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Rüttgers M, Waldmann M, Vogt K, Ilgner J, Schröder W, Lintermann A. Automated surgery planning for an obstructed nose by combining computational fluid dynamics with reinforcement learning. Comput Biol Med 2024; 173:108383. [PMID: 38555704 DOI: 10.1016/j.compbiomed.2024.108383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Revised: 02/26/2024] [Accepted: 03/24/2024] [Indexed: 04/02/2024]
Abstract
Septoplasty and turbinectomy are among the most common interventions in the field of rhinology. Their constantly debated success rates and the lack of quantitative flow data of the entire nasal airway for planning the surgery necessitate methodological improvement. Thus, physics-based surgery planning is highly desirable. In this work, a novel and accurate method is developed to enhance surgery planning by physical aspects of respiration, i.e., to plan anti-obstructive surgery, for the first time a reinforcement learning algorithm is combined with large-scale computational fluid dynamics simulations. The method is integrated into an automated pipeline based on computed tomography imaging. The proposed surgical intervention is compared to a surgeon's initial plan, or the maximum possible intervention, which allows the quantitative evaluation of the intended surgery. Two criteria are considered: (i) the capability to supply the nasal airway with air expressed by the pressure loss and (ii) the capability to heat incoming air represented by the temperature increase. For a test patient suffering from a deviated septum near the nostrils and a bony spur further downstream, the method recommends surgical interventions exactly at these locations. For equal weights on the two criteria (i) and (ii), the algorithm proposes a slightly weaker correction of the deviated septum at the first location, compared to the surgeon's plan. At the second location, the algorithm proposes to keep the bony spur. For a larger weight on criterion (i), the algorithm tends to widen the nasal passage by removing the bony spur. For a larger weight on criterion (ii), the algorithm's suggestion approaches the pre-surgical state with narrowed channels that favor heat transfer. A second patient is investigated that suffers from enlarged turbinates in the left nasal passage. For equal weights on the two criteria (i) and (ii), the algorithm proposes a nearly complete removal of the inferior turbinate, and a moderate reduction of the middle turbinate. An increased weight on criterion (i) leads to an additional reduction of the middle turbinate, and a larger weight on criterion (ii) yields a solution with only slight reductions of both turbinates, i.e., focusing on a sufficient heat exchange between incoming air and the air-nose interface. The proposed method has the potential to improve the success rates of the aforementioned surgeries and can be extended to further biomedical flows.
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Affiliation(s)
- Mario Rüttgers
- Jülich Supercomputing Centre, Forschungszentrum Jülich GmbH, Wilhelm-Johnen-Straße, 52425 Jülich, Germany; Institute of Aerodynamics and Chair of Fluid Mechanics, RWTH Aachen University, Wüllnerstraße 5a, 52062 Aachen, Germany; Jülich Aachen Research Alliance, Center for Simulation and Data Science, 52074 Aachen, Germany.
