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Liu J, Younk R, Drahos LM, Nagrale SS, Yadav S, Widge AS, Shoaran M. Neural Decoding and Feature Selection Techniques for Closed-Loop Control of Defensive Behavior. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.06.597165. [PMID: 38895388 PMCID: PMC11185693 DOI: 10.1101/2024.06.06.597165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/21/2024]
Abstract
Objective Many psychiatric disorders involve excessive avoidant or defensive behavior, such as avoidance in anxiety and trauma disorders or defensive rituals in obsessive-compulsive disorders. Developing algorithms to predict these behaviors from local field potentials (LFPs) could serve as foundational technology for closed-loop control of such disorders. A significant challenge is identifying the LFP features that encode these defensive behaviors. Approach We analyzed LFP signals from the infralimbic cortex and basolateral amygdala of rats undergoing tone-shock conditioning and extinction, standard for investigating defensive behaviors. We utilized a comprehensive set of neuro-markers across spectral, temporal, and connectivity domains, employing SHapley Additive exPlanations for feature importance evaluation within Light Gradient-Boosting Machine models. Our goal was to decode three commonly studied avoidance/defensive behaviors: freezing, bar-press suppression, and motion (accelerometry), examining the impact of different features on decoding performance. Main results Band power and band power ratio between channels emerged as optimal features across sessions. High-gamma (80-150 Hz) power, power ratios, and inter-regional correlations were more informative than other bands that are more classically linked to defensive behaviors. Focusing on highly informative features enhanced performance. Across 4 recording sessions with 16 subjects, we achieved an average coefficient of determination of 0.5357 and 0.3476, and Pearson correlation coefficients of 0.7579 and 0.6092 for accelerometry jerk and bar press rate, respectively. Utilizing only the most informative features revealed differential encoding between accelerometry and bar press rate, with the former primarily through local spectral power and the latter via inter-regional connectivity. Our methodology demonstrated remarkably low time complexity, requiring < 110 ms for training and < 1 ms for inference. Significance Our results demonstrate the feasibility of accurately decoding defensive behaviors with minimal latency, using LFP features from neural circuits strongly linked to these behaviors. This methodology holds promise for real-time decoding to identify physiological targets in closed-loop psychiatric neuromodulation.
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Orlandic L, Thevenot J, Teijeiro T, Atienza D. A Multimodal Dataset for Automatic Edge-AI Cough Detection. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2023; 2023:1-7. [PMID: 38082667 DOI: 10.1109/embc40787.2023.10340413] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2023]
Abstract
Counting the number of times a patient coughs per day is an essential biomarker in determining treatment efficacy for novel antitussive therapies and personalizing patient care. Automatic cough counting tools must provide accurate information, while running on a lightweight, portable device that protects the patient's privacy. Several devices and algorithms have been developed for cough counting, but many use only error-prone audio signals, rely on offline processing that compromises data privacy, or utilize processing and memory-intensive neural networks that require more hardware resources than can fit on a wearable device. Therefore, there is a need for wearable devices that employ multimodal sensors to perform accurate, privacy-preserving, automatic cough counting algorithms directly on the device in an edge Artificial Intelligence (edge-AI) fashion. To advance this research field, we contribute the first publicly accessible cough counting dataset of multimodal biosignals. The database contains nearly 4 hours of biosignal data, with both acoustic and kinematic modalities, covering 4,300 annotated cough events from 15 subjects. Furthermore, a variety of non-cough sounds and motion scenarios mimicking daily life activities are also present, which the research community can use to accelerate machine learning (ML) algorithm development. A technical validation of the dataset reveals that it represents a wide variety of signal-to-noise ratios, which can be expected in a real-life use case, as well as consistency across experimental trials. Finally, to demonstrate the usability of the dataset, we train a simple cough vs non-cough signal classifier that obtains a 91% sensitivity, 92% specificity, and 80% precision on unseen test subject data. Such edge-friendly AI algorithms have the potential to provide continuous ambulatory monitoring of the numerous chronic cough patients.
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Supervised Machine Learning and Deep Learning Techniques for Epileptic Seizure Recognition Using EEG Signals-A Systematic Literature Review. BIOENGINEERING (BASEL, SWITZERLAND) 2022; 9:bioengineering9120781. [PMID: 36550987 PMCID: PMC9774931 DOI: 10.3390/bioengineering9120781] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Revised: 10/07/2022] [Accepted: 10/11/2022] [Indexed: 12/13/2022]
Abstract
Electroencephalography (EEG) is a complicated, non-stationary signal that requires extensive preprocessing and feature extraction approaches to be accurately analyzed. In recent times, Deep learning (DL) has shown great promise in exploiting the characteristics of EEG signals as it can learn relevant features from raw data autonomously. Although studies involving DL have become more common in the last two years, the topic of whether DL truly delivers advantages over conventional Machine learning (ML) methodologies remains unsettled. This study aims to present a detailed overview of the main challenges in the field of seizure detection, prediction, and classification utilizing EEG data, and the approaches taken to solve them using ML and DL methods. A systematic review was conducted surveying peer-reviewed publications published between 2017 and 16 July 2022 using two scientific databases (Web of Science and Scopus) totaling 6822 references after discarding duplicate publications. Whereas 2262 articles were screened based on the title, abstract, and keywords, only 214 were eligible for full-text assessment. A total of 91 papers have been included in this survey after meeting the eligible inclusion and exclusion criteria. The most significant findings from the review are summarized, and several important concepts involving ML and DL for seizure detection, prediction, and classification are discussed in further depth. This review aims to learn more about the different approaches for identifying different types and stages of epileptic seizures, which may then be employed to enhance the lives of epileptic patients in the future, as well as aid experts in the field.
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Ahmad I, Wang X, Zhu M, Wang C, Pi Y, Khan JA, Khan S, Samuel OW, Chen S, Li G. EEG-Based Epileptic Seizure Detection via Machine/Deep Learning Approaches: A Systematic Review. COMPUTATIONAL INTELLIGENCE AND NEUROSCIENCE 2022; 2022:6486570. [PMID: 35755757 PMCID: PMC9232335 DOI: 10.1155/2022/6486570] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Accepted: 05/10/2022] [Indexed: 12/21/2022]
Abstract
Epileptic seizure is one of the most chronic neurological diseases that instantaneously disrupts the lifestyle of affected individuals. Toward developing novel and efficient technology for epileptic seizure management, recent diagnostic approaches have focused on developing machine/deep learning model (ML/DL)-based electroencephalogram (EEG) methods. Importantly, EEG's noninvasiveness and ability to offer repeated patterns of epileptic-related electrophysiological information have motivated the development of varied ML/DL algorithms for epileptic seizure diagnosis in the recent years. However, EEG's low amplitude and nonstationary characteristics make it difficult for existing ML/DL models to achieve a consistent and satisfactory diagnosis outcome, especially in clinical settings, where environmental factors could hardly be avoided. Though several recent works have explored the use of EEG-based ML/DL methods and statistical feature for seizure diagnosis, it is unclear what the advantages and limitations of these works are, which might preclude the advancement of research and development in the field of epileptic seizure diagnosis and appropriate criteria for selecting ML/DL models and statistical feature extraction methods for EEG-based epileptic seizure diagnosis. Therefore, this paper attempts to bridge this research gap by conducting an extensive systematic review on the recent developments of EEG-based ML/DL technologies for epileptic seizure diagnosis. In the review, current development in seizure diagnosis, various statistical feature extraction methods, ML/DL models, their performances, limitations, and core challenges as applied in EEG-based epileptic seizure diagnosis were meticulously reviewed and compared. In addition, proper criteria for selecting appropriate and efficient feature extraction techniques and ML/DL models for epileptic seizure diagnosis were also discussed. Findings from this study will aid researchers in deciding the most efficient ML/DL models with optimal feature extraction methods to improve the performance of EEG-based epileptic seizure detection.
