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Journal articles on the topic 'Nasal aerodynamics'

Author: Grafiati
Published: 30 May 2022
Last updated: 31 May 2022

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1

Kleven, M., M. C. Melaaen, M. Reimers, and P. G. Djupesland. "Computational modelling of nasal aerodynamics." Journal of Biomechanics 39 (January 2006): S271. http://dx.doi.org/10.1016/s0021-9290(06)84042-x.

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2

Zajac, David J., Robert Mayo, Ryuta Kataoka, and James Y. Kuo. "Aerodynamic and Acoustic Characteristics of a Speaker with Turbulent Nasal Emission: A Case Report." Cleft Palate-Craniofacial Journal 33, no. 5 (September 1996): 440–44. http://dx.doi.org/10.1597/1545-1569_1996_033_0440_aaacoa_2.3.co_2.

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Aerodynamic and acoustic characteristics were determined from the speech of an adult female with mild mental retardation and severe velopharyngeal inadequacy. The speaker's productions of /s/ were characterized by consistent nasal grimacing and turbulent air emission. Aerodynamic assessment estimated the size of the velopharyngeal orifice to exceed 200 mm2 during plosive production. Nasal cross-sectional area was estimated to be 35 mm2 during quiet breathing. Nasometric evaluation indicated nasalance of 63% associated with the “Zoo” passage. Acoustic analysis of the separately recorded oral and nasal speech signals indicated spectral energies in the region of approximately 2.5 to 7.0 kHz associated with nasal emission during /s/ production. The occurrence of these frequencies suggested an acoustic/perceptual function of the nasal grimace. Pressure-flow evidence also suggested that the nasal grimace, perhaps with lingual assistance, functioned to enhance speech aerodynamics.
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3

Shcherbakov, Dmitrii, Valeria Kokareva, Nikita Cheremnykh, and Aygul Shcherbakova. "Computational Aerodynamics in Nasal Septal Perforation." International Journal of Biomedicine 10, no. 1 (March 15, 2020): 82–85. http://dx.doi.org/10.21103/article10(1)_cr3.

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4

Stoakes, Hywel M., Janet M. Fletcher, and Andrew R. Butcher. "Nasal coarticulation in Bininj Kunwok: An aerodynamic analysis." Journal of the International Phonetic Association 50, no. 3 (February 12, 2019): 305–32. http://dx.doi.org/10.1017/s0025100318000282.

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Bininj Kunwok (BKw), a language spoken in Northern Australia, restricts the degree of anticipatory nasalization, as suggested by previous aerodynamic and acoustic analyses (Butcher 1999). The current study uses aerodynamic measurements of speech to investigate patterns of nasalization and nasal articulation in Bininj Kunwok to compare with Australian languages more generally. The role of nasal coarticulation in ensuring language compre-hensibility a key question in phonetics research today is explored. Nasal aerodynamics is measured in intervocalic, word-medial nasals in the speech of five female speakers of BKw and data are analyzed using Smoothing Spline Analysis of Variance (SSANOVA) and Functional Data Analysis averaging techniques. Results show that in a VNV sequence there is very little anticipatory vowel nasalization with no restriction on carryover nasalization for a following vowel. The maximum peak nasal flow is delayed until the oral release of a nasal for coronal articulations, indicating a delayed velum opening gesture. Patterns of anticipatory nasalization appears similar to nasal airflow in French non-nasalized vowels in oral vowel plus nasal environments (Delvaux et al. 2008). Findings show that Bininj Kunwok speakers use language specific strategies in order to limit anticipatory nasalization, enhancing place of articulation cues at a site of intonational prominence which also is also the location of the majority of place of articulation contrasts within the language. Patterns of airflow suggest enhancement and coarticulatory resistance in prosodically prominent VN and VNC sequences which we interpret as evidence of speakers maintaining a phonological contrast to enhance place of articulation cues.
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5

NAYEBOSSADRI, SHAHRZAD, ELDAD J. AVITAL, FARIBORZ MOTALLEBI, and GUY KENYON. "NASAL INTERNAL AND EXTERNAL AERODYNAMICS FOR HEALTHY AND BLOCKED CAVITIES." Journal of Mechanics in Medicine and Biology 18, no. 05 (August 2018): 1850050. http://dx.doi.org/10.1142/s0219519418500501.

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Human nasal airflow in a healthy and partially blocked cavities is investigated using computational and experimental means. While previous studies focused on the flow inside the nasal cavity, this study also looks at the external air stream coming out of the nostrils. The aim is to investigate the airflow subject to partial blocking in the nasal cavity and assess the potential of using a flow visualization method to identify abnormal nasal geometry. Two methods of study are used: Computational Fluid Dynamics (CFD) and experiment based on Particle Image Velocimetry (PIV). Nasal cavity geometry is reconstructed from CT scans. The flow visualization Schileren method is also demonstrated. The computational results agree well with the previous results in terms of Nasal Resistance (NR) and character of the internal flow. Good agreement is also found in the external aerodynamics during expiration between the computational and experimental results. Several generic partial blockages are investigated to show changes in NR, turbulence energy and the air stream leaving the nostrils during expiration. Anterior blockages are found to have more profound effects on all these three aspects, but all show effects on the external air stream. A possible universal angle for the external air stream emitted by a healthy nasal cavity is discussed.
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6

Levine, Samuel C., Howard Levine, Gordon Jacobs, and Jerry Kasick. "A Technique to Model the Nasal Airway for Aerodynamic Study." Otolaryngology–Head and Neck Surgery 95, no. 4 (November 1986): 442–49. http://dx.doi.org/10.1177/019459988609500405.

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This article presents a new technique for creation of a model that can be used to study the aerodynamics of the nasal airway. The model is employed to determine parameters used to calculate nasal resistance and modified to compare various types of nasal obstruction. It quantitatively compares the importance of septal deviation, turbinate size, and nasopharyngeal port size to airflow. A new parameter of nasal resistance is introduced.
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7

Chen, X. B., S. C. Leong, H. P. Lee, V. F. H. Chong, and D. Y. Wang. "Aerodynamic effects of inferior turbinate surgery on nasal airflow--a computational fluid dynamics model." Rhinology journal 48, no. 4 (December 1, 2010): 394–400. http://dx.doi.org/10.4193/rhino09.196.

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BACKGROUND: Turbinate reduction surgery may be indicated for inferior turbinate enlargement when conservative treatment fails. The aim of this study was to evaluate the effects of inferior turbinate surgery on nasal aerodynamics using computational fluid dynamics (CFD) simulations. METHODS: CFD simulations were performed for the normal nose, enlarged inferior turbinate and following three surgical procedures: (1) resection of the lower third free edge of the inferior turbinate, (2) excision of the head of the inferior turbinate and (3) radical inferior turbinate resection. The models were constructed from MRI scans of a healthy human subject and a turbulent flow model was used for the numerical simulation. The consequences of the three turbinate surgeries were compared with originally healthy nasal model as well as the one with severe nasal obstruction. RESULTS: In the normal nose, the bulk of streamlines traversed the common meatus adjacent to the inferior and middle turbinate in a relatively vortex free flow. When the inferior turbinate was enlarged, the streamlines were directed superiorly at higher velocity and increased wall shear stress in the nasopharynx. Of the three surgical techniques simulated, wall shear stress and intranasal pressures achieved near-normal levels after resection of the lower third. In addition, airflow streamlines and turbulence improved although it did not return to normal conditions. As expected, radical turbinate resection resulted in intra-nasal aerodynamics of atrophic rhinitis demonstrated in previous CFD studies. CONCLUSION: There is little evidence that inspired air is appropriately conditioned following radical turbinate surgery. Partial reduction of the hypertropic turbinate results in improved nasal aerodynamics, which was most evident following resection of the lower third. The results were based on a single individual and cannot be generalised without similar studies in other subjects.
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8

Bezshapochniy, S. B., Iu A. Gasiuk, V. V. Loburets, and A. V. Loburets. "AERODYNAMICS OF NASAL CAVITY AND ACCESSORY SINUSES OF THE NOSE." Bulletin of Problems Biology and Medicine 4 (2018): 52. http://dx.doi.org/10.29254/2077-4214-2018-4-1-146-52-56.

