scholarly journals Model-Based Analysis and Optimization of the Mapping of Cortical Sources in the Spontaneous Scalp EEG

2007 ◽  
Vol 8 (3) ◽  
pp. 173-189 ◽  
Author(s):  
Andrei V. Sazonov ◽  
Jan W. M. Bergmans ◽  
Pierre J. M. Cluitmans ◽  
Paul A. M. Griep ◽  
Johan B. A. M. Arends ◽  
...  
Keyword(s):  
Generation Model ◽  
Volume Conduction ◽  
Channel Correlation ◽  
Scalp Eeg ◽  
Observation Function ◽  
Scalp Electroencephalogram ◽  
The Impact ◽  
Electroencephalogram Eeg ◽  
Model Based Analysis ◽  
Conduction Properties

The mapping of brain sources into the scalp electroencephalogram (EEG) depends on volume conduction properties of the head and on an electrode montage involving a reference. Mathematically, thissource mapping(SM) is fully determined by anobservation function(OF) matrix. This paper analyses the OF-matrix for a generation model for the desynchronized spontaneous EEG. The model involves a four-shell spherical volume conductor containing dipolar sources that are mutually uncorrelated so as to reflect the desynchronized EEG. The reference is optimized in order to minimize the impact in the SM of the sources located distant from the electrodes. The resulting reference is called thelocalized reference(LR). The OF-matrix is analyzed in terms of the relative power contribution of the sources and the cross-channel correlation coefficient for five existing references as well as for the LR. It is found that theHjorth Laplacian referenceis a fair approximation of the LR, and thus is close to optimum for practical intents and purposes. The other references have a significantly poorer performance. Furthermore, the OF-matrix is analyzed for limits to the spatial resolution for the EEG. These are estimated to be around 2 cm.

scholarly journals High-Frequency Oscillations in the Scalp Electroencephalogram: Mission Impossible without Computational Intelligence

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Peter Höller ◽  
Eugen Trinka ◽  
Yvonne Höller
Keyword(s):  
High Frequency ◽  
Visual Detection ◽  
Signal To Noise Ratio ◽  
Physiological Activity ◽  
Automated Detection ◽  
Detection Algorithms ◽  
Scalp Eeg ◽  
High Frequency Oscillations ◽  
Scalp Electroencephalogram ◽  
Electroencephalogram Eeg

High-frequency oscillations (HFOs) in the electroencephalogram (EEG) are thought to be a promising marker for epileptogenicity. A number of automated detection algorithms have been developed for reliable analysis of invasively recorded HFOs. However, invasive recordings are not widely applicable since they bear risks and costs, and the harm of the surgical intervention of implantation needs to be weighted against the informational benefits of the invasive examination. In contrast, scalp EEG is widely available at low costs and does not bear any risks. However, the detection of HFOs on the scalp represents a challenge that was taken on so far mostly via visual detection. Visual detection of HFOs is, in turn, highly time-consuming and subjective. In this review, we discuss that automated detection algorithms for detection of HFOs on the scalp are highly warranted because the available algorithms were all developed for invasively recorded EEG and do not perform satisfactorily in scalp EEG because of the low signal-to-noise ratio and numerous artefacts as well as physiological activity that obscures the tiny phenomena in the high-frequency range.

EEG Analysis of Imagined Speech

2020 ◽  
pp. 679-692
Author(s):  
Sadaf Iqbal ◽  
Muhammed Shanir P.P. ◽  
Yusuf Uzzaman Khan ◽  
Omar Farooq
Keyword(s):  
Mean Absolute Deviation ◽  
Eeg Analysis ◽  
Absolute Deviation ◽  
Scalp Eeg ◽  
Computer Interfaces ◽  
Eeg Data ◽  
Scalp Electroencephalogram ◽  
Electroencephalogram Eeg ◽  
Control State ◽  
Excellent Tool

Scalp electroencephalogram (EEG) is one of the most commonly used methods to acquire EEG data for brain-computer interfaces (BCIs). Worldwide a large number of people suffer from disabilities which impair normal communication. Communication BCIs are an excellent tool which helps the affected patients communicate with others. In this paper scalp EEG data is analysed to discriminate between the imagined vowel sounds /a/, /u/ and no action or rest as control state. Mean absolute deviation (MAD) and Arithmetic mean are used as features to classify data into one of the classes /a/, /u/ or rest. With high classification accuracies of 87.5-100% for two class problem and 78.33-96.67% for three class problem that have been obtained in this work, this algorithm can be used in communication BCIs, to develop speech prosthesis and in synthetic telepathy systems.