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Affiliation(s)
- Ijaz Ahmad
- CAS Key Laboratory of Human-Machine Intelligence-Synergy Systems, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
- Shenzhen College of Advanced Technology, University of Chinese Academy of Sciences, Shenzhen, China
- Guangdong-Hong Kong-Macao Joint Laboratory of Human-Machine Intelligence-Synergy Systems, Chinese Academy of Sciences, Shenzhen, China
| | - Xin Wang
- CAS Key Laboratory of Human-Machine Intelligence-Synergy Systems, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
- Shenzhen College of Advanced Technology, University of Chinese Academy of Sciences, Shenzhen, China
- Guangdong-Hong Kong-Macao Joint Laboratory of Human-Machine Intelligence-Synergy Systems, Chinese Academy of Sciences, Shenzhen, China
| | - Mingxing Zhu
- Shenzhen College of Advanced Technology, University of Chinese Academy of Sciences, Shenzhen, China
- School of Electronics and Information Engineering, Harbin Institute of Technology, Shenzhen, China
| | - Cheng Wang
- CAS Key Laboratory of Human-Machine Intelligence-Synergy Systems, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
- Shenzhen College of Advanced Technology, University of Chinese Academy of Sciences, Shenzhen, China
- Guangdong-Hong Kong-Macao Joint Laboratory of Human-Machine Intelligence-Synergy Systems, Chinese Academy of Sciences, Shenzhen, China
| | - Yao Pi
- School of Biomedical Engineering, Sun Yat-Sen University, Guangzhou, China
| | - Javed Ali Khan
- Department of Software Engineering, University of Science and Technology, Bannu, Khyber Pakhtunkhwa, Pakistan
| | - Siyab Khan
- Institute of Computer Science and Information Technology, The University of Agriculture, Peshawar, Khyber Pakhtunkhwa, Pakistan
| | - Oluwarotimi Williams Samuel
- CAS Key Laboratory of Human-Machine Intelligence-Synergy Systems, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
- Guangdong-Hong Kong-Macao Joint Laboratory of Human-Machine Intelligence-Synergy Systems, Chinese Academy of Sciences, Shenzhen, China
| | - Shixiong Chen
- CAS Key Laboratory of Human-Machine Intelligence-Synergy Systems, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
- Guangdong-Hong Kong-Macao Joint Laboratory of Human-Machine Intelligence-Synergy Systems, Chinese Academy of Sciences, Shenzhen, China
| | - Guanglin Li
- CAS Key Laboratory of Human-Machine Intelligence-Synergy Systems, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
- Guangdong-Hong Kong-Macao Joint Laboratory of Human-Machine Intelligence-Synergy Systems, Chinese Academy of Sciences, Shenzhen, China
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Ye H, Fan Z, Li G, Wu Z, Hu J, Sheng X, Chen L, Zhu X. Spontaneous State Detection Using Time-Frequency and Time-Domain Features Extracted From Stereo-Electroencephalography Traces. Front Neurosci 2022; 16:818214. [PMID: 35368269 PMCID: PMC8968069 DOI: 10.3389/fnins.2022.818214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Accepted: 02/15/2022] [Indexed: 11/23/2022] Open
Abstract
As a minimally invasive recording technique, stereo-electroencephalography (SEEG) measures intracranial signals directly by inserting depth electrodes shafts into the human brain, and thus can capture neural activities in both cortical layers and subcortical structures. Despite gradually increasing SEEG-based brain-computer interface (BCI) studies, the features utilized were usually confined to the amplitude of the event-related potential (ERP) or band power, and the decoding capabilities of other time-frequency and time-domain features have not been demonstrated for SEEG recordings yet. In this study, we aimed to verify the validity of time-domain and time-frequency features of SEEG, where classification performances served as evaluating indicators. To do this, using SEEG signals under intermittent auditory stimuli, we extracted features including the average amplitude, root mean square, slope of linear regression, and line-length from the ERP trace and three traces of band power activities (high-gamma, beta, and alpha). These features were used to detect the active state (including activations to two types of names) against the idle state. Results suggested that valid time-domain and time-frequency features distributed across multiple regions, including the temporal lobe, parietal lobe, and deeper structures such as the insula. Among all feature types, the average amplitude, root mean square, and line-length extracted from high-gamma (60–140 Hz) power and the line-length extracted from ERP were the most informative. Using a hidden Markov model (HMM), we could precisely detect the onset and the end of the active state with a sensitivity of 95.7 ± 1.3% and a precision of 91.7 ± 1.6%. The valid features derived from high-gamma power and ERP in this work provided new insights into the feature selection procedure for further SEEG-based BCI applications.
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Affiliation(s)
- Huanpeng Ye
- State Key Laboratory of Mechanical System and Vibration, School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Zhen Fan
- Department of Neurosurgery of Huashan Hospital, Fudan University, Shanghai, China
| | - Guangye Li
- State Key Laboratory of Mechanical System and Vibration, School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Zehan Wu
- Department of Neurosurgery of Huashan Hospital, Fudan University, Shanghai, China
| | - Jie Hu
- Department of Neurosurgery of Huashan Hospital, Fudan University, Shanghai, China
| | - Xinjun Sheng
- State Key Laboratory of Mechanical System and Vibration, School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Liang Chen
- Department of Neurosurgery of Huashan Hospital, Fudan University, Shanghai, China
- *Correspondence: Liang Chen
| | - Xiangyang Zhu
- State Key Laboratory of Mechanical System and Vibration, School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai, China
- Xiangyang Zhu
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Li G, Jiang S, Meng J, Chai G, Wu Z, Fan Z, Hu J, Sheng X, Zhang D, Chen L, Zhu X. Assessing differential representation of hand movements in multiple domains using stereo-electroencephalographic recordings. Neuroimage 2022; 250:118969. [DOI: 10.1016/j.neuroimage.2022.118969] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2021] [Revised: 01/28/2022] [Accepted: 02/02/2022] [Indexed: 01/03/2023] Open
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Anuragi A, Singh Sisodia D, Pachori RB. Epileptic-seizure classification using phase-space representation of FBSE-EWT based EEG sub-band signals and ensemble learners. Biomed Signal Process Control 2022. [DOI: 10.1016/j.bspc.2021.103138] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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Anuragi A, Sisodia DS, Pachori RB. Automated FBSE-EWT based learning framework for detection of epileptic seizures using time-segmented EEG signals. Comput Biol Med 2021; 136:104708. [PMID: 34358996 DOI: 10.1016/j.compbiomed.2021.104708] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Revised: 07/25/2021] [Accepted: 07/25/2021] [Indexed: 11/19/2022]
Abstract
Epilepsy is a neurological disorder that has severely affected many people's lives across the world. Electroencephalogram (EEG) signals are used to characterize the brain's state and detect various disorders. The EEG signals are non-stationary and non-linear in nature. Therefore, it is challenging to accurately process and learn from the recorded EEG signals in order to detect disorders like epilepsy. This paper proposed an automated learning framework using the Fourier-Bessel series expansion-based empirical wavelet transform (FBSE-EWT) method for detecting epileptic seizures from EEG signals. The scale-space boundary detection method was adopted to segment the Fourier-Bessel series expansion (FBSE) spectrum of multiple frame-size time-segmented EEG signals. Multiple frame-size time-segmented EEG signal's analysis was done using four different frame sizes: full, half, quarter, and half-quarter length of recorded EEG signals. Two different time-segmentation approaches were investigated on EEG signals: 1) segmenting signals based on multiple frame-size and 2) segmenting signals based on multiple frame-size with zero-padding the remaining signal. The FBSE-EWT method was applied to decompose the EEG signals into narrow sub-band signals. Features such as line-length (LL), log-energy-entropy (LEnt), and norm-entropy (NEnt) were computed from various frequency range sub-band signals. The relief-F feature ranking method was employed to select the most significant features; this reduces the computational burden of the models. The top-ranked accumulated features were used for classification using least square-support machine learning (LS-SVM), support vector machine (SVM), k-nearest neighbor (k-NN), and ensemble bagged tree classifiers. The proposed framework for epileptic seizure detection was evaluated on two publicly available benchmark EEG datasets: the Bonn EEG dataset and Children's Hospital Boston (CHB) and the Massachusetts Institute of Technology (MIT), well known as the CHB-MIT scalp EEG dataset. Training and testing of the models were performed using the 10-fold cross-validation technique. The FBSE-EWT based learning framework was compared with other state-of-the-art methods using both datasets. Experimental results showed that the proposed framework achieved 100 % classification accuracy on the Bonn EEG dataset, whereas 99.84 % classification accuracy on the CHB-MIT scalp EEG dataset.
