Publications by authors named "Andrea Aliverti"

166 Publications

Respiratory function assessment at the time of a new respiratory virus pandemic.

Respir Med 2021 Aug 10;187:106570. Epub 2021 Aug 10.

Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milan, Italy.

We must be aware that new respiratory virus pandemic can happen frequently. Standard lung function tests should keep their crucial role to assist the clinicians in the decision-making process, but they are at risk for the spread of infection because of the generated droplets. We used opto-electronic plethysmography to investigate the post-COVID-19 syndrome on 12 patients after ICU. We found normal ventilatory pattern at rest, a restrictive pattern located in the ribcage during vital capacity and surgical mask to significantly increase minute ventilation. The attention on unconventional respiratory function tests should be sponsored for the important information they can provide.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.rmed.2021.106570DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8352651PMC
August 2021

Effects of diaphragmatic control on multiparametric analysis of the sniff nasal inspiratory pressure test and inspiratory muscle activity in healthy subjects.

PLoS One 2021 22;16(7):e0253132. Epub 2021 Jul 22.

PneumoCardioVascular Lab/HUOL, Hospital Universitário Onofre Lopes, Empresa Brasileira de Serviços Hospitalares and Departamento de Fisioterapia Universidade Federal do Rio Grande do Norte, Natal, Brazil.

Background: We investigated the influence of diaphragmatic activation control (diaphC) on the relaxation rate, contractile properties and electrical activity of the inspiratory muscles of healthy subjects. Assessments were performed non-invasively using the sniff inspiratory pressure test (SNIP) and surface electromyography, respectively.

Methods: Twenty-two subjects (10 men and 12 women) performed 10 sniff maneuvers in two different days: with and without diaphC instructions. For the SNIP test with diaphC, the subjects were instructed to perform intense activation of the diaphragm. The tests with the best SNIP values were used for analysis.

Results: The maneuver with diaphC when compared to the maneuver without diaphC exhibited significant lower values for: SNIP (p <0.01), maximum relaxation rate (MRR) (p <0.01), maximum rate of pressure development (MRPD) (p <0.01), contraction times (CT) (p = 0.02) and electrical activity of the sternocleidomastoid (SCM) (p <0.01), scalene (SCL) (p = 0.01) and intercostal (CI) (p = 0.03) muscles. In addition, the decay constant (tau, τ) and relaxation time (½ RT) did not present any changes.

Conclusion: The diaphragmatic control performed during the SNIP test influences the inspiratory pressure and the contractile properties of inspiratory muscles. This occurs due to changes in the pattern of muscle recruitment, which change force velocity characteristics of the test. Thus, instruction on diaphC should be encouraged for better performance of the SNIP test and for evaluation targeting the diaphragm muscle activity.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0253132PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8297810PMC
July 2021

Changes in electromyographic activity, mechanical power, and relaxation rates following inspiratory ribcage muscle fatigue.

Sci Rep 2021 Jun 14;11(1):12475. Epub 2021 Jun 14.

Dipartimento Di Elettronica, Informazione E Bioingegneria, Politecnico Di Milano, Milan, Italy.

Muscle fatigue is a complex phenomenon enclosing various mechanisms. Despite technological advances, these mechanisms are still not fully understood in vivo. Here, simultaneous measurements of pressure, volume, and ribcage inspiratory muscle activity were performed non-invasively during fatigue (inspiratory threshold valve set at 70% of maximal inspiratory pressure) and recovery to verify if inspiratory ribcage muscle fatigue (1) leads to slowing of contraction and relaxation properties of ribcage muscles and (2) alters median frequency and high-to-low frequency ratio (H/L). During the fatigue protocol, sternocleidomastoid showed the fastest decrease in median frequency and slowest decrease in H/L. Fatigue was also characterized by a reduction in the relative power of the high-frequency and increase of the low-frequency. During recovery, changes in mechanical power were due to changes in shortening velocity with long-lasting reduction in pressure generation, and slowing of relaxation [i.e., tau (τ), half-relaxation time (½RT), and maximum relaxation rate (MRR)] was observed with no significant changes in contractile properties. Recovery of median frequency was faster than H/L, and relaxation rates correlated with shortening velocity and mechanical power of inspiratory ribcage muscles; however, with different time courses. Time constant of the inspiratory ribcage muscles during fatigue and recovery is not uniform (i.e., different inspiratory muscles may have different underlying mechanisms of fatigue), and MRR, ½RT, and τ are not only useful predictors of inspiratory ribcage muscle recovery but may also share common underlying mechanisms with shortening velocity.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41598-021-92060-yDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8203654PMC
June 2021

Thoracoabdominal asynchrony and paradoxical motion in Duchenne muscular dystrophy and healthy subjects during cough: A case control study.

Pediatr Pulmonol 2021 Jul 18;56(7):2136-2145. Epub 2021 Apr 18.

Departamento de Fisioterapia, Pneumo CardioVascular Lab/HUOL, Hospital Universitário Onofre Lopes, Empresa Brasileira de Serviços Hospitalares (EBSERH), Universidade Federal do Rio Grande do Norte, Natal, Rio Grande do Norte, Brasil.

Objective: To assess thoracoabdominal asynchrony (TAA) and inspiratory paradoxical motion at different positionings in subjects with Duchenne muscular dystrophy (DMD) versus healthy subjects during quiet spontaneous breathing (QB) and cough.

Methods: This is a case control study with a matched-pair design. We assessed 14 DMD subjects and 12 controls using optoelectronic plethysmography (OEP) during QB and spontaneous cough in 3 positions: supine, supine with headrest raised at 45°, and sitting with back support at 80°. The TAA was assessed using phase angle (θ) between upper (RCp) and lower rib cage (RCa) and abdomen (AB), as well as the percentage of inspiratory time the RCp (IP ), RCa (IP ), and AB (IP ) moved in opposite directions.

