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Burgos MA, Bastir M, Pérez-Ramos A, Sanz-Prieto D, Heuzé Y, Maréchal L, Esteban-Ortega F. Assessing nasal airway resistance and symmetry: An approach to global perspective through computational fluid dynamics. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2024; 40:e3830. [PMID: 38700070 DOI: 10.1002/cnm.3830] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2024] [Revised: 03/18/2024] [Accepted: 04/15/2024] [Indexed: 05/05/2024]
Abstract
This study aimed to explore the variability in nasal airflow patterns among different sexes and populations using computational fluid dynamics (CFD). We focused on evaluating the universality and applicability of dimensionless parameters R (bilateral nasal resistance) and ϕ (nasal flow asymmetry), initially established in a Caucasian Spanish cohort, across a broader spectrum of human populations to assess normal breathing function in healthy airways. In this retrospective study, CT scans from Cambodia (20 males, 20 females), Russia (20 males, 18 females), and Spain (19 males, 19 females) were analyzed. A standardized CFD workflow was implemented to calculate R-ϕ parameters from these scans. Statistical analyses were conducted to assess and compare these parameters across different sexes and populations, emphasizing their distribution and variances. Our results indicated no significant sex-based differences in the R parameter across the populations. However, moderate sexual dimorphism in the ϕ parameter was observed in the Cambodian group. Notably, no geographical differences were found in either R or ϕ parameters, suggesting consistent nasal airflow characteristics across the diverse human groups studied. The study also emphasized the importance of using dimensionless variables to effectively analyze the relationships between form and function in nasal airflow. The observed consistency of R-ϕ parameters across various populations highlights their potential as reliable indicators in both medical practice and further CFD research, particularly in diverse human populations. Our findings suggest the potential applicability of dimensionless CFD parameters in analyzing nasal airflow, highlighting their utility across diverse demographic and geographic contexts. This research advances our understanding of nasal airflow dynamics and underscores the need for additional studies to validate these parameters in broader population cohorts. The approach of employing dimensionless parameters paves the way for future research that eliminates confounding size effects, enabling more accurate comparisons across different populations and sexes. The implications of this study are significant for the advancement of personalized medicine and the development of diagnostic tools that accommodate individual variations in nasal airflow.
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Affiliation(s)
- Manuel A Burgos
- Department of Thermal and Fluid Engineering, Fluid Mechanics and Thermal Engineering Group, Polytechnic University of Cartagena, Cartagena, Spain
| | - Markus Bastir
- Department of Paleobiology, Paleoanthropology Group, National Museum of Natural Sciences - Spanish National Research Council, Madrid, Spain
| | - Alejandro Pérez-Ramos
- Faculty of Science, Department of Ecology and Geology, Paleobiology, Paleoclimatology and Paleogeography Group, University of Málaga, Málaga, Spain
- Faculty of Science, Department of Surgery, Paleobiology, Paleoclimatology and Paleogeography Group, University of Málaga, Málaga, Spain
| | - Daniel Sanz-Prieto
- Department of Thermal and Fluid Engineering, Fluid Mechanics and Thermal Engineering Group, Polytechnic University of Cartagena, Cartagena, Spain
- Faculty of Sciences, Department of Biology, Autonomous University of Madrid, Madrid, Spain
| | - Yann Heuzé
- PACEA UMR 5199, University of Bordeaux, French National Centre for Scientific Research, Ministère de la Culture, Pessac, France
| | - Laura Maréchal
- PACEA UMR 5199, University of Bordeaux, French National Centre for Scientific Research, Ministère de la Culture, Pessac, France
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Bastir M, Sanz-Prieto D, Burgos MA, Pérez-Ramos A, Heuzé Y, Maréchal L, Evteev A, Toro-Ibacache V, Esteban-Ortega F. Beyond skeletal studies: A computational analysis of nasal airway function in climate adaptation. AMERICAN JOURNAL OF BIOLOGICAL ANTHROPOLOGY 2024; 184:e24932. [PMID: 38516761 DOI: 10.1002/ajpa.24932] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Revised: 03/01/2024] [Accepted: 03/12/2024] [Indexed: 03/23/2024]
Abstract
OBJECTIVES Ecogeographic variation in human nasal anatomy has historically been analyzed on skeletal morphology and interpreted in the context of climatic adaptations to respiratory air-conditioning. Only a few studies have analyzed nasal soft tissue morphology, actively involved in air-conditioning physiology. MATERIALS AND METHODS We used in vivo computer tomographic scans of (N = 146) adult individuals from Cambodia, Chile, Russia, and Spain. We conducted (N = 438) airflow simulations during inspiration using computational fluid dynamics to analyze the air-conditioning capacities of the nasal soft tissue in the inflow, functional, and outflow tract, under three different environmental conditions: cold-dry; hot-dry; and hot-humid. We performed statistical comparisons between populations and sexes. RESULTS Subjects from hot-humid regions showed significantly lower air-conditioning capacities than subjects from colder regions in all the three conditions, specifically within the isthmus region in the inflow tract, and the anterior part of the internal functional tract. Posterior to the functional tract, no differences were detected. No differences between sexes were found in any of the tracts and under any of the conditions. DISCUSSION Our statistical analyses support models of climatic adaptations of anterior nasal soft tissue morphology that fit with, and complement, previous research on dry skulls. However, our results challenge a morpho-functional model that attributes air-conditioning capacities exclusively to the functional tract located within the nasal cavity. Instead, our findings support studies that have suggested that both, the external nose and the intra-facial soft tissue airways contribute to efficiently warming and humidifying air during inspiration. This supports functional interpretations in modern midfacial variation and evolution.
