Deep Learning with a Recurrent Network Structure in the Sequence Modeling of Imbalanced Data for ECG-Rhythm Classifier

The interpretation of Myocardial Infarction (MI) via electrocardiogram (ECG) signal is a challenging task. ECG signals’ morphological view show significant variation in different patients under different physical conditions. Several learning algorithms have been studied to interpret MI. However, the drawback of machine learning is the use of heuristic features with shallow feature learning architectures. To overcome this problem, a deep learning approach is used for learning features automatically, without conventional handcrafted features. This paper presents sequence modeling based on deep learning with recurrent network for ECG-rhythm signal classification. The recurrent network architecture such as a Recurrent Neural Network (RNN) is proposed to automatically interpret MI via ECG signal. The performance of the proposed method is compared to the other recurrent network classifiers such as Long Short-Term Memory (LSTM) and Gated Recurrent Unit (GRU). The objective is to obtain the best sequence model for ECG signal processing. This paper also aims to study a proper data partitioning ratio for the training and testing sets of imbalanced data. The large imbalanced data are obtained from MI and healthy control of PhysioNet: The PTB Diagnostic ECG Database 15-lead ECG signals. According to the comparison result, the LSTM architecture shows better performance than standard RNN and GRU architecture with identical hyper-parameters. The LSTM architecture also shows better classification compared to standard recurrent networks and GRU with sensitivity, specificity, precision, F1-score, BACC, and MCC is 98.49%, 97.97%, 95.67%, 96.32%, 97.56%, and 95.32%, respectively. Apparently, deep learning with the LSTM technique is a potential method for classifying sequential data that implements time steps in the ECG signal.

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Complex Deep Learning Models for Denoising of Human Heart ECG signals

10.31224/osf.io/3sdfa ◽

2020 ◽

Author(s):

Corneliu Arsene

Keyword(s):

Deep Learning ◽

Real Time ◽

Short Term Memory ◽

Wearable Sensors ◽

Real Life ◽

Ecg Signal ◽

Great Success ◽

Processing Unit ◽

Ecg Signals ◽

Real Time Applications

Effective and powerful methods for denoising real electrocardiogram (ECG) signals are important for wearable sensors and devices. Deep Learning (DL) models have been used extensively in image processing and other domains with great success but only very recently have been used in processing ECG signals. This paper presents several DL models namely Convolutional Neural Networks (CNNs), Long Short-Term Memory (LSTM), Restricted Boltzmann Machine (RBM) together with the more conventional filtering methods (low pass filtering, high pass filtering, Notch filtering) and the standard wavelet-based technique for denoising EEG signals. These methods are trained, tested and evaluated on different synthetic and real ECG datasets taken from the MIT PhysioNet database and for different simulation conditions (i.e. various lengths of the ECG signals, single or multiple records). The results show the CNN model is a performant model that can be used for off-line denoising ECG applications where it is satisfactory to train on a clean part of an ECG signal from an ECG record, and then to test on the same ECG signal, which would have some high level of noise added to it. However, for real-time applications or near-real time applications, this task becomes more cumbersome, as the clean part of an ECG signal is very probable to be very limited in size. Therefore the solution put forth in this work is to train a CNN model on 1 second ECG noisy artificial multiple heartbeat data (i.e. ECG at effort), which was generated in a first instance based on few sequences of real signal heartbeat ECG data (i.e. ECG at rest). Afterwards it would be possible to use the trained CNN model in real life situations to denoise the ECG signal. This corresponds also to reality, where usually the human is put at rest and the ECG is recorded and then the same human is asked to do some physical exercises and the ECG is recorded at effort. The quality of results is assessed visually but also by using the Root Mean Squared (RMS) and the Signal to Noise Ratio (SNR) measures. All CNN models used an NVIDIA TITAN V Graphical Processing Unit (GPU) with 12 GB RAM, which reduces drastically the computational times. Finally, as an element of novelty, the paper presents also a Design of Experiment (DoE) study which intends to determine the optimal structure of a CNN model, which type of study has not been seen in the literature before.