Results: During cough, DMD group showed higher RCp and RCa θ (p < .05), RCp and AB θ (p < .05) in supine and 45° positions, and higher RCp and Rca θ (p = .006) only in supine position compared with controls. Regarding the intragroup analysis, during cough, DMD group presented higher RCp and AB θ (p = .02) and RCa and AB θ (p = .002) in supine and higher RCa and AB θ (p = .002) in 45° position when compared to 80°. Receiver operating characteristic curve analyzes were able to discriminate TAA between controls and DMD in RCa supine position (area under the curve: 0.81, sensibility: 78.6% and specificity: 91.7%, p = .001).

Conclusion: Subjects with DMD yields TAA with insufficient deflation of chest wall compartments and rib cage distortion during cough, by noninvasive assessment.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/ppul.25412DOI Listing
July 2021

Respiratory muscle imaging by ultrasound and MRI in neuromuscular disorders.

Eur Respir J 2021 Apr 16. Epub 2021 Apr 16.

Department of Neurology, Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, the Netherlands

Respiratory muscle weakness is common in neuromuscular disorders and leads to significant respiratory difficulties. Therefore, reliable and easy assessment of respiratory muscle structure and function in neuromuscular disorders is crucial. In the last decade, ultrasound and MRI emerged as promising imaging techniques to assess respiratory muscle structure and function. Respiratory muscle imaging directly measures the respiratory muscles and, in contrast to pulmonary function testing, is independent of patient effort. This makes respiratory muscle imaging suitable to use as tool in clinical respiratory management and as outcome parameter in upcoming drug trials for neuromuscular disorders, particularly in children. In this narrative review, we discuss the latest studies and technological developments in imaging of the respiratory muscles by US and MR, and its clinical application and limitations. We aim to increase understanding of respiratory muscle imaging and facilitate its use as outcome measure in daily practice and clinical trials.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1183/13993003.00137-2021DOI Listing
April 2021

Validation of a new wearable device for type 3 sleep test without flowmeter.

PLoS One 2021 16;16(4):e0249470. Epub 2021 Apr 16.

Centro Cardiologico Monzino, IRCCS, Milano, Italy.

Background: Ventilation monitoring during sleep is performed by sleep test instrumentation that is uncomfortable for the patients due to the presence of the flowmeter. The objective of this study was to evaluate if an innovative type 3 wearable system, the X10X and X10Y, is able to correctly detect events of apnea and hypopnea and to classify the severity of sleep apnea without the use of a flowmeter.

Methods: 40 patients with sleep disordered breathing were analyzed by continuous and simultaneous recording of X10X and X10Y and another certified type 3 system, SOMNOtouch, used for comparison. Evaluation was performed in terms of quality of respiratory signals (scores from 1, lowest, to 5, highest), duration and classification of apneas, as well as identification and duration of hypopneas.

Results: 580 periods were evaluated. Mean quality assigned score was 3.37±1.42 and 3.25±1.35 for X10X and X10Y and SOMNOtouch, respectively. The agreement between the two systems was evaluated with grades 4 and 5 in 383 out of 580 cases. A high correlation (r2 = 0.921; p<0.001) was found between the AHI indexes obtained from the two systems. X10X and X10Y devices were able to correctly classify 72.3% of the obstructive apneas, 81% of the central apneas, 61.3% of the hypopneas, and 64.6% of the mixed apneas when compared to SOMNOtouch device.

Conclusion: The X10X and X10Y devices are able to provide a correct grading of sleep respiratory disorders without the need of a nasal cannula for respiratory flow measurement and can be considered as a type 3 sleep test device for screening tests.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0249470PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8051765PMC
April 2021

Over three decades of natural history of limb girdle muscular dystrophy type R1/2A and R2/2B: Mathematical modelling of a multifactorial study.

Neuromuscul Disord 2021 06 27;31(6):489-497. Epub 2021 Feb 27.

Scientific Institute IRCCS E. Medea, NeuroMuscular Unit, Bosisio Parini, LC, Italy.

We aimed to describe the natural history of Limb Girdle Muscular Dystrophy type 2A and 2B over more than three decades by considering muscular strength, motor, cardiac and respiratory function. 428 visits of nineteen 2A and twenty 2B patients were retrospectively analysed through a regression model to create the curves of evolution with disease duration of muscle strength (through Medical Research Council grading), motor function measure scale (D1, D2 and D3 domains) and cardio-pulmonary function tests. Clinically relevant muscular and motor function alterations occurred after the first decade of disease, while mild respiratory function alterations started after the second, with preserved cardiac function. Although type 2A showed relatively stronger distal lower limb muscles, while type 2B started with relatively stronger upper limb muscles, the corresponding motor functions were similar, becoming severely compromised after 25 years of disease. This was the longest retrospective study in types 2A and 2B. It defined curves of disease evolution not only from a neuromuscular, but also from functional, cardiac, and respiratory points of view, to be used to evaluate how the natural progression is changed by therapies. Due to slow disease progression, it was not possible to identify time sensitive endpoints.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.nmd.2021.02.018DOI Listing
June 2021

Computational fluid dynamics of the airways after left-upper pulmonary lobectomy: A case study.

Int J Numer Method Biomed Eng 2021 Jul 18;37(7):e3462. Epub 2021 Jun 18.

Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milan, Italy.

Pulmonary lobectomy is the gold standard intervention for lung cancer removal and consists of the complete resection of the affected lung lobe, which, coupled with the re-adaptation of the remaining thoracic structures, decreases the postoperative pulmonary function of the patient. Current clinical practice, based on spirometry and cardiopulmonary exercise tests, does not consider local changes, providing an average at-the-mouth estimation of residual functionality. Computational Fluid Dynamics (CFD) has proved a valuable solution to obtain quantitative and local information about airways airflow dynamics. A CFD investigation was performed on the airway tree of a left-upper pulmonary lobectomy patient, to quantify the effects of the postoperative alterations. The patient-specific bronchial models were reconstructed from pre- and postoperative CT scans. A parametric laryngeal model was merged to the geometries to account for physiological-like inlet conditions. Numerical simulations were performed in Fluent. The postoperative configuration revealed fluid dynamic variations in terms of global velocity (+23%), wall pressure (+48%), and wall shear stress (+39%). Local flow disturbances emerged at the resection site: a high-velocity peak of 4.92 m/s was found at the left-lower lobe entrance, with a local increase of pressure at the suture zone (18 Pa). The magnitude of pressure and secondary flows increased in the trachea and flow dynamics variations were observed also in the contralateral lung, causing altered lobar ventilation. The results confirmed that CFD is a patient-specific approach for a quantitative evaluation of fluid dynamics parameters and local ventilation providing additional information with respect to current clinical approaches.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/cnm.3462DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8365666PMC
July 2021

Detection and Classification of Bronchiectasis Through Convolutional Neural Networks.

