scholarly journals A novel Venturi system to generate high flow with titratable FiO2

ABOUTOPEN ◽  
2021 ◽  
Vol 8 (1) ◽  
pp. 88-91
Author(s):  
Andrea Coppadoro ◽  
Giacomo Bellani
Keyword(s):  
Positive Airway Pressure ◽  
Fold Increase ◽  
Ambient Air ◽  
High Flow ◽  
Positive End Expiratory Pressure ◽  
Total Flow ◽  
Total Flow Rate ◽  
And Performance ◽  
Reliable Solution ◽  
Single Oxygen

Venturi-based flow generators are commonly used for noninvasive continuous positive airway pressure (CPAP) of high-flow nasal oxygen (HFNO). The system is simple and allows to increase the total flow while decreasing the FiO2 starting from a single oxygen source. In this report we describe the characteristics and performance of a novel Venturi system (EasyVEE, Levate, BG, Italy), which allows to vary the size of the port through which ambient air is entrained, hence allowing a continuous modulation of FiO2. The system allowed to modify FiO2 continuously between 35% and 80% and, consequently, a 1.5- to 4.5-fold increase of the total flow rate. A minimal decrease in entrainment performance was observed for positive end-expiratory pressure levels above 12.5 cmH2O. EasyVEE system appears to be a simple, flexible, and reliable solution to generate continuous flow for noninvasive respiratory support interfaces.

scholarly journals The influence of chemical parameters on the in-situ metal carbonyl complex formation studied with the fast on-line reaction apparatus (FORA)

2021 ◽  
Vol 109 (4) ◽  
pp. 243-260 ◽  
Author(s):  
Yves Wittwer ◽  
Robert Eichler ◽  
Dominik Herrmann ◽  
Andreas Türler
Keyword(s):  
Metal Carbonyl ◽  
Ambient Air ◽  
Single Atom ◽  
Carbonyl Complex ◽  
Carbonyl Complexes ◽  
On Line ◽  
Carrier Gases ◽  
And Performance ◽  
Atom Chemistry

Abstract A new setup named Fast On-line Reaction Apparatus (FORA) is presented which allows for the efficient investigation and optimization of metal carbonyl complex (MCC) formation reactions under various reaction conditions. The setup contains a 252Cf-source producing short-lived Mo, Tc, Ru and Rh isotopes at a rate of a few atoms per second by its 3% spontaneous fission decay branch. Those atoms are transformed within FORA in-situ into volatile metal carbonyl complexes (MCCs) by using CO-containing carrier gases. Here, the design, operation and performance of FORA is discussed, revealing it as a suitable setup for performing single-atom chemistry studies. The influence of various gas-additives, such as CO2, CH4, H2, Ar, O2, H2O and ambient air, on the formation and transport of MCCs was investigated. O2, H2O and air were found to harm the formation and transport of MCCs in FORA, with H2O being the most severe. An exception is Tc, for which about 130 ppmv of H2O caused an increased production and transport of volatile compounds. The other gas-additives were not influencing the formation and transport efficiency of MCCs. Using an older setup called Miss Piggy based on a similar working principle as FORA, it was additionally investigated if gas-additives are mostly affecting the formation or only the transport stability of MCCs. It was found that mostly formation is impacted, as MCCs appear to be much less sensitive to reacting with gas-additives in comparison to the bare Mo, Tc, Ru and Rh atoms.

scholarly journals Effects of water salinity on the foam dynamics for EOR application

2021 ◽  
Author(s):  
Svetlana Rudyk ◽  
Sami Al-Khamisi ◽  
Yahya Al-Wahaibi
Keyword(s):  
Flow Rate ◽  
Liquid Flow ◽  
Apparent Viscosity ◽  
Liquid Flow Rate ◽  
Salinity Range ◽  
Porous System ◽  
Foam Formation ◽  
Total Flow ◽  
Total Flow Rate ◽  
Foam Flow