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9

Dayal, Anupriya, John S. Rhee, and Guilherme J. M. Garcia. "Impact of Middle versus Inferior Total Turbinectomy on Nasal Aerodynamics." Otolaryngology–Head and Neck Surgery 155, no. 3 (July 22, 2016): 518–25. http://dx.doi.org/10.1177/0194599816644915.

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10

Moshkin, M. P., D. V. Petrovski, A. E. Akulov, A. V. Romashchenko, L. A. Gerlinskaya, V. L. Ganimedov, M. I. Muchnaya, et al. "Nasal aerodynamics protects brain and lung from inhaled dust in subterranean diggers, Ellobius talpinus." Proceedings of the Royal Society B: Biological Sciences 281, no. 1792 (October 7, 2014): 20140919. http://dx.doi.org/10.1098/rspb.2014.0919.

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Inhalation of air-dispersed sub-micrometre and nano-sized particles presents a risk factor for animal and human health. Here, we show that nasal aerodynamics plays a pivotal role in the protection of the subterranean mole vole Ellobius talpinus from an increased exposure to nano-aerosols. Quantitative simulation of particle flow has shown that their deposition on the total surface of the nasal cavity is higher in the mole vole than in a terrestrial rodent Mus musculus (mouse), but lower on the olfactory epithelium. In agreement with simulation results, we found a reduced accumulation of manganese in olfactory bulbs of mole voles in comparison with mice after the inhalation of nano-sized MnCl 2 aerosols. We ruled out the possibility that this reduction is owing to a lower transportation from epithelium to brain in the mole vole as intranasal instillations of MnCl 2 solution and hydrated nanoparticles of manganese oxide MnO · (H 2 O) x revealed similar uptake rates for both species. Together, we conclude that nasal geometry contributes to the protection of brain and lung from accumulation of air-dispersed particles in mole voles.
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11

Ismail, Husham Farouk, Elamir Abu Abaida Ali Osman, Ahmad Khaleel AL-Omari, and Olig Grigorovitsh Avrunin. "The Role of Paranasal Sinuses in the Aerodynamics of the Nasal Cavities." International Journal of Life Science and Medical Research 2, no. 3 (September 26, 2012): 52–55. http://dx.doi.org/10.5963/lsmr0203004.

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12

Faramarzi, Mohammad, Mohammad Hossein Baradaranfar, Omid Abouali, Saeid Atighechi, Goodarz Ahmadi, Pejman Farhadi, Erfan Keshavarzian, Nasim Behniafard, and Amin Baradaranfar. "Numerical Investigation of the Flow Field in Realistic Nasal Septal Perforation Geometry." Allergy & Rhinology 5, no. 2 (January 2014): ar.2014.5.0090. http://dx.doi.org/10.2500/ar.2014.5.0090.

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The computational fluid dynamics (CFD) are used to evaluate the physiological function of the nose. We evaluated the aerodynamics of the nasal cavity in a patient with septal perforation (SP), pre- and postvirtual repair. Three-dimensional nasal models were reconstructed, and then a wide range of the pressure drops and flow rates were analyzed. The airflow velocity is higher in the central region and is lower around the boundary of the SP. The air velocity in the SP increases as the pressure drop increases. Furthermore, at the anterior part of the SP, the shear stress is higher in the upper part. In addition, the repair of SP does not affect the total nasal airflow rate and the velocity contour patterns. The potential usage of the CFD technique as a predictive technique to explore the details and a preoperative assessment tool to help in clinical decision making in nasal surgery is emphasized.
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13

Nosova, YA V., O. H. Avrunin, N. O. Shushlyapyna, Ibrahim Yunuss Abdelkhamid, and Alofy Bender Aly Salekh. "Diagnostic significance of methods for determining nasal breathing disorders." Optoelectronic Information-Power Technologies 41, no. 1 (July 28, 2021): 47–58. http://dx.doi.org/10.31649/1681-7893-2021-41-1-47-58.

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In the diagnosis of nasal breathing disorders, the main instrumental diagnostic methods are optical endoscopy of the nose, X-ray computed spiral (or cone-beam) tomography of the nose and paranasal sinuses, as well as rhinomanometry. The statistics included 286 patients with nasal breathing disorders and a control group of 60 people. Patients were divided into two groups - with nasal breathing disorders of different nature and conditional norm (control group). The probability of error in detecting nasal breathing disorders is 0.27 (normalized Euclidean distance 1.82). Taking into account the addition of computed tomography data to the discrimination model, the diagnostic error decreases to 0.11 at a distance of 3.19. When rhinomanometry data are added to the model, the total normalized Euclidean distance increases to 3.96, and the probability of making a diagnostic decision, respectively, decreases to 0.05. Thus, rhinomanometric data make it possible to supplement the results of functional tests with information about changes in the architectonics of the nasal cavity by assessing the effect of anatomical structures on nasal aerodynamics and further reduce the likelihood of errors in diagnostic decisions when detecting disturbances in nasal breathing.
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14

Naughton, John P., Andrew Y. Lee, Eric Ramos, David Wootton, and Howard D. Stupak. "Effect of Nasal Valve Shape on Downstream Volume, Airflow, and Pressure Drop: Importance of the Nasal Valve Revisited." Annals of Otology, Rhinology & Laryngology 127, no. 11 (September 7, 2018): 745–53. http://dx.doi.org/10.1177/0003489418791597.

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Objectives: The relative importance of the nasal valve relative to the remainder of the nasal airway remains unknown. The goal of this article was to objectively measure the shape of the nasal inlet and its effect on downstream airflow and nasal cavity volume using a physical model and a physiologic flow model. Methods: A patient who had isolated nasal valve surgery and had pre- and postoperative computed tomography scans available for analysis was studied. Nasal inlet shape measurements, computational fluid dynamics, and nasal volume analysis were performed using the computed tomography data. In addition, a physical model was used to determine the effect of nasal obstruction on downstream soft tissue. Results: The postoperative shape of the nasal inlet was improved in terms of length and degree of tortuosity. Whereas the operated-on region at the nasal inlet showed an only 25% increase in cross-sectional area postoperatively, downstream nonoperated sites in the nasal cavity revealed increases in area ranging from 33% to 51%. Computational fluid dynamics analysis showed that airway resistance decreased by 42%, and pressure drop was reduced by 43%. Intraluminal mucosal expansion was found with nasal obstruction in the physical model. Conclusion: By decreasing the degree of bending and length at the nasal valve, inspiratory downstream nonoperated sites of the nasal cavity showed improvement in volume and airflow, suggesting that the nasal valve could play an oversized role in modulating the aerodynamics of the airway. This was confirmed with the physical model of nasal obstruction on downstream mucosa.
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15

Li, Lifeng, Hongrui Zang, Demin Han, Murugappan Ramanathan, Ricardo L. Carrau, and Nyall R. London. "Impact of a Concha Bullosa on Nasal Airflow Characteristics in the Setting of Nasal Septal Deviation: A Computational Fluid Dynamics Analysis." American Journal of Rhinology & Allergy 34, no. 4 (February 11, 2020): 456–62. http://dx.doi.org/10.1177/1945892420905186.