J Thorac Imaging 2021 Mar 24. Epub 2021 Mar 24.

Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano Respiratory Unit and Cystic Fibrosis Adult Center, Fondazione IRCCS Ca'Granda Ospedale Maggiore Policlinico Department of Pathophysiology and Transplantation, Università degli Studi di Milano Department of Radiology, Fondazione IRCCS Ca'Granda Ospedale Maggiore Policlinico Milan, University of Milan, Milan Department of Clinical Sciences, Section of Radiology, University of Parma, Parma Department of Radiology, ASST Lodi, Ospedale Maggiore di Lodi, Lodi, Italy.

Purpose: Bronchiectasis is a chronic disease characterized by an irreversible dilatation of bronchi leading to chronic infection, airway inflammation, and progressive lung damage. Three specific patterns of bronchiectasis are distinguished in clinical practice: cylindrical, varicose, and cystic. The predominance and the extension of the type of bronchiectasis provide important clinical information. However, characterization is often challenging and is subject to high interobserver variability. The aim of this study is to provide an automatic tool for the detection and classification of bronchiectasis through convolutional neural networks.

Materials And Methods: Two distinct approaches were adopted: (i) direct network performing a multilabel classification of 32×32 regions of interest (ROIs) into 4 classes: healthy, cylindrical, cystic, and varicose and (ii) a 2-network serial approach, where the first network performed a binary classification between normal tissue and bronchiectasis and the second one classified the ROIs containing abnormal bronchi into one of the 3 bronchiectasis typologies. Performances of the networks were compared with other architectures presented in the literature.

Results: Computed tomography from healthy individuals (n=9, age=47±6, FEV1%pred=109±17, FVC%pred=116±17) and bronchiectasis patients (n=21, age=59±15, FEV1%pred=74±25, FVC%pred=91±22) were collected. A total of 19,059 manually selected ROIs were used for training and testing. The serial approach provided the best results with an accuracy and F1 score average of 0.84, respectively. Slightly lower performances were observed for the direct network (accuracy=0.81 and F1 score average=0.82). On the test set, cylindrical bronchiectasis was the subtype classified with highest accuracy, while most of the misclassifications were related to the varicose pattern, mainly to the cylindrical class.

Conclusion: The developed networks accurately detect and classify bronchiectasis disease, allowing to collect quantitative information regarding the radiologic severity and the topographical distribution of bronchiectasis subtype.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1097/RTI.0000000000000588DOI Listing
March 2021

Smart Textiles and Sensorized Garments for Physiological Monitoring: A Review of Available Solutions and Techniques.

Sensors (Basel) 2021 Jan 26;21(3). Epub 2021 Jan 26.

Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, 20133 Milan, Italy.

Several wearable devices for physiological and activity monitoring are found on the market, but most of them only allow spot measurements. However, the continuous detection of physiological parameters without any constriction in time or space would be useful in several fields such as healthcare, fitness, and work. This can be achieved with the application of textile technologies for sensorized garments, where the sensors are completely embedded in the fabric. The complete integration of sensors in the fabric leads to several manufacturing techniques that allow dealing with both the technological challenges entailed by the physiological parameters under investigation, and the basic requirements of a garment such as perspiration, washability, and comfort. This review is intended to provide a detailed description of the textile technologies in terms of materials and manufacturing processes employed in the production of sensorized fabrics. The focus is pointed at the technical challenges and the advanced solutions introduced with respect to conventional sensors for recording different physiological parameters, and some interesting textile implementations for the acquisition of biopotentials, respiratory parameters, temperature and sweat are proposed. In the last section, an overview of the main garments on the market is depicted, also exploring some relevant projects under development.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/s21030814DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7865961PMC
January 2021

Physiological changes and compensatory mechanisms by the action of respiratory muscles in a porcine model of phrenic nerve injury.

J Appl Physiol (1985) 2021 03 14;130(3):813-826. Epub 2021 Jan 14.

Section of Anaesthesiology and Intensive Care, Department of Surgical Sciences, Uppsala University, Uppsala, Sweden.

Phrenic nerve damage may occur as a complication of specific surgical procedures, prolonged mechanical ventilation, or physical trauma. The consequent diaphragmatic paralysis or dysfunction can lead to major complications. The purpose of this study was to elucidate the role of the nondiaphragmatic respiratory muscles during partial or complete diaphragm paralysis induced by unilateral and bilateral phrenic nerve damage at different levels of ventilatory pressure support in an animal model. Ten pigs were instrumented, the phrenic nerve was exposed from the neck, and spontaneous respiration was preserved at three levels of pressure support, namely, high, low, and null, at baseline condition, after left phrenic nerve damage, and after bilateral phrenic nerve damage. Breathing pattern, thoracoabdominal volumes and asynchrony, and pressures were measured at each condition. Physiological breathing was predominantly diaphragmatic and homogeneously distributed between right and left sides. After unilateral damage, the paralyzed hemidiaphragm was passively dragged by the ipsilateral rib cage muscles and the contralateral hemidiaphragm. After bilateral damage, the drive to and the work of breathing of rib cage and abdominal muscles increased, to compensate for diaphragmatic paralysis, ensuing paradoxical thoracoabdominal breathing. Increasing level of pressure support ventilation replaces this muscle group compensation. When the diaphragm is paralyzed (unilaterally and/or bilaterally), there is a coordinated reorganization of nondiaphragmatic respiratory muscles as compensation that might be obscured by high level of pressure support ventilation. Noninvasive thoracoabdominal volume and asynchrony assessment could be useful in phrenic nerve-injured patients to estimate the extent and type of inspiratory muscle dysfunction. This was the first (to our knowledge) implanted porcine model of phrenic nerve injury with a detailed multidimensional analysis of different degrees of diaphragmatic paralysis (unilateral and bilateral). Noninvasive thoracoabdominal volume and asynchrony assessment was shown to be useful in estimating the extent of diaphragmatic dysfunction and the consequent coordinated reorganization of nondiaphragmatic respiratory muscles. High level of pressure support ventilation was proved to obscure the interaction and compensation of respiratory muscles to deal with phrenic nerve injury.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1152/japplphysiol.00781.2020DOI Listing
March 2021

Priming the cardiodynamic phase of pulmonary oxygen uptake through voluntary modulations of the respiratory pump at the onset of exercise.

