scholarly journals Real-Time Excitation of Slow Oscillations during Deep Sleep Using Acoustic Stimulation

Sensors ◽  
2021 ◽  
Vol 21 (15) ◽  
pp. 5169
Author(s):  
Marek Piorecky ◽  
Vlastimil Koudelka ◽  
Vaclava Piorecka ◽  
Jan Strobl ◽  
Daniela Dudysova ◽  
...  
Keyword(s):  
Real Time ◽  
Slow Wave ◽  
Phase Synchronization ◽  
Phase Locking ◽  
Acoustic Stimulation ◽  
Deep Sleep ◽  
Sound Stimulation ◽  
Eeg Data ◽  
Stimulation Method ◽  
And Function

Slow-wave synchronous acoustic stimulation is a promising research and therapeutic tool. It is essential to clearly understand the principles of the synchronization methods, to know their performances and limitations, and, most importantly, to have a clear picture of the effect of stimulation on slow-wave activity (SWA). This paper covers the mentioned and currently missing parts of knowledge that are essential for the appropriate development of the method itself and future applications. Artificially streamed real sleep EEG data were used to quantitatively compare the two currently used real-time methods: the phase-locking loop (PLL) and the fixed-step stimulus in our own implementation. The fixed-step stimulation method was concluded to be more reliable and practically applicable compared to the PLL method. The sleep experiment with chronic insomnia patients in our sleep laboratory was analyzed in order to precisely characterize the effect of sound stimulation during deep sleep. We found that there is a significant phase synchronization of delta waves, which were shown to be the most sensitive metric of the effect of acoustic stimulation compared to commonly used averaged signal and power analyses. This finding may change the understanding of the effect and function of the SWA stimulation described in the literature.

scholarly journals Assessment of potential capabilities of Dreem: An ambulatory device for EEG phase-locked acoustic stimulation during sleep

2019 ◽  
Vol 9 (1) ◽  
pp. 96-112
Author(s):  
A.N. Puchkova ◽  
O.N. Tkachenko ◽  
I.P. Trapeznikov ◽  
I.A. Piletskaya ◽  
E.V. Tiunova ◽  
...  
Keyword(s):  
Slow Wave ◽  
Brain Activity ◽  
Modern Society ◽  
Acoustic Stimulation ◽  
Sleep Eeg ◽  
Deep Sleep ◽  
Sleep Staging ◽  
Night Sleep ◽  
Delta Wave ◽  
Photo Sensor

Sleep disorders are one of the significant problems in the modern society. Current research is on the lookout for the nonpharmacological ways to improve sleep quality and slow wave brain activity that plays a crucial role in homeostasis and cognitive functions. One of the promising approaches is acoustic stimulation that is phase-locked to deep sleep EEG rhythms. It was already shown that such stimulation improves slow wave brain activity. This article describes Dreem: a wireless consumer device that performs acoustic sleep stimulation in home conditions. The device has dry EEG electrodes, photo sensor for pulse oximetry, and an accelerometer. The inbuilt software detects deep sleep, performs audio stimulation on the ascending slope of the delta wave and does automatic sleep staging. In the pilot study of the device, three subjects made 10 to 24 recordings of night sleep with EEG recording and stimulation. The raw data recorded by the device is available to the user and is sufficient for sleep staging and basic sleep analysis. Automatic hypnograms reflect the structure of a normal night sleep. EEG averaged by the stimulation markers demonstrated the high efficacy of slow wave detectors and placement of stimulations on the ascending slope of a delta wave. Dreem device is of interest for the sleep researchers as an easy to use tool for an out-of-lab data acquisition.

scholarly journals Enhancement of Sleep Quality and Stability Using Acoustic Stimulation During Slow Wave Sleep

2018 ◽  
Vol 5 (4) ◽  
pp. 126-134
Author(s):  
Aminollah Golrou ◽  
Ali Sheikhani ◽  
Ali Motie Nasrabadi ◽  
Mohammad Reza Saebipour
Keyword(s):  
Sleep Quality ◽  
Slow Wave ◽  
Slow Wave Sleep ◽  
Acoustic Stimulation ◽  
Deep Sleep ◽  
Quality Of Sleep ◽  
Slow Oscillations ◽  
Random Frequency ◽  
Improve Sleep Quality

Background: One of the challenges today is that the quality of sleep has weakened by many external factors, which we are not even aware of and which directly affect sleep. Sleep quality has an essential role in maintaining the cognitive function and memory consolidation of individuals. So far, various studies have been done to improve the quality of sleep by using external electrical stimulation, vestibular and olfactory system stimulation. Methods: In this study, the increase in sleep quality was considered by simultaneous acoustic stimulation in a deep sleep to increase the density of slow oscillations. Slow oscillations are the important events recorded in electroencephalography (EEG) and hallmark deep sleep. Acoustic stimulation of pink noise with random frequency ranging from 0.8 to 1.1 Hz was used to improve sleep quality. Results: Eight healthy adults (mean age: 28.4±7.8 years) studied in 3 nights under 3 conditions: accommodation night, stimulation night (STIM) and no stimulation night (SHAM), in counterbalanced order. Significant characteristics of the objective and subjective quality of sleep have been extracted from the acquired EEG and compared in the last 2 nights. Also, the arousal and cyclic alternating pattern characteristics have been measured to assess sleep stability over 2 nights of STIM and SHAM. Conclusion: Our findings confirm this goal of the study that applying designed acoustic stimulation simultaneously in the slow wave sleep (SWS) stage increases the duration of deep sleep and ultimately improves overall sleep stability and quality. Keywords: Sleep quality enhancement; Acoustic stimulation; Slow wave sleep; CAP & arousals; Sleep stability; EEG