EEG Analysis of Imagined Speech

2016 ◽  
Vol 3 (2) ◽  
pp. 32-44
Author(s):  
Sadaf Iqbal ◽  
Muhammed Shanir P.P. ◽  
Yusuf Uzzaman Khan ◽  
Omar Farooq
Keyword(s):  
Mean Absolute Deviation ◽  
Eeg Analysis ◽  
Absolute Deviation ◽  
Scalp Eeg ◽  
Computer Interfaces ◽  
Eeg Data ◽  
Scalp Electroencephalogram ◽  
Electroencephalogram Eeg ◽  
Control State ◽  
Excellent Tool

Scalp electroencephalogram (EEG) is one of the most commonly used methods to acquire EEG data for brain-computer interfaces (BCIs). Worldwide a large number of people suffer from disabilities which impair normal communication. Communication BCIs are an excellent tool which helps the affected patients communicate with others. In this paper scalp EEG data is analysed to discriminate between the imagined vowel sounds /a/, /u/ and no action or rest as control state. Mean absolute deviation (MAD) and Arithmetic mean are used as features to classify data into one of the classes /a/, /u/ or rest. With high classification accuracies of 87.5-100% for two class problem and 78.33-96.67% for three class problem that have been obtained in this work, this algorithm can be used in communication BCIs, to develop speech prosthesis and in synthetic telepathy systems.

scholarly journals The Effect of Health Shock and Basic Medical Insurance on Family Educational Investment for Children in China

2021 ◽  
Vol 18 (10) ◽  
pp. 5242
Author(s):  
Pu Liao ◽  
Zhihong Dou ◽  
Xingxing Guo
Keyword(s):  
Negative Impact ◽  
Medical Insurance ◽  
Generation Model ◽  
Two Phase ◽  
Parental Health ◽  
Health Shock ◽  
Basic Medical Insurance ◽  
Child Education ◽  
The Impact ◽  
Basic Medical

This paper explores the role of basic medical insurance in protecting family investment in child education. First, this paper establishes a two-phase overlapping generation model to theoretically analyse the impact of basic medical insurance on investment in child education under the influence of the impact of parental health. The results show that health shock reduces parental investment in child education, and medical insurance significantly alleviates the negative impact of parental health shock on investment in child education. Furthermore, this paper establishes a two-way fixed effect regression model based on the data of China Family Panel Studies (CFPS) in 2014 and 2016 to empirically test the above results. The results showed that parental health shocks negatively affect investment in child education, and paternal health shock has a more significant impact than maternal health shock. However, medical insurance significantly reduces this negative impact, provides security in investment in child education, and promotes the improvement of human capital.

Detection of Intracranial Signatures of Interictal Epileptiform Discharges from Concurrent Scalp EEG

2016 ◽  
Vol 26 (04) ◽  
pp. 1650016 ◽  
Author(s):  
Loukianos Spyrou ◽  
David Martín-Lopez ◽  
Antonio Valentín ◽  
Gonzalo Alarcón ◽  
Saeid Sanei
Keyword(s):  
Detection Algorithm ◽  
The Other ◽  
Intracranial Eeg ◽  
Scalp Eeg ◽  
Epileptiform Discharges ◽  
Interictal Epileptiform Discharges ◽  
Scalp Electroencephalogram ◽  
Patients With Epilepsy ◽  
Electrical Activities ◽  
The Brain