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Affiliation(s)
- Arti Anuragi
- Department of Computer Science & Engineering, National Institute of Technology Raipur, G E Road, Raipur, Chhattisgarh, 492010, India.
| | - Dilip Singh Sisodia
- Department of Computer Science & Engineering, National Institute of Technology Raipur, G E Road, Raipur, Chhattisgarh, 492010, India.
| | - Ram Bilas Pachori
- Department of Electrical Engineering, Indian Institute of Technology Indore, Simrol, Indore, Madhya predesh, 453552, India.
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10
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Murphy BM, Goulding RM, O'Toole JM. Detection of Transient Bursts in the EEG of Preterm Infants using Time-Frequency Distributions and Machine Learning. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2020; 2020:1023-1026. [PMID: 33018159 DOI: 10.1109/embc44109.2020.9175154] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Short-duration bursts of spontaneous activity are important markers of maturation in the electroencephalogram (EEG) of premature infants. This paper examines the application of a feature-less machine learning approach for detecting these bursts. EEGs were recorded over the first 3 days of life for infants with a gestational age below 30 weeks. Bursts were annotated on the EEG from 36 infants. In place of feature extraction, the time-series EEG is transformed into a time-frequency distribution (TFD). A gradient boosting machine is then trained directly on the whole TFD using a leave-one-out procedure. TFD kernel parameters, length of the Doppler and lag windows, are selected within a nested cross-validation procedure during training. Results indicate that detection performance is sensitive to Doppler-window length but not lag-window length. Median area under the receiver operator characteristic for detection is 0.881 (inter-quartile range 0.850 to 0.913). Examination of feature importance highlights a critical wideband region <15 Hz in the TFD. Burst detection methods form an important component in any fully-automated brain-health index for the vulnerable preterm infant.
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Ghimatgar H, Kazemi K, Helfroush MS, Pillay K, Dereymaker A, Jansen K, Vos MD, Aarabi A. Neonatal EEG sleep stage classification based on deep learning and HMM. J Neural Eng 2020; 17:036031. [DOI: 10.1088/1741-2552/ab965a] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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12
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O' Toole JM, Boylan GB. Machine learning without a feature set for detecting bursts in the EEG of preterm infants. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2020; 2019:5799-5802. [PMID: 31947170 DOI: 10.1109/embc.2019.8856533] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Deep neural networks enable learning directly on the data without the domain knowledge needed to construct a feature set. This approach has been extremely successful in almost all machine learning applications. We propose a new framework that also learns directly from the data, without extracting a feature set. We apply this framework to detecting bursts in the EEG of premature infants. The EEG is recorded within days of birth in a cohort of infants without significant brain injury and born <; 30 weeks of gestation. The method first transforms the time-domain signal to the time-frequency domain and then trains a machine learning method, a gradient boosting machine, on each time-slice of the time-frequency distribution. We control for oversampling the time-frequency distribution with a significant reduction (<; 1%) in memory and computational complexity. The proposed method achieves similar accuracy to an existing multi-feature approach: area under the characteristic curve of 0.98 (with 95% confidence interval of 0.96 to 0.99), with a median sensitivity of 95% and median specificity of 94%. The proposed framework presents an accurate, simple, and computational efficient implementation as an alternative to both the deep learning approach and to the manual generation of a feature set.
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Siddiqui MK, Morales-Menendez R, Huang X, Hussain N. A review of epileptic seizure detection using machine learning classifiers. Brain Inform 2020; 7:5. [PMID: 32451639 PMCID: PMC7248143 DOI: 10.1186/s40708-020-00105-1] [Citation(s) in RCA: 91] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2019] [Accepted: 05/09/2020] [Indexed: 01/13/2023] Open
Abstract
Epilepsy is a serious chronic neurological disorder, can be detected by analyzing the brain signals produced by brain neurons. Neurons are connected to each other in a complex way to communicate with human organs and generate signals. The monitoring of these brain signals is commonly done using Electroencephalogram (EEG) and Electrocorticography (ECoG) media. These signals are complex, noisy, non-linear, non-stationary and produce a high volume of data. Hence, the detection of seizures and discovery of the brain-related knowledge is a challenging task. Machine learning classifiers are able to classify EEG data and detect seizures along with revealing relevant sensible patterns without compromising performance. As such, various researchers have developed number of approaches to seizure detection using machine learning classifiers and statistical features. The main challenges are selecting appropriate classifiers and features. The aim of this paper is to present an overview of the wide varieties of these techniques over the last few years based on the taxonomy of statistical features and machine learning classifiers-'black-box' and 'non-black-box'. The presented state-of-the-art methods and ideas will give a detailed understanding about seizure detection and classification, and research directions in the future.
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Affiliation(s)
- Mohammad Khubeb Siddiqui
- School of Engineering and Sciences, Tecnologico de Monterrey, Av. E. Garza Sada 2501, Monterrey, Nuevo Leon Mexico
| | - Ruben Morales-Menendez
- School of Engineering and Sciences, Tecnologico de Monterrey, Av. E. Garza Sada 2501, Monterrey, Nuevo Leon Mexico
| | - Xiaodi Huang
- School of Computing and Mathematics, Charles Sturt University, 2640 Albury, NSW Australia
| | - Nasir Hussain
- College of Applied Studies and Community Service, King Saud University, Riyadh, Kingdom of Saudi Arabia
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Pillay K, Dereymaeker A, Jansen K, Naulaers G, De Vos M. Applying a data-driven approach to quantify EEG maturational deviations in preterms with normal and abnormal neurodevelopmental outcomes. Sci Rep 2020; 10:7288. [PMID: 32350387 PMCID: PMC7190650 DOI: 10.1038/s41598-020-64211-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Accepted: 04/11/2020] [Indexed: 12/02/2022] Open
Abstract
Premature babies are subjected to environmental stresses that can affect brain maturation and cause abnormal neurodevelopmental outcome later in life. Better understanding this link is crucial to developing a clinical tool for early outcome estimation. We defined maturational trajectories between the Electroencephalography (EEG)-derived ‘brain-age’ and postmenstrual age (the age since the last menstrual cycle of the mother) from longitudinal recordings during the baby’s stay in the Neonatal Intensive Care Unit. Data consisted of 224 recordings (65 patients) separated for normal and abnormal outcome at 9–24 months follow-up. Trajectory deviations were compared between outcome groups using the root mean squared error (RMSE) and maximum trajectory deviation (δmax). 113 features were extracted (per sleep state) to train a data-driven model that estimates brain-age, with the most prominent features identified as potential maturational and outcome-sensitive biomarkers. RMSE and δmax showed significant differences between outcome groups (cluster-based permutation test, p < 0.05). RMSE had a median (IQR) of 0.75 (0.60–1.35) weeks for normal outcome and 1.35 (1.15–1.55) for abnormal outcome, while δmax had a median of 0.90 (0.70–1.70) and 1.90 (1.20–2.90) weeks, respectively. Abnormal outcome trajectories were associated with clinically defined dysmature and disorganised EEG patterns, cementing the link between early maturational trajectories and neurodevelopmental outcome.
