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1.
Annu Int Conf IEEE Eng Med Biol Soc ; 2021: 5446-5449, 2021 11.
Artículo en Inglés | MEDLINE | ID: mdl-34892358

RESUMEN

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 (SupplO2) has been prescribed with the aim to maintain SpO2 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 SupplO2 on cardiovascular and respiratory autonomic regulation. Linear and nonlinear indices were extracted from the beat-to-beat variability of heart rate (HR), systolic (SYS) blood pressure and respiration (RESP) in IPF patients and healthy subjects spontaneously breathing ambient air (AA) and during SupplO2 at 3 L/min. It was found that the effects on autonomic nervous systems (ANS) regulation were better demonstrated by the Granger causality (GC) method. GC was significantly higher (p<0.01) in patients compared to controls for the interactions RESP→SYS and BBI→SYS.Clinical Relevance-Short-term SupplO2 in IPF could adversely affect systolic blood pressure variability in particular. This study may help in the management of SupplO2 administration.


Asunto(s)
Sistema Cardiovascular , Fibrosis Pulmonar Idiopática , Humanos , Fibrosis Pulmonar Idiopática/terapia , Oxígeno , Calidad de Vida , Frecuencia Respiratoria
2.
Oral Oncol ; 116: 105157, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-33454219

RESUMEN

A patient suffering from metastatic pancreatobiliary adenocarcinoma was referred to our hospital's stomatology department after a rapidly progressing swelling in the right mandibular angle, trismus and preauricular pain of 3-month duration. A mandible CT scan showed extensive bone rarefaction and a thickening of the contiguous soft tissues that involved the medial masseter and pterygoid muscle. The morphological findings and immunohistochemical profile were compatible with bone metastasis from pancreatic adenocarcinoma. Therefore, palliative treatment was proposed to the patient. Pancreatic cancer metastases to the oral cavity are extremely rare and characterized by its poor prognosis. Herein we describe the ninth case of metastatic spread to the jaw which is also remarkably the longest surviving reported case up to date.


Asunto(s)
Adenocarcinoma , Neoplasias Mandibulares , Neoplasias Pancreáticas , Adenocarcinoma/diagnóstico , Adenocarcinoma/patología , Humanos , Mandíbula , Neoplasias Mandibulares/diagnóstico por imagen , Neoplasias Mandibulares/secundario , Boca , Neoplasias Pancreáticas/diagnóstico , Neoplasias Pancreáticas/patología , Neoplasias Pancreáticas
4.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 702-705, 2020 07.
Artículo en Inglés | MEDLINE | ID: mdl-33018084

RESUMEN

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. In this study, we analyze the average Hilbert-Huang spectrum (HHS) of cardiovascular variability signals by CEEMDAN during a head-up tilt test (HUTT) in 12 healthy female subjects and 18 orthostatic intolerance female patients. Beat-to-beat intervals (BBI) as well as systolic (SYS) blood pressure variability time series were analyzed. In addition, instantaneous amplitudes and frequencies of specific intrinsic mode functions (IMF) were investigated separately to define the influence of the disease on ANS regulation. Female groups demonstrated statistical differences in the high-frequency band of BBI but higher differences for the high and low-frequency bands of SYS from the mechanical transition of HUTT.Clinical Relevance- A relevant outcome of the study is the average HHS of healthy female subjects along HUTT. This HHS may be used as reference to help diagnose OI when HHS of the cardiovascular variability signals of any subject deviates from the normal course.


Asunto(s)
Sistema Cardiovascular , Intolerancia Ortostática , Sistema Nervioso Autónomo , Femenino , Humanos , Posición de Pie , Pruebas de Mesa Inclinada
7.
Annu Int Conf IEEE Eng Med Biol Soc ; 2019: 5987-5990, 2019 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-31947211

RESUMEN

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 0.1 to 3 Hz the monopolar raw signal of the electrode number 1, of a 4-by-4 sensor array, which was located near to the tocodynamometer transducer. Multiscale entropy (MSE) analysis measures the entropy over multiple time scales to provide the complexity of the EHG time series. The results pointed out that such nonlinear technique has the potential to discriminate contractions from both groups using the area under the MSE curve (AUC) as index. The highest complexity was obtained for group P (N= 8) as AUC was 13.9233 ± 0.2015 while the lowest complexity was for group L, with N=8 and AUC of 5.1675 ± 0.0783 (p<; 0.0001). Consequently, the complexity of EHG by MSE could provide an index to discriminate between the electrical uterine activity generated during pregnancy or at labor.


