Electropneumatic system for the simulation of the pulmonary viscoelastic effect in a mechanical ventilation scenario (original) (raw)
Related papers
Computer-controlled mechanical simulation of the artificially ventilated human respiratory system
IEEE Transactions on Biomedical Engineering, 2003
A mechanical lung simulator can be used to simulate specific lung pathologies, to test lung-function equipment, and in instruction. A new approach to mechanical simulation of lung behavior is introduced that uses a computer-controlled active mechatronic system. The main advantage of this approach is that the static and dynamic properties of the simulator can easily be adjusted via the control software. A nonlinear single-compartment mathematical model of the artificially ventilated respiratory system has been derived and incorporated into the simulator control system. This model can capture both the static and dynamic compliance of the respiratory system as well as nonlinear flow-resistance properties. Parameters in this model can be estimated by using data from artificially ventilated patients. It is shown that the simulation model fits patient data well. This mathematical model of the respiratory system was then matched to a model of the available physical equipment (the simulator, actuators, and the interface electronics) in order to obtain the desired lung behavior. A significant time delay in the piston motion control loop has been identified, which can potentially cause oscillations or even instability for high compliance values. Therefore, a feedback controller based on the Smith-predictor scheme was developed to control the piston motion. The control system, implemented on a personal computer, also includes a user-friendly interface to allow easy parameter setting.
Scientific Reports
Simulation models in respiratory research are increasingly used for medical product development and testing, especially because in-vivo models are coupled with a high degree of complexity and ethical concerns. This work introduces a respiratory simulation system, which is bridging the gap between the complex, real anatomical environment and the safe, cost-effective simulation methods. The presented electro-mechanical lung simulator, xPULM, combines in-silico, ex-vivo and mechanical respiratory approaches by realistically replicating an actively breathing human lung. The reproducibility of sinusoidal breathing simulations with xPULM was verified for selected breathing frequencies (10–18 bpm) and tidal volumes (400–600 ml) physiologically occurring during human breathing at rest. Human lung anatomy was modelled using latex bags and primed porcine lungs. High reproducibility of flow and pressure characteristics was shown by evaluating breathing cycles (nTotal = 3273) with highest stand...
Applied Sciences, 2021
During mechanical ventilation, a disparity between flow, pressure and volume demands of the patient and the assistance delivered by the mechanical ventilator often occurs. This paper introduces an alternative approach of simulating and evaluating patient–ventilator interactions with high fidelity using the electromechanical lung simulator xPULM™. The xPULM™ approximates respiratory activities of a patient during alternating phases of spontaneous breathing and apnea intervals while connected to a mechanical ventilator. Focusing on different triggering events, volume assist-control (V/A-C) and pressure support ventilation (PSV) modes were chosen to test patient–ventilator interactions. In V/A-C mode, a double-triggering was detected every third breathing cycle, leading to an asynchrony index of 16.67%, which is classified as severe. This asynchrony causes a significant increase of peak inspiratory pressure (7.96 ± 6.38 vs. 11.09 ± 0.49 cmH2O, p < 0.01)) and peak expiratory flow (−2...
The Hybrid Pneumatic-Numerical Model of Lungs - Metrological Aspects of the Design
2009
The main purpose of this paper is presenting the new hybrid (pneumo-numerical) model of lungs as well as some results of its successful experimental exam inations. This kind of models enables simulation of different lung properties including rheological and nonlinear feat ures and may be also applied to develop different lungs mech anics measuring systems. The presented model design approach is based on the linear impedance transformation from t he numerical to pneumatic signal environments. Some metrological aspects of the model design and function are considered e.g. statical and dynamical accuracy of the impedance transformation. The hybrid lungs model was experimentally verified in the typical respiration-model set-up evidencing its good dynamical and statical properties.
Mechanical evaluation of a respiratory device
Medical Engineering & Physics, 2005
The objective of the present article is to mechanically characterize the behavior of the Flutter VRP 1 , a respiratory physiotherapy device. The device basically resembles a smoke-pipe with a conical cavity where a stainless steel sphere is located and which floats up and down due to the intermittent air flow of patients. The sphere maintains an oscillatory movement whose frequency is function of the air flow and orientation of the device. The oscillatory frequency of the sphere inside the Flutter when matched with the natural frequency of the thoracic chest of the patient will produce the effect of resonance which by its turn will move the pulmonary secretions. A numerical formulation was made and an experimental set up was assembled in order to study the oscillatory frequency of the sphere under different conditions of air flow, fluid pressure, device orientations and sphere's materials and weights. Interesting results presented by this article point to the mechanical optimization of the device and show information that certainly will be beneficial to the professionals of the respiratory physiotherapy.
