• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 30
  • 25
  • 5
  • 3
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 75
  • 75
  • 75
  • 16
  • 15
  • 13
  • 12
  • 12
  • 11
  • 11
  • 11
  • 9
  • 9
  • 9
  • 8
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
71

Generalized estimation of the ventilatory distribution from the multiple‑breath nitrogen washout

Motta-Ribeiro, Gabriel Casulari, Jandre, Frederico Caetano, Wrigge, Hermann, Giannella-Neto, Antonio 10 August 2016 (has links) (PDF)
Background: This work presents a generalized technique to estimate pulmonary ventilation-to-volume (v/V) distributions using the multiple-breath nitrogen washout, in which both tidal volume (VT) and the end-expiratory lung volume (EELV) are allowed to vary during the maneuver. In addition, the volume of the series dead space (vd), unlike the classical model, is considered a common series unit connected to a set of parallel alveolar units. Methods: The numerical solution for simulated data, either error-free or with the N2 measurement contaminated with the addition of Gaussian random noise of 3 or 5 % standard deviation was tested under several conditions in a computational model constituted by 50 alveolar units with unimodal and bimodal distributions of v/V. Non-negative least squares regression with Tikhonov regularization was employed for parameter retrieval. The solution was obtained with either unconstrained or constrained (VT, EELV and vd) conditions. The Tikhonov gain was fixed or estimated and a weighting matrix (WM) was considered. The quality of estimation was evaluated by the sum of the squared errors (SSE) (between reference and recovered distributions) and by the deviations of the first three moments calculated for both distributions. Additionally, a shape classification method was tested to identify the solution as unimodal or bimodal, by counting the number of shape agreements after 1000 repetitions. Results: The accuracy of the results showed a high dependence on the noise amplitude. The best algorithm for SSE and moments included the constrained and the WM solvers, whereas shape agreement improved without WM, resulting in 97.2 % for unimodal and 90.0 % for bimodal distributions in the highest noise condition. Conclusions: In conclusion this generalized method was able to identify v/V distributions from a lung model with a common series dead space even with variable VT. Although limitations remain in presence of experimental noise, appropriate combination of processing steps were also found to reduce estimation errors.
72

Vliv metody uvolňování dýchacích cest u pacientů s chronickou obstrukční plicní nemocí / The Effect of Airway Clearance Techniques on Patients with Chronic Obstructive Pulmonary Disease

Milibari, Hussam January 2018 (has links)
Title The effect of airway clearance techniques on patients with Chronic Obstructive Pulmonary Disease. Objective The main purpose of this study is to expose and evaluate the efficacy of airway clearance techniques on patients with Chronic Obstructive Pulmonary Disease by using pulmonary functions and Quality of Life measurements from recent studies. Methodology This thesis is literature review. The selected studies were according to inclusion and exclusion criteria. The selections of recent studies were published from the year of 2000 until 2017 in English language. The following research databases were selected to identify the relevant topic: PubMed, MEDLINE, Embase, Cochrane, PEDro, and CINAHL. The parameters' results from the articles have been also selected by evaluation the statistical differences according to the P-values. Results Twenty-three articles out of 117 have been found according to inclusion criteria, exclusion criteria, and outcome measures. The techniques were active cycle of breathing technique (ACBT), positive expiratory pressure (PEP), temporary of positive expiratory pressure (T-PEP), Oscillating positive expiratory pressure (O-PEP), high-frequency chest wall oscillation (HFCWO), slow expiration with glottis opened in lateral posture (ELTGOL), postural drainage, and autogenic...
73

Generalized estimation of the ventilatory distribution from the multiple‑breath nitrogen washout

Motta-Ribeiro, Gabriel Casulari, Jandre, Frederico Caetano, Wrigge, Hermann, Giannella-Neto, Antonio January 2016 (has links)
Background: This work presents a generalized technique to estimate pulmonary ventilation-to-volume (v/V) distributions using the multiple-breath nitrogen washout, in which both tidal volume (VT) and the end-expiratory lung volume (EELV) are allowed to vary during the maneuver. In addition, the volume of the series dead space (vd), unlike the classical model, is considered a common series unit connected to a set of parallel alveolar units. Methods: The numerical solution for simulated data, either error-free or with the N2 measurement contaminated with the addition of Gaussian random noise of 3 or 5 % standard deviation was tested under several conditions in a computational model constituted by 50 alveolar units with unimodal and bimodal distributions of v/V. Non-negative least squares regression with Tikhonov regularization was employed for parameter retrieval. The solution was obtained with either unconstrained or constrained (VT, EELV and vd) conditions. The Tikhonov gain was fixed or estimated and a weighting matrix (WM) was considered. The quality of estimation was evaluated by the sum of the squared errors (SSE) (between reference and recovered distributions) and by the deviations of the first three moments calculated for both distributions. Additionally, a shape classification method was tested to identify the solution as unimodal or bimodal, by counting the number of shape agreements after 1000 repetitions. Results: The accuracy of the results showed a high dependence on the noise amplitude. The best algorithm for SSE and moments included the constrained and the WM solvers, whereas shape agreement improved without WM, resulting in 97.2 % for unimodal and 90.0 % for bimodal distributions in the highest noise condition. Conclusions: In conclusion this generalized method was able to identify v/V distributions from a lung model with a common series dead space even with variable VT. Although limitations remain in presence of experimental noise, appropriate combination of processing steps were also found to reduce estimation errors.
74

Vliv velikosti defektu a operační techniky na dlouhodobou morbiditu dětí s vrozenou brániční kýlou / The influence of defect size and surgical technique on long-term morbidity in children with congenital diaphragmatic hernia

Rounová, Petra January 2013 (has links)
52 8 Summary The influence of defect size and surgical technique on the long-term morbidity of children with congenital diaphragmatic hernia Objective: The aim of this study is to evaluate the effects of diaphragm reconstruction using a synthetic non-absorbable patch from polytetrafluoroethylene (PTFE, Gore-Tex) and primary repair of diaphragm defects on the long-term morbidity in children after surgery of congenital diaphragmatic hernia (CDH), with a primary interest in the influence of these techniques on the occurrence of skeletal deformities and the development of pulmonary functions. One part of this study is to introduce a new objective method for perioperative evaluation of the size of diaphragmatic defects to enable comparison of results among various centres and methods used for diaphragmatic reconstruction. Another part of this study is to evaluate the validity of lung function assessment using four unique methods of Infant Pulmonary Function Tests (IPFT) in children under 13 kg of body weight. Material and Methods: A study of 69 patients operated on between 1996-2010 for CDH, in which the clinical part of the study was performed between the years 2009-2011. The clinical study evaluated anthropometric examination, pulmonary function testing and a questionnaire study which focused on long-term...
75

Successful Treatment of Respiratory Insufficiency Due to Adult Acid Maltase Deficiency With Noninvasive Positive Pressure Ventilation

Puruckherr, Michael, Pooyan, Payam, Girish, Mirle R., Byrd, Ryland P., Roy, Thomas M. 01 July 2004 (has links)
Acid maltase deficiency (AMD) is a rare autosomal recessive genetic disorder that results in an accumulation of glycogen in the lysosomal storage vacuoles. It is classified as a glycogen storage disease (type II) and is also known as Pompe's disease. The prognosis of the patient with AMD is poor and the main cause of death is respiratory failure. We report a female patient whose respiratory insufficiency was documented to occur most severely during rapid eye movement sleep and who benefited clinically from the institution of nocturnal noninvasive bilevel positive airway pressure.

Page generated in 0.0778 seconds