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Affiliation(s)
- Kirubin Pillay
- Institute of Biomedical Engineering (IBME), Department of Engineering Science, University of Oxford, Oxford, United Kingdom. .,Department of Paediatrics, John Radcliffe Hospital, University of Oxford, Oxford, United Kingdom.
| | - Anneleen Dereymaeker
- Department of Development and Regeneration, University Hospitals Leuven, Neonatal Intensive Care Unit, KU Leuven (University of Leuven), Leuven, Belgium
| | - Katrien Jansen
- Department of Development and Regeneration, University Hospitals Leuven, Neonatal Intensive Care Unit, KU Leuven (University of Leuven), Leuven, Belgium.,Department of Development and Regeneration, University Hospitals Leuven, Child Neurology, University of Leuven (KU Leuven), Leuven, Belgium
| | - Gunnar Naulaers
- Department of Development and Regeneration, University Hospitals Leuven, Neonatal Intensive Care Unit, KU Leuven (University of Leuven), Leuven, Belgium
| | - Maarten De Vos
- Institute of Biomedical Engineering (IBME), Department of Engineering Science, University of Oxford, Oxford, United Kingdom
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Marchi V, Stevenson N, Koolen N, Mazziotti R, Moscuzza F, Salvadori S, Pieri R, Ghirri P, Guzzetta A, Vanhatalo S. Measuring Cot-Side the Effects of Parenteral Nutrition on Preterm Cortical Function. Front Hum Neurosci 2020; 14:69. [PMID: 32256325 PMCID: PMC7090162 DOI: 10.3389/fnhum.2020.00069] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Accepted: 02/14/2020] [Indexed: 01/08/2023] Open
Abstract
Early nutritional compromise after preterm birth is shown to affect long-term neurodevelopment, however, there has been a lack of early functional measures of nutritional effects. Recent progress in computational electroencephalography (EEG) analysis has provided means to measure the early maturation of cortical activity. Our study aimed to explore whether computational metrics of early sequential EEG recordings could reflect early nutritional care measured by energy and macronutrient intake in the first week of life. A higher energy or macronutrient intake was assumed to associate with improved development of the cortical activity. We analyzed multichannel EEG recorded at 32 weeks (32.4 ± 0.7) and 36 weeks (36.6 ± 0.9) of postmenstrual age in a cohort of 28 preterm infants born before 32 weeks of postmenstrual age (range: 24.3–32 weeks). We computed several quantitative EEG measures from epochs of quiet sleep (QS): (i) spectral power; (ii) continuity; (iii) interhemispheric synchrony, as well as (iv) the recently developed estimate of maturational age. Parenteral nutritional intake from day 1 to day 7 was monitored and clinical factors collected. Lower calories and carbohydrates were found to correlate with a higher reduction of spectral amplitude in the delta band. Lower protein amount associated with higher discontinuity. Both higher proteins and lipids intake correlated with a more developmental increase in interhemispheric synchrony as well as with better progress in the estimate of EEG maturational age (EMA). Our study shows that early nutritional balance after preterm birth may influence subsequent maturation of brain activity in a way that can be observed with several intuitively reasoned and transparent computational EEG metrics. Such measures could become early functional biomarkers that hold promise for benchmarking in the future development of therapeutic interventions.
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Affiliation(s)
- Viviana Marchi
- Institute of Life Sciences, Scuola Superiore San'Anna, Pisa, Italy.,Department of Developmental Neuroscience, IRCCS Fondazione Stella Maris, Pisa, Italy.,BABA Center, Pediatric Research Center, Children's Hospital, Helsinki University Hospital, Helsinki, Finland
| | - Nathan Stevenson
- BABA Center, Pediatric Research Center, Children's Hospital, Helsinki University Hospital, Helsinki, Finland.,Department of Clinical Neurophysiology and Neuroscience Center, University of Helsinki and Helsinki University Hospital, Helsinki, Finland.,Brain Modelling Group, QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia
| | - Ninah Koolen
- BABA Center, Pediatric Research Center, Children's Hospital, Helsinki University Hospital, Helsinki, Finland
| | | | - Francesca Moscuzza
- Department of Maternal and Child Health, Division of Neonatology and Neonatal Intensive Care Unit, Santa Chiara Hospital, University of Pisa, Pisa, Italy
| | - Stefano Salvadori
- Institute of Clinical Physiology, National Research Council, Pisa, Italy
| | - Rossella Pieri
- Department of Developmental Neuroscience, IRCCS Fondazione Stella Maris, Pisa, Italy
| | - Paolo Ghirri
- Department of Maternal and Child Health, Division of Neonatology and Neonatal Intensive Care Unit, Santa Chiara Hospital, University of Pisa, Pisa, Italy.,Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Andrea Guzzetta
- Department of Developmental Neuroscience, IRCCS Fondazione Stella Maris, Pisa, Italy.,Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Sampsa Vanhatalo
- BABA Center, Pediatric Research Center, Children's Hospital, Helsinki University Hospital, Helsinki, Finland.,Department of Clinical Neurophysiology and Neuroscience Center, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
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16
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Lee S, Zhao X, Davis KA, Topjian AA, Litt B, Abend NS. Quantitative EEG predicts outcomes in children after cardiac arrest. Neurology 2019; 92:e2329-e2338. [PMID: 30971485 DOI: 10.1212/wnl.0000000000007504] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Accepted: 01/17/2019] [Indexed: 02/06/2023] Open
Abstract
OBJECTIVE To determine whether quantitative EEG (QEEG) features predict neurologic outcomes in children after cardiac arrest. METHODS We performed a single-center prospective observational study of 87 consecutive children resuscitated and admitted to the pediatric intensive care unit after cardiac arrest. Full-array conventional EEG data were obtained as part of clinical management. We computed 8 QEEG features from 5-minute epochs every hour after return of circulation. We developed predictive models utilizing random forest classifiers trained on patient age and 8 QEEG features to predict outcome. The features included SD of each EEG channel, normalized band power in alpha, beta, theta, delta, and gamma wave frequencies, line length, and regularity function scores. We measured outcomes using Pediatric Cerebral Performance Category (PCPC) scores. We evaluated the models using 5-fold cross-validation and 1,000 bootstrap samples. RESULTS The best performing model had a 5-fold cross-validation accuracy of 0.8 (0.88 area under the receiver operating characteristic curve). It had a positive predictive value of 0.79 and a sensitivity of 0.84 in predicting patients with favorable outcomes (PCPC score of 1-3). It had a negative predictive value of 0.8 and a specificity of 0.75 in predicting patients with unfavorable outcomes (PCPC score of 4-6). The model also identified the relative importance of each feature. Analyses using only frontal electrodes did not differ in prediction performance compared to analyses using all electrodes. CONCLUSIONS QEEG features can standardize EEG interpretation and predict neurologic outcomes in children after cardiac arrest.
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Affiliation(s)
- Seungha Lee
- From the Department of Bioengineering (S.L., X.Z., B.L.), The University of Pennsylvania; Department of Neurology (K.A.D., B.L., N.S.A.), Perelman School of Medicine at the University of Pennsylvania; and the Departments of Pediatrics (N.S.A.) and Anesthesia and Critical Care Medicine (A.A.T., N.S.A.), Children's Hospital of Philadelphia and Perelman School of Medicine at the University of Pennsylvania, Philadelphia
| | - Xuelong Zhao
- From the Department of Bioengineering (S.L., X.Z., B.L.), The University of Pennsylvania; Department of Neurology (K.A.D., B.L., N.S.A.), Perelman School of Medicine at the University of Pennsylvania; and the Departments of Pediatrics (N.S.A.) and Anesthesia and Critical Care Medicine (A.A.T., N.S.A.), Children's Hospital of Philadelphia and Perelman School of Medicine at the University of Pennsylvania, Philadelphia
| | - Kathryn A Davis
- From the Department of Bioengineering (S.L., X.Z., B.L.), The University of Pennsylvania; Department of Neurology (K.A.D., B.L., N.S.A.), Perelman School of Medicine at the University of Pennsylvania; and the Departments of Pediatrics (N.S.A.) and Anesthesia and Critical Care Medicine (A.A.T., N.S.A.), Children's Hospital of Philadelphia and Perelman School of Medicine at the University of Pennsylvania, Philadelphia
| | - Alexis A Topjian
- From the Department of Bioengineering (S.L., X.Z., B.L.), The University of Pennsylvania; Department of Neurology (K.A.D., B.L., N.S.A.), Perelman School of Medicine at the University of Pennsylvania; and the Departments of Pediatrics (N.S.A.) and Anesthesia and Critical Care Medicine (A.A.T., N.S.A.), Children's Hospital of Philadelphia and Perelman School of Medicine at the University of Pennsylvania, Philadelphia
| | - Brian Litt
- From the Department of Bioengineering (S.L., X.Z., B.L.), The University of Pennsylvania; Department of Neurology (K.A.D., B.L., N.S.A.), Perelman School of Medicine at the University of Pennsylvania; and the Departments of Pediatrics (N.S.A.) and Anesthesia and Critical Care Medicine (A.A.T., N.S.A.), Children's Hospital of Philadelphia and Perelman School of Medicine at the University of Pennsylvania, Philadelphia
| | - Nicholas S Abend
- From the Department of Bioengineering (S.L., X.Z., B.L.), The University of Pennsylvania; Department of Neurology (K.A.D., B.L., N.S.A.), Perelman School of Medicine at the University of Pennsylvania; and the Departments of Pediatrics (N.S.A.) and Anesthesia and Critical Care Medicine (A.A.T., N.S.A.), Children's Hospital of Philadelphia and Perelman School of Medicine at the University of Pennsylvania, Philadelphia.
