Semi-supervised COVID-19 volumetric pulmonary lesion estimation on CT images using probabilistic active contour and CNN segmentation.

Purpose: A semi-supervised two-step methodology is proposed to obtain a volumetric estimation of COVID-19-related lesions on Computed Tomography (CT) images.

Methods: First, damaged tissue was segmented from CT images using a probabilistic active contours approach. Second, lung parenchyma was extracted using a previously trained U-Net.

Effects of Supplemental Oxygen on Cardiovascular and Respiratory Interactions by Extended Partial Directed Coherence in Idiopathic Pulmonary Fibrosis.

Idiopathic pulmonary fibrosis (IPF) is a chronic and restrictive disease characterized by fibrosis and inflammatory changes in lung tissue producing a reduction in diffusion capacity and leading to exertional chronic arterial hypoxemia and dyspnea. Furthermore, clinically, supplemental oxygen (SupplO) has been prescribed to IPF patients to improve symptoms. However, the evidence about the benefits or disadvantages of oxygen supplementation is not conclusive.

Cardiovascular and Respiratory Interactions in Idiopathic Pulmonary Fibrosis by Extended Partial Directed Coherence: Short-term Effects of Supplemental Oxygen.

Idiopathic pulmonary fibrosis (IPF) is a progressive interstitial lung disease that can lead to chronic arterial hypoxemia, hypercapnia, and dyspnea. To improve clinical symptoms in IPF patients, supplemental oxygen (SupplO) has been prescribed with the aim to maintain SpO level, and consequently to relieve dyspnea, increase physical activity and improve quality of life. In this study, we investigated the effect of disease and short-term SupplO on cardiovascular and respiratory autonomic regulation.

Simultaneous Estimation of Instantaneous Heart and Respiratory Rates using Image Photoplethysmography on a Single Smartphone.

Heart rate (HR) and respiratory rate (RR) are very important physiological variables useful to evaluate the cardiorespiratory system. At present, there is a great interest by the general population in knowing their health status, quickly and easily. Accordingly, several approaches have been proposed to achieve that goal.

Time-Frequency Analysis of Cardiovascular Variability during an Orthostatic Stress by Complete EMD.

Diverse analysis techniques have been used to comprehend the regulation by the autonomic nervous system (ANS) of the cardiovascular system when a human being faces a stressor. Recently, however, the complete ensemble empirical mode decomposition (EMD) with adaptive noise (CEEMDAN) allows analyzing nonstationary signals in a nonlinear and time- variant way. Consequently, CEEMDAN may provide a means to obtain clues about ANS regulation in health and disease.

Hemodynamic response to low-flow acute supplemental oxygen in idiopathic pulmonary fibrosis and elderly healthy subjects.

Background: Hemodynamic response to supplemental oxygen in idiopathic pulmonary fibrosis (IPF) is still not well known.

Objective: To determine and compare the effect of low-flow acute supplemental oxygen on the hemodynamics of IPF patients and matched healthy subjects.

Methods: Descriptive and comparative study in 20 IPF-patients and 19 Control-subjects, (60-80 years old) breathing ambient air followed by acute nasal low-flow (3 L/min) supplemental oxygen.

Temporal cardiovascular causality during orthostatic stress by extended partial directed coherence.

The aim of this study was to investigate the temporal dynamic behavior of cardiovascular interactions between heart period and systolic blood pressure during a 20-min head-up tilt test at 70° in young women with orthostatic intolerance compared to healthy women. Methods included the lagged and extended partial directed coherence applied to short-term windows shifted by 5 seconds, extracted from a multivariate set of cardiovascular and respiratory time series. Findings revealed significantly increased information flow (p <; 0.

Characterization of EHG Contractions at Pregnancy and Term Labor by Multiscale Entropy Analysis.

Monitoring uterine activity by electrohysterogram (EHG), associated with contractions both in pregnancy and labor, may contribute to the knowledge for evaluating possible risks to the binomial mother-fetus. In this context, the aim of the present study was to explore the complexity of EHG generated by women during the third trimester of pregnancy (group P) and at term labor (group L). The EHG was obtained by band-pass filtering in the range from 0.

Time-Frequency Analysis of Cardiovascular and Cardiorespiratory Interactions During Orthostatic Stress by Extended Partial Directed Coherence.

