Relationships among glottis opening, respiratory flow, and upper airway resistance in humans

Baier, H.; Wanner, Adam; Zarzecki, S.; Sackner, Marvin A.

doi:10.1152/jappl.1977.43.4.603

Cited by 75 publications

(59 citation statements)

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“…For example, the average area of the glottis aperture as measured by our image-based method with 10 healthy human subjects was 0.98 cm 2 . This estimation was in good agreement with that from computational calculation by Rigau et al 13 In addition, the change wave of the quanti¯ed area of glottis aperture opening as obtained by our imagebased assessment clearly revealed that the glottis aperture opened on inspiration and narrowed on expiration during quiet breathing, which was in agreement with previous visual observations reported by Baier et al 26 and Brancatisano et al 27 It should be noted that while the measurement was highly reproducible for a given individual, the variations between individual subjects were considerably large ($30%). These large variations could be in part due to the small sample size (n ¼ 10) used in this study, or the inherent di®erence in the airway anatomies between the individuals.…”

Section: Discussionsupporting

confidence: 92%

IMAGE-BASEDIN VIVOQUANTITATIVE ASSESSMENT OF HUMAN AIRWAY OPENING AND CONTRACTILITY BY FIBER OPTICAL NASOPHARYNGOSCOPY IN HEALTHY AND ASTHMATIC SUBJECTS

Deng

2013

J. Innov. Opt. Health Sci.

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Assessment of human airway lumen opening is important in diagnosing and understanding the mechanisms of airway dysfunctions such as the excessive airway narrowing in asthma and chronic obstructive pulmonary disease (COPD). Although there are indirect methods to evaluate the airway calibre, direct in vivo measurement of the airway calibre has not been commonly available. With recent advent of the°exible¯ber optical nasopharyngoscope with video recording it has become possible to directly visualize the passages of upper and lower airways. However, quantitative analysis of the recorded video images has been technically challenging. Here, we describe an automatic image processing and analysis method that allows for batch analysis of the images recorded during the endoscopic procedure, thus facilitates image-based quanti¯cation of the airway opening. Video images of the airway lumen of volunteer subject were acquired using ā ber optical nasopharyngoscope, and subsequently processed using Gaussian smoothing¯lter, threshold segmentation, di®erentiation, and Canny image edge detection, respectively. Thus the area of the open airway lumen was identi¯ed and computed using a predetermined converter of the image scale to true dimension of the imaged object. With this method we measured the opening/narrowing of the glottis during tidal breathing with or without making \Hee" sound or cough. We also used this method to measure the opening/narrowing of the primary bronchus of either healthy or asthmatic subjects in response to histamine and/or albuterol treatment, which also provided an indicator of the airway contractility. Our results demonstrate that the imagebased method accurately quanti¯ed the area change waveform of either the glottis or the bronchus as observed by using the optical nasopharygoscope. Importantly, the opening/narrowing of the airway lumen generally correlated with the air°ow and resistance of the airways, and could di®erentiate the level of airway contractility between the healthy and asthmatic This is an Open Access article published by World Scienti¯c Publishing Company. It is distributed under the terms of the Creative Commons Attribution 3.0 (CC-BY) License. Further distribution of this work is permitted, provided the original work is properly cited.

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Section: Discussionsupporting

confidence: 92%

IMAGE-BASEDIN VIVOQUANTITATIVE ASSESSMENT OF HUMAN AIRWAY OPENING AND CONTRACTILITY BY FIBER OPTICAL NASOPHARYNGOSCOPY IN HEALTHY AND ASTHMATIC SUBJECTS

Deng

2013

J. Innov. Opt. Health Sci.

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“…Larger Rrs,e than Rrs,i at baseline are in keeping with prior reports from the literature [2,4,5]. Lung volume, a major determinant of airway resistance, would be unlikely to play a significant role, provided the time-triggered signal sampling did not bias the computation of tidal volume, due to asymmetry of breathing flow between inspiration and expiration.…”

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confidence: 85%

“…Owing to the fact that measurements are performed during tidal breathing, the upper airway may significantly impact on the respiratory resistance (Rrs) [1,2]. The glottic aperture narrows during tidal expiration [3], contributing to Rrs being larger than in inspiration [2,4,5]. Acute bronchial obstruction promotes further laryngeal narrowing [6][7][8], which is expected to impact the Rrs measured during expiration.…”

mentioning

confidence: 99%

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Bronchial obstruction and reversibility in children: inspiratory or expiratory resistance?

Ioan¹,

Coutier²,

Bonabel³

et al. 2014

European Respiratory Journal

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“…Rrs showed significant flow dependence and Mch was associated with an increase in K1 and K2, which are both determined by Reynolds number [24]. The latter increases with induced airway obstruction, and turbulent flow extends to parts of the airways in which it was previously laminar [25].…”

Section: Discussionmentioning

confidence: 99%

Methacholine-induced volume dependence of respiratory resistance in preschool children

Marchal

Loos²,

Monin³

et al. 1999

Eur Respir J

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Enhanced negative volume dependence of airway resistance is associated with bronchoconstriction in tracheostomized paralysed open-chest animals. Significant upper airways responses may be associated with bronchoconstriction and could thereby alter the pattern of volume dependence in spontaneously breathing subjects. The aim of the study was to test whether volume dependence of respiratory resistance (Rrs) could be demonstrated in preschool children undergoing routine methacholine challenge.The volume dependence of respiratory oscillation resistance at 12 and 20 Hz (Rrs,12 and Rrs,20) was examined in eight 4±5.5-yr-old children showing a positive response to methacholine. Multiple linear regression analysis was also used to account for flow dependence during tidal breathing (Rrs,12 or Rrs,20=K1+K2|V'|+K3V).Rrs,12 and Rrs,20 yielded similar results. Negative volume dependence was present at baseline and significantly enhanced by methacholine (p<0.01). For instance, the mean SD inspiratory K3 at 20 Hz was -4.11.3 hPa . s . L -2 at baseline and -15.04.3 hPa . s . L -2 after methacholine, in which case it was also larger on expiration than on inspiration (p<0.05), possibly as a result of upper airway responses. A significant increase in the negative volume dependence of respiratory resistance may thus be shown in preschool children in response to methacholine. The volume dependence (K3) during inspiration may be particularly useful in detecting bronchoconstriction, because it is less likely to be affected by upper airway mechanisms than during expiration.

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Relationships among glottis opening, respiratory flow, and upper airway resistance in humans

Cited by 75 publications

References 0 publications

IMAGE-BASEDIN VIVOQUANTITATIVE ASSESSMENT OF HUMAN AIRWAY OPENING AND CONTRACTILITY BY FIBER OPTICAL NASOPHARYNGOSCOPY IN HEALTHY AND ASTHMATIC SUBJECTS

IMAGE-BASEDIN VIVOQUANTITATIVE ASSESSMENT OF HUMAN AIRWAY OPENING AND CONTRACTILITY BY FIBER OPTICAL NASOPHARYNGOSCOPY IN HEALTHY AND ASTHMATIC SUBJECTS

Bronchial obstruction and reversibility in children: inspiratory or expiratory resistance?

Methacholine-induced volume dependence of respiratory resistance in preschool children

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