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17
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O'Toole JM, Boylan GB. Quantitative Preterm EEG Analysis: The Need for Caution in Using Modern Data Science Techniques. Front Pediatr 2019; 7:174. [PMID: 31131267 PMCID: PMC6509809 DOI: 10.3389/fped.2019.00174] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Accepted: 04/16/2019] [Indexed: 11/19/2022] Open
Abstract
Hemodynamic changes during neonatal transition increase the vulnerability of the preterm brain to injury. Real-time monitoring of brain function during this period would help identify the immediate impact of these changes on the brain. Neonatal EEG provides detailed real-time information about newborn brain function but can be difficult to interpret for non-experts; preterm neonatal EEG poses even greater challenges. An objective quantitative measure of preterm brain health would be invaluable during neonatal transition to help guide supportive care and ultimately protect the brain. Appropriate quantitative measures of preterm EEG must be calculated and care needs to be taken when applying the many techniques available for this task in the era of modern data science. This review provides valuable information about the factors that influence quantitative EEG analysis and describes the common pitfalls. Careful feature selection is required and attention must be paid to behavioral state given the variations encountered in newborn EEG during different states. Finally, the detrimental influence of artifacts on quantitative EEG analysis is illustrated.
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Affiliation(s)
- John M O'Toole
- Department of Paediatrics and Child Health, INFANT Research Centre, University College Cork, Cork, Ireland
| | - Geraldine B Boylan
- Department of Paediatrics and Child Health, INFANT Research Centre, University College Cork, Cork, Ireland
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18
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Weeke LC, Toet MC, de Vries LS. Amplitude-Integrated EEG and Its Potential Role in Augmenting Management Within the NICU. Neurology 2019. [DOI: 10.1016/b978-0-323-54392-7.00014-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
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19
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Pillay K, Dereymaeker A, Jansen K, Naulaers G, Van Huffel S, De Vos M. Automated EEG sleep staging in the term-age baby using a generative modelling approach. J Neural Eng 2018; 15:036004. [DOI: 10.1088/1741-2552/aaab73] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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20
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Dereymaeker A, Pillay K, Vervisch J, De Vos M, Van Huffel S, Jansen K, Naulaers G. Review of sleep-EEG in preterm and term neonates. Early Hum Dev 2017; 113:87-103. [PMID: 28711233 PMCID: PMC6342258 DOI: 10.1016/j.earlhumdev.2017.07.003] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Neonatal sleep is a crucial state that involves endogenous driven brain activity, important for neuronal survival and guidance of brain networks. Sequential EEG-sleep analysis in preterm infants provides insights into functional brain integrity and can document deviations of the biologically pre-programmed process of sleep ontogenesis during the neonatal period. Visual assessment of neonatal sleep-EEG, with integration of both cerebral and non-cerebral measures to better define neonatal state, is still considered the gold standard. Electrographic patterns evolve over time and are gradually time locked with behavioural characteristics which allow classification of quiet sleep and active sleep periods during the last 10weeks of gestation. Near term age, the neonate expresses a short ultradian sleep cycle, with two distinct active and quiet sleep, as well as brief periods of transitional or indeterminate sleep. Qualitative assessment of neonatal sleep is however challenged by biological and environmental variables that influence the expression of EEG-sleep patterns and sleep organization. Developing normative EEG-sleep data with the aid of automated analytic methods, can further improve our understanding of extra-uterine brain development and state organization under stressful or pathological conditions. Based on those developmental biomarkers of normal and abnormal brain function, research can be conducted to support and optimise sleep in the NICU, with the ultimate goal to improve therapeutic interventions and neurodevelopmental outcome.
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Affiliation(s)
- Anneleen Dereymaeker
- Department of Development and Regeneration, University Hospitals Leuven, Neonatal Intensive Care Unit, KU Leuven (University of Leuven), Leuven, Belgium.
| | - Kirubin Pillay
- Institute of Biomedical Engineering (IBME), Department of Engineering Science, University of Oxford, Oxford, United Kingdom..
| | - Jan Vervisch
- Department of Development and Regeneration, University Hospitals Leuven, Neonatal Intensive Care Unit, KU Leuven (University of Leuven), Leuven, Belgium; Department of Development and Regeneration, University Hospitals Leuven, Child Neurology, KU Leuven (University of Leuven), Leuven, Belgium.
| | - Maarten De Vos
- Institute of Biomedical Engineering (IBME), Department of Engineering Science, University of Oxford, Oxford, United Kingdom..
| | - Sabine Van Huffel
- KU Leuven (University of Leuven), Department of Electrical Engineering-ESAT, Division Stadius, Leuven, Belgium; Imec, Leuven, Belgium.
| | - Katrien Jansen
- Department of Development and Regeneration, University Hospitals Leuven, Neonatal Intensive Care Unit, KU Leuven (University of Leuven), Leuven, Belgium; Department of Development and Regeneration, University Hospitals Leuven, Child Neurology, KU Leuven (University of Leuven), Leuven, Belgium.
| | - Gunnar Naulaers
- Department of Development and Regeneration, University Hospitals Leuven, Neonatal Intensive Care Unit, KU Leuven (University of Leuven), Leuven, Belgium.
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21
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Koolen N, Oberdorfer L, Rona Z, Giordano V, Werther T, Klebermass-Schrehof K, Stevenson N, Vanhatalo S. Automated classification of neonatal sleep states using EEG. Clin Neurophysiol 2017; 128:1100-1108. [DOI: 10.1016/j.clinph.2017.02.025] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Revised: 02/02/2017] [Accepted: 02/23/2017] [Indexed: 02/06/2023]
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22
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O'Toole JM, Boylan GB, Lloyd RO, Goulding RM, Vanhatalo S, Stevenson NJ. Detecting bursts in the EEG of very and extremely premature infants using a multi-feature approach. Med Eng Phys 2017; 45:42-50. [PMID: 28431822 PMCID: PMC5461890 DOI: 10.1016/j.medengphy.2017.04.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Revised: 03/27/2017] [Accepted: 04/02/2017] [Indexed: 11/22/2022]
Abstract
Machine learning approach enables accurate detection of bursts in preterm EEG. Features of amplitude and spectral shape capture discriminating information. Improves reliability of estimates of inter-burst intervals.
Aim: To develop a method that segments preterm EEG into bursts and inter-bursts by extracting and combining multiple EEG features. Methods: Two EEG experts annotated bursts in individual EEG channels for 36 preterm infants with gestational age < 30 weeks. The feature set included spectral, amplitude, and frequency-weighted energy features. Using a consensus annotation, feature selection removed redundant features and a support vector machine combined features. Area under the receiver operator characteristic (AUC) and Cohen’s kappa (κ) evaluated performance within a cross-validation procedure. Results: The proposed channel-independent method improves AUC by 4–5% over existing methods (p < 0.001, n=36), with median (95% confidence interval) AUC of 0.989 (0.973–0.997) and sensitivity–specificity of 95.8–94.4%. Agreement rates between the detector and experts’ annotations, κ=0.72 (0.36–0.83) and κ=0.65 (0.32–0.81), are comparable to inter-rater agreement, κ=0.60 (0.21–0.74). Conclusions: Automating the visual identification of bursts in preterm EEG is achievable with a high level of accuracy. Multiple features, combined using a data-driven approach, improves on existing single-feature methods.
