scholarly journals A new nasal acoustic reflection technique to estimate pharyngeal cross-sectional area during sleep

2000 ◽  
Vol 88 (4) ◽  
pp. 1457-1466 ◽  
Author(s):  
J. Huang ◽  
N. Itai ◽  
T. Hoshiba ◽  
T. Fukunaga ◽  
K. Yamanouchi ◽  
...  
Keyword(s):  
Acoustic Waves ◽  
Nasal Septum ◽  
Cross Sectional Area ◽  
New Method ◽  
New Technique ◽  
Sectional Area ◽  
Cross Sectional ◽  
Acoustic Reflection ◽  
Nasal Cavities ◽  
Airway Model

The conventional acoustic reflection technique in which acoustic waves are launched through the mouth cannot be applied during sleep, nor can it be applied to the nasopharynx, which is the major site of occlusion in patients with obstructive sleep apnea syndrome. We propose a new technique of nasal acoustic reflection to measure pharyngeal cross-sectional areas including the nasopharynx. The acoustic waves are introduced simultaneously to both nostrils during spontaneous nasal breathing. A new algorithm takes into account the nasal septum with asymmetric nasal cavities on both sides and assumes prior knowledge of the cross-sectional area of the nasal cavities and the position of the nasal septum. This method was tested on an airway model with a septum and on healthy human subjects. The conventional technique gave inaccurate measurements for pharyngeal cross-sectional areas for an airway model with asymmetric branching, whereas the new technique measured them almost perfectly. The oro- and hypopharyngeal cross-sectional area measurements acquired by the new method were not different from those obtained by the conventional method in normal subjects. This new method can be used as a monitor of upper airway dimensions in nocturnal polysomnography.

A three-microphone acoustic reflection technique using transmitted acoustic waves in the airway

2013 ◽  
Vol 115 (8) ◽  
pp. 1119-1125 ◽  
Author(s):  
Yuki Fujimoto ◽  
Jyongsu Huang ◽  
Toshiharu Fukunaga ◽  
Ryo Kato ◽  
Mari Higashino ◽  
...  
Keyword(s):  
Acoustic Waves ◽  
Cross Sectional Area ◽  
Distance Functions ◽  
Sectional Area ◽  
Wave Tube ◽  
Cross Sectional ◽  
Reflected Waves ◽  
Acoustic Reflection ◽  
Obstructive Sleep ◽  
And Function

The acoustic reflection technique noninvasively measures airway cross-sectional area vs. distance functions and uses a wave tube with a constant cross-sectional area to separate incidental and reflected waves introduced into the mouth or nostril. The accuracy of estimated cross-sectional areas gets worse in the deeper distances due to the nature of marching algorithms, i.e., errors of the estimated areas in the closer distances accumulate to those in the further distances. Here we present a new technique of acoustic reflection from measuring transmitted acoustic waves in the airway with three microphones and without employing a wave tube. Using miniaturized microphones mounted on a catheter, we estimated reflection coefficients among the microphones and separated incidental and reflected waves. A model study showed that the estimated cross-sectional area vs. distance function was coincident with the conventional two-microphone method, and it did not change with altered cross-sectional areas at the microphone position, although the estimated cross-sectional areas are relative values to that at the microphone position. The pharyngeal cross-sectional areas including retropalatal and retroglossal regions and the closing site during sleep was visualized in patients with obstructive sleep apnea. The method can be applicable to larger or smaller bronchi to evaluate the airspace and function in these localized airways.

Changes in the parameters of nasal breathing and parameters of the upper respiratory tract during orthognathic operations in patients with II and III skeletal class of jaw anomalies

2020 ◽  
pp. 22-27
Author(s):  
S.Sh. Gammadaeva ◽  
M.I. Misirkhanova ◽  
A.Yu. Drobyshev
Keyword(s):  
Respiratory Tract ◽  
Nasal Cavity ◽  
Nasal Septum ◽  
Cross Sectional Area ◽  
Upper Respiratory Tract ◽  
Sectional Area ◽  
Nasal Breathing ◽  
Cross Sectional ◽  
Skeletal Class ◽  
Upper Respiratory