AbstractFactors limiting foam injection for EOR application are exceptionally low rock permeability and exceedingly high salinity of the formation water. In this regard, foam formation using internal olefin sulfonate is investigated over a wide salinity range (1, 5, 8, 10, and 12% NaCl) through 10 mD limestone. The relationships between pressure drop (dP), apparent viscosity, liquid flow rate, total flow rate, salinity, foam texture, and length of foam drops at the outlet used as an indicator of viscosity are studied. Foaming is observed up to 12% NaCl, compared to a maximum of 8% NaCl in similar core-flooding experiments with 50 mD limestone and 255 mD sandstone. Thus, the salinity limit of foam formation has increased significantly due to the low permeability, which can be explained by the fact that the narrow porous system acts like a membrane with smaller holes. Compared to the increasing dP reported for highly permeable rocks, dP linearly decreases in almost the entire range of gas fraction (fg) at 1–10% NaCl. As fg increases, dP at higher total flow rate is higher at all salinities, but the magnitude of dP controls the dependence of apparent viscosity on total flow rate. Low dP is measured at 1% and 10% NaCl, and high dP is measured at 5, 8, and 12% NaCl. In the case of low dP, the apparent viscosity is higher at higher total flow rate with increasing gas fraction, but similar at two total flow rates with increasing liquid flow rate. In the case of high dP, the apparent viscosity is higher at lower total flow rate, both with an increase in the gas fraction and with an increase in the liquid flow rate. A linear correlation is found between dP or apparent viscosity and liquid flow rate, which defines it as a governing factor of foam flow and can be considered when modeling foam flow.

scholarly journals Performance of EasyBreath Decathlon Snorkeling mask for delivering continuous positive airway pressure

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Alberto Noto ◽  
Claudia Crimi ◽  
Andrea Cortegiani ◽  
Massimiliano Giardina ◽  
Filippo Benedetto ◽  
...  
Keyword(s):  
Continuous Positive Airway Pressure ◽  
Airway Pressure ◽  
High Performance ◽  
Positive Airway Pressure ◽  
High Flow ◽  
Hospital Capacity ◽  
System Generator ◽  
Flow Generator ◽  
Full Face ◽  
Support Devices

AbstractDuring the COVID-19 pandemic, the need for noninvasive respiratory support devices has dramatically increased, sometimes exceeding hospital capacity. The full-face Decathlon snorkeling mask, EasyBreath (EB mask), has been adapted to deliver continuous positive airway pressure (CPAP) as an emergency respiratory interface. We aimed to assess the performance of this modified EB mask and to test its use during different gas mixture supplies. CPAP set at 5, 10, and 15 cmH2O was delivered to 10 healthy volunteers with a high-flow system generator set at 40, 80, and 120 L min−1 and with a turbine-driven ventilator during both spontaneous and loaded (resistor) breathing. Inspiratory CO2 partial pressure (PiCO2), pressure inside the mask, breathing pattern and electrical activity of the diaphragm (EAdi) were measured at all combinations of CPAP/flows delivered, with and without the resistor. Using the high-flow generator set at 40 L min−1, the PiCO2 significantly increased and the system was unable to maintain the target CPAP of 10 and 15 cmH2O and a stable pressure within the respiratory cycle; conversely, the turbine-driven ventilator did. EAdi significantly increased with flow rates of 40 and 80 L min−1 but not at 120 L min−1 and with the turbine-driven ventilator. EB mask can be safely used to deliver CPAP only under strict constraints, using either a high-flow generator at a flow rate greater than 80 L min−1, or a high-performance turbine-driven ventilator.

EXTRACTION OF MINUTE GAS BUBBLES FROM LIQUIDS FLOWING IN A SIMULATED CARDIOPULMONARY BYPASS SYSTEM BY A VENTURI-ASPIRATOR UNIT

2002 ◽  
Vol 02 (03n04) ◽  
pp. 297-312
Author(s):  
WEN-JEI YANG ◽  
AMR EID ◽  
R. ECHIGO
Keyword(s):  
Cardiopulmonary Bypass ◽  
Flow Rate ◽  
Whole Blood ◽  
Pressure Difference ◽  
Gas Bubbles ◽  
Blood Oxygenation ◽  
Straight Tube ◽  
Suction Pressure ◽  
Total Flow ◽  
Total Flow Rate

