A New Method for Assessing Flow-Volume Measurements by Means of a Simple Isoflow Electronic Pocket Device (IfloPen™)

1993 ◽  
pp. 56-63
Author(s):  
A. Schibler ◽  
C. Casaulta Aebischer ◽  
J. Bischofberger ◽  
C. Liardet ◽  
R. Kraemer
Keyword(s):  
New Method ◽  
Flow Volume ◽  
Volume Measurements

Flow-volume measurements with a spirometer

Lung ◽  
1979 ◽  
Vol 157 (1) ◽  
pp. 201-208 ◽  
Author(s):  
E. Svenonius ◽  
R. Kautto ◽  
M. Arborelius
Keyword(s):  
Flow Volume ◽  
Volume Measurements

scholarly journals Effects of contour propagation and background corrections in different MRI flow software packages

2015 ◽  
Vol 4 (6) ◽  
pp. 205846011558912 ◽  
Author(s):  
D Boye ◽  
O Springer ◽  
F Wassmer ◽  
S Scheidegger ◽  
L Remonda ◽  
...  
Keyword(s):  
Magnetic Field Gradient ◽  
Flow Analysis ◽  
Aortic Insufficiency ◽  
Background Correction ◽  
Flow Volume ◽  
Software Packages ◽  
Contour Propagation ◽  
Volume Measurements ◽  
Different Diameters ◽  
Manual Correction

Background Velocity-encoded magnetic resonance imaging (VENC-MRI) is a commonly used technique in cardiac examinations. This technique utilizes the phase shift properties of protons moving along a magnetic field gradient. VENC-MRI offers a unique way of measuring the severity of valve regurgitation by directly quantifying the regurgitation flow volume. Purpose To compare flow analysis results of different software programs and to assess the effect of background correction in sample patient cases. Material and Methods A phantom was built out of Polymethyl methacrylate (PMMA) which provides tubes of different diameters. These tubes can be connected to an external water circuit to generate a water flow inside the tubes. Expected absolute flow quantities inside the tubes were determined from preset tube- and flow-parameters. Different flow conditions were measured with a VENC-MRI sequence and the images evaluated using different software packages. In a second step six randomly selected patients showing different degrees of aortic insufficiency were evaluated in clinical terms. Results The contour propagation algorithms used in the software packages performed differently even on static phantom geometry. In terms of clinical evaluation the software packages performed similarly. Enabling background correction or leaving out manual correction of propagated contours changed results for severity of aortic insufficiency. Conclusion Turning on background correction and manual correction of propagated contours in MRI flow volume measurements is strongly recommended.

scholarly journals Errors in blood flow volume measurements by pulsed Doppler ultrasound

2010 ◽  
Vol 43 (8) ◽  
pp. 641-647
Author(s):  
Kazuyuki Maeno ◽  
Shoichirou Nakanishi ◽  
Naomi Ohta ◽  
Kazushi Ohmachi ◽  
Takahiro Ohta ◽  
...  
Keyword(s):  
Blood Flow ◽  
Doppler Ultrasound ◽  
Flow Volume ◽  
Pulsed Doppler ◽  
Blood Flow Volume ◽  
Pulsed Doppler Ultrasound ◽  
Volume Measurements

scholarly journals A New Method to Evaluate the Combined Performance of Check Dams and Afforestation on Debris Flows Mitigation in a Dry-hot Valley

2021 ◽  
Author(s):  
Liqun Lyu ◽  
Mengzhen Xu ◽  
Guanyu Zhou ◽  
Zhaoyin Wang
Keyword(s):  
Debris Flow ◽  
Debris Flows ◽  
Yunnan Province ◽  
New Method ◽  
Energy Conditions ◽  
Vegetation Coverage ◽  
Economic Losses ◽  
Flow Volume ◽  
Jiangjia Gully ◽  
Check Dams

Abstract Debris flows in waterways can transport large amounts of sediment downstream, which can cause serious damage and economic losses. The vegetation cover in the valley of the Xiaojiang River in Yunnan Province, China—classified as a dry-hot valley—was significantly reduced by logging in the 1950s. Soil erosion intensified and 107 gullies developed, which led to debris flows along the 86 km length of the river. Jiangjia Gully is a tributary of the Xiaojiang River. Historically, debris flows have occurred frequently, blocking the Xiaojiang River seven times between 1957 and 2000. Since 2000, the construction of check dams and afforestation have decreased the volume of debris flows in the three tributaries of Jiangjia Gully. However, different combinations of check dams and afforestation were adopted in the three tributaries of Jiangjia Gully, which has led to the different trends in debris flows behaviour. A new method was established to evaluate the mitigative effect of check dams and afforestation on debris flows. We found that the debris flow volume was proportional to the gravity energy of soil and rock on the gully bank and inversely proportional to the vegetation coverage in a dry-hot valley setting. The method revealed that under different gravity energy conditions, the implementation order of check dam construction and afforestation is important for debris flow mitigation.

Compressibility Determinations Without Volume Measurements

1936 ◽  
Vol 3 (4) ◽  
pp. A136-A140 ◽  
Author(s):  
E. S. Burnett
Keyword(s):  
Ideal Gas ◽  
New Method ◽  
Mass Measurements ◽  
Real Gas ◽  
Gas Laws ◽  
Volume Measurements

Abstract The author describes a new method of determining the isothermal deviations of a real gas from compliance with ideal gas laws. This method eliminates all volume and mass measurements from the experimental observations, and permits calculation of the deviations from observations of pressures and temperatures only.

Airway Physiology

2019 ◽  
Author(s):  
Gilbert S Tang
Keyword(s):  
Airway Resistance ◽  
Hypoxic Pulmonary Vasoconstriction ◽  
Work Of Breathing ◽  
Lung Compliance ◽  
Flow Volume ◽  
Carbon Dioxide Transport ◽  
Basic Principles ◽  
Pulmonary Vasoconstriction ◽  
Volume Measurements ◽  
Airway Physiology

An understanding of airway physiology is important for the anesthesiologist, tasked with supporting the patient's respiratory functions which are altered in the conduct of anesthesia and surgery, or which may be abnormal due to co-existing disease. Airflow and airway resistance, lung compliance, spirometric values, flow-volume measurements, work of breathing, ventilation-perfusion matching, and oxygen-carbon dioxide transport are some of the basic principles. Clinical application of physiology allows the anesthesiologist to anticipate and manage changes that may occur when anesthetizing the patient, altering position or manipulating the airway. This review contains 5 tables, and 25 references. Keywords: Ohm’s law, laminar vs turbulent flow, Reynold’s number, Heliox, Bernoulli’s principle, compliance vs elasticity, Law of Laplace, spirometry, dead space, hypoxic pulmonary vasoconstriction

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