The study analyzed the functional parameters of nasal breathing, linear parameters of the nasal aperture, nasal cavity and nasopharynx, volumetric parameters of the upper airways in patients with II and III skeletal class of jaw anomalies before and after orthognathic surgery. The respiratory function of the nose was assessed using a rhinomanometric complex. According to rhinoresistometry data, nasal resistance and hydraulic diameter were assessed. According to the data of acoustic rhinometry, the minimum cross-sectional area along the internal valve, the minimum cross-sectional area on the head of the inferior turbinate and nasal septum and related parameters were estimated. According to the CBCT data, the state of the nasal septum, the inferior turbinates, the nasal aperture, the state of the nasal cavity, and the linear values of the upper respiratory tract (nasopharynx) were analyzed. The patients were divided into 4 groups according to the classification of the patency of the nasal passages by

Effect of position and lung volume on upper airway geometry

1987 ◽  
Vol 63 (1) ◽  
pp. 375-380 ◽  
Author(s):  
J. M. Fouke ◽  
K. P. Strohl
Keyword(s):  
Lung Volume ◽  
Supine Position ◽  
Upper Airway ◽  
Upright Position ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Position Change ◽  
Cross Sectional ◽  
Acoustic Reflection ◽  
Residual Capacity

The occurrence of upper airway obstruction during sleep and with anesthesia suggests the possibility that upper airway size might be compromised by the gravitational effects of the supine position. We used an acoustic reflection technique to image airway geometry and made 180 estimates of effective cross-sectional area as a function of distance along the airway in 10 healthy volunteers while they were supine and also while they were seated upright. We calculated z-scores along the airway and found that pharyngeal cross-sectional area was smaller in the supine than in the upright position in 9 of the 10 subjects. For all subjects, pharyngeal cross-sectional area was 23 +/- 8% smaller in the supine than in the upright position (P less than or equal to 0.05), whereas glottic and tracheal areas were not significantly altered. Because changing from the upright to the supine position causes a decrease in functional residual capacity (FRC), six of these subjects were placed in an Emerson cuirass, which was evacuated producing a positive transrespiratory pressure so as to restore end-expiratory lung volume to that seen before the position change. In the supine posture an increase in end-expiratory lung volume did not change the cross-sectional area at any point along the airway. We conclude that pharyngeal cross-sectional area decreases as a result of a change from the upright to the supine position and that the mechanism of this change is independent of the change in FRC.

Photometries: a new method of measuring the cross-sectional area of the subglottis

1992 ◽  
Vol 17 (2) ◽  
pp. 141-145 ◽  
Author(s):  
N. S. JONES ◽  
R. M. IRVING ◽  
G. R. FORD ◽  
A. BALAKRISHNAN ◽  
D. M. ALBERT
Keyword(s):  
Cross Sectional Area ◽  
New Method ◽  
Sectional Area ◽  
Cross Sectional ◽  
The Cross

A new method for analyzing data from continuous depth-sensing microindentation tests

1990 ◽  
Vol 5 (1) ◽  
pp. 123-126 ◽  
Author(s):  
D. L. Joslin ◽  
W. C. Oliver
Keyword(s):  
Surface Roughness ◽  
Elastic Modulus ◽  
Cross Sectional Area ◽  
New Method ◽  
Sectional Area ◽  
Depth Sensing ◽  
Cross Sectional ◽  
The Cross ◽  
Effect Of Surface

A new parameter, hardness/modulus2 (H/E2), has been derived from the equations used to calculate the hardness and elastic modulus from data taken during continuous depth-sensing microindentation tests. This paper discusses the use of this parameter to treat the data obtained from a sample whose surface roughness was of the same scale as the size of the indents. The resulting data were widely scattered. This scatter was reduced when the data were plotted in terms of H/E2 versus stiffness. The effect of surface roughness on the hardness and elastic modulus results is removed via stiffness measurements, provided single contacts are made between the indenter and the specimen. The function relating the cross-sectional area of the indenter versus the distance from its point is not required for calculation of H/E2, but the hardness and modulus cannot be determined separately. The parameter H/E2 indicates resistance to plastic penetration in this case.