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Affiliation(s)
- Markus Bastir
- Paleoanthropology Group, Department of Paleobiology, National Museum of Natural Sciences-Spanish National Research Council, Madrid, Spain
| | - Daniel Sanz-Prieto
- Paleoanthropology Group, Department of Paleobiology, National Museum of Natural Sciences-Spanish National Research Council, Madrid, Spain
- Fluid Mechanics and Thermal Engineering Group, Department of Thermal and Fluid Engineering, Polytechnic University of Cartagena, Cartagena, Spain
- Department of Biology, Faculty of Sciences, Autonomous University of Madrid, Madrid, Spain
| | - Manuel A Burgos
- Fluid Mechanics and Thermal Engineering Group, Department of Thermal and Fluid Engineering, Polytechnic University of Cartagena, Cartagena, Spain
| | - Alejandro Pérez-Ramos
- Paleobiology, Paleoclimatology, and Paleogeography Group, Department of Ecology and Geology, Faculty of Science, University of Málaga, Malaga, Spain
| | - Yann Heuzé
- CNRS, Ministère de la Culture, PACEA, Université de Bordeaux, Pessac, France
| | - Laura Maréchal
- CNRS, Ministère de la Culture, PACEA, Université de Bordeaux, Pessac, France
| | - Andrej Evteev
- Anuchin Research Institute and Museum of Anthropology, Lomonosov Moscow State University, Moscow, Russia
| | - Viviana Toro-Ibacache
- Center for Quantitative Analysis in Dental Anthropology, Faculty of Dentistry, University of Chile, Santiago, Chile
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Wei J, He X, Yang Q, Gu Q, Zhang X, Sui X, Zhou R, Feng W. Numerical simulation of the influence of nasal cycle on nasal airflow. Sci Rep 2024; 14:12161. [PMID: 38802510 PMCID: PMC11130131 DOI: 10.1038/s41598-024-63024-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Accepted: 05/23/2024] [Indexed: 05/29/2024] Open
Abstract
To study the characteristics of nasal airflow in the presence of nasal cycle by computational fluid dynamics. CT scan data of a healthy Chinese individual was used to construct a three-dimensional model of the nasal cavity to be used as simulation domain. A sinusoidal airflow velocity is set at the nasal cavity entrance to reproduce the breathing pattern of a healthy human. There was a significant difference in the cross-sectional area between the two sides of the nasal cavity. Particularly, the decongested side is characterized by a larger cross-section area, and consequently, by a larger volume with respect to the congested side. The airflow velocity, pressure, and nasal resistance were higher on the congested narrow side. The temperature regulation ability on the congested narrow side was stronger than that on the decongested wider side. During the nasal cycle, there are differences in the nasal cavity function between the congested and decongested sides. Therefore, when evaluating the impact of various factors on nasal cavity function, the nasal cycle should be considered.
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Affiliation(s)
- Jing Wei
- School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing, China
| | - Xuan He
- School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing, China
| | - Qing Yang
- School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing, China
| | - Qifei Gu
- School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing, China
| | - Xiaodan Zhang
- School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing, China
| | - Xue Sui
- School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing, China
| | - Rui Zhou
- School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing, China.
| | - Wei Feng
- Department of Otolaryngology, Wangjing Hospital, China Academy of Chinese Medical Sciences, Beijing, China.
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Burgos M, Rosique L, Piqueras F, García-Navalón C, Sevilla-García M, Hellín D, Esteban F. Reducing variability in nasal surgery outcomes through computational fluid dynamics and advanced 3D virtual surgery techniques. Heliyon 2024; 10:e26855. [PMID: 38463850 PMCID: PMC10920157 DOI: 10.1016/j.heliyon.2024.e26855] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Revised: 02/20/2024] [Accepted: 02/21/2024] [Indexed: 03/12/2024] Open
Abstract
Objectives This study aims to delineate the specific impact of using computational fluid dynamics (CFD) and 3D virtual surgery techniques in otolaryngology surgery, focusing on their roles in enhancing the precision of nasal surgery and optimizing future patient outcomes. The central objective was to assess whether these advanced technologies could reduce variability in surgical approaches and decision-making among specialists, thereby improving the consistency and efficacy of patient care in cases of nasal obstruction. Methods and results Our methodology involved a detailed analysis of pre- and post-operative scenarios using CFD feedback. Six otolaryngologists participated, employing virtual surgery techniques on two patients with diagnosed nasal obstruction. The CFD analysis focused on quantifying key airflow parameters: right nasal flow rate (QR), left nasal flow rate (QL), flow symmetry (Ф), and bilateral nasal resistance (R). These parameters were meticulously compared before and after the application of CFD feedback to evaluate changes in surgical planning and outcomes. Quantitative analysis revealed a notable decrease in the standard deviation of the measured parameters among the specialists post-CFD feedback, indicating reduced variability in surgical approaches. Specifically, for Patient #1 the standard deviation for QR values dropped from 0.694 L/min to 0.602 L/min, and for QL values from 0.676 L/min to 0.584 L/min, and for Patient #2, the standard deviation for QR values decreased from 2.204 L/min to 0.958 L/min, and for QL values from 2.295 L/min to 1.014 L/min. Moreover, the variability range, represented by the differences between the maximum and minimum values for Ф and R, diminished significantly. Post-operative average values for all parameters showed a convergence towards ideal basal levels, suggesting a more uniform and effective surgical strategy across different surgeons. Conclusions Both integration of CFD and 3D virtual surgery techniques in otolaryngology can substantially reduce variability in surgical planning and decision-making, ultimately leading to improved patient outcomes. These advanced tools have the potential to standardize the diagnosis and treatment of nasal pathologies, contributing to more effective and consistent care. Future research in this area should focus on larger patient cohorts and further exploration of the potential benefits and applications of CFD and virtual surgery in otolaryngology.
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Affiliation(s)
- M.A. Burgos
- Department of Ingeniería Térmica y de Fluidos, Universidad Politécnica de Cartagena, Spain
| | - Lina Rosique
- Department of Otolaryngology, Hospital General Universitario Morales Meseguer, Murcia, Spain
| | - F. Piqueras
- Department of Otolaryngology, Hospital General Universitario Morales Meseguer, Murcia, Spain
| | - C. García-Navalón
- Department of Otolaryngology, Consorcio Hospital General Universitario de Valencia, Spain
| | - M.A. Sevilla-García
- Department of Otolaryngology, Hospital Clínico Universitario Virgen de la Arrixaca, Murcia, Spain
| | - D. Hellín
- Department of Otolaryngology, Hospital Clínico Universitario Virgen de la Arrixaca, Murcia, Spain
| | - F. Esteban
- Department of Surgery, School of Medicine, University of Seville, Spain
- Department of Otolaryngology, Hospital Universitario Virgen del Rocío, Seville, Spain
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Na Y, Kwon KW, Jang YJ. Impact of nasal septal perforation on the airflow and air-conditioning characteristics of the nasal cavity. Sci Rep 2024; 14:2337. [PMID: 38281976 PMCID: PMC10822863 DOI: 10.1038/s41598-024-52755-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Accepted: 01/23/2024] [Indexed: 01/30/2024] Open
Abstract
We investigated (1) how nasal septal perforations (NSPs) modify nasal airflow and air-conditioning characteristics and (2) how the modifications of nasal airflow are influenced by the size and location of the NSP. Computed tomography scans of 14 subjects with NSPs were used to generate nasal cavity models. Virtual repair of NSPs was conducted to examine the sole effect of NSPs on airflow. The computational fluid dynamics technique was used to assess geometric and airflow parameters around the NSPs and in the nasopharynx. The net crossover airflow rate, the increased wall shear stress (WSS) and the surface water-vapor flux on the posterior surface of the NSPs were not correlated with the size of the perforation. After the virtual closure of the NSPs, the levels in relative humidity (RH), air temperature (AT) and nasal resistance did not improve significantly both in the choanae and nasopharynx. A geometric parameter associated with turbinate volume, the surface area-to-volume ratio (SAVR), was shown to be an important factor in the determination of the RH and AT, even in the presence of NSPs. The levels of RH and AT in the choanae and nasopharynx were more influenced by SAVR than the size and location of the NSPs.