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Affiliation(s)
- John M O'Toole
- Neonatal Brain Research Group, Irish Centre for Fetal and Neonatal Translational Research (INFANT), University College Cork, Ireland.
| | - Geraldine B Boylan
- Neonatal Brain Research Group, Irish Centre for Fetal and Neonatal Translational Research (INFANT), University College Cork, Ireland.
| | - Rhodri O Lloyd
- Neonatal Brain Research Group, Irish Centre for Fetal and Neonatal Translational Research (INFANT), University College Cork, Ireland.
| | - Robert M Goulding
- Neonatal Brain Research Group, Irish Centre for Fetal and Neonatal Translational Research (INFANT), University College Cork, Ireland.
| | - Sampsa Vanhatalo
- Department of Clinical Neurophysiology, Children's Hospital, HUS Medical Imaging Center, University of Helsinki and Helsinki University Hospital, Helsinki, Finland.
| | - Nathan J Stevenson
- Neonatal Brain Research Group, Irish Centre for Fetal and Neonatal Translational Research (INFANT), University College Cork, Ireland.
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23
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Dereymaeker A, Pillay K, Vervisch J, Van Huffel S, Naulaers G, Jansen K, De Vos M. An Automated Quiet Sleep Detection Approach in Preterm Infants as a Gateway to Assess Brain Maturation. Int J Neural Syst 2017; 27:1750023. [PMID: 28460602 PMCID: PMC6342251 DOI: 10.1142/s012906571750023x] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Sleep state development in preterm neonates can provide crucial information regarding functional brain maturation and give insight into neurological well being. However, visual labeling of sleep stages from EEG requires expertise and is very time consuming, prompting the need for an automated procedure. We present a robust method for automated detection of preterm sleep from EEG, over a wide postmenstrual age (PMA = gestational age + postnatal age) range, focusing first on Quiet Sleep (QS) as an initial marker for sleep assessment. Our algorithm, CLuster-based Adaptive Sleep Staging (CLASS), detects QS if it remains relatively more discontinuous than non-QS over PMA. CLASS was optimized on a training set of 34 recordings aged 27–42 weeks PMA, and performance then assessed on a distinct test set of 55 recordings of the same age range. Results were compared to visual QS labeling from two independent raters (with inter-rater agreement Kappa = 0. 93), using Sensitivity, Specificity, Detection Factor (DF = proportion of visual QS periods correctly detected by CLASS) and Misclassification Factor (MF = proportion of CLASS-detected QS periods that are misclassified). CLASS performance proved optimal across recordings at 31–38 weeks (median DF = 1.0, median MF 0–0.25, median Sensitivity 0.93–1.0, and median Specificity 0.80–0.91 across this age range), with minimal misclassifications at 35–36 weeks (median MF = 0). To illustrate the potential of CLASS in facilitating clinical research, normal maturational trends over PMA were derived from CLASS-estimated QS periods, visual QS estimates, and nonstate specific periods (containing QS and non-QS) in the EEG recording. CLASS QS trends agreed with those from visual QS, with both showing stronger correlations than nonstate specific trends. This highlights the benefit of automated QS detection for exploring brain maturation.
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Affiliation(s)
- Anneleen Dereymaeker
- 1 Department of Development and Regeneration, University Hospitals Leuven, Neonatal Intensive Care Unit, KU Leuven (University of Leuven), Leuven, Belgium
| | - Kirubin Pillay
- 2 Institute of Biomedical Engineering (IBME), Department of Engineering Science, University of Oxford, Oxford, United Kingdom
| | - Jan Vervisch
- 3 Department of Development and Regeneration, University Hospitals Leuven, Neonatal Intensive Care, Unit & Child Neurology, KU Leuven, (University of Leuven), Leuven, Belgium
| | - Sabine Van Huffel
- 4 Department of Electrical Engineering-ESAT, Division Stadius, KU Leuven (University of Leuven), Leuven, Belgium.,5 imec, Leuven, Belgium
| | - Gunnar Naulaers
- 1 Department of Development and Regeneration, University Hospitals Leuven, Neonatal Intensive Care Unit, KU Leuven (University of Leuven), Leuven, Belgium
| | - Katrien Jansen
- 3 Department of Development and Regeneration, University Hospitals Leuven, Neonatal Intensive Care, Unit & Child Neurology, KU Leuven, (University of Leuven), Leuven, Belgium
| | - Maarten De Vos
- 6 Institute of Biomedical Engineering (IBME), Department of Engineering Science, University of Oxford, Old Road Campus Research Building, OX3 7DG, Oxford, United Kingdom
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24
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Caicedo A, Thewissen L, Smits A, Naulaers G, Allegaert K, Van Huffel S. Relation Between EEG Activity and Brain Oxygenation in Preterm Neonates. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 977:133-139. [PMID: 28685437 DOI: 10.1007/978-3-319-55231-6_18] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
This study investigates the relationship between brain oxygenation, assessed by means of near infrared spectroscopy (NIRS), and brain function, assessed by means of electroencephalography (EEG). Using NIRS signals measuring the regional cerebral oxygen saturation (rScO2) and computing the fractional tissue oxygen extraction (FTOE), we compared how these variables relate to different features extracted from the EEG, such as the inter-burst interval (IBI) duration and amplitude, the amplitude of the EEG, and the amplitude of the burst. A cohort of 22 neonates undergoing sedation by propofol was studied and a regression of the NIRS-derived values to the different EEG features was made. We found that higher values of FTOE were related to higher values of EEG amplitude. These results might be of used in the monitoring of proper brain function in neonates.
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Affiliation(s)
- Alexander Caicedo
- Department of Electrical Engineering, STADIUS-ESAT, KU Leuven, Leuven, Belgium. .,imec, Leuven, Belgium.
| | | | - Anne Smits
- Department of Development and Regeneration, KU Leuven, Leuven, Belgium.,Intensive Care and Department of Surgery, Erasmus MC Sophia Children's Hospital, Rotterdam, The Netherlands
| | - Gunnar Naulaers
- Department of Development and Regeneration, KU Leuven, Leuven, Belgium
| | - Karel Allegaert
- Department of Development and Regeneration, KU Leuven, Leuven, Belgium
| | - Sabine Van Huffel
- Department of Electrical Engineering, STADIUS-ESAT, KU Leuven, Leuven, Belgium.,imec, Leuven, Belgium
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25
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Novel Burst Suppression Segmentation in the Joint Time-Frequency Domain for EEG in Treatment of Status Epilepticus. COMPUTATIONAL AND MATHEMATICAL METHODS IN MEDICINE 2016; 2016:2684731. [PMID: 27872655 PMCID: PMC5107253 DOI: 10.1155/2016/2684731] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/09/2016] [Revised: 09/10/2016] [Accepted: 10/05/2016] [Indexed: 12/23/2022]
Abstract
We developed a method to distinguish bursts and suppressions for EEG burst suppression from the treatments of status epilepticus, employing the joint time-frequency domain. We obtained the feature used in the proposed method from the joint use of the time and frequency domains, and we estimated the decision as to whether the measured EEG was a burst segment or suppression segment by the maximum likelihood estimation. We evaluated the performance of the proposed method in terms of its accordance with the visual scores and estimation of the burst suppression ratio. The accuracy was higher than the sole use of the time or frequency domains, as well as conventional methods conducted in the time domain. In addition, probabilistic modeling provided a more simplified optimization than conventional methods. Burst suppression quantification necessitated precise burst suppression segmentation with an easy optimization; therefore, the excellent discrimination and the easy optimization of burst suppression by the proposed method appear to be beneficial.