Acoustic Rhinometric Assessment of the Nasal Valve

1997 ◽  
Vol 11 (5) ◽  
pp. 379-386 ◽  
Author(s):  
Renato Roithmann ◽  
Jerry Chapnik ◽  
Noe Zamel ◽  
Sergio Menna Barreto ◽  
Philip Cole
Keyword(s):  
Cross Section ◽  
Nasal Obstruction ◽  
Cross Sectional Area ◽  
Acoustic Rhinometry ◽  
Sectional Area ◽  
Nasal Valve ◽  
Cross Sectional ◽  
Nasal Cavities ◽  
Before And After ◽  
Valve Area

The aims of this study are to assess nasal valve cross-sectional areas in healthy noses and in patients with nasal obstruction after rhinoplasty and to evaluate the effect of an external nasal dilator on both healthy and obstructive nasal valves. Subjects consisted of (i) volunteers with no nasal symptoms, nasal cavities unremarkable to rhinoscopy and normal nasal resistance and (ii) patients referred to our clinic complaining of postrhinoplasty nasal obstruction. All subjects were tested before and after topical decongestion of the nasal mucosa and with an external nasal dilator. In 79 untreated healthy nasal cavities the nasal valve area showed two constrictions: the proximal constriction averaged 0.78 cm2 cross-section and was situated 1.18 cm from the nostril, the distal constriction averaged 0.70 cm2 cross-section at 2.86 cm from the nostril. Mucosal decongestion increased cross-sectional area of the distal constriction significantly (p < 0.0001) but not the proximal. External dilation increased cross-sectional area of both constrictions significantly (p < 0.0001). In 26 post-rhinoplasty obstructed nasal cavities, only a single constriction was detected, averaging 0.34 cm2 cross-section at 2.55 cm from the nostril and 0.4 cm2 at 2.46 cm from the nostril, before and after mucosal decongestion respectively. External dilation increased the minimum cross-sectional area to 0.64 cm2 in these nasal cavities (p < 0.0001). We conclude that the nasal valve area in patients with postrhinoplasty nasal obstruction is significantly smaller than in healthy nasal cavities as shown by acoustic rhinometry. Acoustic rhinometry objectively determines the structural and mucovascular components of the nasal valve area and external dilation is an effective therapeutical approach in the management of nasal valve obstruction.

Effect of Head Posture on Airflow and Pressure Behavior of Human Upper Airway During Snoring

2020 ◽  
Author(s):  
Junshi Wang ◽  
Pan Han ◽  
Ruixuan Tang ◽  
Hong Tang ◽  
Younghoon Kwon ◽  
...  
Keyword(s):  
Upper Airway ◽  
Cross Sectional Area ◽  
High Speed Photography ◽  
Sectional Area ◽  
Cross Sectional ◽  
Head Posture ◽  
Pressure Behavior ◽  
Pharyngeal Airway ◽  
Aerodynamic Pressure ◽  
Airway Model

Abstract Snoring is a common breathing disorder during sleep. It is hypothesized that head posture during sleep could change the bending angle and the cross-sectional area of the airway, which could cause changes in airflow and aerodynamic pressure during sleep. In this work, an experiment-driven computational study was conducted to examine the aerodynamics and pressure behavior in human upper airway during snoring. An anatomically accurate human upper airway model associated with a dynamic uvula was reconstructed from human magnetic resonance image (MRI) and high-speed photography. The airway bending at different head posture and the corresponding change in airway cross-sectional area are modeled based on measurements from literature. An immersed-boundary-method (IBM)-based direct numerical simulation (DNS) flow solver was adopted to simulate the corresponding unsteady flows of the bent airway model in all their complexity. Analyses were performed on vortex dynamics and pressure fluctuations in the pharyngeal airway. It was found that the vortex formation and aerodynamic pressure were significantly affected by the airway bending. A head-neck junction extension posture tends to facilitate the airflow through the upper human airway. Fast Fourier transformation (FFT) analysis of the pressure time history revealed the existence of higher order harmonics of base frequency with significant pressure amplitudes and energy intensities. The results of this study help better understand the pathology of snoring under the influence of head posture from an aerodynamic perspective.

Nasoantral window assessment by acoustic rhinometry

1994 ◽  
Vol 108 (7) ◽  
pp. 567-568 ◽  
Author(s):  
J. Marais ◽  
A. G. D. Maran
Keyword(s):  
Cross Sectional Area ◽  
Acoustic Rhinometry ◽  
Sectional Area ◽  
Cross Sectional ◽  
Nasal Cavities

AbstractTwenty-five patients who had each had inferior meatal antrostomies performed were endoscopically examined and assessed with acoustic rhinometry six weeks and six months after surgery. No significant increase in nasal cross-sectional area could be demonstrated at the site of the antrostomy in the post-operative cases, although the nasoantral window was found to be patent in 44 of the 50 nasal cavities.

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