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Affiliation(s)
- Yang Na
- Department of Mechanical Engineering, Konkuk University, Seoul, 05029, Korea
| | - Kyung Won Kwon
- Department of Otolaryngology, Asan Medical Center, University of Ulsan, College of Medicine, 88 Olympic-ro 43-gil, Songpa-gu, Seoul, 05505, Korea
| | - Yong Ju Jang
- Department of Otolaryngology, Asan Medical Center, University of Ulsan, College of Medicine, 88 Olympic-ro 43-gil, Songpa-gu, Seoul, 05505, Korea.
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Burgos M, Pérez-Ramos A, Mulot B, Sanz-Prieto D, Esteban F, Bastir M. Advancements in veterinary medicine: the use of Flowgy for nasal airflow simulation and surgical predictions in big felids (a case study in lions). Front Vet Sci 2024; 10:1181036. [PMID: 38327815 PMCID: PMC10847520 DOI: 10.3389/fvets.2023.1181036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Accepted: 12/26/2023] [Indexed: 02/09/2024] Open
Abstract
Flowgy is a semi-automated tool designed to simulate airflow across the nasal passage and detect airflow alterations in humans. In this study, we tested the use and accuracy of Flowgy in non-human vertebrates, using large felids as the study group. Understanding the dynamics of nasal airflow in large felids such as lions (Panthera leo) is crucial for their health and conservation. Therefore, we simulated airflow during inspiration through the nasal passage in three lions (Panthera leo), two of which were siblings (specimens ZPB_PL_002 and ZPB_PL_003), without breathing obstructions. However, one of the specimens (ZPB_PL_001) exhibited a slight obstruction in the nasal vestibule, which precluded the specimen from breathing efficiently. Computed tomography (CT) scans of each specimen were obtained to create detailed three-dimensional models of the nasal passage. These models were then imported into Flowgy to simulate the airflow dynamics. Virtual surgery was performed on ZPB_PL_001 to remove the obstruction and re-simulate the airflow. In parallel, we simulated the respiration of the two sibling specimens and performed an obstructive operation followed by an operation to remove the obstruction at the same level and under the same conditions as the original specimen (ZPB_PL_001). Thus, we obtained a pattern of precision for the operation by having two comparable replicas with the obstructed and operated specimens. The simulations revealed consistent airflow patterns in the healthy specimens, demonstrating the accuracy of Flowgy. The originally obstructed specimen and two artificially obstructed specimens showed a significant reduction in airflow through the right nostril, which was restored after virtual surgery. Postoperative simulation indicated an improvement of >100% in respiratory function. Additionally, the temperature and humidity profiles within the nostrils showed marked improvements after surgery. These findings underscore the potential of Flowgy in simulating nasal airflow and predicting the outcomes of surgical interventions in large felids. This could aid in the early detection of respiratory diseases and inform clinical decision-making, contributing to improved veterinary care and conservation efforts. However, further research is needed to validate these findings in other species and explore the potential of integrating Flowgy with other diagnostic and treatment tools in veterinary medicine.
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Affiliation(s)
- Manuel Burgos
- Dpto. de Ingeniería Térmica y de Fluidos, Universidad Politécnica de Cartagena, Murcia, Spain
| | - Alejandro Pérez-Ramos
- Dpto. de Ecología y Geología, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain
| | - Baptiste Mulot
- ZooParc de Beauval and Beauval Nature, Saint-Aignan, France
| | - Daniel Sanz-Prieto
- Department of Paleobiology, Museo Nacional de Ciencias Naturales, Madrid, Spain
| | - Francisco Esteban
- Servicio Andaluz de Salud, Hospital Universitario Virgen del Rocío, Servicio de Otorrinolaringología, Sevilla, Spain
| | - Markus Bastir
- Department of Paleobiology, Museo Nacional de Ciencias Naturales, Madrid, Spain
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Na Y, Kwon KW, Jang YJ. Impact of the Location of Nasal Septal Deviation on the Nasal Airflow and Air Conditioning Characteristics. Facial Plast Surg 2023; 39:393-400. [PMID: 36564036 DOI: 10.1055/s-0042-1759764] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
The location of nasal septal deviation (NSD) directly impacts nasal physiology. The objective is to examine, using computational fluid dynamics (CFD), the difference in the airflow and air conditioning characteristics according to the location of NSD. Twenty patients with septal deviation were divided into two: 10 caudal septal deviation (CSD) and 10 posterior septal deviation (PSD). Physiological variables were compared and numerical models for nasal cavity were created with CT scans. Cases with CSD had distinctive features including restricted airflow partition, larger nasal resistance, and decreased surface heat flux in the more obstructed side (MOS), and lower humidity and air temperature in the lesser obstructed side (LOS). Physiological differences were observed according to the location of septal deviation, CSD cases exhibit significantly more asymmetric airflow characteristics and air conditioning capacity between LOS and MOS.
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Affiliation(s)
- Yang Na
- Department of Mechanical Engineering, Konkuk University, Seoul, Korea
| | - Kyung Won Kwon
- Department of Otolaryngology, Asan Medical Center, University of Ulsan, College of Medicine, Seoul, Korea
| | - Yong Ju Jang
- Department of Otolaryngology, Asan Medical Center, University of Ulsan, College of Medicine, Seoul, Korea
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Morawska-Kochman M, Malecha ZM, Zub K, Kielar J, Dudek K, Nelke K, Zatonski T. Physical Conditions Prevailing in the Nasal and Maxillary Sinus Cavities Based on Numerical Simulation. MEDICINA (KAUNAS, LITHUANIA) 2023; 59:1094. [PMID: 37374298 DOI: 10.3390/medicina59061094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Revised: 05/28/2023] [Accepted: 05/30/2023] [Indexed: 06/29/2023]
Abstract
Background and Objectives: This paper presents a unique study that links the physical conditions in the nasal passage with conditions that favour the development of bacterial strains and the colonization of the mucous membranes of the nose and paranasal sinuses. The physical parameters considered were air flow, pressure, humidity, and temperature. Materials and Methods: Numerical models of the human nose and maxillary sinus were retrospectively reconstructed from CT images of generally healthy young subjects. The state-of-the-art numerical methods and tools were then used to determine the temperature, humidity, airflow velocity, and pressure at specific anatomical locations. Results: The results were compared with optimal conditions for bacterial growth in the nose and sinuses. Conclusions: Temperature, humidity, air velocity, and pressure were shown to play critical roles in the selection and distribution of microorganisms. Furthermore, certain combinations of physical parameters can favour mucosal colonisation by various strains of bacteria.