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26
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Estimating functional brain maturity in very and extremely preterm neonates using automated analysis of the electroencephalogram. Clin Neurophysiol 2016; 127:2910-2918. [DOI: 10.1016/j.clinph.2016.02.024] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Revised: 01/25/2016] [Accepted: 02/12/2016] [Indexed: 01/29/2023]
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27
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Dereymaeker A, Koolen N, Jansen K, Vervisch J, Ortibus E, De Vos M, Van Huffel S, Naulaers G. The suppression curve as a quantitative approach for measuring brain maturation in preterm infants. Clin Neurophysiol 2016; 127:2760-2765. [PMID: 27417049 DOI: 10.1016/j.clinph.2016.05.362] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Revised: 05/27/2016] [Accepted: 05/31/2016] [Indexed: 02/08/2023]
Abstract
OBJECTIVES We apply the suppression curve (SC) as an automated approach to describe the maturational change in EEG discontinuity in preterm infants. This method allows to define normative values of interburst intervals (IBIs) at different postmenstrual ages (PMA). METHODS Ninety-two multichannel EEG recordings from 25 preterm infants (born ⩽32weeks) with normal developmental outcome at 9months, were first analysed using the Line Length method, an established method for burst detection. Subsequently, the SC was defined as the 'level of EEG discontinuity'. The mean and the standard deviation of the SC, as well as the IBIs from each recording were calculated and correlated with PMA. RESULTS Over the course of development, there is a decrease in EEG discontinuity with a strong linear correlation between the mean SC and PMA till 34weeks. From 30weeks PMA, differences between discontinuous and continuous EEG become smaller, which is reflected by the decrease of the standard deviation of the SC. IBIs are found to have a significant correlation with PMA. CONCLUSIONS Automated detection of individual maturational changes in EEG discontinuity is possible with the SC. These changes include more continuous tracing, less amplitude differences and shorter suppression periods, reflecting development of the vigilance states. SIGNIFICANCE The suppression curve facilitates automated assessment of EEG maturation. Clinical applicability is straight forward since values for IBIs according to PMA are generated automatically.
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Affiliation(s)
- A Dereymaeker
- Department of Development and Regeneration, University Hospitals Leuven, Neonatal Intensive Care Unit, University of Leuven (KU Leuven), Leuven, Belgium.
| | - N Koolen
- Division STADIUS, Department of Electrical Engineering (ESAT), University of Leuven (KU Leuven), Leuven, Belgium; iMinds-KU Leuven Medical IT Department, Leuven, Belgium.
| | - K Jansen
- Department of Development and Regeneration, University Hospitals Leuven, Neonatal Intensive Care Unit, University of Leuven (KU Leuven), Leuven, Belgium; Department of Development and Regeneration, University Hospitals Leuven, Child Neurology, University of Leuven (KU Leuven), Belgium.
| | - J Vervisch
- Department of Development and Regeneration, University Hospitals Leuven, Neonatal Intensive Care Unit, University of Leuven (KU Leuven), Leuven, Belgium; Department of Development and Regeneration, University Hospitals Leuven, Child Neurology, University of Leuven (KU Leuven), Belgium.
| | - E Ortibus
- Department of Development and Regeneration, University Hospitals Leuven, Child Neurology, University of Leuven (KU Leuven), Belgium.
| | - M De Vos
- Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, Oxford, UK.
| | - S Van Huffel
- Division STADIUS, Department of Electrical Engineering (ESAT), University of Leuven (KU Leuven), Leuven, Belgium; iMinds-KU Leuven Medical IT Department, Leuven, Belgium.
| | - G Naulaers
- Department of Development and Regeneration, University Hospitals Leuven, Neonatal Intensive Care Unit, University of Leuven (KU Leuven), Leuven, Belgium.
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28
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Koolen N, Dereymaeker A, Räsänen O, Jansen K, Vervisch J, Matic V, Naulaers G, De Vos M, Van Huffel S, Vanhatalo S. Early development of synchrony in cortical activations in the human. Neuroscience 2016; 322:298-307. [PMID: 26876605 PMCID: PMC4819727 DOI: 10.1016/j.neuroscience.2016.02.017] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Revised: 02/05/2016] [Accepted: 02/08/2016] [Indexed: 11/26/2022]
Abstract
We study the early development of cortical activations synchrony index (ASI). Cortical activations become increasingly synchronized during the last trimester. Interhemispheric synchrony increases more than intrahemispheric synchrony. Our EEG metric ASI can be directly translated to experimental animal studies. ASI holds promise as an early functional biomarker of brain networks.
Early intermittent cortical activity is thought to play a crucial role in the growth of neuronal network development, and large scale brain networks are known to provide the basis for higher brain functions. Yet, the early development of the large scale synchrony in cortical activations is unknown. Here, we tested the hypothesis that the early intermittent cortical activations seen in the human scalp EEG show a clear developmental course during the last trimester of pregnancy, the period of intensive growth of cortico-cortical connections. We recorded scalp EEG from altogether 22 premature infants at post-menstrual age between 30 and 44 weeks, and the early cortical synchrony was quantified using recently introduced activation synchrony index (ASI). The developmental correlations of ASI were computed for individual EEG signals as well as anatomically and mathematically defined spatial subgroups. We report two main findings. First, we observed a robust and statistically significant increase in ASI in all cortical areas. Second, there were significant spatial gradients in the synchrony in fronto-occipital and left-to-right directions. These findings provide evidence that early cortical activity is increasingly synchronized across the neocortex. The ASI-based metrics introduced in our work allow direct translational comparison to in vivo animal models, as well as hold promise for implementation as a functional developmental biomarker in future research on human neonates.
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Affiliation(s)
- N Koolen
- Division STADIUS, Department of Electrical Engineering (ESAT), University of Leuven, Leuven, Belgium; iMinds-KU Leuven Medical IT Department, Leuven, Belgium.
| | - A Dereymaeker
- Department of Development and Regeneration, Neonatology, University of Leuven, Leuven, Belgium
| | - O Räsänen
- Department of Signal Processing and Acoustics, Aalto University, Espoo, Finland
| | - K Jansen
- Department of Development and Regeneration, Neonatology, University of Leuven, Leuven, Belgium
| | - J Vervisch
- Department of Development and Regeneration, Neonatology, University of Leuven, Leuven, Belgium
| | - V Matic
- Division STADIUS, Department of Electrical Engineering (ESAT), University of Leuven, Leuven, Belgium; iMinds-KU Leuven Medical IT Department, Leuven, Belgium
| | - G Naulaers
- Department of Development and Regeneration, Neonatology, University of Leuven, Leuven, Belgium
| | - M De Vos
- Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, Oxford, UK
| | - S Van Huffel
- Division STADIUS, Department of Electrical Engineering (ESAT), University of Leuven, Leuven, Belgium; iMinds-KU Leuven Medical IT Department, Leuven, Belgium
| | - S Vanhatalo
- Department of Children's Clinical Neurophysiology, HUS Medical Imaging Center and Children's Hospital, Helsinki University Central Hospital and University of Helsinki, Helsinki, Finland
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Fürbass F, Herta J, Koren J, Westover MB, Hartmann MM, Gruber A, Baumgartner C, Kluge T. Monitoring burst suppression in critically ill patients: Multi-centric evaluation of a novel method. Clin Neurophysiol 2016; 127:2038-46. [PMID: 26971487 DOI: 10.1016/j.clinph.2016.02.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Revised: 01/29/2016] [Accepted: 02/03/2016] [Indexed: 11/16/2022]
Abstract
OBJECTIVE To develop a computational method to detect and quantify burst suppression patterns (BSP) in the EEGs of critical care patients. A multi-center validation study was performed to assess the detection performance of the method. METHODS The fully automatic method scans the EEG for discontinuous patterns and shows detected BSP and quantitative information on a trending display in real-time. The method is designed to work without setting any patient specific parameters and to be insensitive to EEG artifacts and periodic patterns. For validation a total of 3982 h of EEG from 88 patients were analyzed from three centers. Each EEG was annotated by two reviewers to assess the detection performance and the inter-rater agreement. RESULTS Average inter-rater agreement between pairs of reviewers was κ=0.69. On average 22% of the review segments included BSP. An average sensitivity of 90% and a specificity of 84% were measured on the consensus annotations of two reviewers. More than 95% of the periodic patterns in the EEGs were correctly suppressed. CONCLUSION A fully automatic method to detect burst suppression patterns was assessed in a multi-center study. The method showed high sensitivity and specificity. SIGNIFICANCE Clinically applicable burst suppression detection method validated in a large multi-center study.