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Background A concha bullosa (CB) of the middle turbinate is frequently observed on the nondeviated side of patients with a nasal septal deviation (NSD). However, the impact of the CB on nasal airflow characteristics in patients with NSD has been incompletely defined. Objective The purpose of this study was to evaluate the impact of a CB in patients with NSD on nasal airflow characteristics using a computational fluid dynamics (CFD) approach. Methods Twenty patients with NSD and a unilateral CB of the middle turbinate on the nondeviated side (study group) were recruited. Another 20 patients with NSD without the formation of a CB (control group) were also enrolled. Using CFD, the maximal airflow velocity, nasal resistance, maximal wall shear stress, and minimal temperature in the bilateral nostrils of each group were assessed. Moreover, the volume of the nasal tract, surface area-to-volume ratio, and the total nasal resistance were compared between the study and control groups. Results In the study group, no significant differences of airflow dynamics between the bilateral nasal cavities were observed. In the control group, however, there were statistically significant differences for maximal airflow velocity, nasal resistance, maximal wall shear stress, and minimal airflow temperature between the bilateral nostrils. The surface area-to-volume ratio and total nasal resistance in the study group was significantly higher and the nasal volume was significantly decreased than that in the control group. Conclusion CB of the middle turbinate on the nondeviated side of patients with NSD rendered airflow characteristics more evenly distributed between the bilateral nostrils as assessed by CFD. From an aerodynamics perspective, a CB may represent a compensatory action to normalize airflow dynamics. However, a CB may also result in constriction of the ipsilateral nasal cavity.
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16

Shcherbakov, D. A., A. I. Kryukov, I. B. Popov, A. S. Krotova, T. S. Madaev, and V. V. Kokareva. "The role of computational aerodynamics of the nasal cavity in diagnostics of septal deviation." Russian Otorhinolaryngology 18, no. 4 (2019): 82–88. http://dx.doi.org/10.18692/1810-4800-2019-4-82-88.

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17

Shcherbakov, D. A., V. V. Kokareva, N. I. Cheremnykh, and T. A. Aleksanyan. "CFD simulation study of aerodynamics in nasal cavity in a case of septal perforation." Vestnik otorinolaringologii 85, no. 1 (2020): 64. http://dx.doi.org/10.17116/otorino20208501164.

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18

Li, Chengyu, Alexander A. Farag, Guillermo Maza, Sam McGhee, Michael A. Ciccone, Bhakthi Deshpande, Edmund A. Pribitkin, Bradley A. Otto, and Kai Zhao. "Investigation of the abnormal nasal aerodynamics and trigeminal functions among empty nose syndrome patients." International Forum of Allergy & Rhinology 8, no. 3 (November 22, 2017): 444–52. http://dx.doi.org/10.1002/alr.22045.

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19

Krivopalov, A. A., and P. A. Shamkina. "Role of decongestants in a complex therapy of acute infectious rhinitis." Meditsinskiy sovet = Medical Council, no. 16 (November 14, 2020): 80–85. http://dx.doi.org/10.21518/2079-701x-2020-16-80-85.

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Nowadays the problem of treating of acute respiratory viral infections, primarily manifested with the clinical picture of acute rhinitis, remains an important problem due to the high prevalence and variety of etiological factors of this disease. Pathogenesis of rhinitis, regardless of the etiology, includes the swelling of the nasal mucosa, the increase in nasal secretion, which blocks nasal breathing and significantly reduces the quality of life. In uncomplicated forms of acute infectious rhinitis, symptomatic treatment is traditionally used, including the elimination therapy and drugs for reducing the nasal mucosa swelling. Topical decongestants have a sympathomimetic effect, affect α1- and α2-adrenergic receptors and help to eliminate swelling of the nasal mucosa and improve nasal breathing, and as a result, restore the patency and aerodynamics of the airways, recover the drainage function of the paranasal sinuses and auditory tube. To date, the pharmaceutical market offers many intranasal decongestants that differ in the duration of exposure, frequency of use, the occurrence of side effects or adverse events. The article shows the pharmacological and pharmacokinetic characteristics of the drug xylometazoline, highlights the results of Russian and foreign studies that demonstrate the efficacy and good tolerability of xylometazoline with a short-term topical course of treatment. The conclusion is made about a good profile of the efficacy and safety of the drug and confirmed that in compliance with the recommendations for the frequency and duration of application, xylometazoline could be recommended for use in a complex symptomatic treatment of acute rhinitis in adults and children.
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20

Sagandykova, Nazym S., Ildar R. Fakhradiyev, Sreekar Reddy Sajjala, Saule A. Taukeleva, Dinara E. Shemetova, Timur M. Saliev, Shynar B. Tanabayeva, and Yong Zhao. "Patient-specific CFD simulation of aerodynamics for nasal pathology: a combined computational and experimental study." Computer Methods in Biomechanics and Biomedical Engineering: Imaging & Visualization 9, no. 5 (February 15, 2021): 470–79. http://dx.doi.org/10.1080/21681163.2020.1858968.

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21

Naumenko, Alexander, Lilia Krinichko, and Rezmak K.F. Mohammed. "Air exchange in the maxillary sinus in the postoperative period after maxillary sinusotomy through the inner and middle nasal airway." OTORHINOLARYNGOLOGY, no. 2(1) 2018 (June 11, 2018): 43–49. http://dx.doi.org/10.37219/2528-8253-2018-2-43.

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There are many computer models that describe the airflow in various anatomical variants and the pathology of the nasal cavity and paranasal sinuses. The data that describe the Reynolds number and airflow velocity in the different section of the nasal cavity of the patients with cyst of the maxillary sinus are very different. The results of operation of the maxillary sinusotomy through the middle nasal airway are disjointed and contradictory. There is also a little information of aerodynamics in the odontogenic pathology of the maxillary sinus. Purpose: Calculate airflow velocity in various sections of the nasal cavity, and air exchange in the maxillary sinus in patients with cysts of the maxillary sinus in the postoperative period after endonasalmaxillary sinusotomy through the lower and middle nasal airway. Material and methods: 112 patients with maxillary sinus cyst were examined. Patients were divided into three clinical groups. The first group, 41 people, included patients who had removed the cysts of the maxillary sinus through the lower nasal airway, as well as intact structures of the middle nasal passage remained. The second group included 38 patients who had removed the maxillary sinus cyst through the middle nasal airway. In the third group, were selected 33 patients, who had not been diagnosed with nasal and nasal sinus pathology, but they were examined by an ENT specialist before implantation of the teeth. Computer tomography of nasal sinuses was performed for all patients. The Planmeca Tomography, manufactured in Finland, was used, with the further processing of information using the software Romexis Viewer. Using the Romexis Viewer software and MeshLabit was measured the size of the anatomical structures of the nasal cavity and nasal sinuses, the calculation of air flow velocity at the airways of the nasal cavity, the calculation of the Reynolds number. To calculate the parameters of external respiration, all patients were examined for external respiration using a mask spirometer. Statistical processing of the obtained data was carried out using SPSS software 13. Results: The rate of air flow that passes through the nasal cavity on the inhalation and exhalation in the postoperative period in patients with cysts of the maxillary sinus that has undergone endonazal maxillary sinusotomy through the lower nasal airway, is statistically no different from those patients who had no pathology of the nasal cavity and nasal sinuses. The volume of air exchange in the case of removal maxillary cyst through the lower nasal airway does not statistically differ from the volume of air exchange in patients without pathology of the nasal cavity and nasal sinuses.
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22

Ryazantsev, S. V., M. A. Budkovaya, E. S. Artemyeva, and N. N. Khamgushkeeva. "Rhinosinusitis with nasal polyps: main aspects of anti-relapse therapy and recovery of nasal breathing." Medical Council, no. 20 (November 16, 2019): 13–18. http://dx.doi.org/10.21518/2079-701x-2019-20-13-18.

