17 results on '"bronchial tree"'
Search Results
2. A computational modeling of airflow and radon progeny deposition in human respiratory system
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Rabi, R., Oufni, L., and Kayouh, N.
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- 2024
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3. Morphology, organo- and histometric features of the heart and lungs of a sexually mature domestic dog (Canis Lupus Familiaris L., 1758)
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Leonid Horalskyi, Ihor Sokulskyi, Maksym Ragulya, Nataliia Kolesnik, and Yuriy Ordin
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comparative anatomy ,histostructure of organs ,cytometric parameters ,cardiomyocytes ,myofibrils ,bronchial tree ,alveolar tree ,Agriculture - Abstract
The cardiovascular system and respiratory organs in animals are interconnected, they perform extremely important functions for the vital activity of the organism, the main of which is gas exchange. Therefore, the study of the cardiovascular system and respiratory organs is an urgent issue of the present. The aim of the study was to morphologically evaluate the macro- and histological structures of the heart and lungs of the domestic dog. Comprehensive morphological methods of research were used: histological, anatomical, organ, histo-, cytometric, and statistical, which provided new data on the peculiarities of macro-, histo-, and cytomorphometric characteristics of the morphological structures of the heart and lungs. The dog heart has a rounded shape, its absolute weight is 167.58±9.46 g (without epicardial fat – 154.22±8.04 g), relative weight – 0.72±0.005%. It was found that cardiomyocytes of the left ventricle had the largest volume, the right ventricle – the smallest, and atrial cardiomyocytes – the smallest. At the same time, the nuclearcytoplasmic ratio of cardiomyocytes of the left ventricle is 0.0224±0.0076, the cardiomyocytes of the right ventricle have a greater value – 0.0275±0.0081 and the atrial cardiomyocytes have the highest value – 0.0367±0.0105. Such ambiguous cytometric parameters of cardiomyocytes are associated with the morphological and functional activity of the myocardial ventricular muscle tissue and its functional features inherent in spontaneous and rhythmic contractions, which result in blood flow through a closed system of vessels. The absolute weight of the domestic dog’s lungs is 201.3±18.4 g, the relative weight is 1.21±0.14%, the ratio of the absolute weight of the left to the right lung is 1:1.33. According to the asymmetry coefficient (1.37:1), the lungs of dogs are of the narrowed-elongated type. The connective tissue stroma of the lungs occupies 59.62±3.4%, the respiratory part – 40.38±2.6%. The data on the morphology of the heart and lungs of the domestic dog, including the results of the study of the macro- and microscopic structure of the organs under investigation, which are presented in the publication, are of great importance for histology and comparative anatomy, and also make a significant contribution to clinical veterinary medicine
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- 2023
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4. Bronchial tree of the human embryo: Examination based on a mammalian model.
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Fujii, Sena, Muranaka, Taiga, Matsubayashi, Jun, Yamada, Shigehito, Yoneyama, Akio, and Takakuwa, Tetsuya
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HUMAN embryos , *COMPUTED tomography , *LUNGS , *BRONCHI , *COMPARATIVE anatomy - Abstract
The symmetry of the right and left bronchi, proposed in a previous comparative anatomical study as the basic model of the mammalian bronchial tree, was examined to determine if it applied to the embryonic human bronchial tree. Imaging data of 41 human embryo specimens at Carnegie stages (CS) 16–23 (equivalent to 6–8 weeks after fertilization) belonging to the Kyoto collection were obtained using phase‐contrast X‐ray computed tomography. Three‐dimensional bronchial trees were then reconstructed from these images. Bronchi branching from both main bronchi were labeled as dorsal, ventral, medial, or lateral systems based on the branching position with numbering starting cranially. The length from the tracheal bifurcation to the branching point of the labeled bronchus was measured, and the right‐to‐left ratio of the same labeled bronchus in both lungs was calculated. In both lungs, the human embryonic bronchial tree showed symmetry with an alternating pattern of dorsal and lateral systems up to segmental bronchus B9 as the basic shape, with a more peripheral variation. This pattern is similar to that described in adult human lungs. Bronchial length increased with the CS in all labeled bronchi, whereas the right‐to‐left ratio was constant at approximately 1.0. The data demonstrated that the prototype of the human adult bronchial branching structure is formed and maintained in the embryonic stage. The morphology and branching position of all lobar bronchi and B6, B8, B9, and the subsegmental bronchus of B10 may be genetically determined. On the other hand, no common structures between individual embryos were found in the peripheral branches after the subsegmental bronchus of B10, suggesting that branch formation in this region is influenced more by environmental factors than by genetic factors. [ABSTRACT FROM AUTHOR]
