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1.
Comput Biol Med ; 173: 108280, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38547655

RESUMO

BACKGROUND: Timely detection of neurodevelopmental and neurological conditions is crucial for early intervention. Specific Language Impairment (SLI) in children and Parkinson's disease (PD) manifests in speech disturbances that may be exploited for diagnostic screening using recorded speech signals. We were motivated to develop an accurate yet computationally lightweight model for speech-based detection of SLI and PD, employing novel feature engineering techniques to mimic the adaptable dynamic weight assignment network capability of deep learning architectures. MATERIALS AND METHODS: In this research, we have introduced an advanced feature engineering model incorporating a novel feature extraction function, the Factor Lattice Pattern (FLP), which is a quantum-inspired method and uses a superposition-like mechanism, making it dynamic in nature. The FLP encompasses eight distinct patterns, from which the most appropriate pattern was discerned based on the data structure. Through the implementation of the FLP, we automatically extracted signal-specific textural features. Additionally, we developed a new feature engineering model to assess the efficacy of the FLP. This model is self-organizing, producing nine potential results and subsequently choosing the optimal one. Our speech classification framework consists of (1) feature extraction using the proposed FLP and a statistical feature extractor; (2) feature selection employing iterative neighborhood component analysis and an intersection-based feature selector; (3) classification via support vector machine and k-nearest neighbors; and (4) outcome determination using combinational majority voting to select the most favorable results. RESULTS: To validate the classification capabilities of our proposed feature engineering model, designed to automatically detect PD and SLI, we employed three speech datasets of PD and SLI patients. Our presented FLP-centric model achieved classification accuracy of more than 95% and 99.79% for all PD and SLI datasets, respectively. CONCLUSIONS: Our results indicate that the proposed model is an accurate alternative to deep learning models in classifying neurological conditions using speech signals.


Assuntos
Doença de Parkinson , Transtorno Específico de Linguagem , Criança , Humanos , Fala , Doença de Parkinson/diagnóstico , Máquina de Vetores de Suporte
2.
J Cardiovasc Electrophysiol ; 35(2): 267-277, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38073065

RESUMO

INTRODUCTION: Development of a rapid means to verify the ventricular tachycardia (VT) isthmus location from heart surface electrogram recordings would be a helpful tool for the electrophysiologist. METHOD: Myocardial infarction was induced in 22 canines by left anterior descending coronary artery ligation under general anesthesia. After 3-5 days, VT was inducible via programmed electrical stimulation at the anterior left ventricular epicardial surface. Bipolar VT electrograms were acquired from 196 to 312 recording sites using a multielectrode array. Electrograms were marked for activation time, and activation maps were constructed. The activation signal, or signature, is defined as the cumulative number of recording sites that have activated per millisecond, and it was utilized to segment each circuit into inner and outer circuit pathways, and as an estimate of best ablation lesion location to prevent VT. RESULTS: VT circuit components were differentiable by activation signals as: inner pathway (mean: 0.30 sites activating/ms) and outer pathway (mean: 2.68 sites activating/ms). These variables were linearly related (p < .001). Activation signal characteristics were dependent in part upon the isthmus exit site. The inner circuit pathway determined by the activation signal overlapped and often extended beyond the activation map isthmus location for each circuit. The best lesion location estimated by the activation signal would likely block an electrical impulse traveling through the isthmus, to prevent VT in all circuits. CONCLUSIONS: The activation signal algorithm, simple to implement for real-time computer display, approximates the VT isthmus location and shape as determined from activation marking, and best ablation lesion location to prevent reinduction.


Assuntos
Ablação por Cateter , Infarto do Miocárdio , Taquicardia Ventricular , Animais , Cães , Sistema de Condução Cardíaco , Taquicardia Ventricular/diagnóstico , Taquicardia Ventricular/cirurgia , Infarto do Miocárdio/diagnóstico , Infarto do Miocárdio/cirurgia , Algoritmos
3.
Comput Methods Programs Biomed ; 241: 107764, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37597351