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Affiliation(s)
- Monika Morawska-Kochman
- Department of Otolaryngology, Head and Neck Surgery, Medical University, Borowska 213, 50-556 Wroclaw, Poland
| | - Ziemowit Miłosz Malecha
- Department of Cryogenics and Aerospace Engineering, Wroclaw University of Science and Technology, Wybrzeze Wyspianskiego 27, 50-370 Wroclaw, Poland
| | - Krzysztof Zub
- Department of Otolaryngology, Head and Neck Surgery, Medical University, Borowska 213, 50-556 Wroclaw, Poland
| | - Jakub Kielar
- Department of Cryogenics and Aerospace Engineering, Wroclaw University of Science and Technology, Wybrzeze Wyspianskiego 27, 50-370 Wroclaw, Poland
| | - Krzysztof Dudek
- Statistical Analysis Centre, Wroclaw Medical University, 50-368 Wroclaw, Poland
| | - Kamil Nelke
- Maxillofacial Surgery Ward, EMC Hospital, Pilczycka 144, 54-144 Wroclaw, Poland
- Health Department, Academy of Applied Sciences, Academy of Silesius, Zamkowa 4, 58-300 Walbrzych, Poland
| | - Tomasz Zatonski
- Department of Otolaryngology, Head and Neck Surgery, Medical University, Borowska 213, 50-556 Wroclaw, Poland
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Na Y, Kim YJ, Kim HY, Jung YG. Improvements in airflow characteristics and effect on the NOSE score after septoturbinoplasty: A computational fluid dynamics analysis. PLoS One 2022; 17:e0277712. [PMID: 36395146 PMCID: PMC9671303 DOI: 10.1371/journal.pone.0277712] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2022] [Accepted: 11/01/2022] [Indexed: 11/19/2022] Open
Abstract
Septoturbinoplasty is a surgical procedure that can improve nasal congestion symptoms in patients with nasal septal deviation and inferior turbinate hypertrophy. However, it is unclear which physical domains of nasal airflow after septoturbinoplasty are related to symptomatic improvement. This work employs computational fluid dynamics modeling to identify the physical variables and domains associated with symptomatic improvement. Sixteen numerical models were generated using eight patients' pre- and postoperative computed tomography scans. Changes in unilateral nasal resistance, surface heat flux, relative humidity, and air temperature and their correlations with improvement in the Nasal Obstruction Symptom Evaluation (NOSE) score were analyzed. The NOSE score significantly improved after septoturbinoplasty, from 14.4 ± 3.6 to 4.0 ± 4.2 (p < 0.001). The surgery not only increased the airflow partition on the more obstructed side (MOS) from 31.6 ± 9.6 to 41.9 ± 4.7% (p = 0.043), but also reduced the unilateral nasal resistance in the MOS from 0.200 ± 0.095 to 0.066 ± 0.055 Pa/(mL·s) (p = 0.004). Improvement in the NOSE score correlated significantly with the reduction in unilateral nasal resistance in the preoperative MOS (r = 0.81). Also, improvement in the NOSE score correlated better with the increase in surface heat flux in the preoperative MOS region from the nasal valve to the choanae (r = 0.87) than in the vestibule area (r = 0.63). Therefore, unilateral nasal resistance and mucous cooling in the preoperative MOS can explain the perceived improvement in symptoms after septoturbinoplasty. Moreover, the physical domain between the nasal valve and the choanae might be more relevant to patient-reported patency than the vestibule area.
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Affiliation(s)
- Yang Na
- Department of Mechanical Engineering, Konkuk University, Gwangjin-gu, Seoul, Korea
| | - Youn-Ji Kim
- Department of Mechanical Engineering, Konkuk University, Gwangjin-gu, Seoul, Korea
| | - Hyo Yeol Kim
- Department of Otorhinolaryngology-Head and Neck Surgery, Samsung Medical Center, Sungkyunkwan University, School of Medicine, Seoul, Korea
| | - Yong Gi Jung
- Department of Otorhinolaryngology-Head and Neck Surgery, Samsung Medical Center, Sungkyunkwan University, School of Medicine, Seoul, Korea
- * E-mail:
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Burgos MA, Pardo A, Rodríguez R, Rodríguez-Balbuena B, Castro D, Piqueras F, Esteban F. Linking Chronic Otitis Media and Nasal Obstruction: A CFD Approach. Laryngoscope 2021; 132:1224-1230. [PMID: 34585755 DOI: 10.1002/lary.29882] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 08/18/2021] [Accepted: 08/28/2021] [Indexed: 11/07/2022]
Abstract
OBJECTIVES To investigate a possible relationship between altered nasal flow and chronic otitis media (COM) using computational fluid dynamics (CFD). STUDY DESIGN Retrospective case series. METHODS Retrospective cohort sample of CT scans from patients with COM and controls without COM to compare the results of various nasal airflow parameters determined by CFD between a group of patients with COM (N = 60) and a control group of subjects without any evidence of ear disease (N = 81). The CT were subjected to various procedures to carry out CFD studies, determining the resistance to nasal flow, the proportion of flow through the right and left nasal cavity, and two nondimensional estimators. The results of CFD studies between patients with COM and controls were compared. RESULTS Whereas only 12.3% of the controls had CFD alteration (10 out of 81), 43.3% of the patients suffering COM displayed alterations of our nondimensional parameters R - ϕ (26 out of 60). CONCLUSIONS According to our results, the incidence of alterations in nasal airflow by studying with CFD is significantly higher in patients with COM than in controls. To our knowledge, this is the first article linking nasal cavity and COM using a CFD approach. Our results support the hypothesis that nasal flow alterations could be implicated in the etiopathogenesis of the COM. LEVEL OF EVIDENCE Level 4 Laryngoscope, 2021.
