Read by QxMD icon Read

forced oscillation technique

Joseph L Garrett, Marina S Leite, Jeremy N Munday
The spatial resolution of atomic force microscopy (AFM) needed to resolve material interfaces is limited by the tip-sample separation ( d) dependence of the force used to record an image. Here, we present a new multiscale functional imaging technique that allows for in situ tunable spatial resolution, which can be applied to a wide range of inhomogeneous materials, devices, and interfaces. Our approach uses a multifrequency method to generate a signal whose d-dependence is controlled by mixing harmonics of the cantilever's oscillation with a modulated force...
August 16, 2018: ACS Applied Materials & Interfaces
Chuan Wu, Bo Yan, Guizao Huang, Bo Zhang, Zhongbin Lv, Qing Li
A numerical method to simulate air flow around a bundle conductor line by means of the FLUENT software is presented and verified by a wind tunnel test for aerodynamic characteristics of a twin bundle conductor line. The lift and drag coefficients of the leeward sub-conductor of a twin bundle conductor varying with its relative position in the wake zone to the windward one under different wind velocities are numerically determined by the presented method. A user-defined subroutine of ABAQUS software is developed to apply the aerodynamic loads on each sub-conductor and the electromagnetic force between sub-conductors...
June 2018: Royal Society Open Science
K Nilsen, K Gove, F Thien, T Wilkinson, B R Thompson
Airway closure has proved to be important in a number of respiratory diseases and may be the primary functional defect in asthma. A surrogate measure of closing volume can be identified using the forced oscillation technique (FOT), by performing a deflation maneuver and examining the resultant reactance (Xrs) lung volume relationship. This study aims to determine if a slow vital capacity maneuver can be used instead of this deflation maneuver and compare it to existing more complex techniques. Three subject groups were included in the study; healthy (n = 29), asthmatic (n = 18), and COPD (n = 10) for a total of 57 subjects...
July 30, 2018: European Journal of Applied Physiology
Kan Kato, Hiroshi Tanaka
BACKGROUND: Usefulness of carrying out the reversibility test after inhaling bronchodilator by forced oscillation technique (FOT) in addition to spirometry was investigated in the diagnosis of bronchial asthma (BA), cough variant asthma (CVA) and allergic rhinitis (AR) with prolonged or chronic cough. METHODS: The subjects were the 622 patients at Idaimaeminamiyojo Clinic in Sapporo who complained cough over three weeks, and underwent bronchial reversibility test with salbutamol by using spirometry and FOT...
2018: Arerugī, [Allergy]
Claudia Calogero, Grazia Fenu, Enrico Lombardi
Lung function is an important tool in the diagnosis and monitoring of patients with asthma at all ages. Airway obstruction is a typical feature of asthma and it can be assessed with several lung function techniques. Spirometry, respiratory resistance and reactance, and lung volumes are available to measure it at different ages and in children. The assessment of a bronchodilator response is always recommended to show the reversibility of the obstruction. Poor lung function is a predictor of poor asthma outcome and a low Forced Expiratory Volume in the first second of expiration percent predicted measured with spirometry, has been shown to be associated with a higher risk of having an exacerbation during the following year independently of the presence of asthma symptoms...
2018: Frontiers in Pediatrics
Alison Pieterse, Susan D Hanekom
Background: Uncertainty exists regarding the physiological basis of physiotherapy strategies to facilitate mucus clearance. The aim of this review was to describe the physiological factors and intrinsic conditions that facilitate airway mucus transport. Method: A scoping review was performed. A systematic literature search of six databases was executed. Eligibility criteria were applied by two researchers to reach the aim of the review. Papers were identified independently by two reviewers on title, abstract and full-text level...
2018: Multidisciplinary Respiratory Medicine
Amin Shams Khorrami, Pouya Rezai
Controllable generation of microdroplets at desired sizes and throughputs is important in many applications. Many biological assays require size-optimized droplets for effective encapsulation of analytes and reagents. To perform size optimization, different-size droplets must be generated from identical sources of samples to prevent potential cross-sample variations or other sources of error. In this paper, we introduce a novel alteration of the co-flow droplet generation technique to achieve multi-size generation of monodispersed droplets...
May 2018: Biomicrofluidics
P P de Oliveira Jorge, J H P de Lima, D C Chong E Silva, D Medeiros, D Solé, G F Wandalsen
PURPOSE: To review available evidence in the literature on impulse oscillometry in the assessment of lung function in children with respiratory diseases, especially asthma. DATA COLLECTION: Research in the Medline, PubMed, and Lilacs databases, with the keywords forced oscillation, impulse oscillometry, asthma and impulse oscillometry. RESULTS: The Impulse Oscillometry System (IOS) allows the measurement of resistance and reactance of airways and is used as a diagnostic resource...