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- 2024
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- View/download PDF
5. A novel approach to pulmonary bronchial tree model construction and performance index study.
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Yang Liu, Weiyan Qiu, Longyu Li, Rongchang Chen, Yan Kang, and Shuangchen Ruan
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PERFORMANCE theory ,SYSTEM failures ,RESPIRATORY diseases ,TREES ,BUILDING performance - Abstract
The demand for respiratory disease and dynamic breathing studies has continuously driven researchers to update the pulmonary bronchial tree’s morphology model. This study aims to construct a bronchial tree morphology model efficiently and effectively with practical algorithms. We built a performance index system using failure branch rate, volume ratio, and coefficient of variation of terminal volumes to evaluate the model performance. We optimized the parameter settings and found the best options to build the morphology model, and we constructed a 14th-generation bronchial tree model with a decent performance index. The dimensions of our model closely matched published data from anatomic in vitro measurements. The proposed model is adjustable and computable and will be used in future dynamic breathing simulations and respiratory disease studies. [ABSTRACT FROM AUTHOR]
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- 2023
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- View/download PDF
6. PHYSICOMATHEMATICAL MODELING OF HUMAN BREATHING IN SITUATIONS OF VARIOUS PULMONARY DISEASES.
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Golysheva, P. S. and Medvedev, A. E.
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LUNGS , *LUNG diseases , *ASTHMA , *CHRONIC obstructive pulmonary disease , *AIR flow , *FLOW simulations , *RESPIRATION - Abstract
Three-dimensional numerical simulations of the air flow in the full human bronchial tree in situations of obstructive and chronic pulmonary diseases are performed. Based on the previously developed three-dimensional analytical model of the lower respiratory airways, the air distributions in the lungs (from the trachea to alveoli) in situations with lung injuries and bronchial asthma are calculated. Breathing modeling is based on a numerical technique of step-by-step computations, which allows one to avoid the loss of solution accuracy caused by the difference in the bronchus scales; moreover, the time needed to calculate the air flow in the lungs can be reduced by several times by using this technique. [ABSTRACT FROM AUTHOR]
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- 2023
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7. Airway obstruction in respiratory viral infections due to impaired mucociliary clearance.
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Bessonov, N. and Volpert, V.
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MUCOCILIARY system , *RESPIRATORY obstructions , *VIRUS diseases , *RESPIRATORY infections , *MUCUS - Abstract
Respiratory viral infections, such as SARS‐CoV‐2 or influenza, can lead to impaired mucociliary clearance in the bronchial tree due to increased mucus viscosity and its hyper‐secretion. We develop in this work a mathematical model to study the interplay between viral infection and mucus motion. The results of numerical simulations show that infection progression can be characterized by three main stages. At the first stage, infection spreads through the most part of mucus producing airways (about 90% of the length) without significant changes in mucus velocity and thickness layer. During the second stage, when it passes through the remaining generations, mucus viscosity increases, its velocity drops down, and it forms a plug. At the last stage, the thickness of the mucus layer gradually increases because mucus is still produced but not removed by the flow. After some time, the thickness of the mucus layer in the small airways becomes comparable with their diameter leading to their complete obstruction. [ABSTRACT FROM AUTHOR]
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- 2023
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8. Intraoperative dental aspiration and ingest, systematic review and algorithm proposal
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Pablo Crespo, Dennis Sigüenza, and Valeria Vázquez
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Dental extraction ,Aspiration ,Tooth ,Postoperative complications ,Bronchial tree ,Internal medicine ,RC31-1245 ,Surgery ,RD1-811 - Abstract
Introduction: The aspiration and ingestion of a molar during its extraction is a rare accident, so there is not enough information about the reported cases. The objective of this study is to carry out a systematic review, analyze the articles on intraoperative dental aspiration and intake, and propose an algorithm for the management of this complication. Materials and methods: A systematic review was carried out following the PRISMA criteria in the PubMed database in January 2023 with the following limitations: studies conducted in humans; English language; reports of aspiration and swallowing of teeth during dental extraction, age was not limited. Exclusion criteria: studies of aspiration and ingestion of foreign bodies that do not involve teeth. Results: A total of 5 articles were obtained with 5 reported cases of aspiration. There were no reports associated with the ingestion of a tooth. The most prevalent sex was male, with all cases reported in men, the average age was 24.4 years. The imaging studies of choice were chest radiography and computed tomography. The right bronchus was the most prevalent location site. The first line treatment was bronchoscopy, followed by tracheotomy and thoracotomy. Conclusion: Tooth extraction is a common surgical procedure, so it is essential to be careful in the event of possible complications such as intraoperative aspiration or tooth ingestion. Tooth aspiration can be a life-threatening complication, so prompt management is important. The proposed algorithm allows adequate management for aspiration and swallowing of teeth.