Interictal epileptiform discharges (IEDs) are transient neural electrical activities that occur in the brain of patients with epilepsy. A problem with the inspection of IEDs from the scalp electroencephalogram (sEEG) is that for a subset of epileptic patients, there are no visually discernible IEDs on the scalp, rendering the above procedures ineffective, both for detection purposes and algorithm evaluation. On the other hand, intracranially placed electrodes yield a much higher incidence of visible IEDs as compared to concurrent scalp electrodes. In this work, we utilize concurrent scalp and intracranial EEG (iEEG) from a group of temporal lobe epilepsy (TLE) patients with low number of scalp-visible IEDs. The aim is to determine whether by considering the timing information of the IEDs from iEEG, the resulting concurrent sEEG contains enough information for the IEDs to be reliably distinguished from non-IED segments. We develop an automatic detection algorithm which is tested in a leave-subject-out fashion, where each test subject’s detection algorithm is based on the other patients’ data. The algorithm obtained a [Formula: see text] accuracy in recognizing scalp IED from non-IED segments with [Formula: see text] accuracy when trained and tested on the same subject. Also, it was able to identify nonscalp-visible IED events for most patients with a low number of false positive detections. Our results represent a proof of concept that IED information for TLE patients is contained in scalp EEG even if they are not visually identifiable and also that between subject differences in the IED topology and shape are small enough such that a generic algorithm can be used.

The impact of global change on the hydropower potential of Europe: a model-based analysis

Energy Policy ◽  
2005 ◽  
Vol 33 (7) ◽  
pp. 839-855 ◽  
Author(s):  
Bernhard Lehner ◽  
Gregor Czisch ◽  
Sara Vassolo
Keyword(s):  
Global Change ◽  
Model Based ◽  
Hydropower Potential ◽  
The Impact ◽  
Model Based Analysis

scholarly journals The impact of EEG in the diagnosis and management of patients with acute impairment of consciousness

2012 ◽  
Vol 70 (1) ◽  
pp. 34-39 ◽  
Author(s):  
João A. G. Ricardo ◽  
Marcondes C. França Jr. ◽  
Fabrício O. Lima ◽  
Clarissa L. Yassuda ◽  
Fernando Cendes
Keyword(s):  
Intensive Care Unit ◽  
Intensive Care ◽  
Emergency Room ◽  
Medical Management ◽  
Clinical Management ◽  
Epileptiform Activity ◽  
Acute Setting ◽  
Diagnosis And Management ◽  
The Impact ◽  
Electroencephalogram Eeg

OBJECTIVES: To assess the frequency of electroencephalogram (EEG) requests in the emergency room (ER) and intensive care unit (ICU) for patients with impairment of consciousness (IC) and its impact in the diagnosis and management. METHODS: We followed patients who underwent routine EEG from ER and ICU with IC until discharge or death. RESULTS: During the study, 1679 EEGs were performed, with 149 (8.9%) from ER and ICU. We included 65 patients and 94 EEGs to analyze. Epileptiform activity was present in 42 (44.7%). EEG results changed clinical management in 72.2% of patients. The main reason for EEG requisition was unexplained IC, representing 36.3% of all EEGs analyzed. Eleven (33%) of these had epileptiform activity. CONCLUSION: EEG is underused in the acute setting. The frequency of epileptiform activity was high in patients with unexplained IC. EEG was helpful in confirming or ruling out the suspected initial diagnosis and changing medical management in 72% of patients.

scholarly journals Hospital at Home: An Evolving Model for Comprehensive Healthcare

2021 ◽  
Author(s):  
Henil Y. Patel ◽  
Daniel J. West
Keyword(s):  
Healthcare Services ◽  
The United States ◽  
Healthcare Management ◽  
Point Of View ◽  
Generation Model ◽  
Model Of Care ◽  
Treatment Protocols ◽  
Hospital At Home ◽  
The Impact ◽  
At Home

