scholarly journals Models for preterm cortical development using non invasive clinical EEG

2017 ◽  
Vol 8 (1) ◽  
Author(s):  
Nora Vanessa de Camp ◽  
Florian Hense ◽  
Bernd Lecher ◽  
Helmut Scheu ◽  
Jürgen Bergeler
Keyword(s):  
Developmental Stages ◽  
Phase Locking ◽  
Cortical Development ◽  
Age Groups ◽  
Model Systems ◽  
Network Activity ◽  
Non Invasive ◽  
Power Spectral ◽  
Eeg Recordings ◽  
Phase Amplitude

AbstractThe objective of this study was to evaluate the piglet and the mouse as model systems for preterm cortical development. According to the clinical context, we used non invasive EEG recordings. As a prerequisite, we developed miniaturized Ag/AgCl electrodes for full band EEG recordings in mice and verified that Urethane had no effect on EEG band power. Since mice are born with a “preterm” brain, we evaluated three age groups: P0/P1, P3/P4 and P13/P14. Our aim was to identify EEG patterns in the somatosensory cortex which are distinguishable between developmental stages and represent a physiologic brain development. In mice, we were able to find clear differences between age groups with a simple power analysis of EEG bands and also for phase locking and power spectral density. Interhemispheric coherence between corresponding regions can only be seen in two week old mice. The canolty maps for piglets as well as for mice show a clear PAC (phase amplitude coupling) pattern during development. From our data it can be concluded that analytic tools relying on network activity, as for example PAC (phase amplitude coupling) are best suited to extract basic EEG patterns of cortical development across species.

EVALUATION OF A NOVEL EEG ANALYSIS METHOD WITH POTENTIAL DIAGNOSTIC APPLICATIONS

2008 ◽  
Vol 31 (4) ◽  
pp. 20
Author(s):  
S R Peters ◽  
B Hu
Keyword(s):  
Wavelet Transforms ◽  
Phase Locking ◽  
Field Potential ◽  
Analysis Method ◽  
Modified Technique ◽  
Diagnostic Potential ◽  
Eeg Recordings ◽  
Phase Amplitude ◽  
Diagnostic Indicator ◽  
Clinical Eeg

Background: Cerebral cortex oscillations as recorded on electroencephalograms involve multiple frequency bands. Phase locking of oscillations of these different frequencies may provide a mechanism by which regions of the brain communicate efficiently. Differences in the character of such phase locking may potentially be a diagnostic tool to differentiate seizure types, as traditional analysis of clinical EEG recordings has seldom considered phase-clocking as a diagnostic indicator. Recently, Canolty et al^1 used a novel metric to quantify cross-frequency phase-amplitude coupling during both spontaneous and induced EEG activity. The technique holds advantages over traditional measures, including easy comparison across trials, robustness to amplitude variation, and simple quantification of preferred phase. Traditional analysis of clinical EEG recordings has seldom considered phase-clocking as a diagnostic indicator. Methods: We adapted the metric of Canolty^1 to perform better with highly rhythmic oscillations, such as those in seizures, by adding multi-segment reshuffling of phase traces. To validate our modified technique, we used artificial sinusoid traces with a known degree of coupling to test the response of our modified analysis method, and to derive empirically, appropriate values for important numerical parameters. Frequency and phase information was acquired with both the Hilbert and wavelet transforms, with similar qualitative results achieved with either. Results: As an initial exploration of diagnostic potential, we applied our metric to field potential data obtained from an anaesthetized rat preparation. We compared the phase-amplitude coupling profiles of sleep oscillations with those of simulated absence seizures and showed consistent differences in the phase amplitude coupling profiles. The data suggest that such differences may be useful in evaluating human seizure data. Conclusions: We conclude that our modified method of data analysis provides an effective approach for measuring normalized phase-amplitude coupling in field potential recordings. Future work will aim to evaluate the possible diagnostic uses of phase-amplitude coupling analysis with data from human seizure patients. Reference: Canolty et al. Science 2006;313:1626. Supported by CIHR, NSERC, and the Health Research Foundation.