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Affiliation(s)
- Manuel A Burgos
- Departamento de Ingeniería Térmica y de Fluidos, Universidad Politécnica de Cartagena, Cartagena, Spain
| | | | - Rafael Rodríguez
- Hospital Universitario Virgen del Rocío, Servicio de Radiodiagnóstico, Servicio Andaluz de Salud, Sevilla, Spain
| | - Beatriz Rodríguez-Balbuena
- Hospital Universitario Virgen del Rocío, Servicio de Otorrinolaringología, Universidad de Sevilla, Sevilla, Spain
| | - David Castro
- Hospital Universitario Virgen del Rocío, Servicio de Otorrinolaringología, Universidad de Sevilla, Sevilla, Spain
| | - Francisco Piqueras
- Servicio de Otorrinolaringología, Hospital General Universitario Morales Meseguer, Murcia, Spain
| | - Francisco Esteban
- Hospital Universitario Virgen del Rocío, Servicio de Otorrinolaringología, Universidad de Sevilla, Sevilla, Spain
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Chung SK, Na Y. Dynamic characteristics of heat capacity of the human nasal cavity during a respiratory cycle. Respir Physiol Neurobiol 2021; 290:103674. [PMID: 33894344 DOI: 10.1016/j.resp.2021.103674] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Revised: 04/06/2021] [Accepted: 04/15/2021] [Indexed: 11/25/2022]
Abstract
The dynamic characteristics of air-conditioning in the human nasal cavity during a respiratory cycle were investigated using unsteady numerical simulations to assess whether inhaled air is sufficiently conditioned by the nasal cavity. Variations in the epithelial surface temperature, surface heat, and water vapor fluxes were found to vary significantly during inspiration while providing substantial air conditioning to the inhaled air, but variations and magnitudes were significantly reduced during the expiration period. Air temperature (31.3-35.3 °C) and relative humidity (85.1-100 %) in the nasopharynx exhibited significant variations during inspiration. Flow rate-weighted average values of the air temperature and relative humidity during inspiration were estimated to be 32.0 °C and 89.1 %, respectively. Inhaled air did not attain alveolar conditions before reaching the nasopharynx, and was therefore thought to be insufficiently conditioned by the nasal cavity alone. A steady flow of approximately 250 mL/s appears to be useful for evaluating the accumulated thermal state of air in the nasopharynx during inspiration.
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Affiliation(s)
- Seung-Kyu Chung
- Department of Otorhinolaryngology: Head and Neck Surgery, Sungkyunkwan University, School of Medicine, Seoul, Republic of Korea
| | - Yang Na
- Department of Mechanical Engineering, Konkuk University, Seoul, Republic of Korea.
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Na Y, Chung SK, Byun S. Numerical study on the heat-recovery capacity of the human nasal cavity during expiration. Comput Biol Med 2020; 126:103992. [PMID: 32987204 DOI: 10.1016/j.compbiomed.2020.103992] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 08/29/2020] [Accepted: 09/13/2020] [Indexed: 12/31/2022]
Abstract
The characteristics of the thermal field in the human nasal cavity during the expiration period were investigated using computational fluid dynamics. Heat and water-vapor recovery features were quantitatively investigated under realistic distributions of the epithelial surface and air temperature. A constant expiratory flow rate of 250 mL/s was assumed. The epithelial surface temperature was approximately 34.3-34.4 °C in the nasopharynx and 33.5-33.6 °C in the vestibule region, and these values are in good agreement with the measurement data in the literature. We observed that heat-recovery from the exhaled air mostly occurred in the posterior turbinate region, and the amount of heat recovered is estimated to be approximately 1/3 of the heat supply during inspiration. Because of this heat transfer from the exhaled air to the epithelial surface, the temperature of the epithelial surface increased in this region, and the exhaled air temperature dropped through the turbinate airway. Water-vapor recovery primarily occurs in the posterior segments of the turbinates; however, the amount of water-vapor transfer was approximately 1/5 of that in inspiration. Accordingly, the relative humidity of the exhaled air remained constant throughout the airway.
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Affiliation(s)
- Yang Na
- Department of Mechanical Engineering, Konkuk University, Seoul 05029, Republic of Korea.
| | - Seung-Kyu Chung
- Department of Otorhinolaryngology: Head and Neck Surgery, Samsung Medical Center, Sungkyunkwan University, School of Medicine, Seoul, Republic of Korea
| | - Seongsu Byun
- Department of Mechanical Engineering, Konkuk University, Seoul 05029, Republic of Korea
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Keustermans W, Huysmans T, Schmelzer B, Sijbers J, Dirckx JJ. The effect of nasal shape on the thermal conditioning of inhaled air: Using clinical tomographic data to build a large-scale statistical shape model. Comput Biol Med 2020; 117:103600. [PMID: 32072966 DOI: 10.1016/j.compbiomed.2020.103600] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Revised: 12/16/2019] [Accepted: 01/01/2020] [Indexed: 11/19/2022]
Abstract
In this paper, we investigate the heating function of the nasal cavity qualitatively, using a high-quality, large-scale statistical shape model. This model consists of a symmetrical and an asymmetrical part and provides a new and unique way of examining changes in nasal heating function resulting from natural variations in nasal shape (as obtained from 100 clinical CT scans). Data collected from patients suffering from different nasal or sinus-related complaints are included. Parameterized models allow us to investigate the effect of continuous deviations in shape from the mean nasal cavity. This approach also enables us to avoid many of the compounded effects on flow and heat exchange, which one would encounter when comparing different patient-specific models. The effects of global size, size-related features, and turbinate size are investigated using the symmetrical shape model. The asymmetrical model is used to investigate different types of septal deviation using Mladina's classification. The qualitative results are discussed and compared with findings from the existing literature.