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- 2023
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9. Comparison of MR‐guided radiotherapy accumulated doses for central lung tumors with non‐adaptive and online adaptive proton therapy.
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Rabe, Moritz, Palacios, Miguel A., van Sörnsen de Koste, John R., Eze, Chukwuka, Hillbrand, Martin, Belka, Claus, Landry, Guillaume, Senan, Suresh, and Kurz, Christopher
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LUNGS , *PROTON beams , *PROTON therapy , *LUNG tumors , *STEREOTACTIC radiotherapy , *WILCOXON signed-rank test , *RADIOTHERAPY - Abstract
Background: Stereotactic body radiation therapy (SBRT) of central lung tumors with photon or proton therapy has a risk of increased toxicity. Treatment planning studies comparing accumulated doses for state‐of‐the‐art treatment techniques, such as MR‐guided radiotherapy (MRgRT) and intensity modulated proton therapy (IMPT), are currently lacking. Purpose: We conducted a comparison of accumulated doses for MRgRT, robustly optimized non‐adaptive IMPT, and online adaptive IMPT for central lung tumors. A special focus was set on analyzing the accumulated doses to the bronchial tree, a parameter linked to high‐grade toxicities. Methods: Data of 18 early‐stage central lung tumor patients, treated at a 0.35 T MR‐linac in eight or five fractions, were analyzed. Three gated treatment scenarios were compared: (S1) online adaptive MRgRT, (S2) non‐adaptive IMPT, and (S3) online adaptive IMPT. The treatment plans were recalculated or reoptimized on the daily imaging data acquired during MRgRT, and accumulated over all treatment fractions. Accumulated dose‐volume histogram (DVH) parameters of the gross tumor volume (GTV), lung, heart, and organs‐at‐risk (OARs) within 2 cm of the planning target volume (PTV) were extracted for each scenario and compared in Wilcoxon signed‐rank tests between S1 & S2, and S1 & S3. Results: The accumulated GTV D98% was above the prescribed dose for all patients and scenarios. Significant reductions (p < 0.05) of the mean ipsilateral lung dose (S2: –8%; S3: –23%) and mean heart dose (S2: –79%; S3: –83%) were observed for both proton scenarios compared to S1. The bronchial tree D0.1cc was significantly lower for S3 (S1: 48.1 Gy; S3: 39.2 Gy; p = 0.005), but not significantly different for S2 (S2: 45.0 Gy; p = 0.094), compared to S1. The D0.1cc for S2 and S3 compared to S1 was significantly (p < 0.05) smaller for OARs within 1–2 cm of the PTV (S1: 30.2 Gy; S2: 24.6 Gy; S3: 23.1 Gy), but not significantly different for OARs within 1 cm of the PTV. Conclusions: A significant dose sparing potential of non‐adaptive and online adaptive proton therapy compared to MRgRT for OARs in close, but not direct proximity of central lung tumors was identified. The near‐maximum dose to the bronchial tree was not significantly different for MRgRT and non‐adaptive IMPT. Online adaptive IMPT achieved significantly lower doses to the bronchial tree compared to MRgRT. [ABSTRACT FROM AUTHOR]
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- 2023
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10. Morphology and specifics of morphometry of lungs and myocardium of heart ventricles of cattle, sheep and horses
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L. P. Horalskyi, М. R. Ragulya, N. M. Glukhova, I. M. Sokulskiy, N. L. Kolesnik, O. F. Dunaievska, B. V. Gutyj, and I. Y. Goralska
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pulmonary acinus ,bronchial tree ,alveolar tree ,cardiomyocytes ,myofibrils ,bronchi ,pulmonary alveoli. ,Science - Abstract