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Objective. This study was conducted to increase effectiveness of anti-relapse therapy of chronic rhinosinusitis with polyps to create a stable long-term remission in the long-term postoperative period.Patients and research methods. 60 patients with total spread of polyposis process in the nasal cavity and paranasal sinuses were examined. All patients underwent endoscopic polysinusotomy and 3 weeks after surgery, basic anti-relapse therapy of PRS in the form Of nasonex intranasal spray of 400 mcg/day for 6 months in combination with irrigation with isotonic salt solutions was prescribed. At the same time, 30 patients 1.5 months after polysinusotomy were additionally given a short course of systemic corticosteroid therapy with Methylprednisolone, starting at 20 mg/day in combination with Omeprazole at 20 mg /day for 14 days. Subjective assessment of the patients ‘condition was carried out by questionnaire, for objective diagnosis acoustic rhinometry and CT of the paranasal sinuses were used.Results. Simultaneous administration of a short course of corticosteroid therapy in combination with prolonged intranasal use of Nasonex spray in patients with nasal polyps in the postoperative period contributed to the most rapid subjective improvement of nasal breathing. The combined scheme in 27 (90%) subjects showed a statistically significant improvement in intra-nasal aerodynamics (p<0.05) 2 months after polysinusotomy according to the results of acoustic rhinometry, the average MPPS1 was 0.67 ± 0,04 cm2 before and after the decongestant test. In 13 patients (44,3%) who received only intranasal corticosteroids reactive edema from the nasal mucosa were more pronounced, which contributed to the formation of zones of pathological narrowing of the nasal flow and a decrease in МППС1 to 0.43 ± 0,04см2 to test with decongestant. 2 years after surgical treatment in patients undergoing a combined course of corticosteroid therapy in relation to patients receiving only monotherapy with intranasal corticosteroids, there was no recurrence of polyposis in 86.7% of cases (26 patients), against 66.7% (20 patients), receiving only intranasal corticosteroids.
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Moshkin, M. P., D. V. Petrovski, A. E. Akulov, A. V. Romashchenko, L. A. Gerlinskaya, V. L. Ganimedov, M. I. Muchnaya, et al. "Correction to ‘Nasal aerodynamics protects brain and lung from inhaled dust in subterranean diggers, Ellobius talpinus ’." Proceedings of the Royal Society B: Biological Sciences 282, no. 1817 (October 22, 2015): 20152308. http://dx.doi.org/10.1098/rspb.2015.2308.

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24

Subbotina, M. V., and V. S. Kokhanov. "Effect of nasal cavity and nasopharynx architectonic disorders on the paranasal sinus development and sinusitis." Russian Otorhinolaryngology 19, no. 5 (2020): 99–105. http://dx.doi.org/10.18692/1810-4800-2020-5-99-105.

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The structure of the paranasal sinuses (PNS) is characterized by pronounced variability and largely depends on the state of the intranasal architectonics, the violation of which may be a predisposing factor for the development of sinusitis. Leading among the disturbances in the architectonics of the nasal cavity and nasopharynx are the nasal septum deviation (NSD), concha bullosa (CB), hypertrophy of the inferior turbinates and pharyngeal tonsil. This review presents an analysis of modern data on the influence of the architectonics of the nasal cavity and nasopharynx on the development of PNS and the formation of inflammatory processes in them. Sources of information - databases Medline, Pubmed, Cochrane, E-library from 2004 to 2019. The search was carried out by keywords. Criteria for inclusion of articles in the review: assessment of multispiral computed tomography of SNP of patients in axial and coronary projections, presence of a control group, sample size of more than 50 people. In the presented review, it is noted that types 3 and 5 of DNP according to the classification of R. Mladina, along with contralateral CB and adenoids, can be predictors of the development of sinusitis. Information about the side of sinusitis formation in relation to the direction of the deformity of the nasal septum, about the effect of other violations of the architectonics of the nasal cavity on sinusitis and the size of the SNP remains controversial. The reasons for the contradictions are the use of different classifications of DNP, the underestimation of the complexes of anatomical anomalies and the mechanisms of aerodynamics of the sinuses, which determine the greater dependence of the volume and ventilation of the sinuses on expiration than on inspiration. Taking these positions into account, the question of the influence of the architectonics of the nasal cavity on the development of the paranasal sinuses and the formation of the inflammatory process in them requires further study.
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Chirkova, Katia, Patricia Basset, and Angélique Amelot. "Voiceless nasal sounds in three Tibeto-Burman languages." Journal of the International Phonetic Association 49, no. 1 (March 23, 2018): 1–32. http://dx.doi.org/10.1017/s0025100317000615.

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This paper focuses on two types of voiceless nasal sounds in Xumi, a Tibeto-Burman language: (i) the voiceless aspirated nasals // [] and // [], and (ii) the voiceless nasal glottal fricative []. We provide a synchronic description of these two types of sounds, and explore their similarities and differences. Xumi voiceless nasal consonants are described with reference to the voiceless nasal consonants // and // in Burmese and Kham Tibetan because Burmese voiceless nasals are the best described type of voiceless nasals, and are therefore used as a reference point for comparison; voiceless nasals in Kham Tibetan, which is in close contact with Xumi, represent a characteristic regional feature. The synchronic description is based on acoustic and aerodynamic measurements (the total duration of the target phonemes, the duration of the voiced period during the target phonemes, mean nasal and oral flow). Our study (i) contributes to a better understanding of voiceless nasals as a type of sound, (ii) provides a first-ever instrumental description (acoustic and aerodynamic) of the voiceless nasal glottal fricative [], as attested in a number of Tibeto-Burman languages of Southwest China, and (iii) suggests a possible phonetic basis for the observed dialectal and diachronic variation between voiceless nasals and [] in some Tibeto-Burman languages.
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Lou, Miao, Luyao Zhang, Jingbin Zhang, Ruiping Ma, Minjie Gong, Zhenzhen Hu, Simin Wang, Ya Zhang, and Guoxi Zheng. "Numerical Simulation of Nasal Airflow Aerodynamics, and Warming and Humidification in Models of Clival Chordoma Pre and Post-Endoscopic Endonasal Surgery." Respiratory Physiology & Neurobiology 291 (September 2021): 103693. http://dx.doi.org/10.1016/j.resp.2021.103693.

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Itzhak, Nadav, and David Greenblatt. "Aerodynamic factors affecting rebreathing in infants." Journal of Applied Physiology 126, no. 4 (April 1, 2019): 952–64. http://dx.doi.org/10.1152/japplphysiol.00784.2018.

