Optimal Determination of Respiratory Airflow Patterns Using a Nonlinear Multicompartment Model for a Lung Mechanics System

Computational and Mathematical Methods in Medicine ◽

10.1155/2012/165946 ◽

2012 ◽

Vol 2012 ◽

pp. 1-11 ◽

Cited By ~ 7

Author(s):

Hancao Li ◽

Wassim M. Haddad

Keyword(s):

Work Of Breathing ◽

Optimality Criteria ◽

Lung Mechanics ◽

Airflow Rate ◽

Multicompartment Model ◽

Classical Calculus ◽

Inspiratory Phase ◽

Respiratory Airflow ◽

Elastic Potential Energy

We develop optimal respiratory airflow patterns using a nonlinear multicompartment model for a lung mechanics system. Specifically, we use classical calculus of variations minimization techniques to derive an optimal airflow pattern for inspiratory and expiratory breathing cycles. The physiological interpretation of the optimality criteria used involves the minimization of work of breathing and lung volume acceleration for the inspiratory phase, and the minimization of the elastic potential energy and rapid airflow rate changes for the expiratory phase. Finally, we numerically integrate the resulting nonlinear two-point boundary value problems to determine the optimal airflow patterns over the inspiratory and expiratory breathing cycles.

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Optimal Determination of Respiratory Airflow Patterns for a General Multicompartment Lung Mechanics System With Nonlinear Resistance and Compliance Parameters

Journal of Dynamic Systems Measurement and Control ◽

10.1115/1.4031596 ◽

2015 ◽

Vol 137 (12) ◽

Cited By ~ 1

Author(s):

Saing Paul Hou ◽

Nader Meskin ◽

Wassim M. Haddad

Keyword(s):

Optimization Criterion ◽

Lung Model ◽

Lung Mechanics ◽

Type Model ◽

Airflow Rate ◽

Mechanics Model ◽

Respiratory Airflow ◽

Elastic Potential Energy ◽

And Function ◽

Nonlinear Resistance

In this paper, we develop a framework for determining optimal respiratory airflow patterns for a multicompartment lung mechanics system with nonlinear resistance and compliance parameters. First, a nonlinear multicompartment lung mechanics model that accounts for nonlinearities in both the airway resistances and the lung compliances is developed. In particular, we assume that the resistive losses are characterized by a Rohrer-type model with resistive losses defined as the sum of linear and quadratic terms of the airflow. The proposed model is more realistic than those presented in the literature, since it takes into account the heterogeneity of lung anatomy and function as well as the nonlinearity of lung resistance and compliance parameters. This model can be used to provide a better understanding of pulmonary function as well as the process of mechanical ventilation. Next, using the proposed nonlinear multicompartment lung model, we develop a framework for determining optimal respiratory airflow patterns. Specifically, an optimization criterion that involves the minimization of the oxygen consumption of the lung muscles and lung volume acceleration for the inspiratory phase, and the minimization of the elastic potential energy and rapid airflow rate changes for the expiratory phase is formulated and solved. The solution to the formulated optimization problem is derived using classical calculus of variation techniques. Finally, several illustrative numerical examples are presented to illustrate the efficacy of the proposed nonlinear multicompartment lung model and the corresponding optimal airflow patterns. Comparison with experimental data shows that our nonlinear resistance model predicts the airflow patterns more accurately than linear resistance models. Moreover, the optimization criterion used in this paper also provides a more accurate prediction of the optimal airflow patterns.

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The Effect of Posture on Ventilation and Lung Mechanics in Preterm and Light-for-Date Infants

PEDIATRICS ◽

10.1542/peds.64.4.429 ◽

1979 ◽

Vol 64 (4) ◽

pp. 429-432 ◽

Cited By ~ 3

Author(s):

Alastair A. Hutchison ◽

Keith R. Ross ◽

George Russell

Keyword(s):

Tidal Volume ◽

Prone Position ◽

Supine Position ◽

Work Of Breathing ◽

Newborn Infants ◽

Lateral Position ◽

Minute Volume ◽

Lung Mechanics ◽

Total Work ◽

Preterm Group

The effect of right lateral, supine, and prone postures on ventilation and lung mechanics was studied in 23 healthy newborn infants, ten preterm and 13 term, "light-for-date." In the preterm group, tidal volume, minute volume, elastic work, inspiratory viscous work, total viscous work, and the total work of breathing were significantly greater in the prone position than in the supine position. Results obtained in the lateral position did not differ significantly from those in the prone or supine positions. Posture did not significantly affect tidal volume or lung mechanics in the light-for-date infants. The prone position is suggested to be the optimum nursing posture for healthy preterm infants.