Respiratory organs and cardiovascular system are interconnected and perform extremely vital functions of the organism, the main goals being performing gas exchange with the environment and emitting carbon dioxide produced in the organism into the environment. Therefore, we carried out comparative histo- and cytomorphometric evaluation of morphological structures of the heart and lungs of cattle, sheep and horses. Using complex methods of research, we determined specifics of microscopic structure and histometric parameters of parenchyma of the lungs and myocardium of the ventricles of the hearts of clinically healthy animals in species aspect – cattle, sheep and horses. The studies revealed that the histoarchitectonics of the studied animals were similar in structure, characteristic of other species of agricultural mammals, and distinct morphometric peculiarities of their histostructures. The study indicated that the respiratory zone of the lungs is most developed in horses. This parameter was lower in ruminants – cattle and sheep. Connective tissue septum of parenchyma of lungs was better expressed in cattle and sheep, and less in horses. At the same time, mean volume of lung alveoli in clinically healthy animals varied: being highest in horses – 699 ± 106 thou µm3, then cattle – 337 ± 43 thou µm3 and sheep – 158 ± 37 thou µm3. Such variation in histometric parameters of parenchyma of the lungs in experimental animals indicates adaptive specifics of the organism of animals in terms of living conditions. Therefore, the respiratory zone was most developed in the lungs of horses, animals that experience significant physical and physiological load on corresponding organs and systems. As a result of histometric studies of myocardium, we determined patterns of sizes of thickness of its cardiomyocytes and volume of their nuclei. We determined that in myocardium of the heart ventricles, in the same microscope field of view, cardiomyocytes of varying thicknesses occur. At the same time, thickness of cardiomyocytes, their mean volume of nuclei in the ventricle myocardium were expressed the most in cattle, then in horses and sheep, and their histometric parameters in myocardium of the left ventricle of the heart in the experimental animals were higher than in the right one. Therefore, thickness of cardiomyocytes of the left ventricle in cattle equaled 14.06 ± 0.41 µm, and volume of nuclei of cardiomyocytes respectively 124.55 ± 7.99 µm3. Similar changes in such parameters of histometry were found in sheep and horses. We attribute such varying histometric parameters of the thickness of cardiomyocytes and volume of their nuclei in myocardium of the left ventricle of the heart in experimental animals, compared with such parameters in the right ventricle, to the activities of the ventricles (the left one generally functions as a pump, right one – as a volumetric) and functional specifics of this myocardium tissue, which is capable of spontaneous rhythmic contractions, resulting in blood flow in the vessels: cardiomyocytes of the left ventricle carry greater load, promoting blood flow in vessels of greater (somatic) blood circulation, respectively cardiomyocytes of the right ventricle – less load, promoting blood flow in vessels of lesser (pulmonary) blood circulation.
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- 2022
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11. Exploring the Impact of Varied Design Approaches and Materials in Respiratory Therapy Education.
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Yang SH, Liu WL, Chen CY, Liu HW, and Chao KY
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- 2024
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12. Morphology and specifics of morphometry of lungs and myocardium of heart ventricles of cattle, sheep and horses.
- Author
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Horalskyi, L. P., Ragulya, М. R., Glukhova, N. M., Sokulskiy, I. M., Kolesnik, N. L., Dunaievska, O. F., Gutyj, B. V., and Goralska, I. Y.
