scholarly journals Clinical analysis of the “small plateau” sign on the flow-volume curve followed by deep learning automated recognition

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Yimin Wang ◽  
Wenya Chen ◽  
Yicong Li ◽  
Changzheng Zhang ◽  
Lijuan Liang ◽  
...  
Keyword(s):  
Airway Hyperresponsiveness ◽  
Upper Airway ◽  
Clinical Analysis ◽  
Flow Volume ◽  
Automated Recognition ◽  
Volume Curve ◽  
Flow Volume Curve ◽  
Relationship Of ◽  
The Relationship ◽  
Airway Abnormalities

Abstract Background Small plateau (SP) on the flow-volume curve was found in parts of patients with suspected asthma or upper airway abnormalities, but it lacks clear scientific proof. Therefore, we aimed to characterize its clinical features. Methods We involved patients by reviewing the bronchoprovocation test (BPT) and bronchodilator test (BDT) completed between October 2017 and October 2020 to assess the characteristics of the sign. Patients who underwent laryngoscopy were assigned to perform spirometry to analyze the relationship of the sign and upper airway abnormalities. SP-Network was developed to recognition of the sign using flow-volume curves. Results Of 13,661 BPTs and 8,168 BDTs completed, we labeled 2,123 (15.5%) and 219 (2.7%) patients with the sign, respectively. Among them, there were 1,782 (83.9%) with the negative-BPT and 194 (88.6%) with the negative-BDT. Patients with SP sign had higher median FVC and FEV1% predicted (both P < .0001). Of 48 patients (16 with and 32 without the sign) who performed laryngoscopy and spirometry, the rate of laryngoscopy-diagnosis upper airway abnormalities in patients with the sign (63%) was higher than those without the sign (31%) (P = 0.038). SP-Network achieved an accuracy of 95.2% in the task of automatic recognition of the sign. Conclusions SP sign is featured on the flow-volume curve and recognized by the SP-Network model. Patients with the sign are less likely to have airway hyperresponsiveness, automatic visualizing of this sign is helpful for primary care centers where BPT cannot available.

Flow-volume curve changes in patients with obstructive sleep apnoea and brief upper airway dysfunction

Respirology ◽  
2000 ◽  
Vol 5 (1) ◽  
pp. 11-18 ◽  
Author(s):  
Alastair H Campbell ◽  
Paul A Guy ◽  
Peter D Rochford ◽  
Christopher J Worsnop ◽  
Robert J Pierce
Keyword(s):  
Obstructive Sleep Apnoea ◽  
Upper Airway ◽  
Sleep Apnoea ◽  
Flow Volume ◽  
Volume Curve ◽  
Obstructive Sleep ◽  
Flow Volume Curve

Physiologic Differentiation of Upper and Lower Airway Obstruction

1977 ◽  
Vol 86 (5) ◽  
pp. 630-632 ◽  
Author(s):  
Frank F. Davidson ◽  
George W. Burke
Keyword(s):  
Airway Obstruction ◽  
Upper Airway ◽  
Lower Airway ◽  
Flow Volume ◽  
Initial Part ◽  
Maximal Flow ◽  
Volume Curve ◽  
Flow Volume Curve ◽  
Lower Airways ◽  
Lower Airway Obstruction

Usual lower airway obstruction and fixed upper airway obstruction can be differentiated physiologically by means of the flow-volume curve. Normally, maximal flow decreases nearly linearly as lung volume decreases during expiration. In lower airway obstruction, this decrease is greatest at the beginning of expiration resulting in a curve that is concave upward. In fixed obstruction (stenosis) flow is constant throughout the initial part of forced maximal expiration and throughout virtually all of inspiration. This results in a plateau or flat curve which is characteristic and different from the curve in obstruction of lower airways. Cases in which this differentiation is clinically important are discussed.

scholarly journals Flow volume curve: A diagnostic tool in extrathoracic airway obstruction

2020 ◽  
Vol 36 (4) ◽  
Author(s):  
Thamir Al-Khlaiwi
Keyword(s):  
Airway Obstruction ◽  
Diagnostic Tool ◽  
Upper Airway ◽  
Lung Pathology ◽  
Flow Volume ◽  
Creative Commons ◽  
Flow Volume Loop ◽  
Volume Curve ◽  
Flow Volume Curve ◽  
Extrathoracic Airway

The flow-volume loop (F/V-loop) is a presentation of inhalation and exhalation of air stream volume during inspiration and expiration. It demonstrates the obstructive, restrictive and mixed pattern lung pathology. Flow-volume loop has been extensively used for evaluating the severity, progression and resolution of various causes of upper-airway conditions. doi: https://doi.org/10.12669/pjms.36.4.2283 How to cite this:Al-Khlaiwi T. Flow volume curve: A diagnostic tool in extrathoracic airway obstruction. Pak J Med Sci. 2020;36(4):---------.  doi: https://doi.org/10.12669/pjms.36.4.2283 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Severe Upper Airway Obstruction Caused by Bullous Pemphigoid: Diagnostic Usefulness of the Flow-Volume Curve