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Affiliation(s)
- Franz Fürbass
- AIT Austrian Institute of Technology, Safety & Security Department, Vienna, Austria.
| | - Johannes Herta
- Medical University of Vienna, Department of Neurosurgery, Vienna, Austria
| | - Johannes Koren
- General Hospital Hietzing with Neurological Center Rosenhuegel, 2nd Neurological Department, Vienna, Austria
| | - M Brandon Westover
- Department of Neurology, Massachusetts General Hospital, Boston, MA, USA; Department of Neurology, Harvard Medical School, Boston, MA, USA
| | - Manfred M Hartmann
- AIT Austrian Institute of Technology, Safety & Security Department, Vienna, Austria
| | - Andreas Gruber
- Medical University of Vienna, Department of Neurosurgery, Vienna, Austria
| | - Christoph Baumgartner
- General Hospital Hietzing with Neurological Center Rosenhuegel, 2nd Neurological Department, Vienna, Austria
| | - Tilmann Kluge
- AIT Austrian Institute of Technology, Safety & Security Department, Vienna, Austria
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Koolen N, Dereymaeker A, Jansen K, Vervisch J, Matic V, De Vos M, Naulaers G, Van Huffel S. The suppression curve as a new representation of the premature EEG maturation. BMC Neurosci 2015. [PMCID: PMC4699151 DOI: 10.1186/1471-2202-16-s1-p216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Matic V, Cherian PJ, Jansen K, Koolen N, Naulaers G, Swarte RM, Govaert P, Van Huffel S, De Vos M. Improving Reliability of Monitoring Background EEG Dynamics in Asphyxiated Infants. IEEE Trans Biomed Eng 2015; 63:973-983. [PMID: 26390441 DOI: 10.1109/tbme.2015.2477946] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The goal of this study is to develop an automated algorithm to quantify background electroencephalography (EEG) dynamics in term neonates with hypoxic ischemic encephalopathy. The recorded EEG signal is adaptively segmented and the segments with low amplitudes are detected. Next, depending on the spatial distribution of the low-amplitude segments, the first part of the algorithm detects (dynamic) interburst intervals (dIBIs) and performs well on the relatively artifact-free EEG periods and well-defined burst-suppression EEG periods. However, on testing the algorithm on EEG recordings of more than 48 h per neonate, a significant number of misclassified and dubious detections were encountered. Therefore, as the next step, we applied machine learning classifiers to differentiate between definite dIBI detections and misclassified ones. The developed algorithm achieved a true positive detection rate of 98%, 97%, 88%, and 95% for four duration-related dIBI groups that we subsequently defined. We benchmarked our algorithm with an expert diagnostic interpretation of EEG periods (1 h long) and demonstrated its effectiveness in clinical practice. We show that the detection algorithm effectively discriminates challenging cases encountered within mild and moderate background abnormalities. The dIBI detection algorithm improves identification of neonates with good clinical outcome as compared to the classification based on the classical burst-suppression interburst interval.
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Koolen N, Dereymaeker A, Rasanen O, Jansen K, Vervisch J, Matic V, De Vos M, Naulaers G, Van Huffel S, Vanhatalo S. Data-driven metric representing the maturation of preterm EEG. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2015; 2015:1492-1495. [PMID: 26736553 DOI: 10.1109/embc.2015.7318653] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Essential information about early brain maturation can be retrieved from the preterm human electroencephalogram (EEG). This study proposes a new set of quantitative features that correlate with early maturation. We exploit the known early trend in EEG content from intermittent to continuous activity, which changes the line length content of the EEG. The developmental shift can be captured in the line length histogram, which we use to obtain 28 features; 20 histogram bins and 8 other statistical measurements. Using the mutual information, we select 6 features with high correlation to the infant's age. This subset appears promising to detect deviances from normal brain maturation. The presented data-driven index holds promise for developing into a computational EEG index of maturation that is highly needed for overall assessment in the Neonatal Intensive Care Units.
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Murphy K, Stevenson NJ, Goulding RM, Lloyd RO, Korotchikova I, Livingstone V, Boylan GB. Automated analysis of multi-channel EEG in preterm infants. Clin Neurophysiol 2014; 126:1692-702. [PMID: 25538005 DOI: 10.1016/j.clinph.2014.11.024] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Revised: 10/17/2014] [Accepted: 11/29/2014] [Indexed: 11/28/2022]
Abstract
OBJECTIVE To develop and validate two automatic methods for the detection of burst and interburst periods in preterm eight-channel electroencephalographs (EEG). To perform a detailed analysis of interobserver agreement on burst and interburst periods and use this as a benchmark for the performance of the automatic methods. To examine mathematical features of the EEG signal and their potential correlation with gestational age. METHODS Multi-channel EEG from 36 infants, born at less than 30 weeks gestation was utilised, with a 10 min artifact-free epoch selected for each subject. Three independent expert observers annotated all EEG activity bursts in the dataset. Two automatic algorithms for burst/interburst detection were applied to the EEG data and their performances were analysed and compared with interobserver agreement. A total of 12 mathematical features of the EEG signal were calculated and correlated with gestational age. RESULTS The mean interobserver agreement was found to be 77% while mean algorithm/observer agreement was 81%. Six of the mathematical features calculated (spectral entropy, Higuchi fractal dimension, spectral edge frequency, variance, extrema median and Hilberts transform amplitude) were found to have significant correlation with gestational age. CONCLUSIONS Automatic detection of burst/interburst periods has been performed in multi-channel EEG of 36 preterm infants. The algorithm agreement with expert observers is found to be on a par with interobserver agreement. Mathematical features of EEG have been calculated which show significant correlation with gestational age. SIGNIFICANCE Automatic analysis of preterm multi-channel EEG is possible. The methods described here have the potential to be incorporated into a fully automatic system to quantitatively assess brain maturity from preterm EEG.
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Affiliation(s)
- Keelin Murphy
- Neonatal Brain Research Group, University College Cork, Cork, Ireland; Department of Paediatrics and Child Health, University College Cork, Cork, Ireland.
| | - Nathan J Stevenson
- Neonatal Brain Research Group, University College Cork, Cork, Ireland; Department of Paediatrics and Child Health, University College Cork, Cork, Ireland
| | - Robert M Goulding
- Neonatal Brain Research Group, University College Cork, Cork, Ireland; Department of Paediatrics and Child Health, University College Cork, Cork, Ireland
| | - Rhodri O Lloyd
- Neonatal Brain Research Group, University College Cork, Cork, Ireland; Department of Paediatrics and Child Health, University College Cork, Cork, Ireland
| | - Irina Korotchikova
- Neonatal Brain Research Group, University College Cork, Cork, Ireland; Department of Paediatrics and Child Health, University College Cork, Cork, Ireland
| | - Vicki Livingstone
- Neonatal Brain Research Group, University College Cork, Cork, Ireland; Department of Paediatrics and Child Health, University College Cork, Cork, Ireland
| | - Geraldine B Boylan
- Neonatal Brain Research Group, University College Cork, Cork, Ireland; Department of Paediatrics and Child Health, University College Cork, Cork, Ireland
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Matic V, Cherian PJ, Koolen N, Naulaers G, Swarte RM, Govaert P, Van Huffel S, De Vos M. Holistic approach for automated background EEG assessment in asphyxiated full-term infants. J Neural Eng 2014; 11:066007. [DOI: 10.1088/1741-2560/11/6/066007] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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