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RESPIRATORY organs , *HEART ventricles , *CARBON dioxide - Abstract
Respiratory organs and cardiovascular system are interconnected and perform extremely vital functions of the organism, the main goals being performing gas exchange with the environment and emitting carbon dioxide produced in the organism into the environment. Therefore, we carried out comparative histo- and cytomorphometric evaluation of morphological structures of the heart and lungs of cattle, sheep and horses. Using complex methods of research, we determined specifics of microscopic structure and histometric parameters of parenchyma of the lungs and myocardium of the ventricles of the hearts of clinically healthy animals in species aspect – cattle, sheep and horses. The studies revealed that the histoarchitectonics of the studied animals were similar in structure, characteristic of other species of agricultural mammals, and distinct morphometric peculiarities of their histostructures. The study indicated that the respiratory zone of the lungs is most developed in horses. This parameter was lower in ruminants – cattle and sheep. Connective tissue septum of parenchyma of lungs was better expressed in cattle and sheep, and less in horses. At the same time, mean volume of lung alveoli in clinically healthy animals varied: being highest in horses – 699 ± 106 thou µm³, then cattle – 337 ± 43 thou µm³ and sheep – 158 ± 37 thou µm³ . Such variation in histometric parameters of parenchyma of the lungs in experimental animals indicates adaptive specifics of the organism of animals in terms of living conditions. Therefore, the respiratory zone was most developed in the lungs of horses, animals that experience significant physical and physiological load on corresponding organs and systems. As a result of histometric studies of myocardium, we determined patterns of sizes of thickness of its cardiomyocytes and volume of their nuclei. We determined that in myocardium of the heart ventricles, in the same microscope field of view, cardiomyocytes of varying thicknesses occur. At the same time, thickness of cardiomyocytes, their mean volume of nuclei in the ventricle myocardium were expressed the most in cattle, then in horses and sheep, and their histometric parameters in myocardium of the left ventricle of the heart in the experimental animals were higher than in the right one. Therefore, thickness of cardiomyocytes of the left ventricle in cattle equaled 14.06 ± 0.41 µm, and volume of nuclei of cardiomyocytes respectively 124.55 ± 7.99 µm³ . Similar changes in such parameters of histometry were found in sheep and horses. We attribute such varying histometric parameters of the thickness of cardiomyocytes and volume of their nuclei in myocardium of the left ventricle of the heart in experimental animals, compared with such parameters in the right ventricle, to the activities of the ventricles (the left one generally functions as a pump, right one – as a volumetric) and functional specifics of this myocardium tissue, which is capable of spontaneous rhythmic contractions, resulting in blood flow in the vessels: cardiomyocytes of the left ventricle carry greater load, promoting blood flow in vessels of greater (somatic) blood circulation, respectively cardiomyocytes of the right ventricle – less load, promoting blood flow in vessels of lesser (pulmonary) blood circulation. [ABSTRACT FROM AUTHOR]
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- 2022
- Full Text
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13. Various reduced-order surrogate models for fluid flow and mass transfer in human bronchial tree.
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Abbasi, Zeinab and Bozorgmehry Boozarjomehry, Ramin
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REDUCED-order models , *FLUID flow , *PROBLEM solving , *BLOOD gases , *AIRWAY (Anatomy) , *RESPIRATORY organs , *MASS transfer - Abstract
The bronchial tree plays a main role in the human respiratory system because the air distribution throughout the lungs and gas exchange with blood occur in the airways whose dimensions vary from several centimeters to micrometers. Organization of about 60,000 conducting airways and 33 million respiratory airways in a limited space results in a complex structure. Due to this inherent complexity and a high number of airways, using target-oriented dimensional reduction is inevitable. In addition, there is no general reduced-order model for various types of problems. This necessitates coming up with an appropriate model from a variety of different reduced-order models to solve the desired problem. Lumped formulation, trumpet, or typical path model of whole or parts of bronchial tree are frequently used reduced-order models. On the other hand, using any of these models results in underestimation of flow heterogeneity leading to inaccurate prediction of the systems whose mechanisms depend on the fluid heterogeneity. In this study, a simple robust model combining mechanistic and non-mechanistic modeling approaches of the bronchial tree is proposed which overcomes the limitations of the previous reduced-order models and gives the same results of a detailed mechanistic model for the first time. This model starts from an accurate multi-branching model of conducting and respiratory airways (i.e., the base model) and suggests a proxy model of conducting airway and reduced-order model of respiratory airways based on the base model to significantly reduce computational cost while retaining the accuracy. The combination of these models suggests various reduced-order surrogate models of the human bronchial tree for different problems. The applications and limitations of each reduced-order model are also discussed. The accuracy of the proposed model in the prediction of fluid heterogeneity has been examined by the simulation of multi-breath inert gas washout because the alveolar slope is the reflection of fluid heterogeneity where the computational time decreases from 121 h (using the base model) to 4.8 s (using the reduced-order model). A parallel strategy for solving the equations is also proposed which decreases run time by 0.18 s making the model suitable for real-time applications. Furthermore, the ability of the model has been evaluated in the modeling of asthmatic lung as an instance of abnormal lungs, and in the modeling of O2–CO2 exchange as an instance of nonlinear reacting systems. The results indicate that the proposed model outperforms previous models based on accuracy, robustness, and run time. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
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14. A novel approach to pulmonary bronchial tree model construction and performance index study.