ABSTRACT Hospital at Home (HaH) is a sustainable, innovative, and next-generation model of healthcare. From the healthcare management point of view, this model provides cost benefits and quality improvement, and from the physicians' point of view, it helps in providing patient-centered medical care and keeps patients away from hospital admission and its complications. The HaH model was first introduced at John Hopkins in the United States in 1995, which showed very promising results in context to the length of stay, readmission rates, patient satisfaction, and hospital-acquired infections. The HaH model of care provides acute critical care to patients at home and reduces unnecessary hospitalization and related complications. The identified patients for this model of care are elderly patients with chronic conditions and multiple comorbidities. The emergence of technology in today's world and the impact of coronavirus disease 2019 (COVID-19) have increased the demand for the HaH model of care. Although there are many benefits and advantages, the HaH model of care has significant barriers and limitations, such as reimbursement for payment, physician and patient resistance, patient safety, and lack of quantifying research data to support the use of this model. Specific training for the physician, nursing, and other members of the HaH multidisciplinary team is necessary for HaH treatment protocols, along with patient and family caregiver education for those who elect the HaH model of care. HaH is the future of comprehensive healthcare services and helps in achieving the triple aim of access to healthcare, improved quality of care, and reduced cost for healthcare.

scholarly journals Bladder Tumor Heterogeneity: The Impact on Clinical Treatment

2015 ◽  
Vol 95 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Chao Chen ◽  
Xiang Jie Qi ◽  
Yan Wei Cao ◽  
Yong Hua Wang ◽  
Xue Cheng Yang ◽  
...  
Keyword(s):  
Bladder Cancer ◽  
Treatment Failure ◽  
Tumor Cells ◽  
Cancer Progression ◽  
Tumor Heterogeneity ◽  
Bladder Tumor ◽  
Gene Sequencing ◽  
Generation Model ◽  
And Control ◽  
The Impact

Bladder cancer relapse and treatment failure in most patients have often been attributed to chemoresistance in tumor cells and metastasis. Emerging evidence indicates that tumor heterogeneity may play an equally important role and extends to virtually all measurable properties of cancer cells. Although the idea of tumor heterogeneity is not new, little attention has been paid to applying it to understand and control bladder cancer progression. With the development of biotechnology, such as Gene sequencing, recent advances in understanding its generation model, original basis, consequent problems, and derived therapies provide great potential for tumor heterogeneity to be considered a new insight in the treatment of bladder cancers.

scholarly journals High similarity between EEG from subcutaneous and proximate scalp electrodes in patients with temporal lobe epilepsy

2018 ◽  
Vol 120 (3) ◽  
pp. 1451-1460 ◽  
Author(s):  
Sigge Weisdorf ◽  
Sirin W. Gangstad ◽  
Jonas Duun-Henriksen ◽  
Karina S. S. Mosholt ◽  
Troels W. Kjær
Keyword(s):  
Temporal Lobe Epilepsy ◽  
Temporal Lobe ◽  
Temporal Dynamics ◽  
Real Life ◽  
High Similarity ◽  
Time Frequency ◽  
Scalp Eeg ◽  
Eeg Recordings ◽  
The Impact

Subcutaneous recording using electroencephalography (EEG) has the potential to enable ultra-long-term epilepsy monitoring in real-life conditions because it allows the patient increased mobility and discreteness. This study is the first to compare physiological and epileptiform EEG signals from subcutaneous and scalp EEG recordings in epilepsy patients. Four patients with probable or definite temporal lobe epilepsy were monitored with simultaneous scalp and subcutaneous EEG recordings. EEG recordings were compared by correlation and time-frequency analysis across an array of clinically relevant waveforms and patterns. We found high similarity between the subcutaneous EEG channels and nearby temporal scalp channels for most investigated electroencephalographic events. In particular, the temporal dynamics of one typical temporal lobe seizure in one patient were similar in scalp and subcutaneous recordings in regard to frequency distribution and morphology. Signal similarity is strongly related to the distance between the subcutaneous and scalp electrodes. On the basis of these limited data, we conclude that subcutaneous EEG recordings are very similar to scalp recordings in both time and time-frequency domains, if the distance between them is small. As many electroencephalographic events are local/regional, the positioning of the subcutaneous electrodes should be considered carefully to reflect the relevant clinical question. The impact of implantation depth of the subcutaneous electrode on recording quality should be investigated further. NEW & NOTEWORTHY This study is the first publication comparing the detection of clinically relevant, pathological EEG features from a subcutaneous recording system designed for out-patient ultra-long-term use to gold standard scalp EEG recordings. Our study shows that subcutaneous channels are very similar to comparable scalp channels, but also point out some issues yet to be resolved.

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