The Experts below are selected from a list of 228 Experts worldwide ranked by ideXlab platform
Warren H. Finlay - One of the best experts on this subject based on the ideXlab platform.
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In vitro deposition measurement of inhaled micrometer-sized particles in extrathoracic airways of children and adolescents during Nose Breathing
Journal of Aerosol Science, 2011Co-Authors: Laleh Golshahi, Michelle Noga, Richard B. Thompson, Warren H. FinlayAbstract:Abstract An in vitro study was conducted with the goal of developing empirical correlations to predict the deposition of particles with an aerodynamic diameter of 0.5–5.3 μm in nasal airways of children with ages 4–14 years. CT images of nasal airways of thirteen healthy subjects and one with congested nasal airways were used for fabricating the replicas by rapid prototyping. Replicas included nasal airways to the level of the upper trachea as well as the face. Four physiological Breathing patterns (sinusoidal waves) of children were simulated by a pulmonary waveform generator. Using an Electrical Low Pressure Impactor (ELPI) we measured deposition of sunflower oil particles generated by a Collison atomizer. Moreover, using the same setup, particle deposition in five adult replicas fabricated using MRI images was measured for direct comparison with the child replicas and in vivo data available for adults. Deposition increased by increasing particle size and flow rate, indicating impaction as the dominant deposition mechanism. Existing correlations for adults were unable to reduce the scatter in the deposition data for children. A correlation was developed for prediction of deposition including the relevant non-dimensional numbers (Stokes and Reynolds numbers) that were calculated considering the dimensions of the airways. The corrected correlations should be useful for exposure estimation of children and for efficient pediatric drug delivery using face masks.
Dieter Köhler - One of the best experts on this subject based on the ideXlab platform.
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Nasal strips without effect on obstructive sleep apnea and snoring
Pneumologie (Stuttgart Germany), 1997Co-Authors: M. Wenzel, Bernd Schönhofer, K. Siemon, Dieter KöhlerAbstract:Recently a Nose plaster (NP, Breathe-Right) has been increasingly used in the treatment of obstructive sleep apnoea (OSA) and snoring. Hence, we examined the use of the NP as a treatment of both OSA and snoring without OSA. The NP has a elastic spine that increases the diameter of the nostril and is thought to reduce the degree of OSA and snoring. According to the polysomnographic data two groups were differentiated: Group A (30 patients with OSA, apnoea index > 10/h, 26 men) and Group B (20 snorers, without OSA, 13 men). After the diagnostic polysomnography the efficacy of the NP was measured with a cardiorespiratory polygraph on the 2 following nights. In the group A the polygraphic data (apnoea index, time of apneas, desaturation index, time of desaturations, mean and nadir SaO2) were studied; in group B the snoring index (snoring events/hour) was measured. A questionnaire scored quality of sleeping, daytime condition and the quality of Nose Breathing. In neither group were the recorded polygraphic findings different with the NP although with the NP an improved Nose Breathing was scored in both groups. In group A 90% of the patients scored the daytime sleepiness unchanged and 10 of 30 patients described an improved quality of sleep. In group B there was no change in the frequency of snoring events with the NP. Neither the degree of OSA nor of snoring without OSA were changed by the NP, which can therefore not be considered a treatment of these conditions. However, the majority of the study population were impressed by the symptomatic improvement in Nose Breathing.
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A New Oxygen Applicator for Simultaneous Mouth and Nose Breathing
Chest, 1993Co-Authors: Dieter Köhler, Martin Knoch, Clemens Sommerfeld, Helen MüllerAbstract:We have developed a new O 2 applicator to try to overcome the problems of long-term oxygen therapy that ensures a sufficient oxygen supply for both nasal and oral Breathing and prevents mucosal irritation. Placed on the upper lip, it is unobtrusive. The principle is as follows: due to an enlarged outlet area, turbulence occurs and the oxygen is reduced. Thus, an oxygen cloud is formed that can be inhaled by both mouth or Nose. The efficiency of our O t applicator was compared with a face mask in six healthy subjects and patients with COPD. A similar increase in Po 2 was found up to an oxygen flow of 2 L/min for nasal and oral Breathing. Mild hypercapnia resulted in three patients with COPD only when a face mask was used and only when patients breathed through the Nose. All patients preferred the new applicator.
Laleh Golshahi - One of the best experts on this subject based on the ideXlab platform.
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In vitro deposition measurement of inhaled micrometer-sized particles in extrathoracic airways of children and adolescents during Nose Breathing
Journal of Aerosol Science, 2011Co-Authors: Laleh Golshahi, Michelle Noga, Richard B. Thompson, Warren H. FinlayAbstract:Abstract An in vitro study was conducted with the goal of developing empirical correlations to predict the deposition of particles with an aerodynamic diameter of 0.5–5.3 μm in nasal airways of children with ages 4–14 years. CT images of nasal airways of thirteen healthy subjects and one with congested nasal airways were used for fabricating the replicas by rapid prototyping. Replicas included nasal airways to the level of the upper trachea as well as the face. Four physiological Breathing patterns (sinusoidal waves) of children were simulated by a pulmonary waveform generator. Using an Electrical Low Pressure Impactor (ELPI) we measured deposition of sunflower oil particles generated by a Collison atomizer. Moreover, using the same setup, particle deposition in five adult replicas fabricated using MRI images was measured for direct comparison with the child replicas and in vivo data available for adults. Deposition increased by increasing particle size and flow rate, indicating impaction as the dominant deposition mechanism. Existing correlations for adults were unable to reduce the scatter in the deposition data for children. A correlation was developed for prediction of deposition including the relevant non-dimensional numbers (Stokes and Reynolds numbers) that were calculated considering the dimensions of the airways. The corrected correlations should be useful for exposure estimation of children and for efficient pediatric drug delivery using face masks.