scholarly journals Recurrence plot structures reflect motor-related EEG pattern

2019 ◽  
pp. 282-286
Author(s):  
Elena Pitsik ◽  
Nikita Frolov
Keyword(s):  
Signal To Noise Ratio ◽  
Brain Activity ◽  
Recurrence Plot ◽  
Mathematical Tool ◽  
Recurrence Plots ◽  
Time Frequency ◽  
Non Invasive ◽  
Power Spectral ◽  
Nonstationary Data ◽  
Eeg Recordings

Detection and classification of motor-related brain patterns from non-invasive electroencephalograms (EEGs) is challenging due to their non-stationarity and low signal-to-noise ratio and requires using advanced mathematical approaches. Traditionally applied methods such as time-frequency analysis and spatial filtering allow to quantify the main attribute of the motor-related brain activity – contralateral desynchronization of mu-band oscillations (8-13 Hz) in sensorimotor cortex – by measuring EEG signal’s amplitude, power spectral density, location etc. However, these features suffer from strong inter- and intra-subject variability. So, special attention is paid to the finding of stable features. In present paper, we investigate application of the recurrence plots – robust mathematical tool for nonstationary data analysis – to explore properties of motor-related EEG samples. Our goal is to show that recurrence plots are sensitive to the changes in brain activity accessed from noninvasive EEG recordings and may provide us a new context for interpretation of motor-related pattern in EEG.

Applanation Tonometry for Assessment of Left Ventricular Systolic Load

2019 ◽  
Vol 12 (2) ◽  
pp. 94-99
Author(s):  
Rene D. Mileva-Popova ◽  
Nina Y. Belova
Keyword(s):  
Arterial Stiffness ◽  
Augmentation Index ◽  
Age Groups ◽  
Systolic Pressure ◽  
Left Ventricular ◽  
Applanation Tonometry ◽  
Non Invasive ◽  
Pressure Area ◽  
Older Subjects ◽  
And Gender

Summary Vascular-ventricular coupling is a major determinant of left ventricular load. The aim of our study was to assess non- invasively left ventricular load and its dependency on central hemodynamics. Sixty-five healthy and gender-matched individuals were divided in two groups according to their age: 20y/o and 50y/o. Applanation tonometry was performed using the Sphygmocor device. Central pressures and pulse wave analysis indices were computed. Central systolic (120±3 vs. 98±2 mm Hg) and pulse pressures (43±3 vs. 29±1 mm Hg) as well as the augmentation index (AIx75) (23±3 vs. 6±2%) were significantly higher in the 50y/o group (p<0.01). These parameters are relevant markers of arterial stiffness and evidenced the development of central arterial morphological and functional alterations in the older subjects. The time-tension index (TTI) computed from the systolic pressure area was significantly higher in the 50y/o subjects as compared to the 20y/o group (2378±66 vs. 1954±73 mmHg×s, p<0.01). Moreover, we have shown the presence of significant correlation between TTI and AIx75 (p<0.01) in both age groups. This finding confirmed the contribution of arterial stiffness for the impaired vascular-ventricular coupling. In conclusion, applanation tonometry might be utilized for non-invasive evaluation of the left ventricular load, which is an important parameter of cardiovascular risk.

Study of functional state of microcirculatory channel system in periodontal tissues in persons of different age groups

2020 ◽  
Vol 20 (2) ◽  
pp. 88-94
Author(s):  
L. Yu. Orekhova ◽  
A. A. Petrov ◽  
E. S. Loboda ◽  
I. V. Berezkina ◽  
K. V. Shadrina
Keyword(s):  
Functional State ◽  
Age Groups ◽  
Peripheral Resistance ◽  
Circulatory System ◽  
Structural Features ◽  
Periodontal Tissues ◽  
Non Invasive ◽  
Age Related ◽  
Group 12 ◽  
Therapeutic Measures

Relevance. The study of age-related features of microcirculation in periodontal tissues, using non-invasive functional research methods, allows us to develop the optimal range of therapeutic measures, as well as form a “personalized therapeutic case”.Purpose. Study of the functional state of the microvasculature in the tissues of the parodont in individuals of various age groups.Materials and methods. A standard dental examination of 80 patients was carried out, the sample of participants was ranked in 4 groups by age: 1 group – 12 years old, 2 group – 15 years old, 3 group – from 16 to 18 years old, 4 group – from 22 to 24 years old. Hygiene and periodontal indices were determined for all patients, such as papillarymarginal-alveolar (PMA) in the Parma modification, the Mulleman bleeding index in the Cowell modification (SBI), and the simplified Green Vermillion index of oral hygiene (OHI–s), caries intensity indicators for a permanent bite (CPI), as well as ultrasound dopplerography of periodontal tissues using the apparatus "Minimax-Doppler-K".Results. When studying microcirculation in periodontal tissues, distinctive characteristics of linear (Vas) and volumetric (Qas) blood flow rates, as well as indicators of pulsation indices (PI) and peripheral resistance (RI) in people of different age groups were recorded.Conclusions. This study confirms the presence of various hemodynamic indicators of periodontal tissues in the studied groups, which is due to structural features of the circulatory system in age periods.

