1. Articles from peter r. eastwood

    1-12 of 12
    1. Does smooth muscle in an intact airway undergo length adaptation during a sustained change in transmural pressure?

      Does smooth muscle in an intact airway undergo length adaptation during a sustained change in transmural pressure?

      In isolated airway smooth muscle (ASM) strips, an increase or decrease in ASM length away from its current optimum length causes an immediate reduction in force production followed by a gradual time-dependent recovery in force, a phenomenon termed length adaptation. In situ, length adaptation may be initiated by a change in transmural pressure (Ptm), which is a primary physiological determinant of ASM length. The present study sought to determine the effect of sustained changes in Ptm and therefore, ASM perimeter, on airway function. We measured contractile responses in whole porcine bronchial segments in vitro before and after a ...

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    2. Effect of the velopharynx on intraluminal pressures in reconstructed pharynges derived from individuals with and without sleep apnea

      Effect of the velopharynx on intraluminal pressures in reconstructed pharynges derived from individuals with and without sleep apnea

      The most collapsible part of the upper airway in the majority of individuals is the velopharynx which is the segment positioned behind the soft palate. As such it is an important morphological region for consideration in elucidating the pathogenesis of obstructive sleep apnea (OSA). This study compared steady flow properties during inspiration in the pharynges of nine male subjects with OSA and nine body-mass index (BMI)- and age-matched control male subjects without OSA. The k – SST turbulence model was used to simulate the flow field in subject-specific pharyngeal geometric models reconstructed from anatomical optical coherence tomography (aOCT) data. While analysis ...

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    3. Phenotyping Airways Disease With Optical Coherence Tomography

      Phenotyping Airways Disease With Optical Coherence Tomography

      Airway diseases are a major concern around the world. However, the pace of new drug and biomarker discovery has lagged behind those of other common disorders such as cardiovascular diseases and diabetes. One major barrier in airways research has been the inability to accurately visualize large and small airway remodeling or dysplastic/neoplastic (either pre or early cancerous) changes using non or minimally invasive instruments. The advent of optical coherence tomography (OCT) has the potential to revolutionize airway research and management by allowing investigators and clinicians to visualize the airway with resolution approaching histology without exposing patients to harmful effects ...

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    4. Elastic Properties of the Central Airways in Obstructive Lung Diseases Measured Using Anatomical Optical Coherence Tomography

      Elastic Properties of the Central Airways in Obstructive Lung Diseases Measured Using Anatomical Optical Coherence Tomography
      Rationale: Our understanding of how airway remodeling affects regional airway elastic properties is limited due to technical difficulties in quantitatively measuring dynamic, in vivo airway dimensions. Such knowledge could help elucidate mechanisms of excessive airway narrowing. Objectives: To utilize anatomical optical coherence tomography (aOCT) to compare central airway elastic properties in control subjects and those with obstructive lung diseases. Methods: Following bronchodilation, airway lumen area (Ai) was measured using aOCT during bronchoscopy in control subjects (n=10) and those with asthma (n=16), chronic obstructive pulmonary disease (COPD) (n=9) and bronchiectasis (n=8). Ai was measured in each of ...
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    5. Distribution of airway narrowing responses across generations and at branching points, assessed in vitro by anatomical optical coherence tomography

      Distribution of airway narrowing responses across generations and at branching points, assessed in vitro by anatomical optical coherence tomography

      Background Previous histological and imaging studies have shown the presence of variability in the degree of bronchoconstriction of airways sampled at different locations in the lung (i.e., heterogeneity). Heterogeneity can occur at different airway generations and at branching points in the bronchial tree. Whilst heterogeneity has been detected by previous experimental approaches its spatial relationship either within or between airways is unknown. Methods In this study, distribution of airway narrowing responses across a portion of the porcine bronchial tree was determined in vitro. The portion comprised contiguous airways spanning bronchial generations (#3-11), including the associated side branches. We used ...

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    6. Airway Narrowing Assessed by Anatomical Optical Coherence Tomography In Vitro: Dynamic Airway Wall Morphology and Function

      Airway Narrowing Assessed by Anatomical Optical Coherence Tomography In Vitro: Dynamic Airway Wall Morphology and Function

      Regulation of airway caliber by lung volume or bronchoconstrictor stimulation is dependent on physiological, structural and mechanical events within the airway wall, including airway smooth muscle (ASM) contraction, deformation of the mucosa and cartilage, and tensioning of elastic matrices linking wall components. Despite close association between events in the airway wall and the resulting airway caliber these have typically been studied separately: the former primarily using histological approaches, the latter with a range of imaging modalities. We describe a new optical technique, anatomical optical coherence tomography (aOCT), which allows changes at the luminal surface (airway caliber) to be temporally related ...