Online Measurement of Glucose Consumption from HepG2 Cells Using an Integrated Bioreactor and Enzymatic Assay

2018 ◽  
Author(s):  
Anna Adams ◽  
Radha Krishna Murthy Bulusu ◽  
Nikita Mukhitov ◽  
Jose Mendoza-Cortes ◽  
Michael Roper
Keyword(s):  
Real Time ◽  
Glucose Concentration ◽  
Hepg2 Cells ◽  
Glucose Consumption ◽  
Microfluidic System ◽  
Structure And Function ◽  
Online Measurement ◽  
Fluorescent Assay ◽  
And Function ◽  
Integrated Bioreactor

In this work, we developed a microfluidic bioreactor for optimizing growth and maintaining structure and function of HepG2, and when desired, the device could be removed and the extracellular output from the bioreactor combined with enzymatic glucose reagents into a droplet-based microfluidic system. The intensity of the resulting fluorescent assay product in the droplets was measured, and was directly correlated to glucose concentration, allowing the effect of insulin on glucose consumption in the HepG2 cells to be observed and quantified online and in near real-time.

Online Measurement of Glucose Consumption from HepG2 Cells Using an Integrated Bioreactor and Enzymatic Assay

2018 ◽  
Author(s):  
Anna Adams ◽  
Radha Krishna Murthy Bulusu ◽  
Nikita Mukhitov ◽  
Jose Mendoza-Cortes ◽  
Michael Roper
Keyword(s):  
Real Time ◽  
Glucose Concentration ◽  
Hepg2 Cells ◽  
Glucose Consumption ◽  
Microfluidic System ◽  
Structure And Function ◽  
Online Measurement ◽  
Fluorescent Assay ◽  
And Function ◽  
Integrated Bioreactor

In this work, we developed a microfluidic bioreactor for optimizing growth and maintaining structure and function of HepG2, and when desired, the device could be removed and the extracellular output from the bioreactor combined with enzymatic glucose reagents into a droplet-based microfluidic system. The intensity of the resulting fluorescent assay product in the droplets was measured, and was directly correlated to glucose concentration, allowing the effect of insulin on glucose consumption in the HepG2 cells to be observed and quantified online and in near real-time.

W1363 Real Time Detection and Function of Melatonin Release from the Mucosa of Guinea Pig Ileum

2008 ◽  
Vol 134 (4) ◽  
pp. A-688 ◽  
Author(s):  
Bhavik A. Patel ◽  
Xiaochun Bian ◽  
James Galligan ◽  
Greg M. Swain
Keyword(s):  
Guinea Pig ◽  
Real Time ◽  
Guinea Pig Ileum ◽  
Real Time Detection ◽  
And Function

scholarly journals Increased neural correlations in primate auditory cortex during slow-wave sleep

2013 ◽  
Vol 109 (11) ◽  
pp. 2732-2738 ◽  
Author(s):  
Elias B. Issa ◽  
Xiaoqin Wang
Keyword(s):  
Auditory Cortex ◽  
Spontaneous Activity ◽  
Slow Wave ◽  
Local Field ◽  
Local Field Potential ◽  
Slow Wave Sleep ◽  
Field Potential ◽  
Sensory Stimulation ◽  
Acoustic Stimulation ◽  
Functional Connections

During sleep, changes in brain rhythms and neuromodulator levels in cortex modify the properties of individual neurons and the network as a whole. In principle, network-level interactions during sleep can be studied by observing covariation in spontaneous activity between neurons. Spontaneous activity, however, reflects only a portion of the effective functional connectivity that is activated by external and internal inputs (e.g., sensory stimulation, motor behavior, and mental activity), and it has been shown that neural responses are less correlated during external sensory stimulation than during spontaneous activity. Here, we took advantage of the unique property that the auditory cortex continues to respond to sounds during sleep and used external acoustic stimuli to activate cortical networks for studying neural interactions during sleep. We found that during slow-wave sleep (SWS), local (neuron-neuron) correlations are not reduced by acoustic stimulation remaining higher than in wakefulness and rapid eye movement sleep and remaining similar to spontaneous activity correlations. This high level of correlations during SWS complements previous work finding elevated global (local field potential-local field potential) correlations during sleep. Contrary to the prediction that slow oscillations in SWS would increase neural correlations during spontaneous activity, we found little change in neural correlations outside of periods of acoustic stimulation. Rather, these findings suggest that functional connections recruited in sound processing are modified during SWS and that slow rhythms, which in general are suppressed by sensory stimulation, are not the sole mechanism leading to elevated network correlations during sleep.

scholarly journals Real-Time Translocation and Function of PKCβII Isoform in Response to Nociceptive Signaling via the TRPV1 Pain Receptor

2011 ◽  
Vol 4 (11) ◽  
pp. 1503-1517 ◽  
Author(s):  
Sravan Mandadi ◽  
Patricia J. Armati ◽  
Basil D. Roufogalis
Keyword(s):  
Real Time ◽  
And Function
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