scholarly journals The brain timewise: how timing shapes and supports brain function

2015 ◽  
Vol 370 (1668) ◽  
pp. 20140170 ◽  
Author(s):  
Riitta Hari ◽  
Lauri Parkkonen
Keyword(s):  
Human Brain ◽  
Brain Imaging ◽  
Brain Function ◽  
Temporal Dynamics ◽  
Generative Models ◽  
Network Activity ◽  
Brain Diseases ◽  
Specific Information ◽  
Non Invasive ◽  
The Brain

We discuss the importance of timing in brain function: how temporal dynamics of the world has left its traces in the brain during evolution and how we can monitor the dynamics of the human brain with non-invasive measurements. Accurate timing is important for the interplay of neurons, neuronal circuitries, brain areas and human individuals. In the human brain, multiple temporal integration windows are hierarchically organized, with temporal scales ranging from microseconds to tens and hundreds of milliseconds for perceptual, motor and cognitive functions, and up to minutes, hours and even months for hormonal and mood changes. Accurate timing is impaired in several brain diseases. From the current repertoire of non-invasive brain imaging methods, only magnetoencephalography (MEG) and scalp electroencephalography (EEG) provide millisecond time-resolution; our focus in this paper is on MEG. Since the introduction of high-density whole-scalp MEG/EEG coverage in the 1990s, the instrumentation has not changed drastically; yet, novel data analyses are advancing the field rapidly by shifting the focus from the mere pinpointing of activity hotspots to seeking stimulus- or task-specific information and to characterizing functional networks. During the next decades, we can expect increased spatial resolution and accuracy of the time-resolved brain imaging and better understanding of brain function, especially its temporal constraints, with the development of novel instrumentation and finer-grained, physiologically inspired generative models of local and network activity. Merging both spatial and temporal information with increasing accuracy and carrying out recordings in naturalistic conditions, including social interaction, will bring much new information about human brain function.

scholarly journals Novel dry electrode EEG headbands for home use: Comparing performance and comfort

2020 ◽  
Vol 6 (3) ◽  
pp. 139-142
Author(s):  
Jens Haueisen ◽  
Patrique Fiedler ◽  
Anna Bernhardt ◽  
Ricardo Gonçalves ◽  
Carlos Fonseca
Keyword(s):  
Brain Activity ◽  
Skin Impedance ◽  
Signal Quality ◽  
The Novel ◽  
Application Time ◽  
Dry Electrodes ◽  
Power Spectral ◽  
Dry Electrode ◽  
Increasing Trend ◽  
Eeg Recordings

AbstractMonitoring brain activity at home using electroencephalography (EEG) is an increasing trend for both medical and non-medical applications. Gel-based electrodes are not suitable due to the gel application requiring extensive preparation and cleaning support for the patient or user. Dry electrodes can be applied without prior preparation by the patient or user. We investigate and compare two dry electrode headbands for EEG acquisition: a novel hybrid dual-textile headband comprising multipin and multiwave electrodes and a neoprene-based headband comprising hydrogel and spidershaped electrodes. We compare the headbands and electrodes in terms of electrode-skin impedance, comfort, electrode offset potential and EEG signal quality. We did not observe considerable differences in the power spectral density of EEG recordings. However, the hydrogel electrodes showed considerably increased impedances and offset potentials, limiting their compatibility with many EEG amplifiers. The hydrogel and spider-shaped electrodes required increased adduction, resulting in a lower wearing comfort throughout the application time compared to the novel headband comprising multipin and multiwave electrodes.

