The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Thomas Similowski - One of the best experts on this subject based on the ideXlab platform.
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Physiological Validation of an Airborne Ultrasound Based Surface Motion Camera for a Contactless Characterization of Breathing Pattern in Humans
Frontiers in Physiology, 2019Co-Authors: Mariececile Nierat, Pierantonio Laveneziana, Bruno-pierre Dubé, Pavel Shirkovskiy, Ros-kiri Ing, Thomas SimilowskiAbstract:Characterizing the Breathing Pattern in naturally Breathing humans brings important information on respiratory mechanics, respiratory muscle, and Breathing control. However, measuring Breathing modifies Breathing (observer effect) through the effects of instrumentation and awareness: measuring human Breathing under true ecological conditions is currently impossible. This study tested the hypothesis that non-contact vibrometry using airborne ultrasound (SONAR) could measure Breathing movements in a contactless and invisible manner. Thus, first, we evaluated the validity of SONAR measurements by testing their interchangeability with pneumotachograph (PNT) measurements obtained at the same time. We also aimed at evaluating the observer effect by comparing Breathing variability obtained by SONAR versus SONAR-PNT measurements. Twenty-three healthy subjects (12 men and 11 women; mean age 33 years - range: 20-54) were studied during resting Breathing while sitting on a chair. Breathing activity was described in terms of ventilatory flow measured using a PNT and, either simultaneously or sequentially, with a SONAR device measuring the velocity of the surface motion of the chest wall. SONAR was focused either anteriorly on the xiphoid process or posteriorly on the lower part of the costal margin. Discrete ventilatory temporal and volume variables and their coefficients of variability were calculated from the flow signal (PNT) and the velocity signal (SONAR) and tested for interchangeability (Passing-Bablok regression). Tidal volume (VT) and displacement were linearly related. Breathing frequency (BF), total cycle time (TT), inspiratory time (TI), and expiratory time (TE) met interchangeability criteria. Their coefficients of variation were not statistically significantly different with PNT and SONAR-only. This was true for both the anterior and the posterior SONAR measurements. Non-contact vibrometry using airborne ultrasound is a valid tool for measuring resting Breathing Pattern.
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repetitive transcranial magnetic stimulation over the supplementary motor area modifies Breathing Pattern in response to inspiratory loading in normal humans
Frontiers in Physiology, 2015Co-Authors: Mariececile Nierat, Anna L. Hudson, Thomas Similowski, Joel Chaskalovic, Louis LavioletteAbstract:In awake humans, Breathing depends on automatic brainstem Pattern generators. It is also heavily influenced by cortical networks. For example, functional magnetic resonance imaging and electroencephalographic data show that the supplementary motor area becomes active when Breathing is made difficult by inspiratory mechanical loads like resistances or threshold valves, which is associated with perceived respiratory discomfort. We hypothesized that manipulating the excitability of the supplementary motor area with repetitive transcranial magnetic stimulation would modify the Breathing Pattern response to an experimental inspiratory load and possibly respiratory discomfort. Seven subjects (three men, age 25 ± 4) were studied. Breathing Pattern and respiratory discomfort during inspiratory loading were described before and after conditioning the supplementary motor area with repetitive stimulation, using an excitatory paradigm (5 Hz stimulation), an inhibitory paradigm, or sham stimulation. No significant change in Breathing Pattern during loading was observed after sham conditioning. Excitatory conditioning shortened inspiratory time (p = 0.001), decreased tidal volume (p = 0.016), and decreased ventilation (p = 0.003), as corroborated by an increased end-tidal expired carbon dioxide (p = 0.013). Inhibitory conditioning did not affect ventilation, but lengthened expiratory time (p = 0.031). Respiratory discomfort was mild under baseline conditions, and unchanged after conditioning of the supplementary motor area. This is the first study to show that repetitive transcranial magnetic stimulation conditioning of the cerebral cortex can alter Breathing Pattern. A 5 Hz conditioning protocol, known to enhance corticophrenic excitability, can reduce the amount of hyperventilation induced by inspiratory threshold loading. Further studies are needed to determine whether and under what circumstances rTMS can have an effect on dyspnoea.
Mariececile Nierat - One of the best experts on this subject based on the ideXlab platform.