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Affiliation(s)
- William Keustermans
- Physics Department, University of Antwerp, Laboratory of Biophysics and Biomedical Physics, Groenenborgerlaan 171, 2020, Antwerp, Belgium.
| | - Toon Huysmans
- Section on Applied Ergonomics and Design, Faculty of Industrial Design Engineering, Delft University of Technology, Landbergstraat 15, 2628, CE Delft, Netherlands
| | - Bert Schmelzer
- ENT Department, ZNA Middelheim Hospital, Lindendreef 1, 2020, Antwerp, Belgium
| | - Jan Sijbers
- Physics Department, University of Antwerp, Imec-Vision Lab, Universiteitsplein 1, 2610, Antwerp, Belgium
| | - Joris Jj Dirckx
- Physics Department, University of Antwerp, Laboratory of Biophysics and Biomedical Physics, Groenenborgerlaan 171, 2020, Antwerp, Belgium
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Inthavong K, Das P, Singh N, Sznitman J. In silico approaches to respiratory nasal flows: A review. J Biomech 2019; 97:109434. [PMID: 31711609 DOI: 10.1016/j.jbiomech.2019.109434] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2019] [Revised: 09/15/2019] [Accepted: 10/17/2019] [Indexed: 12/20/2022]
Abstract
The engineering discipline of in silico fluid dynamics delivers quantitative information on airflow behaviour in the nasal regions with unprecedented detail, often beyond the reach of traditional experiments. The ability to provide visualisation and analysis of flow properties such as velocity and pressure fields, as well as wall shear stress, dynamically during the respiratory cycle may give significant insight to clinicians. Yet, there remains ongoing challenges to advance the state-of-the-art further, including for example the lack of comprehensive CFD modelling on varied cohorts of patients. The present article embodies a review of previous and current in silico approaches to simulating nasal airflows. The review discusses specific modelling techniques required to accommodate physiologically- and clinically-relevant findings. It also provides a critical summary of the reported results in the literature followed by an outlook on the challenges and topics anticipated to drive research into the future.
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Affiliation(s)
| | - Prashant Das
- Department of Mechanical Engineering, University of Alberta, Edmonton, Canada
| | - Narinder Singh
- Dept of Otolaryngology, Head & Neck Surgery, Westmead Hospital Clinical School, Faculty of Medicine, University of Sydney, Australia
| | - Josué Sznitman
- Department of Biomedical Engineering, Technion - Israel Institute of Technology, Haifa, Israel
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Sanmiguel-Rojas E, Burgos MA, Esteban-Ortega F. Nasal surgery handled by CFD tools. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2018; 34:e3126. [PMID: 29968373 DOI: 10.1002/cnm.3126] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Revised: 06/14/2018] [Accepted: 06/24/2018] [Indexed: 06/08/2023]
Abstract
Annually, hundreds of thousands of surgical interventions to correct nasal airway obstruction are performed throughout the world. Recent studies have noted that a significant number of patients have persistent symptoms of nasal obstruction postoperatively. In the present work, we introduce a new methodology that raises the success rate of nasal cavity surgery. In this procedure, the surgeon performs virtual surgery on a 3D nasal model of a patient prior to the real surgery. The main goal of the methodology is to guide the surgeon throughout the virtual operation using mathematical estimators based on CFD results. The virtual surgery intervention ends as soon as the estimators fall into a region of a Cartesian coordinate system with a high success probability. This region is defined according to a statistical analysis of estimators corresponding to sets of healthy and diseased cavities. As examples of this application, this study includes 2 surgical operations performed with this innovative methodology on patients with severe nasal obstruction. The patients underwent nasal surgery according to the final nasal geometry revealed by CFD-guided virtual surgery. Currently, both subjects show high degrees of satisfaction.
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Affiliation(s)
- Enrique Sanmiguel-Rojas
- Escuela de Ingenierías Industriales, Andalucía Tech, Universidad of Málaga, 29071, Málaga, Spain
| | - Manuel Antonio Burgos
- Departamento de Ingenieŕıa Térmica y de Fluidos, Universidad Politécnica de Cartagena, Cartagena, Spain
| | - Francisco Esteban-Ortega
- Departamento de Otorrinolaringología, Hospital Universitario Virgen del Rocío, Universidad de Sevilla, Sevilla, Spain
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Burgos MA, Sanmiguel-Rojas E, Rodríguez R, Esteban-Ortega F. A CFD approach to understand nasoseptal perforations. Eur Arch Otorhinolaryngol 2018; 275:2265-2272. [PMID: 30043077 DOI: 10.1007/s00405-018-5073-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2018] [Accepted: 07/20/2018] [Indexed: 11/29/2022]
Abstract
INTRODUCTION Nasoseptal perforations (NSP) are becoming common in the modern world, and can cause a wide variety of symptoms, including a sensation of nasal obstruction, epistaxis, crusting, dryness, headache, nasal pain and a whistling sound. There is an extensive range of surgical treatment techniques, but reported results were rarely statistically significant. The lack of consistent surgical results may be related to the lack of knowledge about the pathophysiology of NSP and how they affect the nasal flow. Computational fluid dynamics (CFD) has proved to be a very useful tool to study nasal function. METHODS We have used CFD software (the program MECOMLAND® and the Digbody® tool for virtual surgery) to investigate the behaviour of the parameters R-[Formula: see text] based on CFD results, when four subjects underwent virtual surgery to induce a septal perforation: two subjects with healthy noses and two patients suffering from nasal airway obstruction. For each case a CFD study was performed, before and after creating an anterior (close to nostrils) or a posterior (close to choanae) NSP. RESULTS In all cases analyzed, a posterior septal perforation did not result in a significant volumetric flow rate [Formula: see text] through the perforation between nasal passages. However, for anterior defects only in those nasal cavities considered diseased or unhealthy, high values of [Formula: see text] were found. CONCLUSION The induced NSP only rendered significant flow alterations in noses with preexisting nasal airway obstruction alterations, whereas in nasal cavities considered as normal the creation of a NSP did not produce significant differences between both sides. We strongly suggest that this finding can explain the variety of symptoms and the number of asymptomatic patients bearing NSP.
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Affiliation(s)
- M A Burgos
- Departamento de Ingeniería Térmica y de Fluidos, Universidad Politécnica de Cartagena, Cartagena, Spain
| | - E Sanmiguel-Rojas
- Departamento de Ingeniería Mecánica, Térmica y de Fluidos, Universidad de Málaga, Andalucía Tech, Campus de Teatinos s/n, 29071, Malaga, Spain.