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Deep Convolutional Bidirectional LSTM Model for identifying Ventricular Tachyarrhythmia using ECG Signal Variability

10.21203/rs.3.rs-1194607/v1 ◽

2021 ◽

Author(s):

MANOJ KUMAR OJHA ◽

Sulochna Wadhwani ◽

Arun Kumar Wadhwani ◽

Anupam Shukla

Keyword(s):

Deep Learning ◽

Electrical Activity ◽

Short Term Memory ◽

Early Stage ◽

Ventricular Tachyarrhythmia ◽

Diagnostic System ◽

Learning Model ◽

Ecg Signal ◽

Ecg Signals ◽

Deep Learning Model

Abstract An electrocardiogram (ECG) signal is used widely to detect ventricular tachyarrhythmia (VTA) and to diagnose heart disease. Deep learning models and large ECG data have made the diagnosis of VTA an attractive task to demonstrate the power of artificial intelligence in clinical applications. One of the life-threatening complications of VTA is cardiac arrest (CA). The VTA is divided into two categories: ventricular fibrillation (VF) and ventricular tachycardia (VT). Abnormal electrical activity in the ventricle causes VT, which leads to CA, whereas the chaotic electrical activity in the ventricle leads to VF. To improve the clinical diagnostic system and to help cardiologists, it is essential to identify the risk of VTA at an early stage. The goal of this paper is to develop an end-to-end (E2E) deep learning model that uses a convolution neural network (CNN) and a bidirectional long-short term memory network (BiLSTM) to classify VT and VF arrhythmias from multiple ECG databases. The CNN extracts features from ECG signals, and BiLSTM learns information. The ECG signals are acquired from the MIT-BIH malignant ventricular arrhythmia database (VFDB) and the Creighton University VTA database (CUDB). These ECG signals indicate that heart rate variability is a fast and dynamic event. Before the method's implementation, ECG signals are windowed at a fixed size according to annotation information and then normalized within each window. In terms of accuracy and sensitivity, the proposed CNN-BiLSTM deep learning model outperforms existing state-of-the-art methods. These results made it possible to obtain a relatively higher average accuracy (AC) of 99.37%, precision (PE) of 97.12%, a sensitivity (SE) of 98.15%, and F-score (FS) of 98.43%, and an overall accuracy of 99.07%, respectively.

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Classification of Skin Disease Using Deep Learning Neural Networks with MobileNet V2 and LSTM

Sensors ◽

10.3390/s21082852 ◽

2021 ◽

Vol 21 (8) ◽

pp. 2852

Author(s):

Parvathaneni Naga Srinivasu ◽

Jalluri Gnana SivaSai ◽

Muhammad Fazal Ijaz ◽

Akash Kumar Bhoi ◽

Wonjoon Kim ◽

...

Keyword(s):

Neural Network ◽

Neural Networks ◽

Deep Learning ◽

Convolutional Neural Network ◽

Skin Disease ◽

Network Architecture ◽

Large Scale ◽

Short Term Memory ◽

Convolutional Networks ◽

Occurrence Matrix

Deep learning models are efficient in learning the features that assist in understanding complex patterns precisely. This study proposed a computerized process of classifying skin disease through deep learning based MobileNet V2 and Long Short Term Memory (LSTM). The MobileNet V2 model proved to be efficient with a better accuracy that can work on lightweight computational devices. The proposed model is efficient in maintaining stateful information for precise predictions. A grey-level co-occurrence matrix is used for assessing the progress of diseased growth. The performance has been compared against other state-of-the-art models such as Fine-Tuned Neural Networks (FTNN), Convolutional Neural Network (CNN), Very Deep Convolutional Networks for Large-Scale Image Recognition developed by Visual Geometry Group (VGG), and convolutional neural network architecture that expanded with few changes. The HAM10000 dataset is used and the proposed method has outperformed other methods with more than 85% accuracy. Its robustness in recognizing the affected region much faster with almost 2× lesser computations than the conventional MobileNet model results in minimal computational efforts. Furthermore, a mobile application is designed for instant and proper action. It helps the patient and dermatologists identify the type of disease from the affected region’s image at the initial stage of the skin disease. These findings suggest that the proposed system can help general practitioners efficiently and effectively diagnose skin conditions, thereby reducing further complications and morbidity.