RESUMO

INTRODUCTION: A quantitative analysis of the components of reentrant ventricular tachycardia (VT) circuitry could improve understanding of its onset and perpetuation. METHOD: In 19 canine experiments, the left anterior descending coronary artery was ligated to generate a subepicardial infarct. The border zone resided at the epicardial surface of the anterior left ventricle and was mapped 3-5 days postinfarction with a 196-312 bipolar multielectrode array. Monomorphic VT was inducible by extrastimulation. Activation maps revealed an epicardial double-loop reentrant circuit and isthmus, causing VT. Several circuit parameters were analyzed: the coupling interval for VT induction, VT cycle length, the lateral isthmus boundary (LIB) lengths, and isthmus width and angle. RESULTS: The extrastimulus interval for VT induction and the VT cycle length were strongly correlated (p < 0.001). Both the extrastimulus interval and VT cycle length were correlated to the shortest LIB (p < 0.005). A derivation was developed to suggest that when conduction block at the shorter LIB is functional, the VT cycle length may depend on the local refractory period and the delay from wavefront pivot around the LIB. Isthmus width and angle were uncorrelated to other parameters. CONCLUSIONS: The shorter LIB is correlated to VT cycle length, hence its circuit loop may drive reentrant VT. The extrastimulation interval, VT cycle length, and shorter LIB are intertwined, and may depend upon the local refractory period. Isthmus width and angle are less correlated, perhaps being more related to electrical discontinuity caused by alterations in infarct shape at depth.


Assuntos
Taquicardia Ventricular , Animais , Cães , Ventrículos do Coração , Vasos Coronários , Eletricidade
4.
Comput Biol Med ; 163: 107063, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37329621

RESUMO

A brain tumor is an abnormal mass of tissue located inside the skull. In addition to putting pressure on the healthy parts of the brain, it can lead to significant health problems. Depending on the region of the brain tumor, it can cause a wide range of health issues. As malignant brain tumors grow rapidly, the mortality rate of individuals with this cancer can increase substantially with each passing week. Hence it is vital to detect these tumors early so that preventive measures can be taken at the initial stages. Computer-aided diagnostic (CAD) systems, in coordination with artificial intelligence (AI) techniques, have a vital role in the early detection of this disorder. In this review, we studied 124 research articles published from 2000 to 2022. Here, the challenges faced by CAD systems based on different modalities are highlighted along with the current requirements of this domain and future prospects in this area of research.


Assuntos
Inteligência Artificial , Neoplasias Encefálicas , Humanos , Encéfalo , Neoplasias Encefálicas/diagnóstico , Crânio , Compostos Radiofarmacêuticos
5.
Int J Mol Sci ; 24(12)2023 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-37373122

RESUMO

Celiac disease (CD) is a chronic autoimmune disorder that affects the small intestine in genetically predisposed individuals. Previous studies have investigated the potential link between CD and cardiovascular disease (CVD); however, the findings have been inconsistent. We aimed to provide an updated review of the literature on the association between CD and CVD. PubMed was searched from inception to January 2023 using keywords including CD, cardiovascular disease, coronary artery disease, cardiac arrhythmia, heart failure, cardiomyopathy, and myocarditis. We summarized the results of the studies, including meta-analyses and original investigations, and presented them according to the different forms of CVD. Meta-analyses published in 2015 provided mixed results regarding the relationship between CD and CVD. However, subsequent original investigations have shed new light on this association. Recent studies indicate that individuals with CD are at a higher risk of developing overall CVD, including an increased risk of myocardial infarction and atrial fibrillation. However, the link between CD and stroke is less established. Further research is needed to determine the link between CD and other cardiac arrhythmias, such as ventricular arrhythmia. Moreover, the relationship between CD and cardiomyopathy or heart failure, as well as myopericarditis, remains ambiguous. CD patients have a lower prevalence of traditional cardiac risk factors, such as smoking, hypertension, hyperlipidemia, and obesity. Therefore, it is important to discover strategies to identify patients at risk and reduce the risk of CVD in CD populations. Lastly, it is unclear whether adherence to a gluten-free diet can diminish or increase the risk of CVD among individuals with CD, necessitating further research in this area. To fully comprehend the correlation between CD and CVD and to determine the optimal prevention strategies for CVD in individuals with CD, additional research is necessary.