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Physiological Validation of an Airborne Ultrasound Based Surface Motion Camera for a Contactless Characterization of Breathing Pattern in Humans
Frontiers in Physiology, 2019Co-Authors: Mariececile Nierat, Pierantonio Laveneziana, Bruno-pierre Dubé, Pavel Shirkovskiy, Ros-kiri Ing, Thomas SimilowskiAbstract:Characterizing the Breathing Pattern in naturally Breathing humans brings important information on respiratory mechanics, respiratory muscle, and Breathing control. However, measuring Breathing modifies Breathing (observer effect) through the effects of instrumentation and awareness: measuring human Breathing under true ecological conditions is currently impossible. This study tested the hypothesis that non-contact vibrometry using airborne ultrasound (SONAR) could measure Breathing movements in a contactless and invisible manner. Thus, first, we evaluated the validity of SONAR measurements by testing their interchangeability with pneumotachograph (PNT) measurements obtained at the same time. We also aimed at evaluating the observer effect by comparing Breathing variability obtained by SONAR versus SONAR-PNT measurements. Twenty-three healthy subjects (12 men and 11 women; mean age 33 years - range: 20-54) were studied during resting Breathing while sitting on a chair. Breathing activity was described in terms of ventilatory flow measured using a PNT and, either simultaneously or sequentially, with a SONAR device measuring the velocity of the surface motion of the chest wall. SONAR was focused either anteriorly on the xiphoid process or posteriorly on the lower part of the costal margin. Discrete ventilatory temporal and volume variables and their coefficients of variability were calculated from the flow signal (PNT) and the velocity signal (SONAR) and tested for interchangeability (Passing-Bablok regression). Tidal volume (VT) and displacement were linearly related. Breathing frequency (BF), total cycle time (TT), inspiratory time (TI), and expiratory time (TE) met interchangeability criteria. Their coefficients of variation were not statistically significantly different with PNT and SONAR-only. This was true for both the anterior and the posterior SONAR measurements. Non-contact vibrometry using airborne ultrasound is a valid tool for measuring resting Breathing Pattern.
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repetitive transcranial magnetic stimulation over the supplementary motor area modifies Breathing Pattern in response to inspiratory loading in normal humans
Frontiers in Physiology, 2015Co-Authors: Mariececile Nierat, Anna L. Hudson, Thomas Similowski, Joel Chaskalovic, Louis LavioletteAbstract:In awake humans, Breathing depends on automatic brainstem Pattern generators. It is also heavily influenced by cortical networks. For example, functional magnetic resonance imaging and electroencephalographic data show that the supplementary motor area becomes active when Breathing is made difficult by inspiratory mechanical loads like resistances or threshold valves, which is associated with perceived respiratory discomfort. We hypothesized that manipulating the excitability of the supplementary motor area with repetitive transcranial magnetic stimulation would modify the Breathing Pattern response to an experimental inspiratory load and possibly respiratory discomfort. Seven subjects (three men, age 25 ± 4) were studied. Breathing Pattern and respiratory discomfort during inspiratory loading were described before and after conditioning the supplementary motor area with repetitive stimulation, using an excitatory paradigm (5 Hz stimulation), an inhibitory paradigm, or sham stimulation. No significant change in Breathing Pattern during loading was observed after sham conditioning. Excitatory conditioning shortened inspiratory time (p = 0.001), decreased tidal volume (p = 0.016), and decreased ventilation (p = 0.003), as corroborated by an increased end-tidal expired carbon dioxide (p = 0.013). Inhibitory conditioning did not affect ventilation, but lengthened expiratory time (p = 0.031). Respiratory discomfort was mild under baseline conditions, and unchanged after conditioning of the supplementary motor area. This is the first study to show that repetitive transcranial magnetic stimulation conditioning of the cerebral cortex can alter Breathing Pattern. A 5 Hz conditioning protocol, known to enhance corticophrenic excitability, can reduce the amount of hyperventilation induced by inspiratory threshold loading. Further studies are needed to determine whether and under what circumstances rTMS can have an effect on dyspnoea.
Nicolino Ambrosino - One of the best experts on this subject based on the ideXlab platform.