| | - R Rodríguez
- Servicio de Radiodiagnóstico, Servicio Andaluz de Salud, Hospital Universitario Virgen del Rocío, Seville, Spain
| | - F Esteban-Ortega
- Servicio de Otorrinolaringología, Hospital Universitario Virgen del Rocío, Universidad de Sevilla, Seville, Spain
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Burgos MA, Sanmiguel-Rojas E, Singh N, Esteban-Ortega F. DigBody ®: A new 3D modeling tool for nasal virtual surgery. Comput Biol Med 2018; 98:118-125. [PMID: 29787939 DOI: 10.1016/j.compbiomed.2018.05.016] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Revised: 05/06/2018] [Accepted: 05/15/2018] [Indexed: 11/19/2022]
Abstract
BACKGROUND AND PURPOSE Recent studies have demonstrated that a significant number of surgical procedures for nasal airway obstruction (NAO) have a high rate of surgical failure. In part, this problem is due to the lack of reliable objective clinical parameters to aid surgeons during preoperative planning. Modeling tools that allow virtual surgery to be performed do exist, but all require direct manipulation of computed tomography (CT) or magnetic resonance imaging (MRI) data. Specialists in Rhinology have criticized these tools for their complex user interface, and have requested more intuitive, user-friendly and powerful software to make virtual surgery more accessible and realistic. In this paper we present a new virtual surgery software tool, DigBody®. METHODS This new surgery module is integrated into the computational fluid dynamics (CFD) program MeComLand®, which was developed exclusively to analyze nasal airflow. DigBody® works directly with a 3D nasal model that mimics real surgery. Furthermore, this surgery module permits direct assessment of the operated cavity following virtual surgery by CFD simulation. RESULTS The effectiveness of DigBody® has been demonstrated by real surgery on two patients based on prior virtual operation results. Both subjects experienced excellent surgical outcomes with no residual nasal obstruction. CONCLUSIONS This tool has great potential to aid surgeons in modeling potential surgical maneuvers, minimizing complications, and being confident that patients will receive optimal postoperative outcomes, validated by personalized CFD testing.
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Affiliation(s)
- M A Burgos
- Departamento de Ingeniería Térmica y de Fluidos, Universidad Politécnica de Cartagena, Cartagena, Spain
| | - E Sanmiguel-Rojas
- Escuela de Ingenierías Industriales, Universidad de Málaga, Campus de Teatinos, 29071, Málaga, Spain.
| | - Narinder Singh
- Department of Otolaryngology, Head and Neck Surgery, Westmead Hospital, Sydney, Australia; University of Sydney, Sydney, Australia
| | - F Esteban-Ortega
- Servicio de Otorrinolaringología, Hospital Universitario Virgen del Rocío, Departamento de Cirugía, Universidad de Sevilla, Sevilla, Spain
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Burgos MA, Sevilla García MA, Sanmiguel Rojas E, Del Pino C, Fernández Velez C, Piqueras F, Esteban Ortega F. Virtual Surgery for Patients With Nasal Obstruction: Use of Computational Fluid Dynamics (MeComLand ® , Digbody ® & Noseland ® ) to Document Objective Flow Parameters and Optimise Surgical Results. ACTA ACUST UNITED AC 2018. [DOI: 10.1016/j.otoeng.2017.05.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
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Sanmiguel-Rojas E, Burgos MA, Del Pino C, Sevilla-García MA, Esteban-Ortega F. Robust nondimensional estimators to assess the nasal airflow in health and disease. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2018; 34:e2906. [PMID: 28574647 DOI: 10.1002/cnm.2906] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Revised: 05/29/2017] [Accepted: 05/30/2017] [Indexed: 06/07/2023]
Abstract
There are significant variations of both human nose shapes and airflow patterns inside nasal cavities, so it is difficult to provide a comprehensive medical identification using a universal template for what otolaryngologists consider normal breathing at rest. In addition, airflow patterns present even more random characteristics in diseased nasal cavities. To give a medical assessment to differentiate the nasal cavities in health and disease, we propose 2 nondimensional estimators obtained from both medical images and computational fluid dynamics. The first mathematical estimator ϕ is a function of geometric features and potential asymmetries between nasal passages, while the second estimator R represents in fluid mechanics terms the total nasal resistance that corresponds to the atmosphere-choana pressure drop. These estimators only require global information such as nasal geometry and magnitudes of flow determined by simulations under laminar conditions. We find that these estimators take low and high values for healthy and diseased nasal cavities, respectively. Our study, based on 24 healthy and 25 diseased Caucasian subjects, reveals that there is an interval of values associated with healthy cavities that clusters in a small region of the plane ϕ-R. Therefore, these estimators can be seen as a first approximation to provide nasal airflow data to the clinician in a noninvasive method, as the computed tomography scan that provides the required images is routinely obtained as a result of the preexisting naso-sinusal condition.
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Affiliation(s)
- E Sanmiguel-Rojas
- Escuela de Ingenierías Industriales, Andalucía Tech, Universidad of Málaga, Málaga, 29071, Spain
| | - M A Burgos
- Departamento de Ingeniería Térmica y de Fluidos, Universidad Politécnica de Cartagena, Cartagena, Spain
| | - C Del Pino
- Escuela de Ingenierías Industriales, Andalucía Tech, Universidad of Málaga, Málaga, 29071, Spain
| | - M A Sevilla-García
- Departamento de Otorrinolaringología, Hospital Universitario Virgen del Rocío, Seville, Spain
| | - F Esteban-Ortega
- Departamento de Otorrinolaringología, Hospital Universitario Virgen del Rocío, Seville, Spain
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Virtual surgery for patients with nasal obstruction: Use of computational fluid dynamics (MeComLand ®, Digbody ® & Noseland ®) to document objective flow parameters and optimise surgical results. ACTA OTORRINOLARINGOLOGICA ESPANOLA 2017; 69:125-133. [PMID: 28923473 DOI: 10.1016/j.otorri.2017.05.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Accepted: 05/24/2017] [Indexed: 11/21/2022]
Abstract
INTRODUCTION Computational fluid dynamics (CFD) is a mathematical tool to analyse airflow. We present a novel CFD software package to improve results following nasal surgery for obstruction. METHODS A group of engineers in collaboration with otolaryngologists have developed a very intuitive CFD software package called MeComLand®, which uses the patient's cross-sectional (tomographic) images, thus showing in detail results originated by CFD such as airflow distributions, velocity profiles, pressure, or wall shear stress. NOSELAND® helps medical evaluation with dynamic reports by using a 3D endoscopic view. Using this CFD-based software a patient underwent virtual surgery (septoplasty, turbinoplasty, spreader grafts, lateral crural J-flap and combinations) to choose the best improvement in nasal flow. OBJECTIVE To present a novel software package to improve nasal surgery results. To apply the software on CT slices from a patient affected by septal deviation. To evaluate several surgical procedures (septoplasty, turbinectomy, spreader-grafts, J-flap and combination among them) to find the best alternative with less morbidity. RESULTS The combination of all the procedures does not provide the best nasal flow improvement. Septoplasty plus turbinoplasty obtained the best results. Turbinoplasty alone rendered almost similar results to septoplasty in our simulation. CONCLUSIONS CFD provides useful complementary information to cover diagnosis, prognosis, and follow-up of nasal pathologies based on quantitative magnitudes linked to fluid flow. MeComLand®, DigBody® and NoseLand® represent a non-invasive, low-cost alternative for the functional study of patients with nasal obstruction.