Assuntos
Doenças Cardiovasculares , Doença Celíaca , Insuficiência Cardíaca , Hipertensão , Miocardite , Humanos , Doenças Cardiovasculares/epidemiologia , Doenças Cardiovasculares/etiologia , Doenças Cardiovasculares/prevenção & controle , Doença Celíaca/complicações , Doença Celíaca/epidemiologia , Hipertensão/complicações , Fatores de Risco , Arritmias Cardíacas/etiologia , Arritmias Cardíacas/complicações , Miocardite/complicações , Insuficiência Cardíaca/complicações
6.
JACC Clin Electrophysiol ; 9(6): 851-861, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37227361

RESUMO

BACKGROUND: Sinus rhythm electrical activation mapping can provide information regarding the ischemic re-entrant ventricular tachycardia (VT) circuit. The information gleaned may include the localization of sinus rhythm electrical discontinuities, which can be defined as arcs of disrupted electrical conduction with large activation time differences across the arc. OBJECTIVES: This study sought to detect and localize sinus rhythm electrical discontinuities that might be present in activation maps constructed from infarct border zone electrograms. METHODS: Monomorphic re-entrant VT with a double-loop circuit and central isthmus was repeatedly inducible by programmed electrical stimulation in the epicardial border zone of 23 postinfarction canine hearts. Sinus rhythm and VT activation maps were constructed from 196 to 312 bipolar electrograms acquired surgically at the epicardial surface and analyzed computationally. A complete re-entrant circuit was mappable from the epicardial electrograms of VT, and isthmus lateral boundary (ILB) locations were ascertained. The difference in sinus rhythm activation time across ILB locations, vs the central isthmus and vs the circuit periphery, was determined. RESULTS: Sinus rhythm activation time differences averaged 14.4 milliseconds across the ILB vs 6.5 milliseconds at the central isthmus and 6.4 milliseconds at the periphery (ie, the outer circuit loop) (P ≤ 0.001). Locations with large sinus rhythm activation difference tended to overlap ILB (60.3% ± 23.2%) compared with their overlap with the entire grid (27.5% ± 18.5%) (P < 0.001). CONCLUSIONS: Disrupted electrical conduction is evident as discontinuity in sinus rhythm activation maps, particularly at ILB locations. These areas may represent permanent fixtures relating to spatial differences in border zone electrical properties, caused in part by alterations in underlying infarct depth. The tissue properties producing sinus rhythm discontinuity at ILB may contribute to functional conduction block formation at VT onset.


Assuntos
Infarto do Miocárdio , Taquicardia Ventricular , Animais , Cães , Sistema de Condução Cardíaco , Taquicardia Ventricular/diagnóstico , Taquicardia Ventricular/cirurgia , Taquicardia Ventricular/etiologia , Bloqueio Cardíaco
7.
Comput Methods Programs Biomed ; 230: 107320, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36608429

RESUMO

BACKGROUND AND OBJECTIVE: Celiac Disease (CD) is characterized by gluten intolerance in genetically predisposed individuals. High disease prevalence, absence of a cure, and low diagnosis rates make this disease a public health problem. The diagnosis of CD predominantly relies on recognizing characteristic mucosal alterations of the small intestine, such as villous atrophy, crypt hyperplasia, and intraepithelial lymphocytosis. However, these changes are not entirely specific to CD and overlap with Non-Celiac Duodenitis (NCD) due to various etiologies. We investigated whether Artificial Intelligence (AI) models could assist in distinguishing normal, CD, and NCD (and unaffected individuals) based on the characteristics of small intestinal lamina propria (LP). METHODS: Our method was developed using a dataset comprising high magnification biopsy images of the duodenal LP compartment of CD patients with different clinical stages of CD, those with NCD, and individuals lacking an intestinal inflammatory disorder (controls). A pre-processing step was used to standardize and enhance the acquired images. RESULTS: For the normal controls versus CD use case, a Support Vector Machine (SVM) achieved an Accuracy (ACC) of 98.53%. For a second use case, we investigated the ability of the classification algorithm to differentiate between normal controls and NCD. In this use case, the SVM algorithm with linear kernel outperformed all the tested classifiers by achieving 98.55% ACC. CONCLUSIONS: To the best of our knowledge, this is the first study that documents automated differentiation between normal, NCD, and CD biopsy images. These findings are a stepping stone toward automated biopsy image analysis that can significantly benefit patients and healthcare providers.