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differences in spontaneous Breathing Pattern and mechanics in patients with severe copd recovering from acute excerbation
European Respiratory Journal, 1999Co-Authors: Michele Vitacca, Enrico Clini, Roberto Porta, Luca Bianchi, Nicolino AmbrosinoAbstract:The aims of this study were to assess spontaneous Breathing Patterns in patients with chronic obstructive pulmonary disease (COPD) recovering from acute exacerbation and to assess the relationship between different Breathing Patterns and clinical and functional parameters of respiratory impairment. Thirty-four COPD patients underwent assessment of lung function tests, arterial blood gases, haemodynamics, Breathing Pattern (respiratory frequency (fR), tidal volume (VT), inspiratory and expiratory time (tI and tE), duty cycle (tI/ttot), VT/tI) and mechanics (oesophageal pressure (Poes), work of Breathing (WOB), pressure-time product and index, and dynamic intrinsic positive end-expiratory pressure (PEEPi,dyn)). According to the presence (group 1) or absence (group 2) of Poes swings during the expiratory phase (premature inspiration), 20 (59%) patients were included in group 1 and 14 (41%) in group 2. Premature inspirations were observed 4.5+/-6.4 times x min(-1) (range 1-31), i.e. 20+/-21% (3.7-100%) of total fR calculated from VT tracings. In group 1 the coefficient of variation in VT, tE, tI/ttot, PEEPi,dyn, Poes and WOB of the eight consecutive breaths immediately preceding the premature inspiration was greater than that of eight consecutive breaths in group 2. There were no significant differences in the assessed parameters between the two groups in the overall population, whereas patients with chronic hypoxaemia in group 1 showed a more severe impairment in clinical conditions, mechanics and lung function than hypoxaemic patients in group 2. In spontaneously Breathing patients with chronic obstructive pulmonary disease recovering from an acute exacerbation, detectable activity of inspiratory muscles during expiration was found in more than half of the cases. This phenomenon was not associated with any significant differences in anthropometric, demographic, physiological or clinical characteristics.
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Breathing Pattern and respiratory mechanics in patients with amyotrophic lateral sclerosis
European Respiratory Journal, 1997Co-Authors: Michele Vitacca, Enrico Clini, D Facchetti, M Pagani, M Poloni, Roberto Porta, Nicolino AmbrosinoAbstract:The aim of this study was to evaluate the time course of Breathing Pattern and respiratory mechanics in patients with amyotrophic lateral sclerosis (ALS). A study was conducted on 25 out of 38 eligible ALS patients. Neurological status, arterial blood gases (ABGs), spirometry, Breathing Pattern (minute ventilation (V'E), tidal volume (VT), respiratory frequency (fR), duty cycle (duration of inspiration/duration of total Breathing cycle (tI/ttot)), respiratory drive (P0.1)), respiratory mechanics (oesophageal pressure (Ppl), dynamic compliance (CL,dyn), pressure time product (PTP) and index (PTI), work of Breathing (WOB)), and respiratory muscle (RM) strength as assessed by maximal oesophageal pressure (Ppl,max) were evaluated at presentation (to) in all patients and after 6 months (t6) in 11 patients. At to, the mean values of the degree of neurological impairment were 60+/-20 and 103+/-30 as assessed by the Norris scale and Medical Research Council (MRC) score, respectively. From the time of the first neurological symptom, survival time ranged 7-50 months. Diurnal ABGs were normal. A mild restrictive Pattern was observed, a forced vital capacity (FVC) <70% of predicted being present in 45% of patients, only FVC % pred (r=0.59; p<0.05), forced expiratory volume in one second (FEV1) % pred (r=0.53; p<0.05) and survival (r=0.64; p<0.05) showing a significant correlation with the Norris scale. A Ppl,max <30 cmH2O was associated with a significantly greater mortality, Ppl,max being correlated with survival (r=0.79, p<0.05). At t6, fR, fR/VT, P0.1/Ppl,max, were significantly increased in comparison to to, while FVC % pred, vital capacity (VC) % pred, FEV1 % pred, VT and Ppl,max were significantly reduced. These results suggest a progressive deterioration in Breathing Pattern and in respiratory muscle strength with progression of disease.
