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Djordje Popovic
University of Southern California
29Publications
9H-index
714Citations
Publications 22
Newest
Objective: To demonstrate the utility of rheoencephalography (REG) for measuring cerebral blood flow and fluid dynamics during different stages of sleep. Methods: Anteroposterior cranial electrical impedance was measured with concurrent polysomnography in a group of healthy subjects during sleep. Transcranial electrical impedance was characterized by measuring the peak-to-trough and envelope of the filtered pulsative REG signal as well as its frequency. The sensitivity of the REG amplitude to ch...
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#1Djordje PopovicH-Index: 9
#2Maja StikicH-Index: 6
Last.Thomas Schnell (UI: University of Iowa)H-Index: 16
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Mental workload is difficult to quantify because it results from an interplay of the objective task load, ambient and internal distractions, capacity of mental resources, and strategy of their utilization. Furthermore, different types of mental resources are mobilized to a different degree in different tasks even if their perceived difficulty is the same. Thus, an ideal mental workload measure needs to quantify the degree of utilization of different mental resources in addition to providing a si...
2 CitationsSource
word count: 250 Total word count: 5604 Institution where the work was performed: Advanced Brain Monitoring, Inc. and Complete Sleep Solutions, Murrieta, CA. Disclosures related to this work: The study was funded by Advanced Brain Monitoring, Inc. All authors are salaried employees of Advanced Brain Monitoring, Inc., the sponsor of this research. As co-inventors of the neck-device, Levendowski, Popovic and Westbrook would only benefit financially if the Night Shift intellectual property was acqui...
30 CitationsSource
#2Djordje Popovic (SC: University of Southern California)H-Index: 9
Last.Gene DavisH-Index: 6
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Sleep deprivation and inefficiency can have a crucial impact on performance. One potential method for ameliorating the impact of bad sleep, or eliminating it all-together, is with sleep stage-dependent sensory stimulation. The effect of superficial facial heating on sleep architecture was studied in 10 subjects. A 20% decrease in sleep onset latency (p < 0.05) was measured when the face was heated by 1oC. These results are support for further development of the patented Somneo, a ubiquitous feed...
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#1Djordje Popovic (SC: University of Southern California)H-Index: 9
#2Michael C. K. Khoo (SC: University of Southern California)H-Index: 25
Last.Philip R. WestbrookH-Index: 14
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SUMMARY Accuracy and limitations of automatic scoring of sleep stages and electroencephalogram arousals from a single derivation (Fp1–Fp2) were studied in 29 healthy adults using a portable wireless polysomnographic recorder. All recordings were scored five times: twice by a referent scorer who viewed the standard polysomnographic montage and observed the American Academy of Sleep Medicine rules (referent scoring and blind rescoring); and once by the same scorer who viewed only the Fp1–Fp2 signa...
19 CitationsSource
#1Carl Stepnowsky (UCSD: University of California, San Diego)H-Index: 28
Last.David M. Rapoport (NYU: New York University)H-Index: 43
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Objectives: Electroencephalography (EEG) assessment in research and clinical studies is limited by the patient burden of multiple electrodes and the time needed to manually score records. The objective of our study was to investigate the accuracy of an automated sleep-staging algorithm which is based on a single bipolar EEG signal. Methods: Three raters each manually scored the polysomnographic (PSG) records from 44 patients referred for sleep evaluation. Twenty-one PSG records were scored by Re...
39 CitationsSource
#1Gene DavisH-Index: 6
Last.Stephanie KorszenH-Index: 3
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Over the last decade, numerous papers have presented the use of dry electrodes capable of acquiring electroencephalogram (EEG) signals through hair. A few of these dry electrode prototypes have even progressed from lab-based EEG acquisition to commercial sales. While the field has improved rapidly as of late, most dry electrodes share a number of shortcomings that limit their potential real world applications including: 1) multiple rigid prongs that require sustained pressure to penetrate hair a...
3 CitationsSource
Background Alterations of sleep duration and architecture have been associated with increased morbidity and mortality, and specifically linked to chronic cardiovascular disease and psychiatric disorders, such as type 2 diabetes or depression. Measurement of sleep quality to assist in the diagnosis or treatment of these diseases is not routinely performed due to the complexity and cost of conventional methods. The objective of this study is to cross-validate the accuracy of an automated algorithm...
14 CitationsSource
#1Robin Johnson (UCLA: University of California, Los Angeles)H-Index: 13
#2Djordje Popovic (UCLA: University of California, Los Angeles)H-Index: 9
Last.Chris Berka (UCLA: University of California, Los Angeles)H-Index: 17
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Abstract A great deal of research over the last century has focused on drowsiness/alertness detection, as fatigue-related physical and cognitive impairments pose a serious risk to public health and safety. Available drowsiness/alertness detection solutions are unsatisfactory for a number of reasons: (1) lack of generalizability, (2) failure to address individual variability in generalized models, and/or (3) lack of a portable, un-tethered application. The current study aimed to address these iss...
86 CitationsSource
#1Maja Stikic (ABM Industries)H-Index: 6
#2Robin Johnson (ABM Industries)H-Index: 13
Last.Chris Berka (ABM Industries)H-Index: 4
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Previous EEG-based fatigue-related research primarily focused on the association between concurrent cognitive performance and time-locked physiology. The goal of this study was to investigate the capability of EEG to assess the impact of fatigue on both present and future cognitive performance during a 20min sustained attention task, the 3-Choice Active Vigilance Task (3CVT), that requires subjects to discriminate one primary target from two secondary non-target geometric shapes. The current stu...
27 CitationsSource
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