scholarly journals Application of Dense Neural Networks for Detection of Atrial Fibrillation and Ranking of Augmented ECG Feature Set

Sensors ◽  
2021 ◽  
Vol 21 (20) ◽  
pp. 6848
Author(s):  
Vessela Krasteva ◽  
Ivaylo Christov ◽  
Stefan Naydenov ◽  
Todor Stoyanov ◽  
Irena Jekova

Considering the significant burden to patients and healthcare systems globally related to atrial fibrillation (AF) complications, the early AF diagnosis is of crucial importance. In the view of prominent perspectives for fast and accurate point-of-care arrhythmia detection, our study optimizes an artificial neural network (NN) classifier and ranks the importance of enhanced 137 diagnostic ECG features computed from time and frequency ECG signal representations of short single-lead strips available in 2017 Physionet/CinC Challenge database. Based on hyperparameters’ grid search of densely connected NN layers, we derive the optimal topology with three layers and 128, 32, 4 neurons per layer (DenseNet-3@128-32-4), which presents maximal F1-scores for classification of Normal rhythms (0.883, 5076 strips), AF (0.825, 758 strips), Other rhythms (0.705, 2415 strips), Noise (0.618, 279 strips) and total F1 relevant to the CinC Challenge of 0.804, derived by five-fold cross-validation. DenseNet-3@128-32-4 performs equally well with 137 to 32 features and presents tolerable reduction by about 0.03 to 0.06 points for limited input sets, including 8 and 16 features, respectively. The feature reduction is linked to effective application of a comprehensive method for computation of the feature map importance based on the weights of the activated neurons through the total path from input to specific output in DenseNet. The detailed analysis of 20 top-ranked ECG features with greatest importance to the detection of each rhythm and overall of all rhythms reveals DenseNet decision-making process, noticeably corresponding to the cardiologists’ diagnostic point of view.

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Miguel Rodrigo ◽  
Albert J Rogers ◽  
Prasanth Ganesan ◽  
Mahmood Alhusseini ◽  
JUSTIN XU ◽  
...  

Introduction: It is unclear whether atrial fibrillation (AF) is best identified on intracardiac recordings by varying shape, rapid rate or extent of irregularity. Prioritizing these features may improve device diagnosis of AF. Hypothesis: AF can be separated from organized atrial flutter (AFL) by electrogram shape, independent of the contributions of rate or regularity. Methods: In 86 patients (25 female, age 65±11 years) we trained a convolutional neural network (CNN) to classify AF or AFL from 64 unipolar electrograms of persistent AF recorded for 60 seconds. In cases labelled as AF, we modified inputs by progressively regularizing (a) electrogram shape; (b) rate or (c) regularity in timing, to define which switched the classification to AFL. Results: The CNN provided a c-statistic of 0.95 ± 0.05 to identify AF or AFL in independent test cohorts not used for training, using 10-fold cross validation. Fig A shows AF in which progressive regularization of shape and timing from #1 to #4 flipped CNN classification into AFL in 45%. EGMs with 100% consistent shape and timing were classified by their cycle length (CL=1/rate): ~90% AF for CL < 175 ms, ~80% AFL for CL from 200-280 ms. Fig. B shows sequences simulated from patient-specific EGMs of AF that were classified as AF in 91 ± 12% of cases even if regular with CL of 200-280 ms, showing AF classification based on EGM shape alone. Figure B illustrates some ‘AF pathognomic’ electrogram shapes in red. Conclusions: AF may be identified by specific EGM shape patterns independent of regularity or rate. Regularity in shape and timing contribute ~45% to AFL classification, and adding CL explains up to 80%. Studies are required to study the mechanistic basis and clinical implications of specific AF-electrogram shapes.