Assuntos
Doença Celíaca , Duodenite , Doenças não Transmissíveis , Humanos , Doença Celíaca/diagnóstico , Duodenite/diagnóstico por imagem , Duodenite/patologia , Inteligência Artificial , Biópsia , Mucosa Intestinal/diagnóstico por imagem
8.
Physiol Meas ; 44(3)2023 03 14.
Artigo em Inglês | MEDLINE | ID: mdl-36599170

RESUMO

Objective.Schizophrenia (SZ) is a severe, chronic psychiatric-cognitive disorder. The primary objective of this work is to present a handcrafted model using state-of-the-art technique to detect SZ accurately with EEG signals.Approach.In our proposed work, the features are generated using a histogram-based generator and an iterative decomposition model. The graph-based molecular structure of the carbon chain is employed to generate low-level features. Hence, the developed feature generation model is called the carbon chain pattern (CCP). An iterative tunable q-factor wavelet transform (ITQWT) technique is implemented in the feature extraction phase to generate various sub-bands of the EEG signal. The CCP was applied to the generated sub-bands to obtain several feature vectors. The clinically significant features were selected using iterative neighborhood component analysis (INCA). The selected features were then classified using the k nearest neighbor (kNN) with a 10-fold cross-validation strategy. Finally, the iterative weighted majority method was used to obtain the results in multiple channels.Main results.The presented CCP-ITQWT and INCA-based automated model achieved an accuracy of 95.84% and 99.20% using a single channel and majority voting method, respectively with kNN classifier.Significance.Our results highlight the success of the proposed CCP-ITQWT and INCA-based model in the automated detection of SZ using EEG signals.


Assuntos
Disfunção Cognitiva , Esquizofrenia , Humanos , Eletroencefalografia/métodos , Esquizofrenia/diagnóstico , Análise de Ondaletas , Carbono , Algoritmos
9.
Eur J Radiol ; 157: 110591, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36356463

RESUMO

PURPOSE: To develop and validate a machine learning (ML) model for the classification of breast lesions on ultrasound images. METHOD: In the present study, three separate data cohorts containing 1288 breast lesions from three countries (Malaysia, Iran, and Turkey) were utilized for MLmodel development and external validation. The model was trained on ultrasound images of 725 breast lesions, and validation was done separately on the remaining data. An expert radiologist and a radiology resident classified the lesions based on the BI-RADS lexicon. Thirteen morphometric features were selected from a contour of the lesion and underwent a three-step feature selection process. Five features were chosen to be fed into the model separately and combined with the imaging signs mentioned in the BI-RADS reference guide. A support vector classifier was trained and optimized. RESULTS: The diagnostic profile of the model with various input data was compared to the expert radiologist and radiology resident. The agreement of each approach with histopathologic specimens was also determined. Based on BI-RADS and morphometric features, the model achieved an area under the receiver operating characteristic (ROC) curve (AUC) of 0.885, which is higher than the expert radiologist and radiology resident performances with AUC of 0.814 and 0.632, respectively in all cohorts. DeLong's test also showed that the AUC of the ML protocol was significantly different from that of the expert radiologist (ΔAUCs = 0.071, 95%CI: (0.056, 0.086), P = 0.005). CONCLUSIONS: These results support the possible role of morphometric features in enhancing the already well-excepted classification schemes.


Assuntos
Neoplasias da Mama , Ultrassonografia Mamária , Feminino , Humanos , Ultrassonografia Mamária/métodos , Neoplasias da Mama/diagnóstico por imagem , Inteligência Artificial , Mama/diagnóstico por imagem , Ultrassonografia
10.
Diagnostics (Basel) ; 12(10)2022 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-36292233