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The rebreathing of expire air, with high carbon dioxide and low oxygen concentrations, has long been implicated in unexplained Sudden Infant Death Syndrome (SIDS) when infants are placed to sleep in a prone (facedown) position. This study elucidates the effect of the aerodynamic parameters Reynolds number, Strouhal number, and Froude number on the percentage of expired air that is reinspired (rebreathed). A nasal module was designed that served as a simplified geometric representation of infant nostrils and placed above a hard, flat surface. Quantitative and flow visualization experiments were performed to measure rebreathing, using water as the working medium, under conditions of dynamic similarity. Different anatomic (e.g., tidal volume, nostril diameter), physiological (e.g., breathing frequency), and environmental (e.g., temperature, distance from the surface) factors were considered. Increases in Strouhal number (simultaneously faster and shallower breathing) always produced higher rebreathed percentages, because rolled-up vortices in the vicinity of the nostrils had less time to move away by self-induction. Positively and negatively buoyant flows resulted in significant rebreathing. In the latter case, consistent with a warm environment and a high percentage of rebreathed CO2, denser gas pooled in the vicinity of the nostrils. Reynolds numbers below 200 also dramatically increased rebreathing because the expired gas pooled much closer to the nostrils. These results clearly elucidated how the prone position dramatically increases rebreathing by a number of different mechanisms. Furthermore, the results offer plausible explanations of why a high-temperature environment and low birthweight are SIDS risk factors. NEW & NOTEWORTHY A fundamentally new aerodynamics-based approach to the study of rebreathing of expired air in infants is presented. Rebreathing is implicated in unexplained Sudden Infant Death Syndrome (SIDS) when infants sleep in a prone position. This is the first time that aerodynamic parameters are systematically varied and their effects on rebreathing quantified. The study provides us with a deeper understanding of the effects of breathing frequency, tidal volume (birthweight) and environmental conditions.
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Wadhwa, Puneet, Hyon-Seok Jang, Se-Hyun Park, Hyoung-Ho Kim, and Eui-Seok Lee. "Computational Fluid Dynamic Analysis of the Pharyngeal Airway after Bimaxillary Orthognathic Surgery in Patients with Mandibular Prognathism." Processes 9, no. 1 (January 14, 2021): 152. http://dx.doi.org/10.3390/pr9010152.

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This study aimed to analyze pharyngeal airflow characteristics and their relationship with the skeletal movement of the maxilla and mandible after bimaxillary orthognathic surgery in patients with skeletal class III (mandibular prognathism) malocclusion. Cone-beam computed tomography (CBCT) was conducted before surgery (T0), immediately after surgery (T1), and at least six months after surgery (T2). Digital imaging and communications in medicine files were transferred to InVivo (Anatomage) software to measure the skeletal changes after surgery. The changes in the maxillary and mandibular position, tongue position, and hyoid bone position were analyzed. Patient-specific models were reconstructed using 3D-Doctor software. The models after converting to the stereolithography (STL) file for Ansys integrated computer engineering and manufacturing code for computational fluid dynamics (ICEM CFD), commercial software were used for calculating the geometry, pressure drop and adjusted pressure coefficient value. The total volume of the upper airway including nasal cavity was reduced by 23% immediately after surgery and recovered to 92.2% of the initial volume six months after surgery. The airflow computation analysis showed a decrease in the pressure drop values immediately after surgery and six months after surgery. The adjusted pressure coefficients were slightly different but the change was statistically insignificant. The airflow characteristics computed using the computational fluid dynamics were correlated to the surgical changes. The surgical changes can affect the aerodynamics of the pharyngeal airway. In clinical practice, this knowledge is useful for developing a suitable orthognathic surgery treatment plan.
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Durand, Marc, Jeremie Pourchez, Bruno Louis, Jean Francois Pouget, Daniel Isabey, Andre Coste, Jean Michel Prades, Philippe Rusch, and Michele Cottier. "Plastinated nasal model: a new concept of anatomically realistic cast." Rhinology journal 49, no. 1 (March 1, 2011): 30–36. http://dx.doi.org/10.4193/rhino09.187.

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BACKGROUND: For many years, researchers have been interested in investigating airflow and aerosol deposition in the nasal cavities. The nasal airways appear to be a complex geometrical system. Thus, in vitro experimental studies are frequently conducted with a more or less biomimetic nasal replica. AIM: This study is devoted to the development of an anatomically realistic nose model with bilateral nasal cavities, i.e. nasal anatomy, airway geometry and aerodynamic properties as close as possible to in vivo behaviour. METHODS: A specific plastination technique of cephalic extremities was developed by the Anatomy Laboratory at the Saint-Etienne University in the last 10 years. The plastinated models obtained were anatomically, geometrically and aerodynamically validated using several techniques (endoscopy, CT scans, acoustic rhinometry and rhinomanometry). RESULTS: Our plastination model exhibited a high level of anatomic quality, including a very good mucosa preservation. Aerodynamical and geometrical investigations highlighted a global behaviour of plastinated models perfectly in accordance with a nasal decongested healthy subject. CONCLUSIONS: The present plastination model provides a realistic cast of nasal airways, and may be a useful tool for nasal flow, drug delivery and aerosol deposition studies.
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Tucker, Benjamin V., and Natasha Warner. "What it means to be phonetic or phonological: the case of Romanian devoiced nasals." Phonology 27, no. 2 (July 21, 2010): 289–324. http://dx.doi.org/10.1017/s0952675710000138.

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Abstract phonological patterns and detailed phonetic patterns can combine to produce unusual acoustic results, but criteria for what aspects of a pattern are phonetic and what aspects are phonological are often disputed. Early literature on Romanian makes mention of nasal devoicing in word-final clusters (e.g. in /basm/ ‘fairy-tale’). Using acoustic, aerodynamic and ultrasound data, the current work investigates how syllable structure, prosodic boundaries, phonetic paradigm uniformity and assimilation influence Romanian nasal devoicing. It provides instrumental phonetic documentation of devoiced nasals, a phenomenon that has not been widely studied experimentally, in a phonetically underdocumented language. We argue that sound patterns should not be separated into phonetics and phonology as two distinct systems, but neither should they all be grouped together as a single, undifferentiated system. Instead, we argue for viewing the distinction between phonetics and phonology as a largely continuous multidimensional space, within which sound patterns, including Romanian nasal devoicing, fall.
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31

Andreassen, Meri L., Herbert A. Leeper, Duncan L. Macrae, and Ian R. Nicholson. "Aerodynamic, Acoustic, and Perceptual Changes following Adenoidectomy." Cleft Palate-Craniofacial Journal 31, no. 4 (July 1994): 263–70. http://dx.doi.org/10.1597/1545-1569_1994_031_0263_aaapcf_2.3.co_2.

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Fourteen children were seen prior to adenoidectomy and at 1 month, 3 months, and 6 months following surgery. On each visit, nasal airway resistance values, nasal cross-sectional area estimates, nasalance scores, and perceptual ratings of nasality were collected. These data were analyzed to identify changes that were related to the time of the test, and to the primary indication for surgery (nasal airway obstruction or recurrent infection). Results revealed significant reduction in nasal airway resistance and significant changes in nasalance following surgery. Perceptual changes were not significant. Clinical Implications of these findings are discussed.
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Chen, Xiao Bing, Heow Pueh Lee, Vincent Fook Hin Chong, and De Yun Wang. "Aerodynamic Characteristics inside the Rhino-Sinonasal Cavity after Functional Endoscopic Sinus Surgery." American Journal of Rhinology & Allergy 25, no. 6 (November 2011): 388–92. http://dx.doi.org/10.2500/ajra.2011.25.3669.