Reis Afc - One of the best experts on this subject based on the ideXlab platform.
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Padrão respiratório e movimento toracoabdominal de crianças respiradoras orais Breathing pattern and thoracoabdominal motion in mouth-Breathing children
2008Co-Authors: Brant Tcs, Marisa Cotta Mancini, Becker Hmg, Reis AfcAbstract:Objective: To characterize the Breathing pattern and thoracoabdominal motion of mouth-Breathing children aged between eight and ten years and to compare these characteristics with those of Nose-Breathing children of the same ages. Methods: This observational study was carried out in a university laboratory. The sample size of 50 subjects was estimated based on the results of a pilot study with ten children in each group (total of 20 children) and considering a significance level of 0.05 and statistical power of 0.80. Twenty-six mouth- Breathing and 25 Nose-Breathing children participated. Calibrated respiratory inductive plethysmography was used to analyze the following variables, among others: respiratory frequency (f), rib cage contribution towards tidal volume (%RC/Vt), phase angle (PhAng) and the ratio between time taken to reach peak inspiratory flow and total inspiratory time (PifT/Ti). Peripheral oxygen saturation of hemoglobin (SpO 2) was measured using pulse oximetry. Statistical analysis was performed using the Student's t test for independent groups or the Mann- Whitney U test, according to the sample distribution of the variables. Results: A total of 4,816 respiratory cycles were analyzed: 2,455 from mouth-breathers and 2,361 from Nose-breathers, with a mean of 94 cycles per child. No statistically significant differences were observed between the groups, for the variables studied (f=20.00±2.68 versus 20.73±2.58, p=0.169; %RC/Vt=39.30±11.86 versus 38.36±10.93, p=0.769; PhAng=14.53±7.97 versus 13.31±7.74, p=0.583; PifT/Ti=57.40±7.16 versus 58.35±5.99, p=0.610; SpO2=96.42±1.52% versus 96.88±1.01%, p=0.208; respectively). Conclusions: These results suggest that mouth-Breathing children show Breathing patterns and thoracoabdominal motion that are similar to those of Nose-Breathing children in the same age group.
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Breathing pattern and thoracoabdominal motion in mouth-Breathing children Padrão respiratório e movimento toracoabdominal de crianças respiradoras orais
2008Co-Authors: Brant Tcs, Marisa Cotta Mancini, Becker Hmg, Reis AfcAbstract:Objective: To characterize the Breathing pattern and thoracoabdominal motion of mouth-Breathing children aged between eight and ten years and to compare these characteristics with those of Nose-Breathing children of the same ages. Methods: This observational study was carried out in a university laboratory. The sample size of 50 subjects was estimated based on the results of a pilot study with ten children in each group (total of 20 children) and considering a significance level of 0.05 and statistical power of 0.80. Twenty-six mouth- Breathing and 25 Nose-Breathing children participated. Calibrated respiratory inductive plethysmography was used to analyze the following variables, among others: respiratory frequency (f), rib cage contribution towards tidal volume (%RC/Vt), phase angle (PhAng) and the ratio between time taken to reach peak inspiratory flow and total inspiratory time (PifT/Ti). Peripheral oxygen saturation of hemoglobin (SpO 2 ) was measured using pulse oximetry. Statistical analysis was performed using the Student's t test for independent groups or the Mann- Whitney U test, according to the sample distribution of the variables. Results: A total of 4,816 respiratory cycles were analyzed: 2,455 from mouth-breathers and 2,361 from Nose-breathers, with a mean of 94 cycles per child. No statistically significant differences were observed between the groups, for the variables studied (f=20.00±2.68 versus 20.73±2.58, p=0.169; %RC/Vt=39.30±11.86 versus 38.36±10.93, p=0.769; PhAng=14.53±7.97 versus 13.31±7.74, p=0.583; PifT/Ti=57.40±7.16 versus 58.35±5.99, p=0.610; SpO 2 =96.42±1.52% versus 96.88±1.01%, p=0.208; respectively). Conclusions: These results suggest that mouth-Breathing children show Breathing patterns and thoracoabdominal motion that are similar to those of Nose-Breathing children in the same age group.
Guangyu Cao - One of the best experts on this subject based on the ideXlab platform.
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Distribution of droplet aerosols generated by mouth coughing and Nose Breathing in an air-conditioned room
Sustainable Cities and Society, 2019Co-Authors: Yixian Zhang, Guohui Feng, Yilin Cai, Zheng Zhang, Guangyu CaoAbstract:Abstract The objective of this study is to understand the distribution of droplet aerosols in an air-conditioned room, which is very important to comprehend how infectious bacteria and viruses transmit from person to person through respiratory activities. To predict droplet aerosols distribution in this paper, adopted Large Eddy Simulation (LES) CFD model coupling with Lagrangian method is established and validated through the experiment in a climate chamber. Mouth coughing and Nose Breathing with changing airflow velocities are investigated in the simulation to study the influence of supply air temperature and relative humidity, ventilation rate and ventilation pattern on the number of suspended, deposited and escaped droplet aerosols. The results show that compared with ventilation rate and air distribution patterns, supply air temperature and relative humidity have less influence on the number of suspected and escaped droplets aerosols with displacement ventilation (DV). Compared with Mixing ventilation (MV), DV has significant effect on reduction of the human exposure. These findings and the adopted simulation method may be used to study the effects of different ventilation systems on distributing droplets aerosols in various indoor spaces, such as buildings and public transports.