RESUMO

Attention deficit hyperactivity disorder (ADHD) is a common neurodevelopmental condition worldwide. In this research, we used an ADHD electroencephalography (EEG) dataset containing more than 4000 EEG signals. Moreover, these EEGs are noisy signals. A new hand-modeled EEG classification model has been proposed to separate healthy versus ADHD individuals using the EEG signals. In this model, a new ternary motif pattern (TMP) has been incorporated. We have mimicked deep learning networks to create this hand-modeled classification method. The Tunable Q Wavelet Transform (TQWT) has been utilized to generate wavelet subbands. We applied the proposed TMP and statistics to construct informative features from both raw EEG signals and wavelet bands by generating TQWT. Herein, features have been generated by 18 subbands and the original EEG signal. Thus, this model is named TMP19. The most informative features have been chosen by deploying neighborhood component analysis (NCA), and the selected features have been classified using the k-nearest neighbor (kNN) classifier. The used ADHD EEG dataset has 14 channels. Thus, these three phases-(i) feature extraction with TQWT, TMP, and statistics; (ii) feature selection by deploying NCA; and (iii) classification with kNN-have been applied to each channel. Iterative hard majority voting (IHMV) has been applied to obtain a higher and more general classification response. Our model attained 95.57% and 77.93% classification accuracies by deploying 10-fold and leave one subject out (LOSO) cross-validations, respectively.

11.
Entropy (Basel) ; 24(9)2022 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-36141147

RESUMO

Atrial fibrillation (AF) is the most common cardiac arrhythmia, and in response to increasing clinical demand, a variety of signals and indices have been utilized for its analysis, which include complex fractionated atrial electrograms (CFAEs). New methodologies have been developed to characterize the atrial substrate, along with straightforward classification models to discriminate between paroxysmal and persistent AF (ParAF vs. PerAF). Yet, most previous works have missed the mark for the assessment of CFAE signal quality, as well as for studying their stability over time and between different recording locations. As a consequence, an atrial substrate assessment may be unreliable or inaccurate. The objectives of this work are, on the one hand, to make use of a reduced set of nonlinear indices that have been applied to CFAEs recorded from ParAF and PerAF patients to assess intra-recording and intra-patient stability and, on the other hand, to generate a simple classification model to discriminate between them. The dominant frequency (DF), AF cycle length, sample entropy (SE), and determinism (DET) of the Recurrence Quantification Analysis are the analyzed indices, along with the coefficient of variation (CV) which is utilized to indicate the corresponding alterations. The analysis of the intra-recording stability revealed that discarding noisy or artifacted CFAE segments provoked a significant variation in the CV(%) in any segment length for the DET and SE, with deeper decreases for longer segments. The intra-patient stability provided large variations in the CV(%) for the DET and even larger for the SE at any segment length. To discern ParAF versus PerAF, correlation matrix filters and Random Forests were employed, respectively, to remove redundant information and to rank the variables by relevance, while coarse tree models were built, optimally combining high-ranked indices, and tested with leave-one-out cross-validation. The best classification performance combined the SE and DF, with an accuracy (Acc) of 88.3%, to discriminate ParAF versus PerAF, while the highest single Acc was provided by the DET, reaching 82.2%. This work has demonstrated that due to the high variability of CFAEs data averaging from one recording place or among different recording places, as is traditionally made, it may lead to an unfair oversimplification of the CFAE-based atrial substrate characterization. Furthermore, a careful selection of reduced sets of features input to simple classification models is helpful to accurately discern the CFAEs of ParAF versus PerAF.

12.
Med Eng Phys ; 110: 103870, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-35989223

RESUMO

PROBLEM: Cough-based disease detection is a hot research topic for machine learning, and much research has been published on the automatic detection of Covid-19. However, these studies are useful for the diagnosis of different diseases. AIM: In this work, we collected a new and large (n=642 subjects) cough sound dataset comprising four diagnostic categories: 'Covid-19', 'heart failure', 'acute asthma', and 'healthy', and used it to train, validate, and test a novel model designed for automatic detection. METHOD: The model consists of four main components: novel feature generation based on a specifically directed knight pattern (DKP), signal decomposition using four pooling methods, feature selection using iterative neighborhood analysis (INCA), and classification using the k-nearest neighbor (kNN) classifier with ten-fold cross-validation. Multilevel multiple pooling decomposition combined with DKP yielded 41 feature vectors (40 extracted plus one original cough sound). From these, the ten best feature vectors were selected. Based on each vector's misclassification rate, redundant feature vectors were eliminated and then merged. The merged vector's most informative features automatically selected using INCA were input to a standard kNN classifier. RESULTS: The model, called DKPNet41, attained a high accuracy of 99.39% for cough sound-based multiclass classification of the four categories. CONCLUSIONS: The results obtained in the study showed that the DKPNet41 model automatically and efficiently classifies cough sounds for disease diagnosis.