An experimental study is performed to extract minute gas bubbles from liquids flowing in a simulated cardiopulmonary bypass system using a Venturi-aspirator unit. In other words, oxygen bubbles in oxygenated blood are simulated by air bubbles in water with AP30 (about same viscosity as whole blood). This study is intended to determine the feasibility of using a Venturi aspirator unit to extract minute gas bubbles from a simulated cardiopulmonary bypass system. Testing of the Venturi-type bubble extraction is carried out using three different test sections. Two Venturis are used, and a straight tube configuration is used as a control. The two Venturis are similar, with the exception that one has a longer inlet cone which causes the entering liquid to accelerate at a slower rate. Results are obtained for effectiveness of the aspirator unit as functions of total flow rate, extraction suction, suction pressure difference, and hydraulic head. It is concluded from the study that:(i) The effectiveness of the Venturis is typically between 90 and 100 percent. It increases with an increase in suction or suction pressure difference but decreases with an increase in total flow rate.(ii) The Venturi is most suitable for extraction of minute gas bubbles, especially for use with AP30 (whole blood), which yields substantially higher effectiveness than water.(iii) It is anticipated that a Venturi-aspirator unit can be superior to other bubble separation device as the cardiopulmonary bypass system for applications in extra corporeal blood oxygenation.

A method for measurement of oxygen uptake in neonates

1979 ◽  
Vol 46 (6) ◽  
pp. 1200-1204 ◽  
Author(s):  
D. B. Raemer ◽  
D. R. Westenskow ◽  
D. K. Gehmlich ◽  
C. P. Richardson ◽  
W. S. Jordan
Keyword(s):  
Intensive Care ◽  
Oxygen Uptake ◽  
Positive Airway Pressure ◽  
Animal Experiments ◽  
Newborn Infants ◽  
Positive End Expiratory Pressure ◽  
Newborn Intensive Care Unit ◽  
Frequent Use ◽  
Newborn Intensive Care

The frequent use of continuous positive airway pressure and positive end-expiratory pressure in newborn infants with pulmonary disease has prevented the use of conventional methods for measuring oxygen uptake (VO2) in intensive-care units. A feed-back replenishment technique for the determination of the oxygen uptake of these newborn infants has been developed. An instrument utilizing this method has been designed and built permitting continuous VO2 monitoring without interfering in the routine ventilatory therapy of the critically ill infant. Theoretical, bench, and animal experiments using room air as an inspired gas indicate instrument accuracies as a percentage of full scale of 2.4, 2.8, and 7.3, respectively. Preliminary trials on infants demonstrate that the instrument functions satisfactorily in the newborn intensive-care unit.

scholarly journals Obstructive sleep apnea and cardiovascular effects-a review

2009 ◽  
Vol 4 (2) ◽  
pp. 41-45
Author(s):  
AKM Mosharraf Hossain ◽  
Mostofa Midhat Pasha
Keyword(s):  
Obstructive Sleep Apnea ◽  
Sleep Apnea ◽  
Continuous Positive Airway Pressure ◽  
Airway Pressure ◽  
Positive Airway Pressure ◽  
Cardiovascular Effects ◽  
Intrathoracic Pressure ◽  
Fold Increase ◽  
Timely Initiation ◽  
Obstructive Sleep

Obstructive sleep apnea (OSA) is the most common form of sleep-disordered breathing, affecting 5-15% of the population. It is characterized by intermittent episodes of partial or complete obstruction of the upper airway during sleep that disrupts normal ventilation and sleep architecture, and is typically associated with excessive daytime sleepiness, snoring, and witnessed apneas. Patients with obstructive sleep apnea present risk to the general public safety by causing 8-fold increase in vehicle accidents, and they may themselves also suffer from the physiologic consequences of OSA; these include hypertension, coronary artery disease, stroke, congestive heart failure, pulmonary hypertension, and cardiac arrhythmias. Of these possible cardiovascular consequences, the association between OSA and hypertension has been found to be the most convincing. Although the exact mechanism has not been understood, there is some evidence that OSA is associated with frequent apneas causing mechanical effects on intrathoracic pressure, cardiac function, and intermittent hypoxemia, which may in turn cause endothelial dysfunction and increase in sympathetic drive. Therapy with continuous positive airway pressure has been demonstrated to improve cardiopulmonary hemodynamics in patients with OSA and may reverse the endothelial cell dysfunction. Limited availability of diagnostic measures and unawareness of physicians, many patients with OSA remain undiagnosed. Awareness and timely initiation of an effective treatment may prevent potential deleterious cardiovascular effects of OSA. Key words: Obstructive Sleep apnea, Hypertension, Atherosclerosis, Continuous positive airway pressure.   doi:10.3329/uhj.v4i2.2075 University Heart Journal Vol. 4 No. 2 July 2008 p.41-45

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