July 5, 2018: Allergologia et Immunopathologia
Yoshimi Kondo, Mariko Nukaga, Mayumi Enseki, Hideyuki Tabata, Kota Hirai, Masahiko Kato, Hiroyuki Mochizuki
OBJECTIVE: Breath sound parameters have been suggested to be a new biomarker of airway conditions in asthmatic patients. We investigated new breath sound parameters to determine their utility for evaluating asthmatic children. METHODS: Fifty-seven children (mean age, 9.0 years, 6-16 years) were included in the present study. The new breath sound parameters, the area under the curve (AUC)>1,000 Hz (A1000 [dBm·Hz]) and the ratio of the A1000 to the total AUC at 100 Hz to the highest frequency of the dBm power spectrum (AT ) (A1000 /AT [%]) were measured before and after β2 agonist inhalation...
July 20, 2018: Tokai Journal of Experimental and Clinical Medicine
Hao Xu, Ping Zhao, Wen-Jing Zhang, Jun-Ying Qiu, Li Tan, Xiao-Cao Liu, Qian Wang, Xi Luo, Yu-Shan She, Dun-An Zang, Bei-Bei Liu, Lei Cao, Xiao-Xue Zhao, Yuan-Yuan Chen, Meng-Yue Li, Jinhua Shen, Yong-Bo Peng, Lu Xue, Meng-Fei Yu, Weiwei Chen, Li-Qun Ma, Gangjian Qin, Qing-Hua Liu
BACKGROUND/AIMS: Tetraethylammonium chloride (TEA) induces oscillatory contractions in mouse airway smooth muscle (ASM); however, the generation and maintenance of oscillatory contractions and their role in ASM are unclear. METHODS: In this study, oscillations of ASM contraction and intracellular Ca2+ were measured using force measuring and Ca2+ imaging technique, respectively. TEA, nifedipine, niflumic acid, acetylcholine chloride, lithium chloride, KB-R7943, ouabain, 2-Aminoethoxydiphenyl borate, thapsigargin, tetrodotoxin, and ryanodine were used to assess the mechanism of oscillatory contractions...
2018: Cellular Physiology and Biochemistry
Ming Liu, Anqiang Sun, Xiaoyan Deng
BACKGROUND AND AIMS: The crossed limbs stent graft technique is regularly employed to treat abdominal aortic aneurysm patients with unfavorable aneurysm necks or widely splayed common iliac arteries. This article numerically evaluates the hemodynamic performance of the crossed limbs strategy by analyzing numerical simulations and conducting experiments using two series of idealized bifurcated stent grafts with different cross angles and cross positions. RESULTS: Results demonstrated that the absolute helicity at outlets decreased with increased cross angles and increased with decreased cross positions...
June 19, 2018: Biomedical Engineering Online
Mariko Nukaga, Hideyuki Tabata, Mayumi Enseki, Kota Hirai, Hiroyuki Furuya, Masahiko Kato, Hiroyuki Mochizuki
BACKGROUND: Breath sound parameters have been suggested to be new biomarkers of airway function in patients with asthma. METHODS: We investigated the effect of bronchodilation on breath sound parameters in sixty-four children (mean age, 8.9 years; range, 6-16 years) using a breath sound analyzer. The breath sound parameters included frequency limiting 50% and 99% of the power spectrum (F50 and F99 ), roll-off from 600-1200 Hz (slope), and spectrum curve indices such as the ratios of the third and fourth power area to the total area of the power spectrum (P3 /PT and P4 /PT ), total area under the curve (A3 /AT and B4 /AT ), and the ratio of power and frequency at 50% and 75% of the highest frequency of the power spectrum (RPF75 and RPF50 )...
June 13, 2018: Respiratory Investigation
Yosuke Wada, Yoshiaki Kitaguchi, Masanori Yasuo, Fumika Ueno, Satoshi Kawakami, Kiyoyasu Fukushima, Keisaku Fujimoto, Masayuki Hanaoka
Introduction: This study was conducted in order to investigate the diversity of respiratory physiology, including the respiratory impedance and reversibility of airway obstruction, based on quantitative computed tomography (CT) in patients with COPD. Patients and methods: Medical records of 174 stable COPD patients were retrospectively reviewed to obtain the patients' clinical data, including the pulmonary function and imaging data. According to the software-based quantification of the degree of emphysema and airway wall thickness, the patients were classified into the "normal by CT" phenotype, the airway-dominant phenotype, the emphysema-dominant phenotype, and the mixed phenotype...
2018: International Journal of Chronic Obstructive Pulmonary Disease
Zachary A Geiger, Kurt M Fujiwara, Kevin Singh, Ruwan Senaratne, Shankari V Rajagopal, Mikhail Lipatov, Toshihiko Shimasaki, Rodislav Driben, Vladimir V Konotop, Torsten Meier, David M Weld
We report the observation and characterization of position-space Bloch oscillations using cold atoms in a tilted optical lattice. While momentum-space Bloch oscillations are a common feature of optical lattice experiments, the real-space center-of-mass dynamics are typically unresolvable. In a regime of rapid tunneling and low force, we observe real-space Bloch oscillation amplitudes of hundreds of lattice sites, in both ground and excited bands. We demonstrate two unique capabilities enabled by tracking of Bloch dynamics in position space: measurement of the full position-momentum phase-space evolution during a Bloch cycle, and direct imaging of the lattice band structure...