- Author
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Liu Y, Qiu W, Li L, Chen R, Kang Y, and Ruan S
- Abstract
The demand for respiratory disease and dynamic breathing studies has continuously driven researchers to update the pulmonary bronchial tree's morphology model. This study aims to construct a bronchial tree morphology model efficiently and effectively with practical algorithms. We built a performance index system using failure branch rate, volume ratio, and coefficient of variation of terminal volumes to evaluate the model performance. We optimized the parameter settings and found the best options to build the morphology model, and we constructed a 14th-generation bronchial tree model with a decent performance index. The dimensions of our model closely matched published data from anatomic in vitro measurements. The proposed model is adjustable and computable and will be used in future dynamic breathing simulations and respiratory disease studies., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Liu, Qiu, Li, Chen, Kang and Ruan.)
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- 2023
- Full Text
- View/download PDF
15. Du CT-Scan aux simulations numériques : construction d'un modèle personnalisé de l'enveloppe du poumon et de tout l'arbre bronchique, application à la plongée en apnée
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Laporte, Thomas, Laboratoire Jean Alexandre Dieudonné (LJAD), Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS)-Université Côte d'Azur (UCA), AlgebRe, geOmetrie, Modelisation et AlgoriTHmes (AROMATH), Inria Sophia Antipolis - Méditerranée (CRISAM), Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-National and Kapodistrian University of Athens (NKUA), Université Côte d'Azur (UCA), Université Côte d'Azur, Benjamin Mauroy, and Angelos Mantzaflaris
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Apprentissage profond ,Space-filling algorithm ,Plongée en apnée ,Deep learning ,Numerical simulation ,Respiratory system ,[INFO.INFO-MO]Computer Science [cs]/Modeling and Simulation ,3D modelling ,Poumon ,Segmentation ,Modélisation 3D ,Bronchial tree ,Arbre bronchique ,Simulation numérique ,Algorithme de remplissage ,Système respiratoire ,Deep-dive apnea ,Lung - Abstract
An accurate description of the morphometry of the lung and airways, which are in line with the morphometric observations, is essential to perform numerical simulations related to the respiratory system. The lung is a complex organ, both because of its respiratory functions and of its particular structure. The airways are assembled together as a dichotomous tree with asymmetric bifurcations, that allows the transport of oxygen and carbon dioxide between the ambient air and the exchange surface with blood.During the thesis, we focused on the creation of a tool to create 3D representations of the morphological structures of the lungs, lobes and bronchial tree. This tool is patient-dependant and is based on the use of thoracic CT scans. The resulting meshes are used for numerical simulations modelling the lung compression during breath-hold diving.We first develop a 2.5D method for segmenting the lung lobes and the first generations of the bronchial tree. This algorithm is based on Deep-Learning methods, notably the U-Net architecture. We perform 2D segmentations of each slice for each axis (axial, coronal and sagittal) of the CT-Scan, allowing to compute a 3D matrix of predictions for each axis. Subsequently, we implemented a tool to combine and make the best of each prediction to generate 3D segmentations of the lung lobes and of the bronchi that are visible on the CT-Scans.Next, we implement a new step by step algorithm to generate patient-specific 3D models of the medium and small airways that are not visible in the CT-Scans. This model is based on the works of Tawhai et al. and Kitaoka et al., which we combine and update to take advantage of each method. We also develop original methods to build the tree structure. The resulting model for the bronchial tree reproduces well the lung morphometry. Our method uses as input data 3D reconstructions of the morphological envelopes of the lung lobes and of the first two levels of airway bifurcations. The mesh of the lung envelope is decomposed step-by-step in sets of sub-volumes of decreasing sizes. An airway is generated for each sub-volume using an original method that is based on how air could feed each sub-volume in an optimal way. The result is a hierarchical decomposition of the mesh of the lung volume and the mesh of the generated airway tree. The statistics of the airway tree resulting from our algorithm is validated against sets of morphometric data from the literature. The meshes resulting from our algorithm are generated to be directly usable by classical numerical methods, such as finite elements or finite volumes.Finally, we study the compression of the lungs during breath-hold diving, where the respiratory system is submitted to extreme conditions such as high water pressure. We define a system of equations that models the effect of the dive on the