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Effect of nocturnal EPAP titration to abolish tidal expiratory flow limitation in COPD patients with chronic hypercapnia: a randomized, cross-over pilot study

Respiratory Research ◽

10.1186/s12931-020-01567-x ◽

2020 ◽

Vol 21 (1) ◽

Author(s):

Emanuela Zannin ◽

Ilaria Milesi ◽

Roberto Porta ◽

Simona Cacciatore ◽

Luca Barbano ◽

...

Keyword(s):

Oxygen Saturation ◽

Work Of Breathing ◽

Lung Mechanics ◽

Intrinsic Peep ◽

Chronic Obstructive ◽

Flow Limitation ◽

Expiratory Flow Limitation ◽

Copd Patients ◽

Ineffective Efforts ◽

Expiratory Flow

Abstract Background Tidal expiratory flow limitation (EFLT) promotes intrinsic PEEP (PEEPi) in patients with chronic obstructive pulmonary disease (COPD). Applying non-invasive ventilation (NIV) with an expiratory positive airway pressure (EPAP) matching PEEPi improves gas exchange, reduces work of breathing and ineffective efforts. We aimed to evaluate the effects of a novel NIV mode that continuously adjusts EPAP to the minimum level that abolishes EFLT. Methods This prospective, cross-over, open-label study randomized patients to one night of fixed-EPAP and one night of EFLT-abolishing-EPAP. The primary outcome was transcutaneous carbon dioxide pressure (PtcCO2). Secondary outcomes were: peripheral oxygen saturation (SpO2), frequency of ineffective efforts, breathing patterns and oscillatory mechanics. Results We screened 36 patients and included 12 in the analysis (age 72 ± 8 years, FEV1 38 ± 14%Pred). The median EPAP did not differ between the EFLT-abolishing-EPAP and the fixed-EPAP night (median (IQR) = 7.0 (6.0, 8.8) cmH2O during night vs 7.5 (6.5, 10.5) cmH2O, p = 0.365). We found no differences in mean PtcCO2 (44.9 (41.6, 57.2) mmHg vs 54.5 (51.1, 59.0), p = 0.365), the percentage of night time with PtcCO2 > 45 mm Hg was lower (62(8,100)% vs 98(94,100)%, p = 0.031) and ineffective efforts were fewer (126(93,205) vs 261(205,351) events/hour, p = 0.003) during the EFLT-abolishing-EPAP than during the fixed-EPAP night. We found no differences in oxygen saturation and lung mechanics between nights. Conclusion An adaptive ventilation mode targeted to abolish EFLT has the potential to reduce hypercapnia and ineffective efforts in stable COPD patients receiving nocturnal NIV. Trial registration: ClicalTrials.gov, NCT04497090. Registered 29 July 2020—Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT04497090.

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Effect of respiratory airflow rate on removal of soluble vapors by the nose.

Journal of Applied Physiology ◽

10.1152/jappl.1974.37.5.654 ◽

1974 ◽

Vol 37 (5) ◽

pp. 654-657 ◽

Cited By ~ 70

Author(s):

E F Aharonson ◽

H Menkes ◽

G Gurtner ◽

D L Swift ◽

D F Proctor

Keyword(s):

Airflow Rate ◽

Respiratory Airflow

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Optimum Posture Determination of Variable Geometry Truss Structures by Optimality Criteria Method.