| | - Moritz Waldmann
- Institute of Aerodynamics and Chair of Fluid Mechanics, RWTH Aachen University, Wüllnerstraße 5a, 52062 Aachen, Germany; Jülich Aachen Research Alliance, Center for Simulation and Data Science, 52074 Aachen, Germany
| | - Klaus Vogt
- Faculty of Medicine, Center of Experimental Surgery, University of Latvia, 1586 Riga, Latvia
| | - Justus Ilgner
- Department of Otorhinolaryngology, Head and Neck Surgery, Uniklinik RWTH Aachen University, Pauwelsstraße 30, 52074 Aachen, Germany
| | - Wolfgang Schröder
- Institute of Aerodynamics and Chair of Fluid Mechanics, RWTH Aachen University, Wüllnerstraße 5a, 52062 Aachen, Germany; Jülich Aachen Research Alliance, Center for Simulation and Data Science, 52074 Aachen, Germany
| | - Andreas Lintermann
- Jülich Supercomputing Centre, Forschungszentrum Jülich GmbH, Wilhelm-Johnen-Straße, 52425 Jülich, Germany; Jülich Aachen Research Alliance, Center for Simulation and Data Science, 52074 Aachen, Germany
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Aljawad H, Rüttgers M, Lintermann A, Schroöder W, Lee KC. Effects of the Nasal Cavity Complexity on the Pharyngeal Airway Fluid Mechanics: A Computational Study. J Digit Imaging 2021; 34:1120-1133. [PMID: 34505957 DOI: 10.1007/s10278-021-00501-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Revised: 07/29/2021] [Accepted: 07/30/2021] [Indexed: 11/29/2022] Open
Abstract
The impact of the human nasal airway complexity on the pharyngeal airway fluid mechanics is investigated at inspiration. It is the aim to find a suitable degree of geometrical reduction that allows for an efficient segmentation of the human airways from cone-beam computed tomography images. The flow physics is simulated by a lattice Boltzmann method on high-performance computers. For two patients, the flow field through the complete upper airway is compared to results obtained from three surface variants with continuously decreasing complexity. The most complex reduced airway model includes the middle and inferior turbinates, while the moderate model only features the inferior turbinates. In the simplest model, a pipe-like artificial structure is attached to the airway. For each model, the averaged pressure is computed at different cross sections. Furthermore, the flow fields are investigated by means of averaged velocity magnitudes, in-plane velocity vectors, and streamlines. By analyzing the averaged pressure loss from the nostrils to each cross section, it is found that only the most complex reduced models are capable of approximating the pressure distribution from the original geometries. In the moderate models, the geometry reductions lead to overpredictions of the pressure loss in the pharynx. Attaching a pipe-like structure leads to a higher deceleration of the incoming flow and underpredicted pressure losses and velocities, especially in the upper part of the pharynx. Dean-like vortices are observed in the moderate and pipe-like models, since their shape comes close to a [Formula: see text]-bend elbow pipe.
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Affiliation(s)
- Hussein Aljawad
- Department of Orthodontics, School of Dentistry, Chonnam National University, Gwangju, Korea
| | - Mario Rüttgers
- Institute of Aerodynamics and Chair of Fluid Mechanics, RWTH Aachen University, Aachen, Germany
| | - Andreas Lintermann
- Jülich Supercomputing Centre, Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Wolfgang Schroöder
- Jülich Aachen Research Alliance, Center for Simulation and Data Science, Aachen, Germany
| | - Kyungmin Clara Lee
- Department of Orthodontics, School of Dentistry, Chonnam National University, Gwangju, Korea.
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Vogt K, Bachmann-Harildstad G, Lintermann A, Nechyporenko A, Peters F, Wernecke KD. The new agreement of the international RIGA consensus conference on nasal airway function tests. Rhinology 2018; 56:133-143. [PMID: 29353289 DOI: 10.4193/rhin17.084] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The report reflects an agreement based on the consensus conference of the International Standardization Committee on the Objective Assessment of the Nasal Airway in Riga, 2nd Nov. 2016. The aim of the conference was to address the existing nasal airway function tests and to take into account physical, mathematical and technical correctness as a base of international standardization as well as the requirements of the Council Directive 93/42/EEC of 14 June 1993 concerning medical devices. Rhinomanometry, acoustic rhinometry, peak nasal inspiratory flow, Odiosoft-Rhino, optical rhinometry, 24-h measurements, computational fluid dynamics, nasometry and the mirrow test were evaluated for important diagnostic criteria, which are the precision of the equipment including calibration and the software applied; validity with sensitivity, specificity, positive and negative predictive values, reliability with intra-individual and inter-individual reproducibility and responsiveness in clinical studies. For rhinomanometry, the logarithmic effective resistance was set as the parameter of high diagnostic relevance. In acoustic rhinometry, the area of interest for the minimal cross-sectional area will need further standardization. Peak nasal inspiratory flow is a reproducible and fast test, which showed a high range of mean values in different studies. The state of the art with computational fluid dynamics for the simulation of the airway still depends on high performance computing hardware and will, after standardization of the software and both the software and hardware for imaging protocols, certainly deliver a better understanding of the nasal airway flux.
