the ramp cycles may be customized to accommodate the specific needs of an individual sleep apnea patient so as to ease the patient's transition from wakefulness to sleep, (3) remote control or patient-sensed operation of the apparatus, (4) employment of safety circuitry, reset circuitry and minimum system leak assurance circuitry, controls and methods, and (5) utilization of clinical control circuitry whereby sleep disorder data may be compiled and appropriate therapy implemented during a one-night sleep study.

Power-conserving control system for turning-off the power and the clocking for data transactions upon certain system inactivity

Abstract: A control system, as for controlling automotive body functions, is powered by a limited capacity electrical power source and is structured and controlled in a manner to minimize consumption of electrical power. The control system conducts data transactions between a central control station and one or more remote controllers connected therewith, and the central control station includes a provision for electronic signal processing for controlling the data transactions with the remote controllers. A power FET is operatively connected to the power source and to a portion of the control system for selectively connecting or disconnecting power to that control system portion. The system employs a NMOS microprocessor. The portion of the control system from which power may be disconnected will typically include the processor. The level of system activity is monitored and a power-down, or "sleep" control signal is automatically provided if a predetermined condition of inactivity occurs. That power-down control signal is operatively applied to certain control circuitry for in turn causing the power switch to disconnect power when the power-down control results. Correspondingly, a timer, which preferably is continuously powered, times a "sleep" interval during which power is disconnected from the relevant control system portion and generates a power-up control signal at the end of some predetermined time. The control circuitry responds to this power-up control signal by causing the power switch to reapply power to the previously disconnected portions of the control system.