Exp Physiol 2021 Feb 6;106(2):555-566. Epub 2021 Jan 6.

Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland.

New Findings: What is the central question of this study? The initial increase in oxygen uptake ( ) at exercise onset results from pulmonary perfusion changes secondary to an increased venous return. Breathing mechanics contribute to venous return through abdominal and intrathoracic pressures variation. Can voluntary breathing techniques (abdominal or rib cage breathing) increase venous return and improve at exercise onset? What is the main finding and its importance? Abdominal and rib cage breathing increase venous return and at exercise onset. This mechanism could be clinically relevant in patients with impaired cardiac function limiting oxygen transport.

Abstract: We examined how different breathing patterns can modulate venous return and alveolar gas transfer during exercise transients in humans. Ten healthy men transitioned from rest to moderate cycling while breathing spontaneously (SP) or with voluntary increases in abdominal (AB) or intrathoracic (RC) pressure swings. We used double body plethysmography to determine blood displacements between the trunk and the extremities (V ). From continuous signals of airflow and O fraction, we calculated breath-by-breath oxygen uptake at the mouth and used optoelectronic plethysmography to correct for lung O store changes and calculate alveolar O transfer ( ). Oesophageal (P ) and gastric (P ) pressures were monitored using balloon-tipped catheters. Cardiac stroke volume was measured using impedance cardiography. During the cardiodynamic phase (Φ1) of -on kinetics (20 s following exercise onset), AB and RC increased total alveolar oxygen transfer compared to SP (227 ± 32, P = 0.019 vs. 235 ± 27, P = 0.001 vs. 206 ± 20 ml, mean ± SD). P and P swings increased with AB (by 24.4 ± 9.6 cmH O, P < 0.001) and RC (by 14.5 ± 5.7 cmH O, P < 0.001), respectively. AB yielded a greater increase in intra-breath V swings compared with RC and SP (+0.30 ± 0.14 vs. +0.16 ± 0.11, P < 0.001 vs. +0.10 ± 0.05 ml, P = 0.006) and increased the sum of stroke volumes compared to SP (4.47 ± 1.28 vs. 3.89 ± 0.96 litres, P = 0.053), while RC produced significant central blood translocation from the extremities compared with SP (by 493 ± 311 ml, P < 0.001). Our findings indicate that combining exercise onset with AB or RC increases venous return, thus increasing mass oxygen transport above metabolic consumption during Φ1 and limiting the oxygen deficit incurred.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1113/EP089180DOI Listing
February 2021

Quantitative inspiratory-expiratory chest CT to evaluate pulmonary involvement in pediatric hematopoietic stem-cell transplantation patients.

Pediatr Pulmonol 2021 05 23;56(5):1026-1035. Epub 2020 Dec 23.

Center for Pulmonary Imaging Research, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA.

Pulmonary complications following allogeneic hematopoietic stem-cell transplantation (HSCT) are a significant source of morbidity and complications may arise from a myriad of infectious and noninfectious sources. These complications may occur soon or many months post-transplantation and can have a broad range of outcomes. Surveillance for pulmonary involvement in the pediatric HSCT population can be challenging due to poor compliance with clinical pulmonary function testing, primarily spirometry, and there may be a role for clinical imaging to provide an additional means of monitoring, particularly in the era of clinical low-dose computed tomography (CT) protocols. In this single-site, retrospective study, a review of our institution's radiological and HSCT databases was conducted to assess the utility of a quantitative CT algorithm to describe ventilation abnormalities on high-resolution chest CT scans of pediatric HSCT patients. Thirteen non-contrast enhanced chest CT examinations acquired both in inspiration and expiration, from 12 deceased HSCT patients (median age at HSCT 10.4 years, median days of CT 162) were selected for the analysis. Also, seven age-matched healthy controls (median age 15.5) with non-contrast-enhanced inspiration-expiration chest CT were selected for comparison. We report that, compared to healthy age-matched controls, HSCT patients had larger percentages of poorly ventilated (median, 13.5% vs. 2.3%, p < .001) and air trapped (median 12.3% vs. 0%, p < .001) regions of lung tissue, suggesting its utility as a potential screening tool. Furthermore, there was wide variation within individual HSCT patients, supporting the use of multivolume CT and quantitative analysis to describe and phenotype post-transplantation lung involvement.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/ppul.25223DOI Listing
May 2021

Longitudinal Assessment of Patients With Cystic Fibrosis Lung Disease With Multivolume Noncontrast MRI and Spirometry.

J Magn Reson Imaging 2021 05 10;53(5):1570-1580. Epub 2020 Dec 10.

Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Università degli Studi di Milano, Centro Fibrosi Cistica, Milan, Italy.

Background: MRI has been suggested as a radiation-free imaging modality to investigate early structural alterations and regional functional impairment in cystic fibrosis (CF) lung disease.

Purpose/hypothesis: To compare functional and morphological MRI changes over the course of the disease to changes in spirometry.

Study Type: Longitudinal retrospective study.

Population: Twenty patients with CF lung disease (at baseline, age = 16.5 (13.3-20.6) years, forced expiratory volume in 1 second (as % of predicted [%pred]) FEV = 71 (59-87) %pred, forced expiratory flow at 25-75% of forced vital capacity FEF = 39 (25-63) %pred.

Field Strength/sequence: 1.5T / T -weighted HASTE; T -weighted TSE-PROPELLER; T -weighted bSSFP; T -weighted 3D GRE.