Asunto(s)
Trabajo de Parto , Contracción Uterina , Monitoreo Uterino , Electromiografía , Entropía , Femenino , Humanos , Embarazo , Útero/fisiología
8.
Annu Int Conf IEEE Eng Med Biol Soc ; 2019: 6359-6362, 2019 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-31947297

RESUMEN

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 <; 0.01) in patients from: a) heart period to blood pressure during supine position which subsequently decreased and b) blood pressure to heart period during the progression of orthostatic phase. Controls developed balanced cardiovascular interactions with smaller information flows than patients.


Asunto(s)
Presión Sanguínea , Sistema Cardiovascular , Intolerancia Ortostática , Femenino , Frecuencia Cardíaca , Humanos , Posición de Pie , Pruebas de Mesa Inclinada
9.
Materials (Basel) ; 11(12)2018 Dec 18.
Artículo en Inglés | MEDLINE | ID: mdl-30567288

RESUMEN

Nanoparticles can be used in a large variety of applications, including magnetic sensing, biological, superconductivity, tissue engineering, and other fields. In this study, we explore the fabrication of gas phase silver nanoparticles using a sputtering evaporation source. This setup composed of a dual magnetron cluster source holds several advantages over other techniques. The system has independent control over the cluster concentration and a wide range of cluster size and materials that can be used for the clusters and for the matrix where it can be embedded. Characterization of these silver nanoparticles was done using transmission electron microscopy (TEM). We obtain a lateral width of 10.6 nm with a dispersion of 0.24 nm. With atomic force microscopy (AFM) a Gaussian fit of this distribution yields and average height of 6.3 nm with a standard deviation of 1.4 nm. We confirm that the deposited silver nanoparticles have a homogenous area distribution, that they have a defined shape and size distribution, and that they are single standing nanoparticles. Given that the scientific literature is not precise regarding the toxic concentration of the nanoparticles, devices such as ours can help clarify these questions. In order to explore further biological applications, we have done preliminary experiments of cell spreading (myoblast adhesion), obtaining interesting morphological changes correlated with the silver concentration on the surface. With a deposited silver concentration ranging from 100⁻620 ng/cm², the cells showed morphological changes in a short time of 2 h. We conclude that this high precision nanoparticle fabrication technique is adequate for further biological research.

10.
Annu Int Conf IEEE Eng Med Biol Soc ; 2018: 2957-2960, 2018 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-30441020

RESUMEN

The aim of this study was to investigate the effect of head-up tilt (HUT) test on male and female young patients, diagnosed with orthostatic intolerance (OI), in comparison to male and female healthy subjects. Twenty seven OI patients (21 women, 6 men) and 26 age-matched healthy subjects (13 women, 13 men) were enrolled in a 70° HUT test. In addition to hemodynamic variables, cardiovascular and respiratory parameters were determined using linear and nonlinear methods to analyze heart rate (HRV) and blood pressure variability (BPV). During the complete test, HRV was lower in healthy men than in female controls. Decreased HRV and increased BPV were observed in female patients compared to healthy women. Furthermore, systolic BPV was increased in male and female patients. However, linear (rmssd) and nonlinear (plvar2) parameters indicated that diastolic BPV decreased in male patients during orthostatic phase, but remained unchanged in female patients. Findings indicated gender dependent mechanisms for the regulation of diastolic blood pressure during orthostatic stress in patients.


Asunto(s)
Sistema Cardiovascular , Intolerancia Ortostática , Presión Sanguínea , Femenino , Frecuencia Cardíaca , Humanos , Masculino , Pruebas de Mesa Inclinada
11.
Med Eng Phys ; 61: 51-60, 2018 11.
Artículo en Inglés | MEDLINE | ID: mdl-30270005

RESUMEN

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. In patients, the global indices indicated a significant decrease of cardiovascular coupling, starting at 10 min after the tilt-up, manifested by reduced baroreflex sensitivity and cardiorespiratory coupling that was initiated 8 min after the onset of the orthostatic phase (OP). A decreased autonomic control on cardiovascular-respiratory couplings was further evidenced by increased alterations of the JSD indices during the OP compared to the supine position in patients compared to controls. Furthermore, findings based on local indices demonstrated that female patients showed reductions and disengagements in cardiovascular (p < 0.001) and cardiorespiratory (p < 0.01) couplings, as early as the first 5 min and during the complete OP.