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Background The aim of this study was to evaluate effects of functional endoscopic sinus surgery (FESS) on transient nasal aerodynamic flow patterns using computational fluid dynamics (CFD) simulations. Methods A three-dimensional model of the nasal cavity was constructed from CT scans of a patient with FESS interventions on the right side of the nasal cavity. CFD simulations were then performed for unsteady aerodynamic flow modeling inside the nasal cavity as well as the sinuses. Results Comparisons of the local velocity magnitude and streamline distributions inside the left and right nasal cavity and maxillary sinus regions were presented. Because of the FESS procedures in the right nasal cavity, existences and distributions of local circulations (vortexes) were found to be significantly different for the same nasal airflow rate but at different acceleration, deceleration, or quiet phases in the maxillary sinus region on the FESS side. Because of inertia effects, local internal airflow with circulation existences was continuous throughout the whole respiration cycle. With a larger peak inspiration flow rate, the airflow intensity inside the enlarged maxillary sinus increased significantly. Possible outcomes on functional performances of the nose were also examined and discussed. Conclusion Surgical enlargements of natural ostium of the maxillary sinus will change the aerodynamic patterns inside the main nasal cavity and maxillary sinus regions, which may affect normal nasal physiological functions. Local inertia effects play more important roles for the internal nasal airflow pattern changes and thus such conventional FESS procedures should be carefully planned.
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Shosted, Ryan K. "Vocalic context as a condition for nasal coda emergence: aerodynamic evidence." Journal of the International Phonetic Association 36, no. 1 (May 18, 2006): 39–58. http://dx.doi.org/10.1017/s0025100306002350.

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Nasal coda emergence (NCE) (sometimes referred to as ‘restoration’) is the process by which a nasal vowel develops an excrescent nasal coda which may or may not have been present in an earlier form of the spoken language. NCE is operative in the Carioca (Rio de Janeiro) dialect of Brazilian Portuguese (CBP), an Ibero-Romance language with five phonemically nasal vowels. The output of NCE (in this language) is usually a velar nasal. It has been suggested that the process may be a function of tongue position (Hajek 1991: 262). To test the null hypothesis that NCE does not correlate with vowel height or anteriority, aerodynamic (nasal and oral flow) signals were obtained from three speakers of CBP. The speakers uttered words ending in nasal vowels while wearing a circumferentially-vented pneumotach split-flow air mask. For comparative purposes, parallel data were gathered from a Hindi and a French speaker as well. The maximum nasal percentage of total flow and the maximum real nasal flow (in ml/s) were measured for each token, averaged across vowels and, in the case of CBP, across speakers. For CBP, the null hypothesis is rejected, lending support to the alternative: vowel height and posteriority indeed condition the emergence of NCE. This suggests a role for the lowered velum and/or raised tongue body in the development of coda obstruents on nasal vowels.
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Avrunin, Oleg, Yana Nosova, Ibrahim Younouss Abdelhamid, Oleksandr Gryshkov, and Birgit Glasmacher. "USING 3D PRINTING TECHNOLOGY TO FULL-SCALE SIMULATION OF THE UPPER RESPIRATORY TRACT." Informatyka, Automatyka, Pomiary w Gospodarce i Ochronie Środowiska 9, no. 4 (December 15, 2019): 60–63. http://dx.doi.org/10.35784/iapgos.681.

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The project "Implementation of rapid prototyping for modelling the upper respiratory tract in normal and typical pathologies" investigates the urgent problem of improving the reliability of diagnosis and effectiveness of treatment of disorders of the nasal breathing. Possibilities of modern 3D-printing technology for creation of individual natural anatomical models of the upper respiratory tract and determination of their aerodynamic characteristics are considered. The characteristics of the laminar boundary layer of the air flow in the parietal region of the nasal cavity are investigated under different modes of breathing in normal and with typical disorders of the nasal breathing. The concept of investigation of the aerodynamic indices of the anatomical structures of the respiratory system by the results of test tests of individual full-scale 3D models, obtained by the data of spiral computed tomography, is being developed. Theoretical bases of the method of computer planning of restorative rhinosurgical interventions in patients with chronic diseases of the nasal cavity are grounded, based on the change of the configuration of the anatomical structures of the nasal cavity taking into account the aerodynamic parameters of respiration. Modern distance learning and testing tools are being created to demonstrate the technology developed, to provide theoretical knowledge, practical skills and to solve situational tasks for a wide range of specialists. Development and research of natural patterns of the upper respiratory tract allows for supplementing and expanding the knowledge about the aerodynamic characteristics of the nasal cavity, to make decisions about therapy in a short period of time. Experience of the Laboratory of the Institute for Multiphase Processes (IMP) of the Leibniz Universität Hannover (LUH) in the development and use of rapid prototyping capabilities in biotechnology will provide technical support to the project.
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Bezshapochny, Sergey B., Oleh G. Avrunin, Andrey V. Loburets, Valery V. Loburets, and Yuri A. Gasyuk. "Forecasting of functional results of septoplasty." OTORHINOLARYNGOLOGY, no. 4(3) 2020 (September 25, 2020): 67–72. http://dx.doi.org/10.37219/2528-8253-2020-4-67.

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Objective: to define the effectiveness of forecasting of the functional result of septoplasty. Materials and methods: forecasting based on endorhinoscopy data, spiral computed tomography, formation of a spatial segmented lofting model of nasal cavity, construction of an aerodynamic model based on a unified generalized voxel tomography of the upper respiratory tract and rhinomanometry, which were conducted in 28 patients. Results: it was found that the correction of various variants of the deviation of nasal septum in more than 80% of cases significantly reduces the aerodynamic nasal resistance. Forecasting at septoplasty allows to quantify functional results, which do not always coincide with the real ones. The introduction of more highly accurate innovative diagnostic methods in the future will improve the efficiency of forecasting in rhinosurgery
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Zajac, David J., and Robert Mayo. "Aerodynamic and Temporal Aspects of Velopharyngeal Function in Normal Speakers." Journal of Speech, Language, and Hearing Research 39, no. 6 (December 1996): 1199–207. http://dx.doi.org/10.1044/jshr.3906.1199.

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Aerodynamic and temporal characteristics of velopharyngeal function were determined for 42 adult male and female speakers. All subjects produced the word "hamper" at self-determined loudness levels and rates of speaking. Measurements of intraoral air pressure, nasal airflow, and estimates of velopharyngeal orifice size were obtained during production of the /m/ and /p/ segments. Volume measurements of nasal airflow were determined for the entire word, the /m/ segment, and the segments preceding /m/. Fifteen timing measures associated with the pressure-flow events of the nasal-plosive sequence were also determined. Results indicated that males generated significantly higher levels of peak intraoral air pressure than females during /p/. Male speakers also exhibited a significantly shorter interval in the rise of oral pressure associated with the /p/ segment. Male and female speakers, however, exhibited similar levels of anticipatory coarticulation as reflected by nasal air volume measurements. Finally, variability of selected measurements within speakers suggested that temporal aspects of velopharyngeal function were more constrained than aerodynamic aspects. The results are discussed relative to (a) sex differences in respiratory and velar function and (b) normative data for adult speakers.
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37

Cole, Philip. "Nasal Patency and Its Assessment." American Journal of Rhinology 1, no. 3 (September 1987): 135–39. http://dx.doi.org/10.2500/105065887781693448.

