Accuracy of Pressure-Flow Estimates of Velopharyngeal Orifice Size in an Analog Model and Human Subjects

1988 ◽  
Vol 31 (4) ◽  
pp. 537-548 ◽  
Author(s):  
Thomas W. Guyette ◽  
Mary A. Carpenter
Keyword(s):  
Nasal Cavity ◽  
Human Subjects ◽  
Nasal Resistance ◽  
Cavity Pressure ◽  
Analog Model ◽  
Pressure Flow ◽  
Sources Of Error ◽  
Potential Sources ◽  
Cover Plates ◽  
Orifice Size

This study examined the accuracy of pressure-flow estimates of velopharyngeal (V-P) orifice size as applied to an analog model and two human subjects. Accuracy was assessed under differing conditions of degree of nasal resistance and type of instrumental interface. Known V-P orifice openings were introduced in the model through use of cover plates and in the humans through use of modified nasopharyngeal obturators. Nasal resistances were altered with perforated nasal plugs. Instrumental interfaces differed principally in the method used to detect nasal cavity pressure. Measures were applied to the hydrokinetic equation to estimate V-P area values. Data from the analog model and the human subjects were comparable in many respects. In low nasal resistance, area estimates were reasonably accurate regardless of the interface utilized. In high nasal resistance error typically increased, although not equally across interface types. Potential sources of error are identified and discussed.

scholarly journals POTENTIAL SOURCES OF ERROR IN CORONARY ARTERIOGRAPHY

1975 ◽  
Vol 124 (3) ◽  
pp. 386-393 ◽  
Author(s):  
DAVID C. LEVIN ◽  
HAROLD A. BALTAXE ◽  
THOMAS A. SOS
Keyword(s):  
Coronary Arteriography ◽  
Sources Of Error ◽  
Potential Sources

Effect of Septal Perforations on Measures of Nasal Resistance

1997 ◽  
Vol 34 (2) ◽  
pp. 129-134 ◽  
Author(s):  
Thomas W. Guyette ◽  
Bonnie E. Smith
Keyword(s):  
Outcome Measures ◽  
Repeated Measures ◽  
Dependent Measure ◽  
Nasal Resistance ◽  
Septal Perforation ◽  
Analog Model ◽  
Repeated Measures Anova ◽  
Nominal Scale ◽  
Independent Variables ◽  
Septal Perforations

Objective The purpose of this investigation was to determine the effect of septal perforations on posterior and anterior rhinomanometric measures of nasal resistance In an analog model. Design The data were analyzed using a repeated-measures ANOVA. Nasal resistance was the dependent variable, while type of rhinomanometry, septal perforation size, and position of resistance (proximal vs. distal) were nominal scale independent variables. Participants The analog model used in this study was similar to that described by Warren and Devereux (1966), except that the nasal cavities of the model were modified to create septal perforations. Outcome Measures The main dependent measure was nasal resistance. Results An important finding of this investigation was that septal perforations resulted in large differences (> 3 cm H2O/L/sec) between posterior and anterior nasal resistance values in the bilateral proximal resistor condition. Conclusions Anterior rhinomanometry may underestimate true nasal resistance when a septal perforation Is present, because the septal perforation prevents accurate measurement of nasopharyngeal pressure. Posterior rhinomanometric measures should accurately reflect nasal resistance despite septal perforations, because the perforation does not invalidate the estimate of nasopharyngeal pressure.

scholarly journals Novel Use of Vitamin B2 as a Fluorescent Tracer in Aerosol and Droplet Contamination Models in Otolaryngology

2020 ◽  
pp. 000348942094958
Author(s):  
Edward S. Sim ◽  
Harish Dharmarajan ◽  
Devi Sai Sri Kavya Boorgu ◽  
Lindsey Goyal ◽  
Michael Weinstock ◽  
...  
Keyword(s):  
Nasal Cavity ◽  
Fluorescent Dyes ◽  
Uv Light ◽  
Human Subjects ◽  
Particle Dispersion ◽  
Mitigation Measures ◽  
Dispersion Pattern ◽  
Vitamin B2 ◽  
Fluorescent Tracers ◽  
Fluorescent Tracer

Objective: During the COVID-19 era, a reliable method for tracing aerosols and droplets generated during otolaryngology procedures is needed to accurately assess contamination risk and to develop mitigation measures. Prior studies have not investigated the reliability of different fluorescent tracers for the purpose of studying aerosols and small droplets. Objectives include (1) comparing vitamin B2, fluorescein, and a commercial fluorescent green dye in terms of particle dispersion pattern, suspension into aerosols and small droplets, and fluorescence in aerosolized form and (2) determining the utility of vitamin B2 as a fluorescent tracer coating the aerodigestive tract mucosa in otolaryngology contamination models. Methods: Vitamin B2, fluorescein, and a commercial fluorescent dye were aerosolized using a nebulizer and passed through the nasal cavity from the trachea in a retrograde-intubated cadaveric head. In another scenario, vitamin B2 was irrigated to coat the nasal cavity and nasopharyngeal mucosa of a cadaveric head for assessment of aerosol and droplet generation from endonasal drilling. A cascade impactor was used to collect aerosols and small droplets ≤14.1 µm based on average aerodynamic diameter, and the collection chambers were visualized under UV light. Results: When vitamin B2 was nebulized, aerosols ≤5.4 µm were generated and the collected particles were fluorescent. When fluorescein and the commercial water tracer dye were nebulized, aerosols ≤8.61 µm and ≤2.08 µm respectively were generated, but the collected aerosols did not appear visibly fluorescent. Endonasal drilling in the nasopharynx coated with vitamin B2 irrigation yielded aerosols ≤3.30 µm that were fluorescent under UV light. Conclusion: Vitamin B2’s reliability as a fluorescent tracer when suspended in aerosols and small droplets ≤14.1 µm and known mucosal safety profile make it an ideal compound compared to fluorescein and commercial water-based fluorescent dyes for use as a safe fluorescent tracer in healthcare contamination models especially with human subjects.