TRANSACTIONS OF THE JAPAN SOCIETY OF MECHANICAL ENGINEERS Series C ◽

10.1299/kikaic.65.4640 ◽

1999 ◽

Vol 65 (640) ◽

pp. 4640-4646 ◽

Cited By ~ 1

Author(s):

Koetsu YAMAZAKI ◽

Ichiro SATOH

Keyword(s):

Optimality Criteria ◽

Truss Structures ◽

Variable Geometry ◽

Optimality Criteria Method ◽

Variable Geometry Truss

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Optimality of Some Block Designs

Calcutta Statistical Association Bulletin ◽

10.1177/0008068319890306 ◽

1989 ◽

Vol 38 (3-4) ◽

pp. 187-194

Author(s):

Mike Jacroux ◽

Rita Saha Ray

Keyword(s):

Wide Class ◽

Incidence Matrix ◽

Block Design ◽

Optimality Criteria ◽

Optimal Designs ◽

Block Designs

In this paper we consider the determination of optimal designs in experimental situations requiring usage of a block design having v treatments assigned to experimental units arranged in b blocks of size k. Using majorization arguments, a design d* having an incidence matrix of the form [Formula: see text] is optimal under a wide class of optimality criteria.

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On the separate determination of lung mechanics in in- and expiration

IFMBE Proceedings - 4th European Conference of the International Federation for Medical and Biological Engineering ◽

10.1007/978-3-540-89208-3_488 ◽

2009 ◽

pp. 2049-2052 ◽

Cited By ~ 3

Author(s):

Knut Möller ◽

Z. Zhao ◽

C. Stahl ◽

S. Schumann ◽

J. Guttmann

Keyword(s):

Lung Mechanics ◽

Separate Determination

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Optimal Actuator/Sensor Placement for Control of Combustion Instabilities

10.1115/imece2001/dsc-24562 ◽

2001 ◽

Author(s):

Nidal Al-Masoud ◽

Tarunraj Singh

Keyword(s):

Finite Number ◽

Lower Order ◽

Optimality Criteria ◽

Higher Order ◽

Control Input ◽

Combustion Instabilities ◽

Multiple Sensors ◽

Higher Order Modes ◽

Controllability And Observability

Abstract In this paper, a methodology is proposed for determination of optimal actuator and sensor locations for the control of combustion instabilities. The proposed approach relies on certain quantitative measures of degree of controllability and observability based on the controllability and observability grammians. These criteria are arrived at by considering the energies of system’s inputs and outputs. The optimality criteria for sensor and actuator locations provide a balance between the importance of the lower order and the higher order modes. It is assumed that the control input is provided by a finite number of point actuators, and the instantaneous conditions in the chamber are monitored, in general, by multiple sensors.

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THE PULMONARY SYNDROME OF WILSON AND MIKITY

PEDIATRICS ◽

10.1542/peds.36.3.374 ◽

1965 ◽

Vol 36 (3) ◽

pp. 374-384

Author(s):

Paul R. Swyer ◽

Maria Delivoria-Papadopoulos ◽

Henry Levison ◽

Bernard J. Reilly ◽

John U. Balis

Keyword(s):

Work Of Breathing ◽

Respiratory Acidosis ◽

Minute Volume ◽

Lung Mechanics ◽

Arterial Oxygen ◽

Wall Thickening ◽

Alveolar Wall ◽

Electron Microscopic ◽

Elastic Resistance ◽

Immature Lung

Eight examples of the Wilson-Mikity Syndrome are reported, 2 of whom died at 127 and 145 days of age respectively. The radiology of the condition is relatively specific and gives strong grounds for suspicion of the diagnosis when taken in the clinical context. Gross, histological, and electron microscopic examinations reveal areas of normality, emphysema, and immaturity. The electron microscope additionally shows areas where the alveolar wall thickening is due to the presence of smooth muscle, reticulin, and collagen. The most likely etiology is a disorder in postnatal alveolar development related to premature birth and functional use of an immature lung. There are changes in lung mechanics with decreased compliance and increased non-elastic resistance to airflow mainly in expiration. The mechanical work of breathing is increased. There is a respiratory acidosis in spite of an increased minute volume. Arterial oxygen desaturation is common, increased by crying and only partially relieved by oxygen. Large R → L shunts have been demonstrated which are probably intrapulmonary.

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