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The propagation of nasal airflow resistance and its indispensable role in the modification of inspiratory air is described. Aerodynamic features and principles of rhinomanometric techniques which are commonly involved in the assessment of nasal patency are outlined. The clinical value of rhinomanometry is discussed in the light of the Toronto experience with several thousand patients.
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Per G. Djupesland, Jose M. Chatkin,. "Aerodynamic Influences on Nasal Nitric Oxide Output Measurements." Acta Oto-Laryngologica 119, no. 4 (January 1999): 479–85. http://dx.doi.org/10.1080/00016489950181035.

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39

Svitlychnyi, Oleksandr. "Remote functional results of septoplasty performed taking into account the aerodynamic analysis of the nasal cavity." OTORHINOLARYNGOLOGY, no. 1(1) 2018 (March 27, 2018): 32–39. http://dx.doi.org/10.37219/2528-8253-2018-1-32.

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The problem of nasal breathing disorders occupies a leading place in otolaryngology. In modern conditions, insurance and evidence-based medicine is acquiring the urgency of searching for objective methods of investigating the function of nasal breathing at the stages of preoperative planning. The development of rhinomanometric methods of investigation makes it possible to increase the functional efficiency of septoplasty. Purposes: To develop a procedure for preoperative aerodynamic analysis of the nasal cavity on the basis of PARM and CT analysis and to evaluate the remote functional results of septoplasty performed taking into account the obtained data. Materials and methods: The article presents the results of a study of 160 patients who underwent septoplasty within 3 years. In the main group, a survey was carried out on the NOSE scale, rhinomanometric studies with a complex of functional samples and analysis of computer tomograms. Based on the data obtained, their surgical treatment was performed (84 patients). Further, the functional results of septoplasty in the main group were compared with the results in the group of patients who underwent septoplasty without taking into account aerodynamic and tomographic analysis (76 patients). Results: According to the results of a comparative analysis of the data of the state of the nasal breathing function, it is established that the above procedure allows more accurate estimation of the aerodynamic features of the nasal cavity and to determine the localization of pathological nasal resistance in the nasal breathing structure. In turn, this allows objectively to plan and conduct septoplasty, which positively affects its functional efficiency and reduces the risk of development of unsatisfactory results in the long term after the operation. Conclusion: When performing surgical interventions on the nose wall, taking into account the data of the anterior active rhinomatometry with the complex of functional tests and tomographic analysis, the total indicator for 3 years after the operation of unsatisfactory functional results was 3.57%, with a similar index of 13.16% in the course of operations without taking into account the above indicators (level of reliability р=0.0133<0,05).
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Zajac, David J. "The Nature of Nasal Fricatives: Articulatory-Perceptual Characteristics and Etiologic Considerations." Perspectives on Speech Science and Orofacial Disorders 25, no. 1 (July 2015): 17–28. http://dx.doi.org/10.1044/ssod25.1.17.

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Nasal fricatives (NFs) are unusual, maladaptive articulations used by children both with and without palatal anomalies to replace oral fricatives. Nasal fricatives vary in articulatory, aerodynamic, and acoustic-perceptual characteristics with two generally distinct types recognized. One type is produced with velopharyngeal (VP) constriction that results in turbulent nasal airflow and, frequently, tissue vibration (flutter) at the VP port. Trost (1981) described these as posterior NFs that have a distinctive snorting quality. A second type of NF is produced without significant VP constriction resulting in turbulent airflow generated at the anterior liminal valve of the nose. Of importance, both types are “active” alternative articulations in that the speaker occludes the oral cavity to direct all airflow through the nose (Harding & Grunwell, 1998). It is this oral gesture that differentiates NFs from obligatory (or passive) nasal air escape that may sound similar due to incomplete VP closure. The purpose of this article is to (1) describe the articulatory, aerodynamic, and acoustic-perceptual nature of NFs, and (2) propose a theoretical framework for the acquisition of NFs by children both with and without cleft palate.
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Bianco, Federico, Elena Pasini, Marcello Nutini, Xabier Murgia, Carolin Stoeckl, Martin Schlun, Uwe Hetzer, et al. "Extended Pharmacopeial Characterization of Surfactant Aerosols Generated by a Customized eFlow Neos Nebulizer Delivered through Neonatal Nasal Prongs." Pharmaceutics 12, no. 4 (April 2, 2020): 319. http://dx.doi.org/10.3390/pharmaceutics12040319.

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The delivery of nebulized medications to preterm infants during Non-Invasive Ventilation (NIV) remains an unmet clinical need. In this regard, the effective delivery of nebulized surfactant has been particularly investigated in preclinical and clinical studies. In this work, we investigated the feasibility of delivering nebulized surfactant through various commercially available nasal prong types. We first performed a compendial characterization of surfactant aerosols generated by the eFlow Neos nebulizer, customized to be used in neonates, determining the amount of surfactant delivered by the device as well as the aerodynamic characteristics of surfactant aerosols. Additionally, we extended the compendial characterization by testing the effect of different nasal prong types on the estimated lung dose using a realistic Continuous Positive Airway Pressure (CPAP) circuit that included a cast of the upper airways of a preterm neonate. The compendial characterization of surfactant aerosols delivered through different nasal prongs achieved relatively high delivered surfactant doses (in the range 63–74% of the nominal dose), with aerodynamic characteristics displaying mass median aerodynamic diameters ranging between 2.52 and 2.81 µm. Nevertheless, when using a representative in vitro setup mimicking NIV in a clinical setting, significant differences were observed in terms of the estimated lung dose accounting for up to two-fold differences (from 10% to 20% estimated lung deposition of the nominal dose) depending on the chosen nasal prong type. Considering that surfactant lung deposition rates are correlated with therapeutic efficacy, this study points out the relevance of choosing the appropriate NIV interface to maximize the lung dose of nebulized medications.
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42

Tachimura, Takashi, Hisanaga Hara, and Takeshi Wada. "Oral Air Pressure and Nasal Air Flow Rate on Levator Veli Palatini Muscle Activity in Patients Wearing a Speech Appliance." Cleft Palate-Craniofacial Journal 32, no. 5 (September 1995): 382–89. http://dx.doi.org/10.1597/1545-1569_1995_032_0382_oapana_2.3.co_2.

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This study was designed to determine if levator veli palatini muscle activity can be elicited by simultaneous changes in oral air pressure and nasal air flow when a speech appliance is in place. The speech appliances routinely worn by 15 subjects were each modified experimentally by drilling a hole in the vertical center of the pharyngeal bulb. The air flow rate into the nasal cavity through the opening in the bulb was altered by changing the circular area of the opening in the bulb from the occluded condition (Condition I), to circular area of 12.6 mm2 (4 mm in diameter; Condition II), and then to 38.5 mm2 (7 mm in diameter; Condition III). Electromyographic activity was measured from the levator veli palatini muscle with changes in nasal air flow rate and oral air pressure. Levator veli palatini muscle activity was correlated with changes in nasal air flow and oral air pressure. Increases in levator veli palatini muscle activity were associated with increases in nasal air flow rate compared to oral air pressure changes. The results indicated that aerodynamic variables of nasal air flow and oral air pressure might be involved in the neural control of speech production in individuals wearing a speech appliance, even if the subjects exhibit velopharyngeal incompetence without using a speech appliance. Also, the stimulating effect of bulb reduction therapy on velopharyngeal function might be achieved through the change in aerodynamic variables in association with the bulb reduction.
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43

Dalston, Rodger M. "Acoustic Assessment of the Nasal Airway." Cleft Palate-Craniofacial Journal 29, no. 6 (November 1992): 520–26. http://dx.doi.org/10.1597/1545-1569_1992_029_0520_aaotna_2.3.co_2.

