Study on the Intravenous Lung Assist Device (ILAD) Using PZT Actuators and PVDF Sensors

2008 ◽  
Vol 381-382 ◽  
pp. 353-356
Author(s):  
Gi Beum Kim ◽  
S.J. Kim ◽  
Y.C. Lee ◽  
C.U. Hong ◽  
H.S. Kang ◽  
...  
Keyword(s):  
Transfer Rate ◽  
Semipermeable Membrane ◽  
Gas Transfer ◽  
Scaling Analysis ◽  
Membrane Oxygenator ◽  
Assist Device ◽  
Dimensionless Groups ◽  
Membrane Vibrations ◽  
Insight Into ◽  
Membrane Vibration

The purpose of this study was to investigate the effect of vibration device in gas transfer rate for usage as intravenous lung assist device. Specific attention was focused on the effect of membrane vibration. Quantitative experimental measurements were performed to evaluate the performance of the device, and to identify membrane vibration dependence on hemolysis. Scaling analysis was then used to infer the dimensionless groups that correlate the performance of a vibrated hollow tube membrane oxygenator. The experimental design and procedure are then given for a device for assessing the effectiveness of membrane vibrations. This ILAD is used to provide some insight into how wall vibrations might enhance the performance of an intravascular lung assist device. The time and the frequency response of PVDF sensor were investigated through various frequencies in the ILAD. In these devices, the flow of blood and the source of oxygen were separated by a semipermeable membrane allows oxygen to diffuse into and out of the f1uid, respectively. The results of experiments have shown vibrating ILAD performs effectively.

Membrane Oxygenator Use With Biventricular Assist Device: Facilitation of Support and Lung Recovery

2016 ◽  
Vol 9 (1) ◽  
pp. 105-109 ◽  
Author(s):  
Kristen Nelson-McMillan ◽  
William J. Ravekes ◽  
William R. Thompson ◽  
Kristen M. Brown ◽  
Larry Wolff ◽  
...  
Keyword(s):  
Ventricular Assist Device ◽  
Negative Impact ◽  
Left Ventricular ◽  
Membrane Oxygenator ◽  
Assist Device ◽  
Ventricular Assist ◽  
Vasopressor Support ◽  
Berlin Heart ◽  
In Series ◽  
Right Ventricular Assist Device

We present the use of a low-resistance membrane oxygenator (Quadrox D, Maquet) in series with a pulsatile right ventricular assist device (Berlin Heart EXCOR, Berlin Heart) in a patient with biventricular support who required high-frequency oscillatory ventilation (HFOV), due to refractory acute respiratory distress syndrome associated with Cytomegalovirus pneumonia. The high mean airway pressure associated with the use of HFOV resulted in a significant negative impact on left ventricular assist device (LVAD) filling that led to a combined respiratory and metabolic acidosis and the need for vasopressor support. Oxygenator placement enabled transition to conventional ventilation and the discontinuation of vasopressor support. This case demonstrates the feasibility and safety of the use of this lung support system in patients requiring ventricular assist device (VAD) support.

scholarly journals Generalized Entropy Generation Expressions in Gases

Entropy ◽  
2019 ◽  
Vol 21 (4) ◽  
pp. 330 ◽  
Author(s):  
Michael Peters
Keyword(s):  
Entropy Generation ◽  
Local Equilibrium ◽  
Approximation Error ◽  
Expansion Method ◽  
Scaling Analysis ◽  
Generalized Entropy ◽  
Process Gas ◽  
Operating Process ◽  
Specific Expansion ◽  
Insight Into

In this study, we generalize our previous methods for obtaining entropy generation in gases without the need to carry through a specific expansion method, such as the Chapman–Enskog method. The generalization, which is based on a scaling analysis, allows for the study of entropy generation in gases for any arbitrary state of the gas and consistently across the conservation equations of mass, momentum, energy, and entropy. Thus, it is shown that it is theoretically possible to alter specific expressions and associated physical outcomes for entropy generation by changing the operating process gas state to regions significantly different than the perturbed, local equilibrium or Chapman–Enskog type state. Such flows could include, for example, hypersonic flows or flows that may be generally called hyper-equilibrium state flows. Our formal scaling analysis also provides partial insight into the nature of entropy generation from an informatics perspective, where we specifically demonstrate the association of entropy generation in gases with uncertainty generated by the approximation error associated with density function expansions.