Assessment: Nonenhanced chest MRI and spirometry were retrospectively collected over a 3-year period from the initial recruitment visit. Images acquired at end-inspiration and end-expiration were registered by software using the optical flow method to measure expiratory-inspiratory differences in MR signal-intensity (Δ H-MRI). Measures of CF functional impairment were defined from Δ H-MRI: Δ H-MRI median, Δ H-MRI quartile coefficient of variation (QCV), and percent low-signal-variation volume (LVV). MR images were also evaluated by three readers using a CF-specific scoring system.

Statistical Tests: Spearman correlation analysis, Spearman rank correlation analysis, linear mixed-effect model analysis, intraclass correlation coefficient.

Results: Functional imaging parameters and total morphological score correlated with all spirometric measures, as did subscores of bronchial wall thickening/bronchiectasis, mucus plugging, and consolidation. Overall, the percent change of Δ1H-MRI median correlated with the percent change of FEV (ΔFEV , r = 0.41, P < 0.01) and the percent change of FEF (ΔFEF25-75%, r = 0.38, P < 0.01). The percent change of LVV correlated with ΔFEV (r = -0.47, P < 0.001) and ΔFEF (r = -0.50, P < 0.001).

Data Conclusion: These preliminary results suggest that nonenhanced multivolume MRI may provide a feasible tool to regionally map early pulmonary alterations for longitudinal evaluation of CF lung disease, without exposing the patients to ionizing radiation.

Level Of Evidence: 3T TECHNICAL EFFICACY STAGE: 5.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/jmri.27461DOI Listing
May 2021

Quantitative CT Analysis in Chronic Hypersensitivity Pneumonitis: A Convolutional Neural Network Approach.

Acad Radiol 2020 Nov 6. Epub 2020 Nov 6.

Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milan, Italy.

Rationale And Objectives: Chronic hypersensitivity pneumonitis (cHP) is a heterogeneous condition, where both small airway involvement and fibrosis may simultaneously occur. Computer-aided analysis of CT lung imaging is increasingly used to improve tissue characterization in interstitial lung diseases (ILD), quantifying disease extension, and progression. We aimed to quantify via a convolutional neural network (CNN) method the extent of different pathological classes in cHP, and to determine their correlation to pulmonary function tests (PFTs) and mosaic attenuation pattern.

Materials And Methods: The extension of six textural features, including consolidation (C), ground glass opacity (GGO), fibrosis (F), low attenuation areas (LAA), reticulation (R) and healthy regions (H), was quantified in 27 cHP patients (age: 56 ± 11.5 years, forced vital capacity [FVC]% = 57 ± 17) acquired at full-inspiration via HRCT. Each class extent was correlated to PFTs and to mosaic attenuation pattern.

Results: H showed a positive correlation with FVC%, FEV1% (forced expiratory volume), total lung capacity%, and diffusion of carbon monoxide (DLCO)% (r = 0.74, r = 0.78, r = 0.73, and r = 0.60, respectively, p < 0.001). GGO, R and C negatively correlated with FVC% and FEV1% with the highest correlations found for R (r = -0.44, and r = -0.46 respectively, p < 0.05); F negatively correlated with DLCO% (r = -0.42, p < 0.05). Patients with mosaic attenuation pattern had significantly more H (p = 0.04) and lower R (p = 0.02) and C (p = 0.0009) areas, and more preserved lung function indices (higher FVC%; p = 0.04 and DLCO%; p = 0.05), but did not show more air trapping in lung function tests.

Conclusion: CNN quantification of pathological tissue extent in cHP improves its characterization and shows correlation with PFTs. LAA can be overestimated by visual, qualitative CT assessment and mosaic attenuation pattern areas in cHP represents patchy ILD rather than small-airways disease.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.acra.2020.10.009DOI Listing
November 2020

Acute Effects of Lung Expansion Maneuvers in Comatose Subjects With Prolonged Bed Rest.

Respir Care 2021 Feb 6;66(2):240-247. Epub 2020 Oct 6.

Physiotherapy Department, Universidade Federal de Pernambuco, Recife, Brazil.

Background: Patients with decreased consciousness are prone to prolonged bed rest and respiratory complications. If effective in reducing atelectasis, lung expansion maneuvers could be used to prevent these complications. In comatose, bedridden subjects, we aimed to assess the acute effect on regional lung aeration of 2 lung expansion techniques: expiratory positive airway pressure and the breath-stacking maneuver. Our secondary aim was to evaluate the influence of these lung expansion techniques on regional ventilation distribution, regional ventilation kinetics, respiratory pattern, and cardiovascular system.

Methods: We enrolled 10 subjects status post neurosurgery, unable to follow commands, and with prolonged bed rest. All subjects were submitted to both expansion techniques in a randomized order. Regional lung aeration, ventilation distribution, and regional ventilation kinetics were measured with electrical impedance tomography.

Results: Lung aeration increased significantly during the application of both expiratory positive airway pressure and breath-stacking ( < .001) but returned to baseline values seconds afterwards. The posterior lung regions had the largest volume increase ( < .001 for groups). Both maneuvers induced asynchronous inflation and deflation between anterior and posterior lung regions. There were no significant differences in cardiovascular variables.

Conclusions: In comatose subjects with prolonged bed rest, expiratory positive airway pressure and breath-stacking promoted brief increases in lung aeration. (ClinicalTrials.gov registration NCT02613832.).
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.4187/respcare.07535DOI Listing
February 2021

Automating the correction of flow integration drift during whole-body plethysmography.