1982 ◽  
Vol 90 (1) ◽  
pp. 20-24 ◽  
Author(s):  
Carl Hallenborg ◽  
Lee D. Rowe ◽  
Cordon Gamsu ◽  
Homer A. Boushey ◽  
Jeffrey A. Golden
Keyword(s):  
Airway Obstruction ◽  
Bullous Pemphigoid ◽  
Upper Airway ◽  
Upper Airway Obstruction ◽  
Oxygen Mixture ◽  
Flow Volume ◽  
Axial Tomography ◽  
Volume Curve ◽  
Maximum Expiratory Flow ◽  
Flow Volume Curve

The site and severity of upper airway obstruction were accurately determined by analysis of the flow-volume curve obtained from a dyspneic patient with bullous pemphigoid. The limitation of maximum inspiratory flow to 0.5 L/s and of maximum expiratory flow to 0.7 L/s over most of the vital capacity suggested that the lumen of the extrathoracic trachea was narrowed to a diameter of 3 mm. The marked improvement in flow with the patient breathing a helium-oxygen mixture further confirmed that flow was limited in a large central airway. The predictions made from analysis of the flow-volume curve were confirmed by fiberoptic bronchoscopic examination and by computerized axial tomography, which revealed severe supraglottic obstruction. After a tracheostomy was performed, maximal inspiratory and expiratory flows were normal.

Analysis of Maximum Expiratory Flow Volume Curves Using Canonical Correlation Analysis

1985 ◽  
Vol 24 (02) ◽  
pp. 91-100 ◽  
Author(s):  
W. van Pelt ◽  
Ph. H. Quanjer ◽  
M. E. Wise ◽  
E. van der Burg ◽  
R. van der Lende
Keyword(s):  
Correlation Analysis ◽  
Canonical Correlation Analysis ◽  
Canonical Correlation ◽  
Flow Volume ◽  
Non Linear ◽  
Maximum Expiratory Flow ◽  
Expiratory Flow ◽  
Relationship Of ◽  
The Relationship ◽  
Age And Sex

SummaryAs part of a population study on chronic lung disease in the Netherlands, an investigation is made of the relationship of both age and sex with indices describing the maximum expiratory flow-volume (MEFV) curve. To determine the relationship, non-linear canonical correlation was used as realized in the computer program CANALS, a combination of ordinary canonical correlation analysis (CCA) and non-linear transformations of the variables. This method enhances the generality of the relationship to be found and has the advantage of showing the relative importance of categories or ranges within a variable with respect to that relationship. The above is exemplified by describing the relationship of age and sex with variables concerning respiratory symptoms and smoking habits. The analysis of age and sex with MEFV curve indices shows that non-linear canonical correlation analysis is an efficient tool in analysing size and shape of the MEFV curve and can be used to derive parameters concerning the whole curve.

Dynamic mechanisms determine functional residual capacity in mice, Mus musculus

1979 ◽  
Vol 46 (5) ◽  
pp. 867-871 ◽  
Author(s):  
A. Vinegar ◽  
E. E. Sinnett ◽  
D. E. Leith
Keyword(s):  
Tidal Volume ◽  
Functional Residual Capacity ◽  
Flow Volume ◽  
Linear Portion ◽  
Volume Curve ◽  
Flow Volume Curve ◽  
Residual Capacity ◽  
Expiratory Flow ◽  
The Difference ◽  
Pentobarbital Sodium Anesthesia

Awake mice (22.6--32.6 g) were anesthetized intravenously during head-out body plethysmography. One minute after pentobarbital sodium anesthesia, tidal volume had fallen from 0.28 +/- 0.04 to 0.14 +/- 0.02 ml and frequency from 181 +/- 20 to 142 +/- 8. Functional residual capacity (FRC) decreased by 0.10 +/- 0.02 ml. Expiratory flow-volume curves were linear, highly repeatable, and submaximal over substantial portions of expiration in awake and anesthetized mice; and expiration was interrupted at substantial flows that abruptly fell to and crossed zero as inspiration interrupted relaxed expiration. FRC is maintained at a higher level in awake mice due to a higher tidal volume and frequency coupled with expiratory braking (persistent inspiratory muscle activity or increased glottal resistance). In anesthetized mice, the absence of braking, coupled with reductions in tidal volume and frequency and a prolonged expiratory period, leads to FRCs that approach relaxation volume (Vr). An equation in derived to express the difference between FRC and Vr in terms of the portion of tidal volume expired without braking, the slope of the linear portion of the expiratory flow-volume curve expressed as V/V, the time fraction of one respiratory cycle spent in unbraked expiration, and respiratory frequency.

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