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Designing for Upper Torso and Arm Anatomy
Published in Karen L. LaBat, Karen S. Ryan, Human Body, 2019
Lung/chest cavity volume is proportional to the radius and height of the relatively conical lungs. In an adult, the difference in lung volume between maximum inhalation and maximum exhalation is approximately 4 to 4.5 liters (244 to 275 in.3) (Miller et al., 2005). Unrestricted rib cage motion and full relaxation and strong contraction of the diaphragm and abdominal wall are needed to produce that degree of volume change. The diaphragm flattens as it contracts, enlarging the chest cavity, causing negative pressure within the chest. This action leads to air intake or inhalation. As the intercostal muscles contract, the ribs move out and up—helping to stabilize the rib cage, preventing collapse, while allowing and assisting the chest cavity to expand. See Sections 4.4.1 and 4.14.4 for additional information on rib cage structure and rib cage motion. When the diaphragm relaxes, it moves up toward the lungs expelling air in exhalation. Abdominal wall muscle contraction against the abdominal contents forces more air from the lungs.
Characterization of obstructive lung diseases from the respiration signal
Published in Debatosh Guha, Badal Chakraborty, Himadri Sekhar Dutta, Computer, Communication and Electrical Technology, 2017
S. Sarkar, S. Pal, S. Bhattacherjee, P. Bhattacharyya
Respiration is a vital parameter in the clinical and diagnostic field (Sarkar, Bhattacherjee, & Pal, 2015). Abnormal respiration and sudden change in the respiratory rate indicate a major physiological imbalance. In OLD, one of the main symptoms is the variable expiratory airflow, i.e., difficulty in exhalation due to bronchoconstriction, airway wall thickening, and excessive mucus production (Buist, 2006; FitzGerald, 2015). These physiological changes in lungs are also reflected in respiration leading to the extraction of features from the respiration signal in this study.
Chapter 19 Blood Flow Measurement
Published in B H Brown, R H Smallwood, D C Barber, P V Lawford, D R Hose, Medical Physics and Biomedical Engineering, 2017
If the concentration of oxygen or carbon dioxide in arterial and mixed venous blood is known, and in addition the rate of inhalation of oxygen or exhalation of carbon dioxide is known, then we can use the Fick equation to calculate the cardiac output. The method works, but it is invasive in that blood gas concentrations have to be measured fairly close to the lungs. The rate of inhalation or exhalation of the gases can be measured using a spirometer (see section 17.4.1).
Reducing COVID-19 airborne transmission risks on public transportation buses: an empirical study on aerosol dispersion and control
Published in Aerosol Science and Technology, 2021
Nathan J. Edwards, Rebecca Widrick, Justin Wilmes, Ben Breisch, Mike Gerschefske, Jon Sullivan, Richard Potember, Angelica Espinoza-Calvio
Portable air tanks provided compressed air to the nebulizer through a low flow regulator at 103 kPa (15 psi) and also to the exhalation simulator at 827 kPa (120 psi) for both the stationary tests as well as on-the-road tests. The exhalation airflows were measured using a medical spirometer (MIR SmartOne) using the standard metrics for human respiratory function of Peak Flow (PEF) and Forced Expiratory Volume in the first second (FEV1). During this study, the simulator dispersed the NaCl aerosols with exhalation air flows of PEF (SD) of 449.8 (50.8) L/min and FEV1 (SD) of 5.80 (0.33) L which are within range of a modest cough (Lindsley et al. 2012; 2013; Hui et al. 2012; Rothenberg et al. 1987). Even though SARS-CoV-2 viral emissions and inhalation loading doses are not fully quantified by the scientific and healthcare communities, and a possible difference in calibrated test emissions, this method of generating aerosol particles with a simulated cough provides significant insights into aerosol dispersion patterns within the buses. The effect of the airflows, velocities of the aerosols, and application of masks were previously studied in (Edwards et al. 2020).
Modeling pressure relationships of inspired air into the human lung bifurcations through simulations
Published in International Journal for Computational Methods in Engineering Science and Mechanics, 2018
Parya Aghasafari, Israr B.M. Ibrahim, Ramana Pidaparti
Human lung is one of the most complicated systems in the respiratory system and has twenty-three generations of branching airways [1]. Inhalation is the passage of air into the lungs to supply the body with oxygen, and the passage of air out of the lungs to extrude carbon dioxide is known as exhalation; this aggregate process is called breathing or ventilation. Diaphragm's contraction causes lung volume expansion during the process of inhalation. Based on the principles of Boyle's Law, lung pressure would decrease due to volume expansion which leads to pressure gradient between the atmosphere and the lung. This pressure gradient allows air to rush into the lungs and inhalation occurs.