scholarly journals POTENTIAL SOURCES OF ERROR IN CORONARY ARTERIOGRAPHY

1975 ◽  
Vol 124 (3) ◽  
pp. 378-385 ◽  
Author(s):  
DAVID C. LEVIN ◽  
HAROLD A. BALTAXE ◽  
JACK G. LEE ◽  
THOMAS A. SOS
Keyword(s):  
Coronary Arteriography ◽  
Sources Of Error ◽  
Potential Sources

scholarly journals Effect of rapid maxillary expansion on the dimension of the nasal cavity and on facial morphology assessed by acoustic rhinometry and rhinomanometry

2012 ◽  
Vol 17 (4) ◽  
pp. 129-133 ◽  
Author(s):  
Carla Enoki Itikawa ◽  
Fabiana Cardoso Pereira Valera ◽  
Mírian Aiko Nakane Matsumoto ◽  
Wilma Terezinha Anselmo Lima
Keyword(s):  
Nasal Cavity ◽  
Nasal Bone ◽  
Inferior Turbinate ◽  
Rapid Maxillary Expansion ◽  
Mouth Breathing ◽  
Acoustic Rhinometry ◽  
Facial Morphology ◽  
Nasal Resistance ◽  
Maxillary Expansion ◽  
Cross Sectional

OBJECTIVE: To assess the effects of rapid maxillary expansion on facial morphology and on nasal cavity dimensions of mouth breathing children by acoustic rhinometry and computed rhinomanometry. METHODS: Cohort; 29 mouth breathing children with posterior crossbite were evaluated. Orthodontic and otorhinolaryngologic documentation were performed at three different times, i.e., before expansion, immediately after and 90 days following expansion. RESULTS: The expansion was accompanied by an increase of the maxillary and nasal bone transversal width. However, there were no significant differences in relation to mucosal area of the nose. Acoustic rhinometry showed no difference in the minimal cross-sectional area at the level of the valve and inferior turbinate between the periods analyzed, although rhinomanometry showed a statistically significant reduction in nasal resistance right after expansion, but were similar to pre-treatment values 90 days after expansion. CONCLUSION: The maxillary expansion increased the maxilla and nasal bony area, but was inefficient to increase the nasal mucosal area, and may lessen the nasal resistance, although there was no difference in nasal geometry. Significance: Nasal bony expansion is followed by a mucosal compensation.

scholarly journals Safety and Pharmacokinetics of Intranasally Administered Heparin

2021 ◽  
Author(s):  
Hannah M. Harris ◽  
Katherine L. Boyet ◽  
Hao Liu ◽  
Rohini Dwivedi ◽  
Nicole M. Ashpole ◽  
...  
Keyword(s):  
Platelet Count ◽  
Nasal Cavity ◽  
In Vivo Imaging ◽  
Human Subjects ◽  
International Normalized Ratio ◽  
Sulfated Polysaccharides ◽  
Two Phase ◽  
Healthy Human ◽  
Serious Adverse Events

Purpose Intranasally administered unfractionated heparin (UFH) and other sulfated polysaccharides are potential prophylactics for COVID-19. The purpose of this research was to measure the safety and pharmacokinetics of clearance of intranasally administered UFH solution from the nasal cavity. Methods Double-blinded daily intranasal dosing in C57Bl6 mice with four doses (60 ng to 60 ug) of UFH was carried out for fourteen consecutive days, with both blood coagulation measurements and subject adverse event monitoring. The pharmacokinetics of fluorescent-labeled UFH clearance from the nasal cavity were measured in mice by in vivo imaging. Intranasal UFH at 2000 U/day solution with nasal spray device was tested for safety in a small number of healthy human subjects. Results UFH showed no evidence of toxicity in mice at any dose measured. No significant changes were observed in activated partial thromboplastin time (aPTT), platelet count, or frequency of minor irritant events over vehicle-only control. Human subjects showed no significant changes in aPTT time, international normalized ratio (INR), or platelet count over baseline measurements. No serious adverse events were observed. In vivo imaging in a mouse model showed a two-phase clearance of UFH from the nasal cavity. After 12 hours, 2.1% of the initial administered UFH remained in the nasal cavity, decaying to background levels after 24 hours. Conclusions UFH showed no toxic effects for extended daily intranasal dosing in mice as well as humans. The clearance kinetics of intranasal heparin solution from the nasal cavity indicates potentially protective levels for up to 12 hours after dosing.

Sign in / Sign up

Export Citation Format

Share Document