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End-to-End Deep Learning Fusion of Fingerprint and Electrocardiogram Signals for Presentation Attack Detection

Sensors ◽

10.3390/s20072085 ◽

2020 ◽

Vol 20 (7) ◽

pp. 2085 ◽

Cited By ~ 1

Author(s):

Rami M. Jomaa ◽

Hassan Mathkour ◽

Yakoub Bazi ◽

Md Saiful Islam

Keyword(s):

Neural Network ◽

Deep Learning ◽

Convolutional Neural Network ◽

Attack Detection ◽

Ecg Signal ◽

Ecg Signals ◽

Biometric Systems ◽

Fingerprint Biometrics ◽

End To End ◽

The Impact

Although fingerprint-based systems are the commonly used biometric systems, they suffer from a critical vulnerability to a presentation attack (PA). Therefore, several approaches based on a fingerprint biometrics have been developed to increase the robustness against a PA. We propose an alternative approach based on the combination of fingerprint and electrocardiogram (ECG) signals. An ECG signal has advantageous characteristics that prevent the replication. Combining a fingerprint with an ECG signal is a potentially interesting solution to reduce the impact of PAs in biometric systems. We also propose a novel end-to-end deep learning-based fusion neural architecture between a fingerprint and an ECG signal to improve PA detection in fingerprint biometrics. Our model uses state-of-the-art EfficientNets for generating a fingerprint feature representation. For the ECG, we investigate three different architectures based on fully-connected layers (FC), a 1D-convolutional neural network (1D-CNN), and a 2D-convolutional neural network (2D-CNN). The 2D-CNN converts the ECG signals into an image and uses inverted Mobilenet-v2 layers for feature generation. We evaluated the method on a multimodal dataset, that is, a customized fusion of the LivDet 2015 fingerprint dataset and ECG data from real subjects. Experimental results reveal that this architecture yields a better average classification accuracy compared to a single fingerprint modality.

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ECG signal classification based on Deep Learning by using Convolutional Neural Network (CNN)

Iraqi Journal of Information & Communications Technology ◽

10.31987/ijict.3.3.106 ◽

2020 ◽

Vol 3 (3) ◽

pp. 12-23

Author(s):

Aqeel M. Hamad alhussainy ◽

Ammar D. Jasim

Keyword(s):

Deep Learning ◽

Classification System ◽

World Health ◽

Geometric Transformation ◽

Ecg Signal ◽

Ecg Signals ◽

Result Show ◽

Automatic Methods ◽

Health Organization

Cardiovascular diseases (CVDs) are consider the main cause of death today According to World Health Organization (WHO),and because that ECG signal is very important tool in monitoring and diagnosis of these disease , different automatic methods were proposed based on this signal. [1]. The manual analysis of ECG signals is suffered different challenges such as differeculty of detecting and classify waveform of this signal, So, many machine learning methods are explored to describe the anomalies ECG signal accurately . Deep learning (DL) can be used in ECG classification, it can improve the quality of the automatic classification system. In this paper , we have proposed a deep learning classification system by using different layers of convolution, rectifier and pooling operations that can be used to increase feature extraction of ECG signal. We have proposed two models, one is used for input signal of 1-D, in which we designed model for classification csv type of data for ECG signal, while in the second proposed system, we used model for 2-D signal after convert it from its csv type . 2-D signal (ECG image) is used in order to augment the two dimensional signal with different methods to increase the accuracy of the model by training it with geometric transformation of the original input images such as rotation, shearing etc.The results are compared with AlexNet and other models based on the metrics, which are used to measure the performance of the proposed work, the result show that, the proposed models improve the efficiency of the classification in the two systems.