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    7. Respiratory gating of anatomical optical coherence tomography images of the human airway

      Respiratory gating of anatomical optical coherence tomography images of the human airway
      Anatomical optical coherence tomography (aOCT) is a longrange endoscopic imaging modality capable of quantifying size and shape of the human airway. A challenge to its in vivo application is motion artifact due to respiratory-related movement of the airway walls. This paper represents the first demonstration of respiratory gating of aOCT airway data, and introduces a novel error measure to guide appropriate parameter selection. Results indicate that at least four gates per respiratory cycle should be used, with only minor improvements as the number of gates is further increased. It is shown that respiratory gating can substantially improve the quality of ...
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    8. Using Optical Coherence Tomography To Improve Diagnostic and Therapeutic Bronchoscopy

      Background Flexible bronchoscopy is a common procedure used in both diagnostic and therapeutic settings but does not readily permit measurement of central airway dimensions. Anatomical optical coherence tomography (aOCT), a modification of conventional optical coherence tomography (OCT), is a novel, light-based imaging tool with the capacity to accurately measure diameter and lumen area of the central airways during bronchoscopy. This study describes the first clinical use of anatomical optical coherence tomography in the lower airways in three individuals with common endobronchial pathologies. Methods During bronchoscopy, a specialized fiber-optic probe was passed through the biopsy channel of a standard flexible bronchoscope ...
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    9. Effect of Body Posture on Pharyngeal Shape and Size in Adults With and Without Obstructive Sleep Apnea

      Study Objectives: In patients with obstructive sleep apnea (OSA), the severity and frequency of respiratory events is increased in the supine body posture compared with the lateral recumbent posture. The mechanism responsible is not clear but may relate to the effect of posture on upper airway shape and size. This study compared the effect...
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    10. Applying anatomical optical coherence tomography to quantitative 3D imaging of the lower airway

      Applying anatomical optical coherence tomography to quantitative 3D imaging of the lower airway
      Endoscopic treatment of lower airway pathologies requires accurate quantification of airway dimensions. We demonstrate the application of a real-time endoscopic optical coherence tomography system that can image lower airway anatomy and quantify airway lumen dimensions intra-operatively. Results ... [Opt. Express 16, 17521-17529 (2008)]
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    11. Respiratory gating of endoscopic OCT images of the upper airway

      Robert A. McLaughlin, Julian J. Armstrong, Sven Becker et al. Anatomical optical coherence tomography (aOCT) is an endoscopic imaging modality that can be used to quantify size and shape of the upper airway. We report the application of respiratory gating to aOCT images. Our results show that respiratory gating can reduce motion artefact in upper airway images ... [Proc. SPIE 7004, 70045V (2008)] published Fri May 16, 2008.
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    12. Evaluation of pharyngeal shape and size using anatomical optical coherence tomography in individuals with and without obstructive sleep apnoea

      Journal of Sleep Research, Volume 17, Issue 2, Page 230-238, June 2008. SummaryThis study compared shape, size and length of the pharyngeal airway in individuals with and without obstructive sleep apnoea (OSA) using a novel endoscopic imaging technique, anatomical optical coherence tomography (aOCT). The study population ...
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    1-12 of 12
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    1. (12 articles) University of Western Australia
    2. (12 articles) Peter R. Eastwood
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    5. (9 articles) Sir Charles Gairdner Hospital
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    Applying anatomical optical coherence tomography to quantitative 3D imaging of the lower airway Respiratory gating of anatomical optical coherence tomography images of the human airway Airway Narrowing Assessed by Anatomical Optical Coherence Tomography In Vitro: Dynamic Airway Wall Morphology and Function Distribution of airway narrowing responses across generations and at branching points, assessed in vitro by anatomical optical coherence tomography Elastic Properties of the Central Airways in Obstructive Lung Diseases Measured Using Anatomical Optical Coherence Tomography Phenotyping Airways Disease With Optical Coherence Tomography MULTIMODAL IMAGING CORRELATION OF THE CONCENTRIC MACULAR RINGS SIGN IN FOVEAL HYPOPLASIA Temporal dynamics of muscle optical properties during degeneration and regeneration in a canine muscle xenograft model Anterior Segment Optical Coherence Tomography in Ocular Argyrosis Automatic intraoperative optical coherence tomography positioning Anatomical features and clinical outcome of a honeycomb-like structure in the coronary artery: reports from 16 consecutive patients 3D-printed corals could improve bioenergy and help coral reefs