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Breathing Pattern ventilatory drive and respiratory muscle strength in patients with chronic heart failure
European Respiratory Journal, 1994Co-Authors: Nicolino Ambrosino, Cristina Opasich, Paola Crotti, Franco Cobelli, Luigi Tavazzi, C RampullaAbstract:The purpose of this study was to evaluate whether chronic heart failure (CHF) may induce changes in Breathing Pattern and ventilatory neural drive. We studied 45 male inpatients with CHF, (25 patients in NYHA class II, 20 in class III) and 22 sex-matched post myocardial infarction patients without left ventricular dysfunction who served as controls. CHF patients underwent right heart catheterization and assessment of cardiac output by thermodilution technique. Patients and controls underwent evaluation of left ventricular ejection fraction by 2D echocardiography, spirometry, diffusion capacity, blood gases, Breathing Pattern, mouth occlusion pressure and respiratory muscle strength determination. Results of CHF patients were compared to controls and evaluated for differences according to the degree in severity of functional impairment. CHF patients showed a slight reduction in lung volumes and in diffusion capacity. In CHF neural drive, as assessed by mouth occlusion pressure (P0.1), was significantly increased in comparison to controls (P0.1 = 1.86 (0.7) and 1.4 (0.6) cmH2O in CHF and controls respectively). Analysis of Breathing Pattern showed only a slight yet significant increase in respiratory frequency while respiratory muscle strength, as assessed by measurement of maximal inspiratory and expiratory pressures (MIP and MEP respectively) was slightly reduced (MIP = 79(27) and 104(28); MEP = 111(32) and 142(33) cmH2O respectively). Observed changes were more relevant in patients with advanced NYHA functional classes whereas no relationship among indices of cardiac and respiratory function was found. We conclude that chronic heart failure induces changes in neural ventilatory drive and respiratory muscle strength related to the severity of the disease.
Yu Ru Kou - One of the best experts on this subject based on the ideXlab platform.
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comparisons of predictive performance of Breathing Pattern variability measured during t piece automatic tube compensation and pressure support ventilation for weaning intensive care unit patients from mechanical ventilation
Critical Care Medicine, 2011Co-Authors: Mauo Ying Bien, Jia Horng Wang, You Shui Lin, Chunghung Shih, Youlan Yang, Hui Wen Lin, Kuanjen Bai, Yu Ru KouAbstract:Objective:To investigate the influence of different ventilatory supports on the predictive performance of Breathing Pattern variability for extubation outcomes in intensive care unit patients.Design and Setting:A prospective measurement of retrospectively analyzed Breathing Pattern variability in a
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Breathing Pattern variability a weaning predictor in postoperative patients recovering from systemic inflammatory response syndrome
Intensive Care Medicine, 2004Co-Authors: Mauo Ying Bien, Shu Shya Hseu, Huey Wen Yien, Benjamin Ing Tiau Kuo, Yuting Lin, Jia Horng Wang, Yu Ru KouAbstract:Objective To investigate whether Breathing Pattern variability can serve as a potential weaning predictor for postoperative patients recovering from systemic inflammatory response syndrome (SIRS).
Mauo Ying Bien - One of the best experts on this subject based on the ideXlab platform.
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comparisons of predictive performance of Breathing Pattern variability measured during t piece automatic tube compensation and pressure support ventilation for weaning intensive care unit patients from mechanical ventilation
Critical Care Medicine, 2011Co-Authors: Mauo Ying Bien, Jia Horng Wang, You Shui Lin, Chunghung Shih, Youlan Yang, Hui Wen Lin, Kuanjen Bai, Yu Ru KouAbstract:Objective:To investigate the influence of different ventilatory supports on the predictive performance of Breathing Pattern variability for extubation outcomes in intensive care unit patients.Design and Setting:A prospective measurement of retrospectively analyzed Breathing Pattern variability in a
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Breathing Pattern variability a weaning predictor in postoperative patients recovering from systemic inflammatory response syndrome
Intensive Care Medicine, 2004Co-Authors: Mauo Ying Bien, Shu Shya Hseu, Huey Wen Yien, Benjamin Ing Tiau Kuo, Yuting Lin, Jia Horng Wang, Yu Ru KouAbstract:Objective To investigate whether Breathing Pattern variability can serve as a potential weaning predictor for postoperative patients recovering from systemic inflammatory response syndrome (SIRS).