Assuntos
Asma , COVID-19 , Humanos , Tosse/diagnóstico , Asma/diagnóstico , Aprendizado de Máquina , Máquina de Vetores de Suporte
13.
Dig Dis Sci ; 67(11): 5158-5167, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-35635630

RESUMO

BACKGROUND/AIMS: When seeking a romantic partner, individuals with celiac disease (CD) must navigate challenging social situations. We aimed to investigate dating-related behaviors in adults with CD. METHODS: A total of 11,884 affiliates of the Celiac Disease Center at Columbia University were invited to participate in an online survey. Adults (≥ 18 years) with biopsy-diagnosed CD were included. Among the 5,249 who opened the email, 538 fully completed the survey (10.2%). The survey included a CD-specific dating attitudes/behaviors questionnaire, a Social Anxiety Questionnaire (SAQ), a CD-specific quality of life instrument (CD-QOL), and a CD Food Attitudes and Behaviors scale (CD-FAB). RESULTS: Respondents were primarily female (86.8%) and the plurality (24.4%) was in the 23-35 year age range. 44.3% had dated with CD, and among them, 68.4% reported that CD had a major/moderate impact on their dating life. A major/moderate impact was more commonly reported among females (69.3%, p < 0.001), 23-35-year-olds (77.7%, p = 0.015), those with a household income < $50 K (81.7%, p = 0.019), and those with a lower CD-QOL score (50.5 vs. 73.4, p = 0.002). While on dates, 39.3% were uncomfortable explaining precautions to waiters, 28.2% engaged in riskier eating behaviors, and 7.5% intentionally consumed gluten. 39.0% of all participants were hesitant to kiss their partner because of CD; females more so than males (41.1% vs. 22.7%, p = 0.005). CONCLUSIONS: The majority of participants felt that CD had a major/moderate impact on their dating life. This impact may result in hesitation toward dating and kissing, decreased QOL, greater social anxiety, and less adaptive eating attitudes and behaviors. CD and the need to adhere to a gluten free diet have a major impact on dating and intimacy.


Assuntos
Doença Celíaca , Corte , Adulto , Feminino , Humanos , Masculino , Doença Celíaca/diagnóstico , Dieta Livre de Glúten , Glutens , Cooperação do Paciente , Qualidade de Vida , Inquéritos e Questionários
14.
J Imaging ; 8(4)2022 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-35448229

RESUMO

Hypertrophic cardiomyopathy (HCM) is a genetic disorder that exhibits a wide spectrum of clinical presentations, including sudden death. Early diagnosis and intervention may avert the latter. Left ventricular hypertrophy on heart imaging is an important diagnostic criterion for HCM, and the most common imaging modality is heart ultrasound (US). The US is operator-dependent, and its interpretation is subject to human error and variability. We proposed an automated computer-aided diagnostic tool to discriminate HCM from healthy subjects on US images. We used a local directional pattern and the ResNet-50 pretrained network to classify heart US images acquired from 62 known HCM patients and 101 healthy subjects. Deep features were ranked using Student's t-test, and the most significant feature (SigFea) was identified. An integrated index derived from the simulation was defined as 100·log10(SigFea/2) in each subject, and a diagnostic threshold value was empirically calculated as the mean of the minimum and maximum integrated indices among HCM and healthy subjects, respectively. An integrated index above a threshold of 0.5 separated HCM from healthy subjects with 100% accuracy in our test dataset.