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Affiliation(s)
- K Vogt
- University of Latvia, Center of Experimental Surgery, Riga, Latvia
| | - G Bachmann-Harildstad
- Department of otorhinolaryngology, Akershus University Hospital and Institute of Clinical Medicine, Akershus University Hospital, Oslo University, Lorenskog, Norway
| | - A Lintermann
- Institute of Aerodynamics and Chair of Fluid Mechanics, RWTH Aachen University, Aachen, Germany
| | - A Nechyporenko
- Kharkiv National University of Radio Electronics, Department of Biomedical Engineering, Kharkiv, Ukraine
| | - F Peters
- Ruhr-Universitat Bochum, Mechanical Engineering, Fluid Mechanics, Bochum, Germany
| | - K D Wernecke
- Charite-Universitatsmedizin Berlin, Berlin, Germany
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Kim SY, Park YC, Lee KJ, Lintermann A, Han SS, Yu HS, Choi YJ. Assessment of changes in the nasal airway after nonsurgical miniscrew-assisted rapid maxillary expansion in young adults. Angle Orthod 2018; 88:435-441. [PMID: 29561652 DOI: 10.2319/092917-656.1] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
OBJECTIVES To evaluate changes in the volume and cross-sectional area of the nasal airway before and 1 year after nonsurgical miniscrew-assisted rapid maxillary expansion (MARME) in young adults. MATERIALS AND METHODS Fourteen patients (mean age, 22.7 years; 10 women, four men) with a transverse discrepancy who underwent cone beam computed tomography before (T0), immediately after (T1), and 1 year after (T2) expansion were retrospectively included in this study. The volume of the nasal cavity and nasopharynx and the cross-sectional area of the anterior, middle, and posterior segments of the nasal airway were measured and compared among the three timepoints using paired t-tests. RESULTS The volume of the nasal cavity showed a significant increase at T1 and T2 ( P < .05), while that of the nasopharynx increased only at T2 ( P < .05). The anterior and middle cross-sectional areas significantly increased at T1 and T2 ( P < .05), while the posterior cross-sectional area showed no significant change throughout the observation period ( P > .05). CONCLUSIONS The results demonstrate that the volume and cross-sectional area of the nasal cavity increased after MARME and were maintained at 1 year after expansion. Therefore, MARME may be helpful in expanding the nasal airway.
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Lintermann A, Meinke M, Schröder W. Fluid mechanics based classification of the respiratory efficiency of several nasal cavities. Comput Biol Med 2013; 43:1833-52. [PMID: 24209929 DOI: 10.1016/j.compbiomed.2013.09.003] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2013] [Revised: 08/14/2013] [Accepted: 09/04/2013] [Indexed: 11/18/2022]
Abstract
The flow in the human nasal cavity is of great importance to understand rhinologic pathologies like impaired respiration or heating capabilities, a diminished sense of taste and smell, and the presence of dry mucous membranes. To numerically analyze this flow problem a highly efficient and scalable Thermal Lattice-BGK (TLBGK) solver is used, which is very well suited for flows in intricate geometries. The generation of the computational mesh is completely automatic and highly parallelized such that it can be executed efficiently on High Performance Computers (HPCs). An evaluation of the functionality of nasal cavities is based on an analysis of pressure drop, secondary flow structures, wall-shear stress distributions, and temperature variations from the nostrils to the pharynx. The results of the flow fields of three completely different nasal cavities allow their classification into ability groups and support the a priori decision process on surgical interventions.
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Affiliation(s)
- Andreas Lintermann
- Institute of Aerodynamics, RWTH Aachen University, Wüllnerstr. 5a, 52062 Aachen, Germany.
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Mosges R, Meinke M, Wein B, Lintermann A, Henkel K, Kleiner M. SP105 – Effect of intranasal mometasone furoate on nasal airflow. Otolaryngol Head Neck Surg 2009. [DOI: 10.1016/j.otohns.2009.06.389] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Mosges R, Meinke M, Lintermann A, Henkel K, Wein B. 3D-visualization Of The Nasal Flow After Allergen Challenge And The Effect Of Mometasone Furoate Nasal Spray (MFNS). J Allergy Clin Immunol 2009. [DOI: 10.1016/j.jaci.2008.12.499] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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