scholarly journals Non-invasive quantification of airflow obstruction severity

2018 ◽  
Vol 27 ◽  
pp. e03_12765
Keyword(s):  
Airflow Obstruction ◽  
Non Invasive ◽  
Obstruction Severity

scholarly journals Delay of airway epithelial wound repair in COPD is associated with airflow obstruction severity

2014 ◽  
Vol 15 (1) ◽  
Author(s):  
Jeanne-Marie Perotin ◽  
Damien Adam ◽  
Juliette Vella-Boucaud ◽  
Gonzague Delepine ◽  
Sebastian Sandu ◽  
...  
Keyword(s):  
Wound Repair ◽  
Airflow Obstruction ◽  
Airway Epithelial ◽  
Obstruction Severity

scholarly journals The Peak Index: Spirometry Metric for Airflow Obstruction Severity and Heterogeneity

2019 ◽  
Vol 16 (8) ◽  
pp. 982-989 ◽  
Author(s):  
Surya P. Bhatt ◽  
Sandeep Bodduluri ◽  
Vrishank Raghav ◽  
Nirav R. Bhakta ◽  
Carla G. Wilson ◽  
...  
Keyword(s):  
Airflow Obstruction ◽  
Obstruction Severity

scholarly journals Quantifying the magnitude of pharyngeal obstruction during sleep using airflow shape

2019 ◽  
Vol 54 (1) ◽  
pp. 1802262 ◽  
Author(s):  
Dwayne L. Mann ◽  
Philip I. Terrill ◽  
Ali Azarbarzin ◽  
Sara Mariani ◽  
Angelo Franciosini ◽  
...  
Keyword(s):  
Gold Standard ◽  
Airflow Obstruction ◽  
Sleep Apnoea ◽  
Shape Features ◽  
Sleep Study ◽  
Shape Information ◽  
Obstructive Sleep ◽  
Ventilatory Drive ◽  
Nasal Pressure ◽  
Obstruction Severity

Rationale and objectivesNon-invasive quantification of the severity of pharyngeal airflow obstruction would enable recognition of obstructiveversuscentral manifestation of sleep apnoea, and identification of symptomatic individuals with severe airflow obstruction despite a low apnoea–hypopnoea index (AHI). Here we provide a novel method that uses simple airflow-versus-time (“shape”) features from individual breaths on an overnight sleep study to automatically and non-invasively quantify the severity of airflow obstruction without oesophageal catheterisation.Methods41 individuals with suspected/diagnosed obstructive sleep apnoea (AHI range 0–91 events·h−1) underwent overnight polysomnography with gold-standard measures of airflow (oronasal pneumotach: “flow”) and ventilatory drive (calibrated intraoesophageal diaphragm electromyogram: “drive”). Obstruction severity was defined as a continuous variable (flow:drive ratio). Multivariable regression used airflow shape features (inspiratory/expiratory timing, flatness, scooping, fluttering) to estimate flow:drive ratio in 136 264 breaths (performance based on leave-one-patient-out cross-validation). Analysis was repeated using simultaneous nasal pressure recordings in a subset (n=17).ResultsGold-standard obstruction severity (flow:drive ratio) varied widely across individuals independently of AHI. A multivariable model (25 features) estimated obstruction severity breath-by-breath (R2=0.58versusgold-standard, p<0.00001; mean absolute error 22%) and the median obstruction severity across individual patients (R2=0.69, p<0.00001; error 10%). Similar performance was achieved using nasal pressure.ConclusionsThe severity of pharyngeal obstruction can be quantified non-invasively using readily available airflow shape information. Our work overcomes a major hurdle necessary for the recognition and phenotyping of patients with obstructive sleep disordered breathing.

Lung Function Decline in Male Heavy Smokers Relates to Baseline Airflow Obstruction Severity

CHEST Journal ◽  
2012 ◽  
Vol 142 (6) ◽  
pp. 1530-1538 ◽  
Author(s):  
Firdaus A.A. Mohamed Hoesein ◽  
Pieter Zanen ◽  
H. Marike Boezen ◽  
Harry J.M. Groen ◽  
Bram van Ginneken ◽  
...  
Keyword(s):  
Lung Function ◽  
Airflow Obstruction ◽  
Lung Function Decline ◽  
Obstruction Severity ◽  
Heavy Smokers

X-ray microtomography

1988 ◽  
Vol 46 ◽  
pp. 998-999
Author(s):  
H.W. Deckman ◽  
B.F. Flannery ◽  
J.H. Dunsmuir ◽  
K.D' Amico
Keyword(s):  
Computed Tomography ◽  
Internal Structure ◽  
Imaging Technique ◽  
Three Dimensional ◽  
Tissue Structure ◽  
Individual Element ◽  
X Ray ◽  
Non Invasive ◽  
Panoramic Imaging ◽  
Three Dimensional Images

We have developed a new X-ray microscope which produces complete three dimensional images of samples. The microscope operates by performing X-ray tomography with unprecedented resolution. Tomography is a non-invasive imaging technique that creates maps of the internal structure of samples from measurement of the attenuation of penetrating radiation. As conventionally practiced in medical Computed Tomography (CT), radiologists produce maps of bone and tissue structure in several planar sections that reveal features with 1mm resolution and 1% contrast. Microtomography extends the capability of CT in several ways. First, the resolution which approaches one micron, is one thousand times higher than that of the medical CT. Second, our approach acquires and analyses the data in a panoramic imaging format that directly produces three-dimensional maps in a series of contiguous stacked planes. Typical maps available today consist of three hundred planar sections each containing 512x512 pixels. Finally, and perhaps of most import scientifically, microtomography using a synchrotron X-ray source, allows us to generate maps of individual element.

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