May 25, 2018: Physical Review Letters
Brian J Lipworth, Sunny Jabbal
Impulse oscillometry (IOS) is the most commonly used type of forced oscillation technique in clinical practice, although relatively little is known about its application in COPD. Resistance at 20 Hz (R20) is unrelated to COPD severity and does not improve with bronchodilatation or bronchoconstriction, inferring a lack of large airway involvement in COPD. Peripheral airway resistance expressed as frequency dependent heterogeneity between 5 Hz and 20 Hz (R5-R20), and peripheral airway compliance as area under the reactance curve (AX), are both closely related to COPD severity and exacerbations...
June 2018: Respiratory Medicine
Mayumi Enseki, Mariko Nukaga, Hiromi Tadaki, Hideyuki Tabata, Kota Hirai, Masahiko Kato, Hiroyuki Mochizuki
BACKGROUND: Cough variant asthma (CVA) is characterized by a chronic cough and bronchial hyperresponsiveness without confirmation of wheezing. Using a breath sound analyzer, we evaluate the characteristics of breath sound in children with CVA. METHODS: Nine children with CVA (median age, 7.0 years) participated. The existence of breath sounds was confirmed by sound spectrogram. Breath sound parameters, the frequency limiting 50% and 99% of the power spectrum (F50 and F99 ), the roll-off from 600 to 1200 Hz (Slope) and spectrum curve indices, the ratio of the third and fourth area to the total area of the power spectrum (P3 /PT and P4 /PT ) and the ratio of power and frequency at 50% and 75% of the highest frequency of the power spectrum (RPF75 and RPF50 ) were calculated before and after β2 agonist inhalation...
May 29, 2018: Allergology International: Official Journal of the Japanese Society of Allergology
Stephen Milne, Christoph Hammans, Stella Watson, Claude S Farah, Cindy Thamrin, Gregory G King
Hyperinflation, gas trapping and their responses to long-acting bronchodilator are clinically important in COPD. The forced oscillation technique (FOT) measures of respiratory system resistance and reactance are sensitive markers of bronchodilator response in COPD. The relationships between changes in resistance and reactance, and changes in hyperinflation and gas trapping, following long-acting bronchodilator (LA-BD) have not been studied. 15 subjects with mild-moderate COPD underwent FOT, spirometry then body plethysmography, before and 2 hours after a single 150 microg dose of the LA-BD indacaterol...
May 25, 2018: COPD
Gaetano Valenza, Alberto Greco, Matteo Bianchi, Mimma Nardelli, Simone Rossi, Enzo Pasquale Scilingo
Noninvasive, objective quantitative techniques to gauge emotional states are fundamental for clinical psychology as they overcome subjective bias of currently used questionnaires. To this end, we investigated brain oscillatory EEG activity during caresslike, affective haptic elicitation conveyed on the forearm at two force (strength of the caress) and three velocity (velocity of the caress) levels. Thirty-two healthy subjects (16 female) were asked to assess each haptic stimulus in terms of arousal (i.e., intensity of emotional perception) and valence (i...
May 20, 2018: Psychophysiology
Masanori Yasuo, Yoshiaki Kitaguchi, Fumiya Kinota, Makoto Kosaka, Kazuhisa Urushihata, Atsuhito Ushiki, Hiroshi Yamamoto, Satoshi Kawakami, Masayuki Hanaoka
BACKGROUND: Pulmonary function tests (PFTs) comprise the traditional method for detecting central airway obstruction (CAO) and evaluating therapeutic effects, but are effort-dependent. By contrast, the forced oscillation technique (FOT) is performed during tidal breathing in an effort-independent mode and is universally used to assess respiratory function in patients with chronic obstructive pulmonary disease (COPD) and asthma. We used the FOT to measure airway resistance and reactance in patients with CAO before and after interventional bronchoscopy and compared the results to data obtained using PFTs...
May 2018: Respiratory Investigation
Norio Kodaka, Toru Yamagishi, Kayo Watanabe, Kumiko Kishimoto, Chihiro Nakano, Takeshi Oshio, Kumiko Niitsuma, Nagashige Shimada, Hiroto Matsuse
OBJECTIVES: International guidelines recommend the use of long-acting bronchodilators for the treatment of chronic obstructive pulmonary disease (COPD), but the usefulness of short-acting bronchodilator assist use for stable COPD remains uncertain. The purpose of the present study was to objectively demonstrate the effects of assist use of procaterol, a short-acting -agonist, on the respiratory mechanics of stable COPD patients treated with a long-acting bronchodilator using forced oscillation technique (FOT) and conventional spirometry...
May 17, 2018: Medical Principles and Practice: International Journal of the Kuwait University, Health Science Centre
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"