Experimental study of cavitation phenomenon in a centrifugal blood pump induced by the failure of inlet cannula

Lin, Zhe; Ruan, Xiangyan; Zou, Jun; Fu, Xin

doi:10.3901/cjme.2014.01.165

Cited by 17 publications

(17 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Another flow characteristic identified as a potential platelet activator is vortical flow structures that allows blood clots to develop [13]. Risk of hemolysis on the other hand is increased during events when the pump is exposed to negative inlet pressures, elevating the risk of cavitation [14,15]. Due to the design of the pumps combined with them operating at high rotational speeds, the above mentioned flow characteristics will appear, especially regions of high shear.…”

Section: Introductionmentioning

confidence: 99%

Flow Characteristics and Coherent Structures in a Centrifugal Blood Pump

Berg

Fuchs

Wittberg

2018

Flow Turbulence Combust

View full text Add to dashboard Cite

Blood clot formation can be initiated by local flow conditions where regions of high shear and long residence time regions, such as flow separation and stagnation, have been identified as risk factors. This study highlights coherent structures, some of which not yet considered in the literature that may contribute to blood clot formation in the ECMO (Extra Corporeal Membrane Oxygenator) circuit. The centrifugal ECMO pump investigated in this study is compact and delivers adequate volume of blood with relatively high pressure in order to compensate for the large pressure drop in the membrane oxygenator. These requirements lead to regions with high shear in several different parts of the pump. In the narrow gap between the pump house and the impeller body (the magnet) a Taylor-Couette-like flow is observed with azimuthally aligned wavy vortices, which are also pushed towards the bottom of the pump-house by the flow generated by the blades. At the bottom gap between the impeller house and the pump house one finds spiraling flow structures, due to the rotation of the former structure. Separation bubbles are found near the tongue of the pump and at the lee sides of the blades. Such vortical structures have in literature been identified as regions where platelets may be activated whereby clots may develop.

show abstract

Section: Introductionmentioning

confidence: 99%

Flow Characteristics and Coherent Structures in a Centrifugal Blood Pump

Berg

Fuchs

Wittberg

2018

Flow Turbulence Combust

View full text Add to dashboard Cite

show abstract

“…The cavitation bubbles, generated in a low-pressure zone, will collapse violently, causing serious damage to blood cells. 18 Another type of cavitation seen in pumps is due to a phenomenon called recirculation. Recirculation is defined as a flow reversal either at the inlet or at the outlet tips of the impeller vanes.…”

Section: Discussionmentioning

confidence: 99%

“…For the experiment, the NPSH value was gradually decreased to study the start of cavitation and its development. 18 , 30 – 32 This could be achieved by throttling the suction valve to reduce the total suction pressure, while properly regulating the discharge valve to retain the flow rate. However, this resulted in cavitation inception far before the pump’s inlet, in the suction valve, irrespective of the flow rate.…”

Section: Discussionmentioning

confidence: 99%

“…The cavitation bubbles, generated in a low-pressure zone, will collapse violently, causing serious damage to blood cells. 18 …”

Section: Discussionmentioning

confidence: 99%

“…35 Furthermore, the higher viscosity can result in the loss of pump efficiency 37,38 and an increase in critical inlet pressure. 18 Another factor specific to the blood is oxyhemoglobin, which releases oxygen into the plasma when its partial pressure decreases. It is clear that this continuous supply of gas into the plasma can further lead to an intensification of the process of gaseous cavitation in the pump.…”

Section: Limitations Of the Studymentioning

confidence: 99%

See 2 more Smart Citations

Is there a “safe” suction pressure in the venous line of extracorporeal circulation system?

Ganushchak

Korver

2020

Perfusion

View full text Add to dashboard Cite

Successes of extracorporeal life support increased the use of centrifugal pumps. However, reports of hemolysis call for caution in using these pumps, especially in neonatology and in pediatric intensive care. Cavitation can be a cause of blood damage. The aim of our study was to obtain information about the cavitation conditions and to provide the safest operating range of centrifugal pumps. A series of tests were undertaken to determine the points at which pump performance decreases 3% and gas bubbles start to appear downstream of the pump. Two pumps were tested; pump R with a closed impeller and pump S with a semiopen impeller. The performance tests demonstrated that pump S has an optimal region narrower than pump R and it is shifted to the higher flows. When the pump performance started to decrease, the inlet pressure varies but close to −150 mmHg in the test with low gas content and higher than −100 mmHg in the tests with increased gas content. The same trend was observed at the points of development of massive gas emboli. Importantly, small packages of bubbles downstream of the pump were registered at relatively high inlet pressures. The gaseous cavitation in centrifugal pumps is a phenomenon that appears with decreasing inlet pump pressures. There are a few ways to increase inlet pump pressures: (1) positioning the pump as low as possible in relation to the patient; (2) selecting appropriate sized venous cannulas and their careful positioning; and (3) controlling patient’s volume status.

show abstract