2021 ◽  
Vol 12 ◽  
Author(s):  
Rahimeh Rouhi ◽  
Marianne Clausel ◽  
Julien Oster ◽  
Fabien Lauer

Atrial Fibrillation (AF) is the most common type of cardiac arrhythmia. Early diagnosis of AF helps to improve therapy and prognosis. Machine Learning (ML) has been successfully applied to improve the effectiveness of Computer-Aided Diagnosis (CADx) systems for AF detection. Presenting an explanation for the decision made by an ML model is considerable from the cardiologists' point of view, which decreases the complexity of the ML model and can provide tangible information in their diagnosis. In this paper, a range of explanation techniques is applied to hand-crafted features based ML models for heart rhythm classification. We validate the impact of the techniques by applying feature selection and classification to the 2017 CinC/PhysioNet challenge dataset. The results show the effectiveness and efficiency of SHapley Additive exPlanations (SHAP) technique along with Random Forest (RF) for the classification of the Electrocardiogram (ECG) signals for AF detection with a mean F-score of 0.746 compared to 0.706 for a technique based on the same features based on a cascaded SVM approach. The study also highlights how this interpretable hand-crafted feature-based model can provide cardiologists with a more compact set of features and tangible information in their diagnosis.


VASA ◽  
2011 ◽  
Vol 40 (6) ◽  
pp. 429-438 ◽  
Author(s):  
Berent ◽  
Sinzinger

Based upon various platelet function tests and the fact that patients experience vascular events despite taking acetylsalicylic acid (ASA or aspirin), it has been suggested that patients may become resistant to the action of this pharmacological compound. However, the term “aspirin resistance” was created almost two decades ago but is still not defined. Platelet function tests are not standardized, providing conflicting information and cut-off values are arbitrarily set. Intertest comparison reveals low agreement. Even point of care tests have been introduced before appropriate validation. Inflammation may activate platelets, co-medication(s) may interfere significantly with aspirin action on platelets. Platelet function and Cox-inhibition are only some of the effects of aspirin on haemostatic regulation. One single test is not reliable to identify an altered response. Therefore, it may be more appropriate to speak about “treatment failure” to aspirin therapy than using the term “aspirin resistance”. There is no evidence based justification from either the laboratory or the clinical point of view for platelet function testing in patients taking aspirin as well as from an economic standpoint. Until evidence based data from controlled studies will be available the term “aspirin resistance” should not be further used. A more robust monitoring of factors resulting in cardiovascular events such as inflammation is recommended.


Author(s):  
I. R. Khuzina ◽  
V. N. Komarov

The paper considers a point of view, based on the conception of the broad understanding of taxons. According to this point of view, rhyncholites of the subgenus Dentatobeccus and Microbeccus are accepted to be synonymous with the genus Rhynchoteuthis, and subgenus Romanovichella is considered to be synonymous with the genus Palaeoteuthis. The criteria, exercising influence on the different approaches to the classification of rhyncholites, have been analyzed (such as age and individual variability, sexual dimorphism, pathological and teratological features, degree of disintegration of material), underestimation of which can lead to inaccuracy. Divestment of the subgenuses Dentatobeccus, Microbeccus and Romanovichella, possessing very bright morphological characteristics, to have an independent status and denomination to their synonyms, has been noted to be unjustified. An artificial system (any suggested variant) with all its minuses is a single probable system for rhyncholites. The main criteria, minimizing its negative sides and proving the separation of the new taxon, is an available mass-scale material. The narrow understanding of the genus, used in sensible limits, has been underlined to simplify the problem of the passing the view about the genus to the other investigators and recognition of rhyncholites for the practical tasks.


2020 ◽  
Vol 10 (2) ◽  
pp. 213-218
Author(s):  
OKSANA KOCHKINA ◽  
◽  
OLGA MARCHUK ◽  