Scaling Analysis and Its Implication for Asphaltene Deposition in a Wellbore

SPE Journal ◽  
2017 ◽  
Vol 23 (02) ◽  
pp. 274-285 ◽  
Author(s):  
Davud Davudov ◽  
Rouzbeh Ghanbarnezhad Moghanloo ◽  
Jonathan Flom
Keyword(s):  
Reynolds Numbers ◽  
Stream Velocity ◽  
Scaling Analysis ◽  
Cross Sectional ◽  
Pressure Losses ◽  
Flow Capacity ◽  
Dimensionless Groups ◽  
Asphaltene Deposition ◽  
The Many ◽  
Hydrodynamic Effects

Summary The study presented here uses order-of-one—or o(1)—scaling analysis to identify dimensionless groups specific to asphaltene deposition along production tubing. The precipitation and subsequent deposition of asphaltene can lead to significant complications related to oilfield production. Aside from the many complications within a reservoir as well as surface equipment, the reduction in cross-sectional area caused by its deposition leads to increased pressure losses, reductions in volumetric flow capacity, and possible flow perturbations within a wellbore. Attempts to mitigate these adverse effects have focused on both hindering the precipitation of asphaltene and preventing its deposition after precipitated. The study used here attempts to quantify various hydrodynamic controls specific to asphaltene deposition. With o(1) scaling analysis, four independent dimensionless groups were generated from momentum and mass-balance equations relating hydrodynamic effects to the rate of asphaltene deposition. The dimensionless group π4 was of particular interest because of its inherent relationship to the rate of deposition. This group was compared with both data and existing correlations taken from literature, and noticeable trends in the deposition rate with respect to average stream velocity were observed. One of the most important trends discerned by these comparisons was a clear distinction whereby the rate of asphaltene deposition, related through π4, decreases with increasing Reynolds numbers (Re) in lower ranges, but actually increases in higher ranges. Although the data did not cover the specific region of transition, various correlations suggest a clear cutoff between what was deemed a favorable regime, or Regime I, and a nonfavorable regime, or Regime II.

Gas transfer and hemolysis in an intravascular lung assist device using a PZT actuator

2009 ◽  
Vol 10 (1) ◽  
pp. 67-73 ◽  
Author(s):  
Chul-Un Hong ◽  
Jeong-Mi Kim ◽  
Min-Ho Kim ◽  
Seong-Jong Kim ◽  
Hyung-Sub Kang ◽  
...  
Keyword(s):  
Gas Transfer ◽  
Assist Device ◽  
Pzt Actuator

scholarly journals Newly Developed Pediatric Membrane Oxygenator that Suppresses Excessive Pressure Drop in Cardiopulmonary Bypass and Extracorporeal Membrane Oxygenation (ECMO)

Membranes ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 362
Author(s):  
Makoto Fukuda ◽  
Asako Tokumine ◽  
Kyohei Noda ◽  
Kiyotaka Sakai
Keyword(s):  
Blood Flow ◽  
Pressure Drop ◽  
Extracorporeal Membrane Oxygenation ◽  
High Performance ◽  
Flow Channel ◽  
Gas Transfer ◽  
Membrane Oxygenator ◽  
Excessive Pressure ◽  
Transfer Rates ◽  
Membrane Oxygenation

This article developes a pediatric membrane oxygenator that is compact, high performance, and highly safe. This novel experimental approach, which imaging the inside of a membrane oxygenator during fluid perfusion using high-power X-ray CT, identifies air and blood retention in the local part of a membrane oxygenator. The cause of excessive pressure drop in a membrane oxygenator, which has been the most serious dysfunction in cardiovascular surgery and extracorporeal membrane oxygenation (ECMO), is the local retention of blood and air inside the oxygenator. Our designed blood flow channel for a membrane oxygenator has a circular channel and minimizes the boundary between laminated parts. The pressure drop in the blood flow channel is reduced, and the maximum gas transfer rates are increased by using this pediatric membrane oxygenator, as compared with the conventional oxygenator. Furthermore, it would be possible to reduce the incidents, which have occurred clinically, due to excessive pressure drop in the blood flow channel of the membrane oxygenator. The membrane oxygenator is said to be the “last stronghold” for patients with COVID-19 receiving ECMO treatment. Accordingly, the specification of our prototype is promising for low weight and pediatric patients.

scholarly journals Edible films and coatings based on mango (var. Ataulfo) by-products to improve gas transfer rate of peach

LWT ◽  
2018 ◽  
Vol 97 ◽  
pp. 624-631 ◽  
Author(s):  
Cristian Torres-León ◽  
António A. Vicente ◽  
María L. Flores-López ◽  
Romeo Rojas ◽  
Liliana Serna-Cock ◽  
...  
Keyword(s):  
Transfer Rate ◽  
Edible Films ◽  
Gas Transfer ◽  
By Products
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