IJERT-MODELING, SIMULATION AND ANALYSIS OF LUNG MECHANICS USING LABVIEW
International Journal of Engineering Research and Technology (IJERT), 2014
https://www.ijert.org/modeling-simulation-and-analysis-of-lung-mechanics-using-labview https://www.ijert.org/research/modeling-simulation-and-analysis-of-lung-mechanics-using-labview-IJERTV1IS6524.pdf The modeling is performed in order to know the behavior of a system. Modeling is needed in the area of medicine to understand the operation of functional systems of the human body. The model construction and the simulation within engineering are effectively recognized. The purpose of this work is to evaluate the characteristics of lung mechanics of normal person and diseased person and to show how computational and engineering basic tools can help in the biomedical studies.
Human respiratory mechanics demonstration model
AJP: Advances in Physiology Education, 2009
Respiratory mechanics is a difficult topic for instructors and students alike. Existing respiratory mechanics models are limited in their abilities to demonstrate any effects of rib cage movement on alveolar and intrapleural pressures. We developed a model that can be used in both large and small classroom settings. This model contains digital pressure displays and computer integration for real-time demonstration of pressure changes that correspond to the different phases of breathing. Moving the simulated diaphragm and rib cage causes a volume change that results in pressure changes visible on the digital sensors and computer display. Device testing confirmed the model's ability to accurately demonstrate pressure changes in proportion to physiological values. Classroom testing in 427 surveyed students showed improved understanding of respiratory concepts (P Ͻ 0.05). We conclude that our respiratory mechanics model is a valuable instructional tool and provide detailed instructions for those who would like to create their own. respiratory physiology; physiology demonstration; pressure changes; classroom tool; student survey OUR GOAL was to design and build a mechanical model that would improve student understanding of human respiratory mechanics. In particular, we sought to develop a model that demonstrates pressure changes in alveolar and intrapleural spaces with breathing as well as the three-dimensional expansion of the thoracic cavity by the rib cage and diaphragm. Although simple homemade models and basic commercial Plexiglas lung models are available (10), they have short life spans and parts that are difficult to replace. Also, most models do not display pulmonary pressures, making it difficult for students to visualize the forces driving gas exchange between the lungs and atmosphere (1, 5, 6). Other models do visualize the pressure changes using analog means, but the models are not interfaced with a computer or are not visually representative of human anatomy (2, 4). Furthermore, no currently available physical models illustrate the expansion of the rib cage. Although most of the lung's volume change is due to contractions of the diaphragm, rib cage movement may contribute between 5% and 42% of the lung's total volume change (3).
Dynamic and Quasi-Static Lung Mechanics System for Gas-Assisted and Liquid-Assisted Ventilation
IEEE Transactions on Biomedical Engineering, 2009
Our aim was to develop a computerized system for real-time monitoring of lung mechanics measurements during both gas and liquid ventilation. System accuracy was demonstrated by calculating regression and percent error of the following parameters compared to standard device: airway pressure difference (∆P aw ), respiratory frequency (f R ), tidal volume (V T ), minute ventilation (V E ), inspiratory and expiratory maximum flows (V in s,m ax , V ex p ,m ax ), dynamic lung compliance (C L ,d y n ), resistance of the respiratory system calculated by method of Mead-Whittenberger (R rs,M W ) and by equivalence to electrical circuits (R rs,ele ), work of breathing (W O B ), and overdistension. Outcome measures were evaluated as function of gas exchange, cardiovascular parameters, and lung mechanics including mean airway pressure (mP aw ). ∆P aw , V T , V in s,m ax , V ex p ,m ax , and V E measurements had correlation coefficients r = 1.00, and %error < 0.5%. f R , C L ,d y n , R rs,M W , R rs,ele , and W O B showed r ≥ 0.98 and %error < 5%. Overdistension had r = 0.87 and %error < 15%. Also, resistance was accurately calculated by a new algorithm. The system was tested in rats in which lung lavage was used to induce acute respiratory failure. After lavage, both gas-and liquidventilated groups had increased mP aw and W O B , with decreased V T , V E , C L ,d y n , R rs,M W , and R rs,ele compared to controls. After 1-h ventilation, both injured group had decreased V T , V E , and C L ,d y n , with increased mP aw , R rs,M W , R rs,ele , and W O B . In lung-injured animals, liquid ventilation restored gas exchange, and cardiovascular and lung functions. Our lung mechanics system was able to closely monitor pulmonary function, including during transitions between gas and liquid phases. has been a Professor of electrical engineering at the High Technical School of Maritime Studies, University of the Basque Country. His current research interests include design of new biomedical devices, lung mechanics, and predictive maintenance in electric devices.