Evaluating Plasma Skimming with Whole Blood in Small Gap Region Imitating Clearance of Blood Pumps

• Published in: Conference proceedings (IEEE Engineering in Medicine and Biology Society. Conf.) Vol. 2019; pp. 5665 - 5669
• Main Authors: Jiang, M., Murashige, T., Sakota, D., Hijikata, W.
• Format: Conference Proceeding Journal Article
• Language: English
• Published: United States IEEE 01.07.2019
• Subjects: Blood; Cells (biology); Discharges (electric); Engineering in medicine and biology; Feeds; Plasmas; Velocity control
• ISSN: 1557-170X; 1558-4615
• DOI: 10.1109/EMBC.2019.8857735

Plasma skimming is the phenomenon whereby the discharge hematocrit is lower than feed hematocrit naturally occurring in the microvessels with Poiseuille flow. It has been studied in Poiseuille flow extensively. Besides, plasma skimming has also been observed and investigated in blood pumps due to its potential to prevent hemolysis by skimming blood cells out of the small gap. However, whether plasma skimming occurs in blood pumps with whole blood has not been verified. Additionally, the independent influence of rotational speed and gap size has not been clarified. Therefore, in order to lay the foundation of applying plasma skimming to the development of blood pumps and also investigate the influence of rotational speed and gap size on plasma skimming respectively, we designed a simplified geometric device which not only imitates the flow inside clearances of blood pumps, but also provides different rotational speed and gap size conditions. We first conducted the verification tests of plasma skimming using whole blood with an initial hematocrit of 44% and the gap size was varied from 10 μm to 240 μm with 10 μm interval. The plasma skimming was verified occurring when the gap was less than 70 μm at a rotational speed of 800 rpm. Since plasma skimming was confirmed, we employed 30% hematocrit blood and performed the following tests to evaluate the influence of rotational speed of 600 rpm, 700 rpm, and 800 rpm respectively. As a result, the hematocrit of sampled blood declined as the rotational speed increased from 600 rpm to 800 rpm. And there was the lowest hematocrit of 16% when the gap was adjusted to 50 μm gap size at 800 rpm. This study further promotes the possibility of applying plasma skimming to the blood pumps with higher hemocapability.