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Burgos MA, Sanmiguel-Rojas E, Del Pino C, Sevilla-García MA, Esteban-Ortega F. New CFD tools to evaluate nasal airflow. Eur Arch Otorhinolaryngol 2017; 274:3121-3128. [PMID: 28547013 DOI: 10.1007/s00405-017-4611-y] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Accepted: 05/13/2017] [Indexed: 11/21/2022]
Abstract
Computational fluid dynamics (CFD) is a mathematical tool to analyse airflow. As currently CFD is not a usual tool for rhinologists, a group of engineers in collaboration with experts in Rhinology have developed a very intuitive CFD software. The program MECOMLAND® only required snapshots from the patient's cross-sectional (tomographic) images, being the output those results originated by CFD, such as airflow distributions, velocity profiles, pressure, temperature, or wall shear stress. This is useful complementary information to cover diagnosis, prognosis, or follow-up of nasal pathologies based on quantitative magnitudes linked to airflow. In addition, the user-friendly environment NOSELAND® helps the medical assessment significantly in the post-processing phase with dynamic reports using a 3D endoscopic view. Specialists in Rhinology have been asked for a more intuitive, simple, powerful CFD software to offer more quality and precision in their work to evaluate the nasal airflow. We present MECOMLAND® and NOSELAND® which have all the expected characteristics to fulfil this demand and offer a proper assessment with the maximum of quality plus safety for the patient. These programs represent a non-invasive, low-cost (as the CT scan is already performed in every patient) alternative for the functional study of the difficult rhinologic case. To validate the software, we studied two groups of patients from the Ear Nose Throat clinic, a first group with normal noses and a second group presenting septal deviations. Wall shear stresses are lower in the cases of normal noses in comparison with those for septal deviation. Besides, velocity field distributions, pressure drop between nasopharynx and the ambient, and flow rates in each nostril were different among the nasal cavities in the two groups. These software modules open up a promising future to simulate the nasal airflow behaviour in virtual surgery intervention scenarios under different pressure or temperature conditions to understand the effects on nasal airflow.
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Affiliation(s)
- M A Burgos
- Departamento de Ingeniería Térmica y de Fluidos, Universidad Politécnica de Cartagena, Cartagena, Spain
| | - E Sanmiguel-Rojas
- Escuela de Ingenierías Industriales, Universidad de Málaga, Campus de Teatinos, 29071, Málaga, Spain
| | - C Del Pino
- Escuela de Ingenierías Industriales, Universidad de Málaga, Campus de Teatinos, 29071, Málaga, Spain.
| | - M A Sevilla-García
- Departamento de Otorrinolaringología, Hospital Universitario Virgen del Rocío, Sevilla, Spain
| | - F Esteban-Ortega
- Departamento de Otorrinolaringología, Hospital Universitario Virgen del Rocío, Sevilla, Spain
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Cal IR, Cercos-Pita JL, Duque D. The incompressibility assumption in computational simulations of nasal airflow. Comput Methods Biomech Biomed Engin 2017; 20:853-868. [PMID: 28367642 DOI: 10.1080/10255842.2017.1307343] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Most of the computational works on nasal airflow up to date have assumed incompressibility, given the low Mach number of these flows. However, for high temperature gradients, the incompressibility assumption could lead to a loss of accuracy, due to the temperature dependence of air density and viscosity. In this article we aim to shed some light on the influence of this assumption in a model of calm breathing in an Asian nasal cavity, by solving the fluid flow equations in compressible and incompressible formulation for different ambient air temperatures using the OpenFOAM package. At low flow rates and warm climatological conditions, similar results were obtained from both approaches, showing that density variations need not be taken into account to obtain a good prediction of all flow features, at least for usual breathing conditions. This agrees with most of the simulations previously reported, at least as far as the incompressibility assumption is concerned. However, parameters like nasal resistance and wall shear stress distribution differ for air temperatures below [Formula: see text]C approximately. Therefore, density variations should be considered for simulations at such low temperatures.
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Affiliation(s)
- Ismael R Cal
- a Nasal Advanced Systems of Airflow Laboratories , Madrid , Spain
| | | | - Daniel Duque
- b Canal de Ensayos Hidrodinámicos (CEHINAV), E.T.S.I Navales , Universidad Politécnica de Madrid , Madrid , Spain
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Jain R, Kumar H, Tawhai M, Douglas R. The impact of endoscopic sinus surgery on paranasal physiology in simulated sinus cavities. Int Forum Allergy Rhinol 2016; 7:248-255. [PMID: 27869357 DOI: 10.1002/alr.21879] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2016] [Revised: 10/05/2016] [Accepted: 10/18/2016] [Indexed: 01/25/2023]
Abstract
BACKGROUND Surgery improves symptoms for the majority of chronic rhinosinusitis (CRS) patients; however, physiological changes in the sinus cavities remain poorly characterized. Direct measurement of changes in airflow, pressure, temperature, humidity, and intranasal spray distribution following surgery is technically challenging. Accordingly, we have used computational fluid dynamic modeling to quantify how these parameters change postoperatively. METHODS Computed tomography images from a normal control, a patient with CRS preoperatively and postoperatively, and a patient following an endoscopic Lothrop procedure (ELP) were used to create 4 three-dimensional models of the sinus cavities. Changes in physiologic parameters and topical drug distribution were modeled (inhaled air at 16°C and 10% humidity) at the maxillary ostium, frontal recess, and sphenoid ostium. RESULTS Large differences were seen between models. Following surgery, the maxillary ostia were found on average to be cooler (by 2.4°C), with an increased airflow (0.26 m/second; from 0 m/second), and a 9% reduction in absolute humidity. Sphenoid ostial parameters followed a similar trend. Significant changes in frontal recess physiology were seen following ELP in which the recess was 4.2°C cooler, had increased airflow (0.76 m/second) and a 17% reduction in absolute humidity. Topical drug distribution increased with surgery, particularly after ELP. CONCLUSION Surgery changes the geometry and physiology of the paranasal sinuses. These changes are likely to have an impact on wound healing, mucociliary function, and microbial ecology in postoperative cavities. Application of this model to further understand the effects of surgery may help to optimize surgical techniques and improve topical drug delivery.
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Affiliation(s)
- Ravi Jain
- Department of Surgery, The University of Auckland, Auckland, New Zealand
| | - Haribalan Kumar
- Auckland Bioengineering Institute, The University of Auckland, Auckland, New Zealand
| | - Merryn Tawhai
- Auckland Bioengineering Institute, The University of Auckland, Auckland, New Zealand
| | - Richard Douglas
- Department of Surgery, The University of Auckland, Auckland, New Zealand
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