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Application of deep learning methods to predict ionosphere parameters in real time

E3S Web of Conferences ◽

10.1051/e3sconf/202019602007 ◽

2020 ◽

Vol 196 ◽

pp. 02007

Author(s):

Vladimir Mochalov ◽

Anastasia Mochalova

Keyword(s):

Neural Network ◽

Deep Learning ◽

Real Time ◽

Network Architecture ◽

Short Term Memory ◽

Neural Network Architecture ◽

Short Term ◽

Learning Methods ◽

Term Memory ◽

Long Short Term Memory

In this paper, the previously obtained results on recognition of ionograms using deep learning are expanded to predict the parameters of the ionosphere. After the ionospheric parameters have been identified on the ionogram using deep learning in real time, we can predict the parameters for some time ahead on the basis of the new data obtained Examples of predicting the ionosphere parameters using an artificial recurrent neural network architecture long short-term memory are given. The place of the block for predicting the parameters of the ionosphere in the system for analyzing ionospheric data using deep learning methods is shown.

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Forex exchange rate forecasting using deep recurrent neural networks

Digital Finance ◽

10.1007/s42521-020-00019-x ◽

2020 ◽

Vol 2 (1-2) ◽

pp. 69-96 ◽

Cited By ~ 1

Author(s):

Alexander Jakob Dautel ◽

Wolfgang Karl Härdle ◽

Stefan Lessmann ◽

Hsin-Vonn Seow

Keyword(s):

Neural Network ◽

Deep Learning ◽

Exchange Rate ◽

Language Processing ◽

Short Term Memory ◽

Recurrent Network ◽

Network Architectures ◽

Exchange Rate Forecasting ◽

Trading Model ◽

Gated Recurrent Units

Abstract Deep learning has substantially advanced the state of the art in computer vision, natural language processing, and other fields. The paper examines the potential of deep learning for exchange rate forecasting. We systematically compare long short-term memory networks and gated recurrent units to traditional recurrent network architectures as well as feedforward networks in terms of their directional forecasting accuracy and the profitability of trading model predictions. Empirical results indicate the suitability of deep networks for exchange rate forecasting in general but also evidence the difficulty of implementing and tuning corresponding architectures. Especially with regard to trading profit, a simpler neural network may perform as well as if not better than a more complex deep neural network.

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Forecasting Ionospheric foF2 Based on Deep Learning Method

Remote Sensing ◽

10.3390/rs13193849 ◽

2021 ◽

Vol 13 (19) ◽

pp. 3849

Author(s):

Xiaojun Li ◽

Chen Zhou ◽

Qiong Tang ◽

Jun Zhao ◽

Fubin Zhang ◽

...

Keyword(s):

Neural Network ◽

Deep Learning ◽

Short Term Memory ◽

Back Propagation ◽

Back Propagation Neural Network ◽

Sequential Data ◽

Activity Maximum ◽

Forecasting Accuracy ◽

Ionosphere Model ◽

Forecasting Performance

In this paper, a deep learning long-short-term memory (LSTM) method is applied to the forecasting of the critical frequency of the ionosphere F2 layer (foF2). Hourly values of foF2 from 10 ionospheric stations in China and Australia (based on availability) from 2006 to 2019 are used for training and verifying. While 2015 and 2019 are exclusive for verifying the forecasting accuracy. The inputs of the LSTM model are sequential data for the previous values, which include local time (LT), day number, solar zenith angle, the sunspot number (SSN), the daily F10.7 solar flux, geomagnetic the Ap and Kp indices, geographic coordinates, neutral winds, and the observed value of foF2 at the previous moment. To evaluate the forecasting ability of the deep learning LSTM model, two different neural network forecasting models: a back-propagation neural network (BPNN) and a genetic algorithm optimized backpropagation neural network (GABP) were established for comparative analysis. The foF2 parameters were forecasted under geomagnetic quiet and geomagnetic disturbed conditions during solar activity maximum (2015) and minimum (2019), respectively. The forecasting results of these models are compared with those of the international reference ionosphere model (IRI2016) and the measurements. The diurnal and seasonal variations of foF2 for the 4 models were compared and analyzed from 8 selected verification stations. The forecasting results reveal that the deep learning LSTM model presents the optimal performance of all models in forecasting the time series of foF2, while the IRI2016 model has the poorest forecasting performance, and the BPNN model and GABP model are between two of them.