Asunto(s)
Sistema Cardiovascular/fisiopatología , Respiración , Estrés Fisiológico , Síncope Vasovagal/fisiopatología , Adulto , Estudios de Casos y Controles , Femenino , Humanos , Dinámicas no Lineales
12.
Annu Int Conf IEEE Eng Med Biol Soc ; 2017: 3489-3492, 2017 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-29060649

RESUMEN

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). All subjects were enrolled in a head-up tilt (HUT) test, breathing normally, including 5 min of supine position and 18 to 28 min of 70° orthostatic phase. The MSD parameters were dynamically obtained for 5-min windows shifted by 1 min during HUT test. In supine position there were no considerable differences. During orthostatic phase, parameters from MSD showed a highly significantly (p=0.00005) increased occurrence of impaired respiratory-cardiovascular interactions in female patients susceptible to vasovagal syncope. This study provided promising results for a new multivariate method to investigate respiratory-cardiovascular interactions.


Asunto(s)
Sistema Cardiovascular , Femenino , Humanos , Postura , Respiración , Síncope Vasovagal , Pruebas de Mesa Inclinada
13.
Carbohydr Polym ; 149: 68-76, 2016 09 20.
Artículo en Inglés | MEDLINE | ID: mdl-27261731

RESUMEN

Ethylene-butyl acrylate copolymer (EBA) with 13% of butyl acrylate content was used to produce blends with 10, 30 and 60% of thermoplastic starch (TPS) plasticized with glycerol. Ethylene-acrylic acid copolymer (EAA) was used as compatibilizer at 20% content with respect to EBA. The blends were characterized by X-ray diffraction, ATR-Fourier Transform Infrared Spectroscopy (ATR-FTIR), Scanning Electron Microscopy (SEM), water-Contact Angle measurements (CA), Differential Scanning Calorimetry (DSC) and Stress-strain mechanical tests. Initiated autoxidation of the polymer blends was studied by chemiluminescence (CL) confirming that the presence of the polyolefin-TPS interphase did not substantially affect the oxidative thermostability of the materials. Three bacterial species have been isolated from the blend films buried in soil and identified as Bacillus subtilis, Bacillus borstelensis and Bacillus licheniformis. Biodegradation of the blends (28days at 45°C) was evaluated by carbon dioxide measurement using the indirect impedance technique.


Asunto(s)
Acrilatos/química , Bacillus/metabolismo , Plásticos/química , Polietileno/química , Polietileno/metabolismo , Almidón/química , Temperatura , Bacillus/fisiología , Biopelículas/crecimiento & desarrollo , Biotransformación , Dióxido de Carbono/metabolismo
14.
Physiol Meas ; 37(3): 314-32, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26849375

RESUMEN

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. The analysis was carried out using shifted short-term segments throughout a head-up tilt test in 24 healthy subjects, 12 men (26 ± 4 years) and 12 age-matched women (26 ± 5 years), at supine position and during OP at 70°. The nonlinear methods demonstrated statistical differences in the autonomic regulation between males and females. Orthostatic stress caused significantly decreased heart rate variability due to increased sympathetic activity mainly in men, already at the beginning and during the complete OP, revealed by (a) increased occurrence of specific word types with constant fluctuations as pW111 from symbolic dynamics, (b) augmented fractal correlation properties by the short-term index alpha1 from detrended fluctuation analysis, (c) increased slope indices (21ati and 31ati) from auto-transinformation and (d) augmented time irreversibility indices demonstrating more temporal asymmetries and nonlinear dynamics in men than in women. After tilt-up, both men and women increased their sympathetic activity but in a different way. Time-dependent gender differences during orthostatic challenge were shown directly between men and women or indirectly comparing baseline and different temporal stages of OP. The proposed dynamical study of autonomic regulation has the advantage of screening the fluctuations of the sympathetic and vagal activities that can be quantified by the temporal behavior of nonlinear indices. The findings in this paper strongly suggest the need for gender separation in studies of the dynamics of autonomic regulation during orthostatic challenge.