Dissimilar Anxiety-like Behavior in Prepubertal and Young Adult Female Rats on Acute Exposure to Aluminium

2021 ◽  
Vol 22 ◽  
Author(s):  
Trina Sengupta ◽  
Sutirtha Ghosh ◽  
Archana Gaur T. ◽  
Prasunpriya Nayak
Keyword(s):  
Body Weight ◽  
Young Adult ◽  
Adult Female ◽  
Developmental Stages ◽  
Elevated Plus Maze ◽  
Age Groups ◽  
Female Rats ◽  
Acute Exposure ◽  
Adult Rats ◽  
Plus Maze

Background: Puberty is a developmental transition in which an estrogenic surge occurs, mediating the release of xenoestrogens, like aluminium. Aluminium’s effect on anxiety in rodents at the different developmental stages is inconsistent. Aims: This study aimed at investigating the effect of the metalloestrogenic property of aluminium on anxiety-like behavioral changes in prepubertal and young adult female rats. Objective: Considering this aim, our objective was to evaluate the anxiety-like behavior by the elevated plus maze in prepubertal and young adult female rats with or without acute exposure to aluminium. Methods: To address this property of aluminium, 5mg/Kg body weight (Al-5) and 10 mg/Kg body weight (Al-10) of aluminium was administered intraperitoneally to female rats at two developmental stages, prepubertal (PP; n = 8 for each dose) and young adult (YA; n = 6 for each dose) for two weeks. Post-treatment, three days behavioral assessment of the rats was done employing elevated plus maze. Results: Reduced escape latency was seen in Al-5, Al-10 pre-pubertal rats, and Al-5 young-adult rats on day 3. A significant reduction in open arm time was seen in the Al-5 young-adult rats. Aluminium treatment in the pre-pubertal rats reduced their head dipping and grooming. Reduced sniffing, head dipping, and stretch-attended posture in the treated young-adult female rats showed that they had impaired risk-taking tendency. Conclusion: Differential effect on the anxiety-like behavior in the pre-pubertal and young-adult female rats might be due to the metalloestrogenic property of aluminium, acting differently on the two age groups.

scholarly journals A Real-Time Phase-Locking System for Non-invasive Brain Stimulation

2018 ◽  
Vol 12 ◽  
Author(s):  
Farrokh Mansouri ◽  
Peter Fettes ◽  
Laura Schulze ◽  
Peter Giacobbe ◽  
Jose Zariffa ◽  
...  
Keyword(s):  
Real Time ◽  
Brain Stimulation ◽  
Phase Locking ◽  
Non Invasive

scholarly journals A Neuromorphic Spiking Neural Network Detects Epileptic High Frequency Oscillations in the Scalp EEG

2021 ◽  
Author(s):  
Karla Burelo ◽  
Georgia Ramantani ◽  
Giacomo Indiveri ◽  
Johannes Sarnthein
Keyword(s):  
Low Power ◽  
Seizure Frequency ◽  
High Frequency ◽  
Therapy Monitoring ◽  
Non Invasive ◽  
Scalp Eeg ◽  
High Frequency Oscillations ◽  
Eeg Recordings ◽  
Active Epilepsy ◽  
Wearable Electronic Devices

Abstract Background: Interictal High Frequency Oscillations (HFO) are measurable in scalp EEG. This has aroused interest in investigating their potential as biomarkers of epileptogenesis, seizure propensity, disease severity, and treatment response. The demand for therapy monitoring in epilepsy has kindled interest in compact wearable electronic devices for long- term EEG recording. Spiking neural networks (SNN) have been shown to be optimal architectures for being embedded in compact low-power signal processing hardware. Methods: We analyzed 20 scalp EEG recordings from 11 patients with pediatric focal lesional epilepsy. We designed a custom SNN to detect events of interest (EoI) in the 80-250 Hz ripple band and reject artifacts in the 500-900 Hz band. Results: We identified the optimal SNN parameters to automatically detect EoI and reject artifacts. The occurrence of HFO thus detected was associated with active epilepsy with 80% accuracy. The HFO rate mirrored the decrease in seizure frequency in 8 patients (p = 0.0047). Overall, the HFO rate correlated with seizure frequency (rho = 0.83, p < 0.0001, Spearman’s correlation).Conclusions: The fully automated SNN detected clinically relevant HFO in the scalp EEG. This is a further step towards non-invasive epilepsy monitoring with a low-power wearable device.

Sign in / Sign up

Export Citation Format

Share Document