In this study, the linear method of extended partial directed coherence (ePDC) was applied to establish the temporal dynamic behavior of cardiovascular and cardiorespiratory interactions during orthostatic stress at a 70° head-up tilt (HUT) test on young age-matched healthy subjects and patients with orthostatic intolerance (OI), both male and female. Twenty 5-min windows were used to analyze the minute-wise progression of interactions from 5 min in a supine position (baseline, BL) until 18 min of the orthostatic phase (OP) without including pre-syncopal phases. Gender differences in controls were present in cardiorespiratory interactions during OP without compromised autonomic regulation.

Detection of Respiratory Crackle Sounds via an Android Smartphone-based System.

Pulmonary auscultation with traditional stethoscope, although useful, has limitations for detecting discontinuous adventitious respiratory sounds (crackles) that commonly occur in respiratory diseases. In this work, we present the development of a mobile health system for the automated detection of crackle sounds, comprised by an acoustical sensor, a smart phone device, and a mobile application (app) implemented in Android. The app allows the physician to record, store, reproduce, and analyze respiratory sounds directly on the smart phone.

Study of impaired cardiovascular and respiratory coupling during orthostatic stress based on joint symbolic dynamics.

The present study investigates the instantaneous coupling among the cardiac, vascular, and respiratory systems, using the heart rate, respiration, and systolic and diastolic blood pressure variability in 12 healthy and 16 vasovagal syncope female subjects during a head-up tilt (HUT) testing protocol at 70° This study contributes to the coupling analysis by using a nonlinear joint symbolic dynamics (JSD) in a high-temporal resolution scheme, based on 5 min segments of the time series that are shifted every minute. For each segment, a bivariate JSD matrix was constructed to obtain global and local coupling indices in accordance to Shannon's entropy and the probability of occurrence of various bivariate words, respectively. The novel approach revealed important findings in the coupling dynamics of the systems, thus allowing the detection of group differences during the early orthostatic phase, and during the HUT test, before the occurrence of any pre-syncopal symptoms.

Multivariate symbolic dynamics for analysis of respiratory-cardiovascular interactions.

In this work, a nonlinear method to study multivariate interactions, called multivariate symbolic dynamics (MSD), was introduced. The usefulness of this technique was studied on respiratory-cardiovascular data from young women with vasovagal syncope (VVS) and from healthy subjects. The study included 16 female patients diagnosed with VVS and 24 age-matched healthy subjects (12 women).

A multichannel acoustic approach to define a pulmonary pathology as combined pulmonary fibrosis and emphysema syndrome.

Interstitial lung diseases (ILDs) have been increasing their relevance in loss of lives according to a recent world wide medical information. Idiopathic pulmonary fibrosis (IPF) and combined pulmonary fibrosis and emphysema syndrome (CPFES) belong to ILD class with the latter having a limited survival prognosis. In clinical environment high resolution computed tomography (HRCT) is used to detect CPFE; however, there is still controversy about the amount of emphysema observed in HRCT to declare CPFES.

Temporal Analysis of Cardiovascular and Respiratory Complexity by Multiscale Entropy Based on Symbolic Dynamics.

The effect of an orthostatic stress on cardiovascular and respiratory complexity was investigated to detect impaired autonomic regulation in patients with vasovagal syncope (VVS). A total of 16 female patients and 12 age-matched healthy female subjects were enrolled in a passive 70° head-up tilt test. Also, 12 age-matched healthy male subjects were enrolled to study gender differences.

Acoustic evaluation of pirfenidone on patients with combined pulmonary fibrosis emphysema syndrome.

The combined pulmonary fibrosis emphysema syndrome (CPFES) overall has a poor prognosis with a 5-year survival of 35-80%. Consequently, to evaluate possible positive effects on patients of novel agents as pirfenidone is relevant. However, the efficacy of pirfenidone in CPFES patients is still not well-known.

Delta space plot analysis of cardiovascular coupling in vasovagal syncope during orthostatic challenge.

In this work, a graphical method to study cardiovascular coupling, called delta space plot analysis (DSPA), was introduced. The graphical representation is susceptible to be parameterized in shape and orientation. The usefulness of this technique was studied on cardiovascular data from patients with vasovagal syncope (VVS) and from controls.