lung, and then perform numerical simulations using finite elements to refine our predictions. The results of these simulations are used to predict the lung volumes during the descent and to evaluate the effect of an emblematic phenomenon occurring during deep diving, called the "blood shift". The "Blood Shift" is a physical and physiological reaction of the body whose effect is to redirect the blood flow to vital organs (brain, heart and lungs), de facto protecting them from hypoxia and high pressure. These numerical simulations provide a visual representation of the compressed lungs throughout the dive and allow to determine a first order of magnitude of the stress suffered by the lung during deep diving.This work allows to build a whole, realistic, personalised model of the lung and to better understand its physiology, such as during apnea diving.; Une description précise de la morphométrie du poumon et des voies respiratoires, conforme aux observations morphométriques, est essentielle pour réaliser des simulations numériques liées au système respiratoire. Le poumon est un organe complexe, tant par ses fonctions respiratoires que par sa structure particulière. Les voies respiratoires se présente comme un arbre dichotomique avec des bifurcations asymétriques, permettant le transport de l'oxygène et du dioxyde de carbone entre l'air ambiant et la surface d'échange avec le sang. Cette thèse présente la création d'un outil permettant de créer des représentations 3D des morphologiques des lobes pulmonaires et de l'arbre bronchique. Cet outil est dépendant du patient et utilise des CT-Scan. Les maillages obtenus sont utilisés pour des simulations numériques modélisant la compression des poumons au cours d'une plongée en apnée. Nous avons développé une méthode 2.5D pour segmenter les lobes pulmonaires et les premières générations de l'arbre bronchique. Cet algorithme est une méthode de segmentation par Deep-Learning, basé sur l'architecture U-Net. Nous effectuons des segmentations 2D de chaque coupe pour chaque axe (axial, coronal et sagittal) du CT-Scan, permettant de calculer une matrice 3D de prédictions pour chaque axe. Nous avons implémenté une méthode permettant de combiner et d'optimiser chaque prédiction pour générer des segmentations 3D des lobes pulmonaires et des bronches visibles sur les CT-Scan. Nous avons implémenté un nouvel algorithme déterministe pour générer des modèles 3D spécifiques au patient des voies respiratoires moyennes et petites qui ne sont pas visibles sur les CT-Scans. Ce modèle est basé sur les travaux de Tawhai et al. et Kitaoka et al., que nous combinons et actualisons pour tirer parti de chaque méthode. Nous développons également des méthodes originales pour construire l'arborescence. Le modèle de l'arbre bronchique obtenu s'inscrit bien la morphométrie du poumon. Notre méthode utilise comme entrée des reconstructions 3D des lobes pulmonaires et des deux premiers niveaux de bifurcations des voies aériennes. Le maillage de l'enveloppe pulmonaire est successivement décomposé en ensembles de sous-volumes de tailles décroissantes. Une branche est générée pour chaque sous-volume à l'aide d'une méthode originale qui se base sur le flux d'air alimentant chaque sous-volume de façon optimale. Le résultat est une décomposition hiérarchique du maillage du volume pulmonaire et la création d'un maillage de l'arbre bronchique. Les statistiques de l'arbre bronchique généré respectent l'ensembles de données morphométriques de la littérature. Les maillages obtenus par notre algorithme sont utilisables par des méthodes numériques classiques, telles que les éléments finis ou les volumes finis.Nous avons étudié la compression des poumons lors de la plongée en apnée, où le système respiratoire est soumis à des conditions extrêmes telles qu'une pression d'eau élevée. Nous définissons un système d'équations qui modélise l'effet de la plongée sur le poumon, puis nous effectuons des simulations numériques à l'aide d'éléments finis pour affiner nos prédictions. Les résultats de ces simulations sont utilisés pour prédire les volumes pulmonaires pendant la descente et pour évaluer l'effet d'un phénomène emblématique se produisant pendant la plongée profonde, appelé le "blood shift". Le "Blood Shift" est une réaction physique et physiologique du corps dont l'effet est de rediriger le flux sanguin vers les organes vitaux (cerveau, cœur et poumons), les protégeant de facto de l'hypoxie et de la haute pression. Ces simulations numériques fournissent une représentation visuelle des poumons comprimés et permettent de déterminer un premier ordre de grandeur du stress subi par le poumon lors de la plongée profonde. Ce travail permet de construire un modèle complet, réaliste et personnalisé du poumon et de mieux comprendre sa physiologie, notamment lors de la plongée en apnée.
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- 2023
16. Perspectives on lung visualization: Three-dimensional anatomical modeling of computed and micro-computed tomographic data in comparative evolutionary morphology and medicine with applications for COVID-19.