The article examines the legal and moral and ethical aspects of a misdemeanor that discredits the honor of an employee of the criminal Executive system. The considered reason for dismissal has the main feature associated with the integration of legal and moral norms, which often raises a lot of questions about the attribution of a particular offense to this basis. Using the analysis of normative legal acts, the authors attempt to identify the signs that contribute to the separation of the studied grounds for dismissal from all their diversity. The classification of offenses that discredit the honor of an employee of the criminal Executive system is presented, which allows to systematize and organize the knowledge obtained about the considered grounds for dismissal. The analysis of a misdemeanor that defames the honor of an employee of the penal system from a moral and ethical position gives an understanding, first of all, that it does not have a clear regulation from the point of view of the law, but the consequences of committing such a misdemeanor are clearly legal. The concepts of “honor” and “dignity” are considered as ethical categories and are analyzed as personal qualities that are manifested in an employee of the penal correction system during the period of service. These categories in the behavior of a person or employee are manifested both externally (assessment from the outside) and internally (self-assessment). The article describes the value orientation of an employee of the criminal Executive system to ethical standards in professional activity, which is an integral part of the moral and ethical side of a misdemeanor that discredits the honor of an employee.


Author(s):  
Zuzana Kvetanová

The submitted study addresses the topic of the current state of the opinion journalism and its genres in the Slovak periodical press. The author draws attention to the question of classification of the opinion journalism of a rational and emotional type from the genre categorization point of view and, simultaneously, reflects on its application in the present journalistic practice. This brings a certain rate of confrontation between the defined theoretical premises and their subsequent practical (non-)implementation. The main objective of the study is to clarify the presence of genres of analytical and literary opinion journalism stated by media theory in the environment of the Slovak periodicals. Presentation of the basic terminological axis and the related explication of journalism genres included in the opinion journalism constitute the secondary objectives of the paper. For the purposes of achieving the set objectives, the author uses methods of logical analysis of text in combination with discourse analysis. Similarly, she predicts the evident presence of the phenomenon of hybridization in the Slovak journalistic practice.


2020 ◽  
pp. 66-74
Author(s):  
E. Zakablukovskiy

The article highlights certain aspects of the discussion on the topic of reductionism vs. holism in the philosophy of medicine. Classic radical reductionism is defeated by the concept of emergence. The s.c. bio-medical point of view on a malady, despite its relevance and clear benefit, is not recognized as universal as its adherents may claim, and it yields to an integral psycho-bio-social model. The author introduces a new classification of holism (vitalistic, social and individualistic) and makes appropriate recommendations to clinicians. It is social holism at the macro level that has proven effective in combating the spread of COVID-19.


2020 ◽  
pp. 65-75
Author(s):  
S. N. Smirnov

The author considers the problems of typification of society. Some concepts of typification of social stratification models in different countries formulated and justified in historical and legal, historical, sociological, and economic scientific literature are reviewed. The circumstances that make it difficult to formulate universal concepts designed for application in the complex of social Sciences are identified. These circumstances include insufficient consideration of legal factors, including the position of the legislator, the specifics of the corporate legal status, and the characteristics of the mechanism for changing individual legal status. The author offers a variant of classification of society types from the point of view of legal registration of their structure. The possibility of distinguishing types such as consolidated companies and segmented companies is justified.


2020 ◽  
Vol 5 (1) ◽  
pp. 243-251
Author(s):  
Akira Horibata ◽  
Tsuneo Kato

AbstractA total of 145 accessions of the genus Citrus and related genera, maintained in the Conservation Garden for Citrus Germplasm at the Experimental Farm of Kindai University, Yuasa, Wakayama, Japan, were examined for their phylogenetic relationships. The present classification was conducted using an inter-retrotransposon amplified polymorphism (IRAP) method based on the insertion polymorphism of a retrotransposon, CIRE1, identified in C. sinensis. The objective of this study was to evaluate the applicability of the IRAP method for citrus classification. The constructed dendrogram showed that the 145 accessions and two outgroup species were successfully classified into five major clades. A large number of C. sinensis accessions were divided into three traditional groups, navel orange, sweet orange, and blood orange, almost corresponding to the sub-clades in the dendrogram. Several other accessions belonging to the same species, and also many hybrid cultivars from crossbreeding, were localized into the respective sub-clades or near positions in the dendrogram. Several unclassified accessions could also be located in the dendrogram, suggesting novel relationships with other accessions. It was concluded that the IRAP method based on CIRE1 insertion polymorphism was suitable for the classification of citrus from a molecular point of view.


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