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Short-Term Load Forecasting Based on Deep Learning Bidirectional LSTM Neural Network

Applied Sciences ◽

10.3390/app11178129 ◽

2021 ◽

Vol 11 (17) ◽

pp. 8129 ◽

Cited By ~ 1

Author(s):

Changchun Cai ◽

Yuan Tao ◽

Tianqi Zhu ◽

Zhixiang Deng

Keyword(s):

Neural Network ◽

Deep Learning ◽

Power Systems ◽

Network Architecture ◽

Short Term Memory ◽

Load Forecasting ◽

Short Term ◽

Architecture Model ◽

Power Load ◽

Short Term Load Forecasting

Accurate load forecasting guarantees the stable and economic operation of power systems. With the increasing integration of distributed generations and electrical vehicles, the variability and randomness characteristics of individual loads and the distributed generation has increased the complexity of power loads in power systems. Hence, accurate and robust load forecasting results are becoming increasingly important in modern power systems. The paper presents a multi-layer stacked bidirectional long short-term memory (LSTM)-based short-term load forecasting framework; the method includes neural network architecture, model training, and bootstrapping. In the proposed method, reverse computing is combined with forward computing, and a feedback calculation mechanism is designed to solve the coupling of before and after time-series information of the power load. In order to improve the convergence of the algorithm, deep learning training is introduced to mine the correlation between historical loads, and the multi-layer stacked style of the network is established to manage the power load information. Finally, actual data are applied to test the proposed method, and a comparison of the results of the proposed method with different methods shows that the proposed method can extract dynamic features from the data as well as make accurate predictions, and the availability of the proposed method is verified with real operational data.

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Abstract 17189: Explaining the Deep Learning Black Box by Identifying Segments of the Single-Lead ECG Signal Used for Detection of Atrial Fibrillation

Circulation ◽

10.1161/circ.142.suppl_3.17189 ◽

2020 ◽

Vol 142 (Suppl_3) ◽

Author(s):

Praharsh Ivaturi ◽

Matteo Gadaleta ◽

Amitabh C Pandey ◽

Michael Pazzani ◽

Steven R Steinhubl ◽

...

Keyword(s):

Atrial Fibrillation ◽

Decision Making ◽

Deep Learning ◽

Network Architecture ◽

Normal Sinus Rhythm ◽

Black Box ◽

P Wave ◽

Ecg Signal ◽

Rr Intervals ◽

Post Hoc

Introduction: Deep learning (DL) has proved effective for automatic identification of atrial fibrillation (AF) using single-lead ECG. Adoption and trust of DL by clinicians is limited by its black box nature. Hypothesis: Post hoc explanations can elucidate what part of ECG signal is used by the black box DL algorithm, quantifying the importance of clinically relevant features in the classification decision. Making DL decision process transparent will help its integration into clinical practice. Methods: 8,528 single-lead ECG recordings collected using AliveCor devices (PhysioNet) were used. Each signal was labeled as normal sinus rhythm, AF, other arrhythmia or noise. DL automatic classification involves a lightweight convolutional neural network architecture - MobileNet - whose performance is analyzed with an explanation method for DL. Results: Each RR interval is divided into 8 equal segments, where segment 1 follows each R peak, 4 and 5 correspond to the isoelectric baseline, and 7 to the P wave. The explanation method substitutes one of these segments with a straight line, and the corresponding change in sensitivity highlights its importance for the DL algorithm decision. MobileNet achieved a sensitivity of 92.5% to identify AF (9.4% of ECGs were in AF). Sensitivity increases by 2.5% when Segment 7 is removed, indicating that the absence of P wave leads the network to classify more frequently samples as AF.(Figure) When Segments 4 and 5 are removed, the sensitivity decreases by 2.5% and 5.0%, and by 26.7% when removed together. When all RR intervals are normalized to the same value (RR in the Figure), sensitivity for AF drops by 78.3%, showing that RR intervals are key for AF detection by DL algorithm. Conclusions: Post hoc explanations for AF detection by DL from single-lead ECG show the importance of common morphological features used for classifying AF. These methods can be used to understand the decision-making process of DL and motivate its clinical adoption.

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