Asunto(s)
Sistema Nervioso Autónomo/fisiología , Caracteres Sexuales , Pruebas de Mesa Inclinada , Adulto , Algoritmos , Entropía , Femenino , Frecuencia Cardíaca/fisiología , Hemodinámica , Humanos , Masculino , Dinámicas no Lineales
15.
Comput Methods Programs Biomed ; 127: 185-96, 2016 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-26775735

RESUMEN

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). The subjects were enrolled in a head-up tilt (HUT) test, breathing normally, including 5min of baseline (BL, supine position) and 18min of 70° orthostatic phase (OP). To increase the time resolution of the analysis the time series were segmented in five-minute overlapping windows with a shift of 1min. Hemodynamic parameters did not show any statistical differences between SYN and CON. Time domain linear analysis revealed increased respiratory frequency and increased blood pressure variability (BPV) in patients during OP meaning increased sympathetic activity and vagal withdrawal. Frequency domain analysis confirmed a predominance of sympathetic tone by steadily increased values of low over high frequency power in BBI and of low frequency power in SYS and DIA in patients during OP. The nonlinear analysis by symbolic dynamics seemed to be highly suitable for differentiation of SYN and CON in the early beginning of OP, i.e., 5min after tilt-up. In particular the index SYS_plvar3 showed less patterns of low variability in patients reflecting a steadily increase in both BPV and sympathetic activity. The proposed dynamical analysis could lead to a better understanding of the temporal underlying mechanisms in healthy subjects and patients under orthostatic stress.


Asunto(s)
Postura , Síncope Vasovagal/etiología , Adulto , Estudios de Casos y Controles , Femenino , Humanos , Modelos Lineales , Adulto Joven
16.
Annu Int Conf IEEE Eng Med Biol Soc ; 2016: 684-687, 2016 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-28268420

RESUMEN

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. The study included 15 female patients diagnosed with VVS and 11 age-matched healthy female subjects. All subjects were enrolled in a head-up tilt (HUT) test, breathing normally, including 5 minutes of supine position (baseline) and 18 minutes of 70° orthostatic phase. The DSPA parameters were obtained at different times during the HUT test, i.e., at baseline, early (first 5 min) and late (10-15 min) orthostatic phases. In baseline there were no considerable differences between female controls and female patients. During the late orthostatic phase, parameters from DSPA showed highly significantly (p=0.000003) reduced cardiovascular coupling in patients. Findings indicated a loss of control on cardiovascular coupling in female patients susceptible to vasovagal syncope during orthostatic challenge. In addition, this study provided promising results for a new graphical method to investigate cardiovascular coupling.


Asunto(s)
Síncope Vasovagal/diagnóstico , Adulto , Presión Sanguínea/fisiología , Sistema Cardiovascular/diagnóstico por imagen , Estudios de Casos y Controles , Electrocardiografía , Femenino , Frecuencia Cardíaca/fisiología , Humanos , Pruebas de Mesa Inclinada , Adulto Joven
17.
Artículo en Inglés | MEDLINE | ID: mdl-26736694

RESUMEN

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. All subjects were enrolled in a head-up tilt (HUT) test, breathing normally, including 5 minutes of supine position (baseline) and 20-40 minutes of 70° orthostatic phase. The STSD parameters were obtained following their behavior at different times during the HUT test, i.e., at baseline, early and middle orthostatic phases. Gender differences including increased sympathetic activity in men were already present in baseline and in the middle tilt phase. In baseline there were no differences between female controls and female patients, but parameters from STSD showed highly significantly (p=0.0007) reduced heart rate variability due to increased sympathetic activity in female patients in the middle tilt phase. Furthermore a new nonlinear index for the estimation of sympatho-vagal balance was introduced.


Asunto(s)
Sistema Nervioso Autónomo/fisiopatología , Mareo/fisiopatología , Corazón/fisiopatología , Adulto , Estudios de Casos y Controles , Femenino , Voluntarios Sanos , Frecuencia Cardíaca/fisiología , Humanos , Masculino , Caracteres Sexuales , Síncope Vasovagal/fisiopatología , Pruebas de Mesa Inclinada , Factores de Tiempo
18.
Comput Methods Programs Biomed ; 114(3): 276-90, 2014 May.
Artículo en Inglés | MEDLINE | ID: mdl-24680639

RESUMEN

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. The performance of ten TFRs for heart, normal tracheal and adventitious lung sounds was assessed using time-frequency patterns obtained by mathematical functions of the thoracic sounds. To find the best TFR performance measures, such as the 2D local (ρ(mean)) and global (ρ) central correlation, the normalized root-mean-square error (NRMSE), the cross-correlation coefficient (ρ(IF)) and the time-frequency resolution (res(TF)) were used. Simulation results pointed out that the Hilbert-Huang spectrum (HHS) had a superior performance as compared with other techniques and then, it can be considered as a reliable TFR for thoracic sounds. Furthermore, the goodness of HHS was assessed using noisy simulated signals. Additionally, HHS was applied to first and second heart sounds taken from a young healthy male subject, to tracheal sound from a middle-age healthy male subject, and to abnormal lung sounds acquired from a male patient with diffuse interstitial pneumonia. It is expected that the results of this research could be used to obtain a better signature of thoracic sounds for pattern recognition purpose, among other tasks.


