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Updated: Jul 10, 2026
An In Vitro Hemodynamic Loop Model to Investigate the Hemocytocompatibility and Host Cell Activation of Vascular Medical Devices
Published on: August 21, 2020
Hemolytic evaluation using polyurethane microcapsule suspensions in circulatory support devices: normalized index of
Osamu Maruyama1, Katsuhiro Yamaguchi, Masahiro Nishida
1Instutute for Human Science and Biomedical Engineering, National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki, Japan. osamu.maruyama@aist.go.jp
Abstract:
We have been developing some types of microcapsule suspensions with polyurethane membranes to evaluate the absolute hemolytic characteristics of the centrifugal blood pumps used in circulatory support devices such as artificial hearts. In order to facilitate/realize hemolysis testing on centrifugal blood pumps that have hemolysis levels as low as those of commercial centrifugal blood pumps, we eliminated capsules with diameters less than 72.2 microm, amounting to 15.4% of all capsules in the conventional suspension (crude suspension [CS]), and adjusted the capsule volume ratio to correspond to a hematocrit of 40%. In this way we succeeded in enhancing the sensitivity of the suspension to microcapsule destruction 61 fold. We used this new suspension (fine suspension [FS]) to perform hemolysis tests on four types of commercial pump with mock circulation systems. Under conditions of 500 mm Hg and 11.2 L/min, we successfully determined the hemolytic characteristics (normalized index of hemolysis [NIH]) of some of the centrifugal blood pumps; the results showed some correlation with those of hemolysis tests on bovine blood and suggest that microcapsule suspensions with polyurethane membranes are useful as standard test solutions for the absolute evaluation of centrifugal blood pumps.
