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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 217 records · Page 12

Regularity of daily life in relation to personality, age, gender, sleep quality and circadian rhythms

A diary-like instrument to measure lifestyle regularity (the 'Social Rhythm Metric'-SRM) was given to 96 subjects (48 women, 48 men), 39 of whom repeated the study after at least one year, with additional objective measures of rest/activity. Lifestyle regularity as measured by the SRM related to age, morningness, subjective sleep quality and time-of-day variations in alertness, but not to gender, extroversion or neuroticism. Statistically significant test-retest correlations of about 0.4 emerged for SRM scores over the 12-30 month delay. Diary-based estimates of bedtime and waketime appeared fairly reliable. In a further study of healthy young men, 4 high SRM scorers ('regular') had a deeper nocturnal body temperature trough than 5 low SRM scorers ('irregular'), suggesting a better functioning circadian system in the 'regular' group.

NASA Discipline Regulatory Physiology↗

Time-on-task decrements in "steer clear" performance of patients with sleep apnea and narcolepsy

Loss of attention with time-on-task reflects the increasing instability of the waking state during performance in experimentally induced sleepiness. To determine whether patients with disorders of excessive sleepiness also displayed time-on-task decrements indicative of wake state instability, visual sustained attention performance on "Steer Clear," a computerized simple RT driving simulation task, was compared among 31 patients with untreated sleep apnea, 16 patients with narcolepsy, and 14 healthy control subjects. Vigilance decrement functions were generated by analyzing the number of collisions in each of six four-minute periods of Steer Clear task performance in a mixed-model analysis of variance and linear regression equations. As expected, patients had more Steer Clear collisions than control subjects (p=0.006). However, the inter-subject variability in errors among the narcoleptic patients was four-fold that of the apnea patients, and 100-fold that of the controls volunteers; the variance in errors among untreated apnea patients was 27-times that of controls. The results of transformed collision data revealed main effects for group (p=0.006), time-on-task (p=0.001), and a significant interaction (p=0.022). Control subjects showed no clear evidence of increasing collision errors with time-on-task (adjusted R2=0.22), while apnea patients showed a trend toward vigilance decrement (adjusted R2=0.42, p=0.097), and narcolepsy patients evidenced a robust linear vigilance decrement (adjusted R2=0.87, p=0.004). The association of disorders of excessive somnolence with escalating time-on-task decrements makes it imperative that when assessment of neurobehavioral performance is conducted in patients, it involves task durations and analyses that will evaluate the underlying vulnerability of potentially sleepy patients to decrements over time in tasks that require sustained attention and timely responses, both of which are key components in safe driving performance.

NASA Discipline Space Human Factors↗

Rotating shift work, sleep, and accidents related to sleepiness in hospital nurses

A hospital-based survey on shift work, sleep, and accidents was carried out among 635 Massachusetts nurses. In comparison to nurses who worked only day/evening shifts, rotators had more sleep/wake cycle disruption and nodded off more at work. Rotators had twice the odds of nodding off while driving to or from work and twice the odds of a reported accident or error related to sleepiness. Application of circadian principles to the design of hospital work schedules may result in improved health and safety for nurses and patients.

Non-NASA Center↗

Application of Bioengineering in Space Exploration - Sleep Study System

Bioengineering has spread roots far and wide among the needs of space exploration. The field creates many of paths to generate information from a variety of sources. One such source is the astronauts on the International Space Station (ISS). As of now the investigation is focused on the quality of sleep of crew members during a long duration flight. Our team is investing time into a piece of hardware’s comfort, waste, and operability. The hardware was not originally designed for space; therefore, the device must be modified to function at a optimal level in space. The design not made for space has generated some ailments, such as discomfort and decreased mobility. A function of the internship was to produce designs that would manage the wires to increase mobility and comfort. The wires excess slack was reduced by the part that was designed. The piece was adjustable, so the patient may adjust the system to their comfort and space compatible material was used. This product will help control the direction and length of the wires, thereby aiding in comforting the patient. This multifaceted design may be used in future for all other wire management for wearable biomedical sensor on orbit.

Biomedical↗

Inflight sleep analysis

Inflight electroencephalogram of Gemini 7 pilot to study sleep cycles and weightlessness effect on electrical activity of brain

Kellaway, P.↗

Electronic sleep analyzer

Electronic instrument automatically monitors the stages of sleep of a human subject. The analyzer provides a series of discrete voltage steps with each step corresponding to a clinical assessment of level of consciousness. It is based on the operation of an EEG and requires very little telemetry bandwidth or time.

Frost, J. D., Jr.↗