15.
Comput Methods Programs Biomed ; 220: 106803, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35429811

RESUMO

BACKGROUND AND OBJECTIVE: Airflow fluctuations caused by cardiac contraction can trigger inappropriate ventilator pressure support in anesthesia machines and intensive care unit mechanical ventilators. Removal of this cardiogenic artifact from the airflow signal would improve ventilator function. The application of singular spectrum analysis (SSA) to remove cardiogenic oscillations from ventilator airflow signals recorded from intubated, mechanically ventilated patients under general anesthesia was evaluated in this study. METHODS: Airflow (liters/minute) and CO2 (mmHg) data were collected at a sampling rate of 125 Hz from the intraoperative monitoring systems using special-purpose software. Simultaneous electrocardiogram signals (mV) were also collected at a sampling rate of 250 Hz. One-dimensional SSA was performed offline on normalized airflow signals using a window length sufficient to span one period of typical respiratory variation. The main components of the airflow waveform are respiratory excursions and cardiogenic oscillations, with respiratory excursions more slowly varying and of higher magnitude. The smooth respiratory waveform was formed from elementary reconstructed series corresponding to the highest singular values obtained with SSA analysis. The quality of respiratory waveform extraction with SSA was determined by calculating the weighted correlation between the selected elementary reconstructed series. RESULTS: Airflow data was recorded from 6 patients. The respiratory component of the airflow signal without cardiogenic oscillations was reconstructed from elementary series corresponding to singular values of highest magnitude. The weighted correlations obtained were greater than 0.96 in the majority of patients studied. Cardiogenic oscillations were reconstructed from elementary reconstructed series corresponding to singular values of lower magnitude. CONCLUSIONS: SSA is effective in extracting higher amplitude respiratory excursions while excluding lower amplitude cardiogenic oscillations and noise from the airflow signal. This study demonstrates that suppression of the cardiogenic artefact with SSA is computationally feasible to augment ventilator performance.


Assuntos
Respiração com Pressão Positiva , Ventiladores Mecânicos , Humanos , Pulmão , Respiração com Pressão Positiva/métodos , Fenômenos Fisiológicos Respiratórios , Análise Espectral
16.
Physiol Meas ; 43(3)2022 04 04.
Artigo em Inglês | MEDLINE | ID: mdl-35377344

RESUMO

Objective.The main objective of this work is to present a hand-modelled one-dimensional signal classification system to detect Attention-Deficit Hyperactivity Disorder (ADHD) disorder using electroencephalography (EEG) signals.Approach.A novel handcrafted feature extraction method is presented in this research. Our proposed method uses a directed graph and an eight-pointed star pattern (EPSPat). Also, tunable q wavelet transforms (TQWT), wavelet packet decomposition (WPD), statistical extractor, iterative Chi2 (IChi2) selector, and the k-nearest neighbors (kNN) classifier have been utilized to develop the EPSPat based learning model. This network uses two wavelet decomposition methods (TQWT and WPD), and 85 wavelet coefficient bands are extracted. The proposed EPSPat and statistical feature creator generate features from the 85 wavelet coefficient bands and the original EEG signal. The learning network is termed EPSPatNet86. The main purpose of the presented EPSPatNet86 is to detect abnormalities of the EEG signals. Therefore, 85 wavelet subbands have been generated to extract features. The created 86 feature vectors have been evaluated using the Chi2 selector and the kNN classifier in the loss value calculation phase. The final features vector is created by employing a minimum loss-valued eight feature vectors. The IChi2 selector selects the best feature vector, which is fed to the kNN classifier. An EEG signal dataset has been used to demonstrate the presented model's EEG signal classification ability. We have used an ADHD EEG dataset since ADHD is a commonly seen brain-related ailment.Main results.Our developed EPSPatNet86 model can detect the ADHD EEG signals with 97.19% and 87.60% accuracy using 10-fold cross and subject-wise validations, respectively.Significance.The calculated results demonstrate that the presented EPSPatNet86 attained satisfactory EEG classification ability. Results show that we can apply our developed EPSPatNet86 model to other EEG signal datasets to detect abnormalities.


Assuntos
Transtorno do Deficit de Atenção com Hiperatividade , Transtorno do Deficit de Atenção com Hiperatividade/diagnóstico , Encéfalo , Análise por Conglomerados , Eletroencefalografia/métodos , Humanos , Análise de Ondaletas
17.
Comput Methods Programs Biomed ; 215: 106609, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34990929

RESUMO

Radiomics is a newcomer field that has opened new windows for precision medicine. It is related to extraction of a large number of quantitative features from medical images, which may be difficult to detect visually. Underlying tumor biology can change physical properties of tissues, which affect patterns of image pixels and radiomics features. The main advantage of radiomics is that it can characterize the whole tumor non-invasively, even after a single sampling from an image. Therefore, it can be linked to a "digital biopsy". Physicians need to know about radiomics features to determine how their values correlate with the appearance of lesions and diseases. Indeed, physicians need practical references to conceive of basics and concepts of each radiomics feature without knowing their sophisticated mathematical formulas. In this review, commonly used radiomics features are illustrated with practical examples to help physicians in their routine diagnostic procedures.