Annu Int Conf IEEE Eng Med Biol Soc 2020 07;2020:5-8

Prolonged measurement of total body volume variations (deltaVb) with whole-body, flow-based plethysmography (WBP) results in a drift of the signal due to changes in temperature and humidity inside the plethysmograph and to numerical integration of the flow to obtain deltaVb. This drift has been previously corrected with the application of a wavelet- based filter using visual inspection of the signal to select the optimal filter level (Uva et al. Front. Physiol. 6:411, 2016), thus introducing potential operator bias. To exclude the latter we compared this approach with a newly developed automatic method based on (1) correction for actual changes in temperature and humidity inside the plethysmograph (algorithm TH) and (2) automatic selection of the wavelet filter level based on comparison between deltaVb and intra-thoracic and abdominal pressure variations measured simultaneously (algorithm WAV). The Pearson's correlation coefficient between deltaVb and the changes in volume of the chest wall (deltaVcw) simultaneously obtained by optoelectronic plethysmography (OEP) was calculated after correction of deltaVb with TH and WAV applied separately, TH and WAV applied consecutively (TH+WAV), manual selection of a wavelet filter based on visual inspection (MAN) or no correction (CTRL). The correlation between deltaVb and deltaVcw increased marginally with WAV, TH+WAV and MAN compared to CTRL (P <; 0.01). Conversely, TH alone yielded a lower correlation (P <; 0.01). It follows that while the automated wavelet filter level selection method (WAV) represents an effective, operator-independent method for the correction of deltaVb, whether or not it is combined with specific correction for changes in thermodynamic conditions inside the plethysmograph, the manual method (MAN) yields satisfactory results without the constraints of intra-thoracic and abdominal pressure measurement.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1109/EMBC44109.2020.9176170DOI Listing
July 2020

A Wearable Device for Breathing Frequency Monitoring: A Pilot Study on Patients with Muscular Dystrophy.

Sensors (Basel) 2020 Sep 18;20(18). Epub 2020 Sep 18.

Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, 20133 Milano, Italy.

Patients at risk of developing respiratory dysfunctions, such as patients with severe forms of muscular dystrophy, need a careful respiratory assessment, and periodic follow-up visits to monitor the progression of the disease. In these patients, at-home continuous monitoring of respiratory activity patterns could provide additional understanding about disease progression, allowing prompt clinical intervention. The core aim of the present study is thus to investigate the feasibility of using an innovative wearable device for respiratory monitoring, particularly breathing frequency variation assessment, in patients with muscular dystrophy. A comparison of measurements of breathing frequency with gold standard methods showed that the device based on the inertial measurement units (IMU-based device) provided optimal results in terms of accuracy errors, correlation, and agreement. Participants positively evaluated the device for ease of use, comfort, usability, and wearability. Moreover, preliminary results confirmed that breathing frequency is a valuable breathing parameter to monitor, at the clinic and at home, because it strongly correlates with the main indexes of respiratory function.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/s20185346DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7571149PMC
September 2020

A Home Telemedicine System for Continuous Respiratory Monitoring.

IEEE J Biomed Health Inform 2021 04 6;25(4):1247-1256. Epub 2021 Apr 6.

This article presents a continuous home telemonitoring system for chronic respiratory patients using 5G connectivity developed in partnership with Vodafone as a part of the 5G Trial in Milan established by the Italian Ministry of Economic Development. The system features a wearable respiratory and activity monitor, an environmental sensor and a pulse oximeter sending the data through a 5G router to a Multi-Edge Computing server, incorporated in the Vodafone 5G infrastructure, where they are stored and accessible for visualization. In particular, activity, respiratory and environmental data are continuously streamed and collected. The solution has been tested on 18 healthy volunteers during non-supervised recordings lasting at least 48 hours. The combination of recognized activities and associated respiratory parameters provided statistically significant variations in breathing patterns between one activity and the other, thus giving more complete information to the clinicians than previously studied telemedicine systems based on spot-checks. In particular, statistically significant differences are found in tidal volume and minute ventilation between horizontal and vertical postures (p < 0.001) and between vertical postures and dynamic activities (p < 0.001); the respiratory rate shows statistically significant differences between horizontal and vertical postures (p < 0.001). Some environmental parameters have different mean values between day and night, such as carbon dioxide (p < 0.001). Trials on patients are needed to further study this telemedicine solution and make it commercially available in the future. The main further technical development suggested is the use of commercial 5G smartphones as routers, in order to make the system usable outside of home settings.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1109/JBHI.2020.3012621DOI Listing
April 2021

Comparison between the Airgo™ Device and a Metabolic Cart during Rest and Exercise.

Sensors (Basel) 2020 Jul 15;20(14). Epub 2020 Jul 15.

Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, 20133 Milan, Italy.

The aim of this study is to compare the accuracy of Airgo™, a non-invasive wearable device that records breath, with respect to a gold standard. In 21 healthy subjects (10 males, 11 females), four parameters were recorded for four min at rest and in different positions simultaneously by Airgo™ and SensorMedics 2900 metabolic cart. Then, a cardio-pulmonary exercise test was performed using the Erg 800S cycle ergometer in order to test Airgo™'s accuracy during physical effort. The results reveal that the relative error median percentage of respiratory rate was of 0% for all positions at rest and for different exercise intensities, with interquartile ranges between 3.5 (standing position) and 22.4 (low-intensity exercise) breaths per minute. During exercise, normalized amplitude and ventilation relative error medians highlighted the presence of an error proportional to the volume to be estimated. For increasing intensity levels of exercise, Airgo™'s estimate tended to underestimate the values of the gold standard instrument. In conclusion, the Airgo™ device provides good accuracy and precision in the estimate of respiratory rate (especially at rest), an acceptable estimate of tidal volume and minute ventilation at rest and an underestimation for increasing volumes.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/s20143943DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7412454PMC
July 2020

Quantitative Multivolume Proton-Magnetic Resonance Imaging in Lung Transplant Recipients: Comparison With Computed Tomography and Spirometry.

Acad Radiol 2020 Jul 8. Epub 2020 Jul 8.

Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milano, Italy.

Rationale And Objectives: Acute and chronic graft rejection remains the major problem in clinical surveillance of lung-transplanted patients and early detection of complications is of capital importance to allow the optimal therapeutic option. The aim of this study was to investigate the role of quantitative non contrast-enhanced magnetic resonance imaging (MRI) as a non-ionizing imaging modality to assess ventilation impairment in patients who have undergone lung transplantation, in comparison with quantitative computed tomography (CT) and spirometry.