- Author
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Schachner ER, Lawson AB, Martinez A, Grand Pre CA, Sabottke C, Abou-Issa F, Echols S, Diaz RE Jr, Moore AJ, Grenier JP, Hedrick BP, and Spieler B
- Abstract
The vertebrate respiratory system is challenging to study. The complex relationship between the lungs and adjacent tissues, the vast structural diversity of the respiratory system both within individuals and between taxa, its mobility (or immobility) and distensibility, and the difficulty of quantifying and visualizing functionally important internal negative spaces have all impeded descriptive, functional, and comparative research. As a result, there is a relative paucity of three-dimensional anatomical information on this organ system in all vertebrate groups (including humans) relative to other regions of the body. We present some of the challenges associated with evaluating and visualizing the vertebrate respiratory system using computed and micro-computed tomography and its subsequent digital segmentation. We discuss common mistakes to avoid when imaging deceased and live specimens and various methods for merging manual and threshold-based segmentation approaches to visualize pulmonary tissues across a broad range of vertebrate taxa, with a particular focus on sauropsids (reptiles and birds). We also address some of the recent work in comparative evolutionary morphology and medicine that have used these techniques to visualize respiratory tissues. Finally, we provide a clinical study on COVID-19 in humans in which we apply modeling methods to visualize and quantify pulmonary infection in the lungs of human patients., (© 2023 American Association for Anatomy.)
- Published
- 2023
- Full Text
- View/download PDF
17. Clasificación de los árboles bronquiales y caminos más transitados utilizando métodos de aprendizaje de máquina
- Author
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Jiménez Prieto, Daniel Iván, Flórez Valencia, Leonardo, Posada Uribe, Luisa Fernanda, and Suárez Venegas, Daniel Ricardo
- Subjects
Artificial intelligence ,Aprendizaje no supervisado ,Maestría en inteligencia artificial - Tesis y disertaciones académicas ,Segmentación ,Mejoramiento de procesos ,Clasificación ,Classification ,Unsupervised learning ,Árbol bronquial ,Inteligencia artificial ,Algorithm ,Segmentation ,Bronchial tree ,Imágenes médicas ,Dijkstra ,Algoritmo ,Jenks natural breaks ,Machine learning ,Aprendizaje de máquina ,Vóxeles ,Medical imaging ,Voxels ,Pulmones ,Lungs ,Aprendizaje de máquinas - Abstract
Reconstruir, segmentar y clasificar el árbol bronquial ha sido de gran importancia en el área de la salud y la ingeniería, con un análisis adecuado podrían identificarse zonas afectadas por diversas enfermedades como cáncer de pulmón o Covid-19 para posteriormente tratarlas, ayudando tanto a sistemas de detección automática como a médicos y a personal de salud en campo. Dada la dificultad de obtener una imagen completa (normalmente tomografías computarizadas) sin errores y por la misma anatomía del pulmón, este problema ha sido atacado ampliamente mediante el procesamiento de imágenes médicas usando métodos de morfologías matemáticas y de crecimiento de regiones entre otros, pero aún no hay un método definitivo. En el presente trabajo se realizó una clasificación del árbol bronquial mediante un proceso de tres etapas, tomando como punto de partida una imagen binaria de los árboles bronquiales.Primero, se realizó un estudio e identificación de los puntos internos y externos de los árboles. Posteriormente se creó y utilizó un algoritmo de aprendizaje de máquina no supervisado, que tiene como base el algoritmo de Dijkstra, y finalmente se realizó un método de clasificación utilizando Jenks Natural Breaks para clasificar aquellas rutas más transitadas dentro de los árboles bronquiales. Reconstructing, segmenting, and classifying the bronchial tree has been of great importance in health and engineering areas, with accurate analysis areas affected by various diseases such as lung cancer or Covid-19 could be identified to treat them afterward, helping both, automated detection systems as doctors and health personnel in the field. Given the difficulty of obtaining a complete image (usually CT scans) without errors and because of the lung anatomy itself, this problem has been widely attacked by processing medical images using methods of mathematical morphologies and growth of regions among others, but still, there is no definitive method. In the present work, a classification of the bronchial tree was carried out through a three-stage process, taking as a starting point a binary image of the bronchial trees. First, a study and identification of the internal and external points of the trees was carried out. Subsequently, an unsupervised machine learning algorithm was created and used, based on the Dijkstra algorithm, and finally, a classification method was executed using Jenks Natural Breaks to classify those busiest routes within the bronchial trees. Magíster en Inteligencia Artificial Maestría
- Published
- 2021
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