Asunto(s)
Ruidos Cardíacos , Ruidos Respiratorios , Algoritmos , Simulación por Computador , Humanos , Masculino , Persona de Mediana Edad , Modelos Teóricos , Reproducibilidad de los Resultados , Procesamiento de Señales Asistido por Computador , Programas Informáticos , Espectrografía del Sonido/métodos , Factores de Tiempo , Tráquea/fisiología
19.
Comput Biol Med ; 45: 58-66, 2014 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-24480164

RESUMEN

Multichannel analysis of lung sounds (LSs) has enabled the generation of a functional image for the temporal and spatial study of LS intensities in healthy and diseased subjects; this method is known as respiratory acoustic thoracic imaging (RATHI). This acoustic imaging technique has been applied to diverse pulmonary conditions, but it is important to contribute to the understanding of RATHI characteristics, such as acoustic spatial distribution, dependence on airflow and variability. The purpose of the current study is to assess the intra-subject and inter-subject RATHI variabilities in a cohort of 12 healthy male subjects (24.3±1.5 years) using diverse quantitative indices. The indices were obtained directly from the acoustic image and did not require scores from human raters, which helps to prevent inter-observer variability. To generate the acoustic image, LSs were acquired at 25 positions on the posterior thoracic surface by means of airborne sound sensors with a wide frequency band from 75 up to 1000 Hz under controlled airflow conditions at 1.0, 1.5 and 2.0 L/s. To assess intra-subject variability, the degree of similitude between inspiratory acoustic images was evaluated through quadratic mutual information based on the Cauchy-Schwartz inequality (I(CS)). The inter-subject variability was assessed by an image registration procedure between RATHIs and X-ray images to allow the computation of average and variance acoustic image in the same coordinate space. The results indicated that intra-subject RATHI similitude, reflected by I(CS-global), averaged 0.960±0.008, 0.958±0.008 and 0.960±0.007 for airflows of 1.0, 1.5, and 2L/s, respectively. As for the inter-subject variability, the variance image values for three airflow conditions indicated low image variability as they ranged from 0.01 to 0.04. In conclusion, the assessment of intra-subject and inter-subject variability by similitude indices indicated that the acoustic image pattern is repeatable along different respiratory cycles and across different subjects. Therefore, RATHI could be used to explore different aspects of spatial distribution and its association with regional pulmonary ventilation.


Asunto(s)
Procesamiento de Imagen Asistido por Computador/métodos , Ruidos Respiratorios/fisiología , Procesamiento de Señales Asistido por Computador , Espectrografía del Sonido/instrumentación , Espectrografía del Sonido/métodos , Adulto , Humanos , Masculino , Radiografía Torácica , Reproducibilidad de los Resultados , Adulto Joven
20.
Artículo en Inglés | MEDLINE | ID: mdl-25570721

RESUMEN

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. Males (N=12) and age-matched females (N=12) were enrolled in a head-up tilt (HUT) test, breathing normally, including 5 minutes of supine position (baseline) and 25-40 minutes of 70° orthostatic phase. The cardiovascular and cardiorespiratory couplings were obtained at baseline, early and middle orthostatic phases. Although in baseline there were some gender differences, parameters from JSD showed highly significant (p=0.0004) differences in specific cardiovascular coupling patterns in the early tilt phase. Furthermore, JSD analysis revealed that in males, due to increased sympathetic activity, exist a lower degree of cardiovascular coupling accompanied with an increased occurrence of tachycardic patterns. On the other hand, the cardiorespiratory coupling revealed only very few slightly significant differences in all three phases.


Asunto(s)
Algoritmos , Voluntarios Sanos , Corazón/fisiología , Respiración , Caracteres Sexuales , Pruebas de Mesa Inclinada , Adulto , Femenino , Humanos , Masculino
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