Dynamics of the cardiovascular autonomic regulation during orthostatic challenge is more relaxed in women.

Linear dynamic analysis of cardiovascular and respiratory time series was performed in healthy subjects with respect to gender by shifted short-term segments throughout a head-up tilt (HUT) test. Beat-to-beat intervals (BBI), systolic (SYS) and diastolic (DIA) blood pressure and respiratory interval (RESP) time series were acquired in 14 men and 15 women. In time domain (TD), the descending slope of the auto-correlation function (ACF) (BBI_a31cor) was more pronounced in women than in men (p<0.

Power Spectral Density Analysis of Electrodermal Activity for Sympathetic Function Assessment.

Time-domain features of electrodermal activity (EDA), the measurable changes in conductance at the skin surface, are typically used to assess overall activation of the sympathetic system. These time domain features, the skin conductance level (SCL) and the nonspecific skin conductance responses (NS.SCRs), are consistently elevated with sympathetic nervous arousal, but highly variable between subjects.

Men and women should be separately investigated in studies of orthostatic challenge due to different gender-related dynamics of autonomic response.

In studies of autonomic regulation during orthostatic challenges only a few nonlinear methods have been considered without investigating the effect of gender in young controls. Especially, the temporal development of the autonomic regulation has not yet been explicitly analyzed using short-term segments in supine position, transition and orthostatic phase (OP). In this study, nonlinear analysis of cardiovascular and respiratory time series was performed to investigate how nonlinear indices are dynamically changing with respect to gender during orthostatic challenges.

Orthostatic stress causes immediately increased blood pressure variability in women with vasovagal syncope.

The cardiovascular and respiratory autonomic nervous regulation has been studied mainly by hemodynamic responses during different physical stressors. In this study, dynamics of autonomic response to an orthostatic challenge was investigated by hemodynamic variables and by diverse linear and nonlinear indices calculated from time series of beat-to-beat intervals (BBI), respiratory cycle duration (RESP), systolic (SYS) and diastolic (DIA) blood pressure. This study included 16 young female patients (SYN) with vasovagal syncope and 12 age-matched female controls (CON).

Automated clustering of independent components for discontinuous sounds thoracic imaging.

Discontinuous lung sounds (DLS), also known as crackles, are abnormal sounds produced by different pulmonary pathologies (PP) whose thoracic spatial distribution and prevalence are relevant for diagnosis purpose. Recently, DLS imaging has been proposed to help diagnose and follow-up PP where automated recognition of DLS is meaningful. The present study focuses on the automated selection of independent components (ICs) associated with DLS.

Temporal analysis of cardiac autonomic regulation during orthostatic challenge by short-term symbolic dynamics.

The gradual shift of cardiac autonomic regulation toward sympathetic predominance and vagal withdrawal during graded head-up tilt test in young controls has been demonstrated by parameters from symbolic dynamics obtained from short-term heart rate variability (HRV) analysis. In this study, the influence of gender and vasovagal syncope (VVS) on the autonomic response to an orthostatic challenge was investigated by HRV analysis using short-term symbolic dynamics (STSD). This study included 24 healthy young subjects (12 males; 12 age-matched females) and 16 female patients diagnosed with VVS.

Gender differences in cardiovascular and cardiorespiratory coupling in healthy subjects during head-up tilt test by Joint Symbolic Dynamics.

Gender related-differences in the autonomic regulation of the cardiovascular and cardiorespiratory systems have been studied mainly by hemodynamic responses during different physical stressors. In this study, the influence of gender on the autonomic response to an orthostatic challenge was investigated by obtaining the cardiovascular and cardiorespiratory coupling using the nonlinear technique known as joint symbolic dynamics (JSD) representation. This study includes 24 healthy young subjects.

Assessment of time-frequency representation techniques for thoracic sounds analysis.

A step forward in the knowledge about the underlying physiological phenomena of thoracic sounds requires a reliable estimate of their time-frequency behavior that overcomes the disadvantages of the conventional spectrogram. A more detailed time-frequency representation could lead to a better feature extraction for diseases classification and stratification purposes, among others. In this respect, the aim of this study was to look for an omnibus technique to obtain the time-frequency representation (TFR) of thoracic sounds by comparing generic goodness-of-fit criteria in different simulated thoracic sounds scenarios.