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Instrumental assessment techniques are needed to acquire quantitative information concerning the form and function of the nasal cavity. Until recently, aerodynamic methods were virtually the only source of such information. Two additional instruments are now available that purport to provide information useful to clinicians interested in assessing nasal form and function. This paper describes both the Nasometer and the acoustic rhinometer. In addition, a more traditional measure involving acoustic analysis of nasal consonants is discussed. Both the known and potential benefits and limitations of each technique are discussed.
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Hinton, Virginia A., and Donald W. Warren. "Relationships between Integrated Oral-nasal Differential Pressure and Velopharyngeal Closure." Cleft Palate-Craniofacial Journal 32, no. 4 (July 1995): 306–10. http://dx.doi.org/10.1597/1545-1569_1995_032_0306_rbiond_2.3.co_2.

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Oral-nasal differential pressures are derived measures that incorporate both active (e.g., articulatory) and passive (e.g., nasal structure) components. This study was designed to examine integrated oral-nasal differential pressures in speakers with different levels of velopharyngeal closure. Integrated oral-nasal differential pressure data were obtained from 20 non cleft adults with normal speech and 166 speakers with repaired palatal clefts. Velopharyngeal competency for the cleft subjects, as determined by aerodynamic assessment, ranged from adequate to grossly incompetent. Results of the data analysis indicate that integrated pressures are not maintained at a consistent level across all groups. This lack of consistency across all degrees of velopharyngeal opening may reflect the flexibility, as well as structural limitations, of a speech pressure regulating system.
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45

Laine, Tellervo, Donald W. Warren, Rodger M. Dalston, W. Michael Hairfield, and Kathleen E. Morr. "Intraoral Pressure, Nasal Pressure and Airflow Rate in Cleft Palate Speech." Journal of Speech, Language, and Hearing Research 31, no. 3 (September 1988): 432–37. http://dx.doi.org/10.1044/jshr.3103.432.

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We have suggested that compensatory behaviors associated with cleft palate may be strategies developed for the purpose of satisfying the requirements of a speech regulating system. The purpose of the present study was to test this hypothesis in subjects demonstrating various degrees of velopharyngeal inadequacy. The pressure-flow technique was used to assess aerodynamic responses to a loss of velar resistance in 74 subjects compared to a control group of 137 subjects with adequate velopharyngeal closure. The results of this study demonstrate that as degree of inadequacy increased, airflow rate also increased. Although intraoral pressure fell as inadequacy increased, many subjects were able to maintain pressures above 3.0 cm H 2 0 by increasing airflow rate. Nasal pressure increased in proportion to the decrease in intraoral pressure While combined nasal plus oral pressure remained constant across groups. These findings suggest that a loss of resistance at the velar port is compensated by an increase in resistance at the nasal port. Airflow rate appears to be adjusted to total upper airway resistance. These findings support our contention that the speech system is constrained to meet aerodynamic requirements.
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46

Watanabe, Soiku, Yasuo Iwabuchi, and Shigeru Furuta. "Measurement of Aerodynamic Pattern in the Simulated Nasal Cavity by Laser Doppler Anemometry." American Journal of Rhinology 6, no. 5 (September 1992): 179–84. http://dx.doi.org/10.2500/105065892781874577.

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Using a polyethylene model, the pattern of airflow in the nasal cavity was studied with the flow rate measured by a laser Doppler anemometer. Airflow in the nasal cavity was arch shaped with the fastest flow occurring near the olfactory fissure. There was little flow in the middle meatus in the inspiratory phase, but reverse flow was observed in expiratory phase, where the flow rate was faster than in the inspiratory phase. These findings offer a rational explanation of such physiological functions as olfaction and the warming and humidification of inspired air.
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Zhang, Ya, Xudong Zhou, Miao Lou, Minjie Gong, Jingbin Zhang, Ruiping Ma, Luyao Zhang, et al. "Computational Fluid Dynamics (CFD) Investigation of Aerodynamic Characters inside Nasal Cavity towards Surgical Treatments for Secondary Atrophic Rhinitis." Mathematical Problems in Engineering 2019 (December 30, 2019): 1–8. http://dx.doi.org/10.1155/2019/6240320.

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Purpose. To use computational fluid dynamics (CFD) technology to fundamentally understand (1) the effect of surgical treatments on nasal physiology for secondary atrophic rhinitis and (2) the priority of operations. Subjects and Methods: With the aid of medical imaging and CFD modeling, three virtual operations (nasoseptal perforation repair, cavity narrowing, and a combination of both) were performed to analyze airflow, nasal resistance, and wall shear stress. Results. Compared with the cavity-narrowing virtual operation, nasal resistance was not significantly altered by septal perforation repair virtual operation. Airflow allocation changed with more air flowing through the olfactory area and less though the nasal floor after all operations, especially the cavity-narrowing operation. Wall shear stress at the original epistaxis area and the nasal floor was reduced after the cavity-narrowing operation. Conclusions. Simulation results suggest that the cavity-narrowing operation takes priority over septal perforation repair if a staged surgery approach is adopted. If only one operation can be chosen, the cavity-narrowing operation is better than the septal perforation repair. This work shows that CFD-based modeling may aid precision medicine.
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Andreassen, Meri L., Bonnie E. Smith, and Thomas W. Guyette. "Pressure-Flow Measurements for Selected Oral and Nasal Sound Segments Produced by Normal Adults." Cleft Palate-Craniofacial Journal 29, no. 1 (January 1992): 1–9. http://dx.doi.org/10.1597/1545-1569_1992_029_0001_pfmfso_2.3.co_2.

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Pressure-flow data are often used to provide information about the adequacy of velopharyngeal valving for speech. However, there is limited information available concerning simultaneous pressure-flow measurements for oral and nasal sound segments produced by normal speakers. This study provides normative pressure, flow, and velopharyngeal orifice area measurements for selected oral and nasal sound segments produced by 10 male and 10 female adult speakers. An aerodynamic categorization scheme of velopharyngeal function, including one typical category and three atypical categories (open, closed, and mixed) is proposed.
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49

Dalston, Rodger M., Donald W. Warren, and Eileen T. Dalston. "A Preliminary Study of Nasal Airway Patency and Its Potential Effect on Speech Performance." Cleft Palate-Craniofacial Journal 29, no. 4 (July 1992): 330–35. http://dx.doi.org/10.1597/1545-1569_1992_029_0330_apsona_2.3.co_2.

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The relationship between nasal airway size and articulatory performance was studied in a group of cleft palate patients. Articulation analysis revealed that children with bilateral cleft lip and palate were nearly twice as likely to manifest compensatory articulations as children with unilateral cleft lip and palate or with cleft palate only. When subjects were grouped according to speech performance, aerodynamic assessment indicated that children with compensatory articulations had significantly larger nasal cross-sectional areas than children without compensatory articulations. The findings suggest that children with comparatively large nasal airways may be at increased risk for developing abnormal speech patterns. If these findings are confirmed by further research, such children may be candidates for relatively early palate repair.
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50

Demasi, Rita, and Didier Demolin. "Acoustic and aerodynamic characteristics of nasal diphthongs in Brazilian Portuguese." Journal of the Acoustical Society of America 132, no. 3 (September 2012): 2002. http://dx.doi.org/10.1121/1.4755406.

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