Assuntos
Neoplasias , Medicina de Precisão , Biópsia , Humanos , Neoplasias/diagnóstico por imagem
18.
Heart Rhythm ; 19(1): 137-153, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34371192

RESUMO

Catheter ablation of postinfarction reentrant ventricular tachycardia (VT) has received renewed interest owing to the increased availability of high-resolution electroanatomic mapping systems that can describe the VT circuits in greater detail, and the emergence and need to target noninvasive external beam radioablation. These recent advancements provide optimism for improving the clinical outcome of VT ablation in patients with postinfarction and potentially other scar-related VTs. The combination of analyses gleaned from studies in swine and canine models of postinfarction reentrant VT, and in human studies, suggests the existence of common electroanatomic properties for reentrant VT circuits. Characterizing these properties may be useful for increasing the specificity of substrate mapping techniques and for noninvasive identification to guide ablation. Herein, we describe properties of reentrant VT circuits that may assist in elucidating the mechanisms of onset and maintenance, as well as a means to localize and delineate optimal catheter ablation targets.


Assuntos
Sistema de Condução Cardíaco/fisiopatologia , Taquicardia Ventricular/fisiopatologia , Animais , Ablação por Cateter , Modelos Animais de Doenças , Técnicas Eletrofisiológicas Cardíacas , Sistema de Condução Cardíaco/cirurgia , Humanos , Infarto do Miocárdio/complicações , Infarto do Miocárdio/fisiopatologia , Taquicardia Ventricular/cirurgia
19.
Nutrients ; 13(12)2021 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-34960046

RESUMO

A gluten-free diet (GFD), which is the only treatment for celiac disease (CeD), is challenging and associated with higher levels of anxiety, disordered eating, and lower quality of life (QOL). We examined various demographic and health factors associated with social anxiety, eating attitudes and behaviors, and QOL. Demographics and health characteristics, QOL, eating attitudes and behaviors, and social anxiety of adults with CeD were acquired using validated measures. The mean scores for QOL, SAQ, and CDFAB were compared across various demographic groups using the Z statistical test. The mean QOL score was 57.8, which is in the moderate range. The social anxiety mean scores were high: 78.82, with 9% meeting the clinical cutoff for social anxiety disorder. Those on a GFD for a short duration had significantly higher SAQ scores (worse anxiety), higher CDFAB scores (worse eating attitudes and behavior), and lower QOL scores. Those aged 23-35 years had lower QOL scores (p < 0.003) and higher SAQ scores (p < 0.003). Being single (p < 0.001) and female (p = 0.026) were associated with higher SAQ scores. These findings suggest that the development of targeted interventions to maximize QOL and healthy eating behaviors as well as to minimize anxiety is imperative for some adults with CeD.


Assuntos
Ansiedade , Doença Celíaca/dietoterapia , Dieta Livre de Glúten , Comportamento Alimentar , Qualidade de Vida , Adolescente , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
20.
Entropy (Basel) ; 23(12)2021 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-34945957

RESUMO

Optical coherence tomography (OCT) images coupled with many learning techniques have been developed to diagnose retinal disorders. This work aims to develop a novel framework for extracting deep features from 18 pre-trained convolutional neural networks (CNN) and to attain high performance using OCT images. In this work, we have developed a new framework for automated detection of retinal disorders using transfer learning. This model consists of three phases: deep fused and multilevel feature extraction, using 18 pre-trained networks and tent maximal pooling, feature selection with ReliefF, and classification using the optimized classifier. The novelty of this proposed framework is the feature generation using widely used CNNs and to select the most suitable features for classification. The extracted features using our proposed intelligent feature extractor are fed to iterative ReliefF (IRF) to automatically select the best feature vector. The quadratic support vector machine (QSVM) is utilized as a classifier in this work. We have developed our model using two public OCT image datasets, and they are named database 1 (DB1) and database 2 (DB2). The proposed framework can attain 97.40% and 100% classification accuracies using the two OCT datasets, DB1 and DB2, respectively. These results illustrate the success of our model.

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