Materials And Methods: Ten lung-transplanted patients (39 ±12 years, forced-expiratory volume in 1 second (FEV1) = 81 ± 27%, forced vital capacity (FVC) = 87 ± 27%) were acquired in breath-hold at full-expiration and full-inspiration with 1.5T MRI and CT. Maps of expiratory-inspiratory difference in MR signal-intensity and CT-density were computed to estimate regional ventilation. Based on expiratory, inspiratory, and expiratory-inspiratory difference values, each pixel was classified as healthy (H), low ventilation (LV), air trapping (AT), and consolidation (C) and the percent extent of each class was quantified.

Results: Overall, expiratory-inspiratory difference in MR signal-intensity correlated to CT-density (r = 0.64, p < 0.0001) and to FEV1 (ρ = 0.71, p = 0.02). The linear correlation between MRI and CT functional maps considering all the four classes is r = 0.93 (p < 0.0001). MRI percent volumes of H, AT, and C correlated to FEV1 %pred, with the highest correlation reported for AT (ρ = -0.82).

Conclusion: Results demonstrated a good agreement between MRI and CT ventilation imaging and between the corresponding percent volumes of lung damage. Quantitative MRI may represent an accurate non-ionizing imaging technique for longitudinal monitoring of lung transplant recipients.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.acra.2020.05.026DOI Listing
July 2020

Comparison of different methods for lung immobilization in an animal model.

Radiother Oncol 2020 09 21;150:151-158. Epub 2020 Jun 21.

Section of Anaesthesiology and Intensive Care Medicine, Department of Surgical Sciences, Uppsala University, Uppsala, Sweden.

Background And Purpose: Respiratory-induced motion introduces uncertainties in the delivery of dose in radiotherapy treatments. Various methods are used clinically, e.g. breath-holding, while there is limited experience with other methods such as apneic oxygenation and high frequency jet ventilation (HFJV). This study aims to compare the latter approaches for lung immobilization and their clinical impact on gas exchange in an animal model.

Materials And Methods: Two radiopaque tumor surrogate markers (TSM) were placed in the central (cTSM) and peripheral (dTSM) regions of the lungs in 9 anesthetized and muscle relaxed pigs undergoing 3 ventilatory interventions (1) HFJV at rates of 200 (JV200), 300 (JV300) and 400 (JV400) min; (2) apnea at continuous positive airway pressure (CPAP) levels of 0, 8 and 16 cmHO; (3) conventional mechanical ventilation (CMV) as reference mode. cTSM and dTSM were visualized using fluoroscopy and their coordinates were computed. The ventilatory pattern was registered, and oxygen and carbon dioxide (pCO) partial pressures were measured.

Results: The highest range of TSM motion, and ventilation was found during CMV, the lowest during apnea. During HFJV the amount of motion varied inversely with increasing frequency. The reduction of TSM motion at JV300, JV400 and all CPAP levels came at the cost of increased pCO, however the relatively low frequency of 200 min for HFJV was the only ventilatory setting that enabled adequate CO removal.

Conclusion: In this model, HFJV at 200 min was the best compromise between immobilization and gas exchange for sessions of 10-min duration.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.radonc.2020.06.024DOI Listing
September 2020

Effects of Positioning on Cough Peak Flow and Muscular Electromyographic Activation in Duchenne Muscular Dystrophy.

Respir Care 2020 Nov 16;65(11):1668-1677. Epub 2020 Jun 16.

PneumoCardioVascular Lab, Hospital Universitario Onofe Lopes, Empresa Brasileira de Serviços Hospitalares, Natal, Brazil.

Background: Advanced stages of Duchenne muscular dystrophy (DMD) result in muscle weakness and the inability to generate an effective cough. Several factors influence the effectiveness of cough in patients with DMD. The aim of this study was to assess whether differences in positioning affect cough peak flow (CPF) and muscular electromyographic activation in subjects with DMD compared with paired healthy subjects.

Methods: Optoelectronic plethysmography and surface electromyography were used to assess chest wall volumes, chest wall inspiratory capacity, CPF, breathing pattern, and electromyographic activity of sternocleidomastoid, scalene, rectus abdominis, and external oblique muscles during inspiratory and expiratory cough phases in the supine position, supine position with headrest raised at 45°, and sitting with back support at 80° in 12 subjects with DMD and 12 healthy subjects.

Results: Subjects with DMD had lower CPF ( < .01) in comparison to control subjects in all positions; the DMD group also exhibited lower CPF ( = .045) in the supine position versus 80°. Moreover, the relative volume contributions of the rib cage and abdominal compartments to tidal volume modified significantly with posture. The electromyographic activity during inspiratory and expiratory cough phases was lower in subjects with DMD compared to healthy subjects for all evaluated muscles ( < .05), but no significant differences were observed with posture change.

Conclusions: In subjects with DMD, posture influenced CPF and the relative contribution of the rib cage and abdominal compartments to tidal volume. However, muscular electromyographic activation was not influenced by posture in subjects with DMD and healthy subjects.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.4187/respcare.07426DOI Listing
November 2020

The impaired diaphragmatic function after bilateral lung transplantation: A multifactorial longitudinal study.

J Heart Lung Transplant 2020 Aug 21;39(8):795-804. Epub 2020 Apr 21.

Thoracic Surgery and Lung Transplantation Unit, Fondazione IRCCS Ca' Granda - Ospedale Maggiore Policlinico of Milan, Milan, Italy.

Background: Lung transplantation is a complex but effective treatment of end-stage pulmonary disease. Among the post-operative complications, phrenic nerve injury, and consequent diaphragmatic dysfunction are known to occur but are hitherto poorly described. We aimed to investigate the effect of lung transplantation on diaphragmatic function with a multimodal approach.

Methods: A total of 30 patients were studied at 4 time points: pre-operatively, at discharge after surgery, and after approximately 6 and subsequently 12 months post surgery. The diaphragmatic function was studied in terms of geometry (assessed by the radius of the diaphragmatic curvature delineated on chest X-ray), weakness (considering changes in forced vital capacity when the patient shifted from upright to supine position), force (maximal pressure during sniff), mobility (excursion of the dome of the diaphragm delineated by ultrasound), contractility (thickening fraction assessed by ultrasound), electrical activity (latency and area of compound muscle action potential during electrical stimulation of phrenic nerve), and kinematics (relative contribution of the abdominal compartment to tidal volume).

Results: Despite good clinical recovery (indicated by spirometry and 6 minutes walking test), a reduction of the diaphragmatic function was detected at discharge; it persisted 6 months later to recover fully 1 year after transplantation. Diaphragmatic dysfunction was demonstrated in terms of force, weakness, electrical activity, and kinematics. Our data suggest that the dysfunction was caused by phrenic nerve neurapraxia or moderate axonotmesis, potentially as a consequence of the surgical procedure (i.e., the use of ice and pericardium manipulation).

Conclusions: The occurrence of diaphragmatic dysfunction in patients with a good clinical recovery indicates that the evaluation of diaphragmatic function should be included in the post-operative assessment after lung transplantation.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.healun.2020.04.010DOI Listing
August 2020

Effects of Inspiratory Load on Chest Wall Kinematics, Breathing Pattern, and Respiratory Muscle Activity of Mouth-Breathing Children.

Respir Care 2020 Sep 7;65(9):1285-1294. Epub 2020 Apr 7.

PneumoCardioVascular Lab, Hospital Universitário Onofre Lopes, Natal, Rio Grande do Norte, Brazil.

Background: We sought to evaluate the acute effects of different inspiratory loads using nasal and oral interfaces on the volumes of the chest wall and its compartments, breathing pattern, and respiratory muscle activation in children with mouth-breathing syndrome.

Methods: Children with mouth-breathing syndrome were randomized into 2 groups, one with an inspiratory load intensity 20% of maximum inspiratory pressure ( = 14), and the other with an inspiratory load intensity 40% of maximum inspiratory pressure ( = 15). The chest wall volumes and electromyography of sternocleidomastoid, rectus abdominis, scalene, and internal intercostal muscles were used to analyze respiration against the 2 load intensities and using 2 interfaces (ie, nasal and oral).

Results: A total of 72 children with mouth-breathing syndrome were recruited, and 29 were evaluated in this study. The use of inspiratory load promoted improvement in the components of the breathing pattern: breathing frequency ( = .039), inspiratory time ( = .03), and total respiratory time ( = .043); and increases in tidal volume ( < .001), end-inspiratory volume ( < .001), and electrical activity of scalene muscles and sternocleidomastoid muscles ( < .001) when compared to quiet breathing. The load imposed via a nasal interface versus an oral interface provided an increase in tidal volume ( = .030), end-inspiratory volume ( = .02), and electrical activity of scalene muscles ( < .001) and sternocleidomastoid muscles ( = .02).

Conclusions: The use of acute inspiratory loads improved the breathing pattern and increased lung volume and electrical activity of inspiratory muscles. This work brings new perspective to the investigation of using nasal interfaces during the application of inspiratory loads. The nasal interface was more effective compared to the oral interface commonly used in clinical practice.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.4187/respcare.06908DOI Listing
September 2020

International Expert Consensus and Recommendations for Neonatal Pneumothorax Ultrasound Diagnosis and Ultrasound-guided Thoracentesis Procedure.

J Vis Exp 2020 03 12(157). Epub 2020 Mar 12.

Department of Neonatology and NICU, Beijing Chaoyang District Maternal and Child Healthcare Hospital; The National Neonatal Lung Ultrasound Training Base.

Pneumothorax (PTX) represents accumulation of the air in the pleural space. A large or tension pneumothorax can collapse the lung and cause hemodynamic compromise, a life-threatening disorder. Traditionally, neonatal pneumothorax diagnosis has been based on clinical images, auscultation, transillumination, and chest X-ray findings. This approach may potentially lead to a delay in both diagnosis and treatment. The use of lung US in diagnosis of PTX together with US-guided thoracentesis results in earlier and more precise management. The recommendations presented in this publication are aimed at improving the application of lung US in guiding neonatal PTX diagnosis and management.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3791/60836DOI Listing
March 2020

Continuous professional development: elevating sleep andbreathing disorder education in Europe.

Breathe (Sheff) 2020 Mar;16(1):190336

Sorbonne Université, INSERM, UMRS1158 Neurophysiologie respiratoire Expérimentale et clinique, Paris, France.

http://bit.ly/30PU01P.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1183/20734735.0336-2019DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7078742PMC
March 2020

Sniff test: Does what we measure at the nose reflect what happens in the chest wall?

Clin Respir J 2020 Jun 27;14(6):589-591. Epub 2020 Feb 27.

Thoracic Surgery and Lung Transplantation Unit, Fondazione IRCCS Ca' Granda-Ospedale Maggiore Policlinico of Milan, Milan, Italy.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/crj.13170DOI Listing
June 2020

Simulation of bronchial airway acoustics in healthy and asthmatic subjects.

PLoS One 2020 10;15(2):e0228603. Epub 2020 Feb 10.

Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milan, Italy.

The onset and development of many airway pathologies affect sound propagation throughout the respiratory system; changes in respiratory sounds are detected primarily by auscultation, which is highly skill dependent. The aim of the present study was to compare healthy and asthmatic pulmonary acoustics by applying a 1D model of wave propagation on CT-based patient-specific geometries. High-resolution CT lung images were acquired in five healthy volunteers and five asthmatic patients at total lung capacity (TLC) and functional residual capacity (FRC). Tracheobronchial trees were reconstructed from CT images. Acoustic pressure, impedance and wall radial velocity were measured by simulating acoustic wave propagation of two external, acoustic pressure waves (1 Pa, 200 and 600 Hz) from the trachea level to the 4th generation. In asthmatic patients, acoustic pressure averaged across the last three generations showed a reduction equal to 29.7% (p<0.01) at FRC, at 200 Hz; input and terminal impedance were 34.5% (p<0.05) higher both at FRC and TLC; wall radial velocity was more than 80% (p<0.05) lower in higher generations both at FRC and TLC. Airway differences in asthma alter acoustic parameters at FRC and TLC, with the greatest difference at FRC and 200 Hz. Acoustic wave propagation analysis represents a quantitative approach that has potential to objectively characterize airway differences in individuals with diseases such as asthma.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0228603PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7010248PMC
May 2020
-->