Ratio of surface roughness to flow scale as additional parameter for shear-induced hemolysis

Nobuo Watanabe, Sunao Ueda, Kentaro Nagashima, Taku Oguri, Toshihiro Mita

Research output: Contribution to journalArticlepeer-review

4 Citations (Scopus)


Background: In addition to the conventional knowledge that shear stress and its exposure time should have a large impact on hemolysis, it became obvious through Dr. Maruyama’s study that surface roughness would be the additional factor for high shear-induced hemolysis. Concerning this new information, we hypothesized that the ratio of surface roughness to the flow scale should play a role as the additional factor for shear-induced hemolysis. The purpose of this study was to develop a constant shear generator as the method to provide a controlled shear flow field with the combination between the controlled surface roughness and the flow scale to the blood cells. Its preliminary application was to validate our hypothesis. Methods: We prototyped the constant shear stress generator with the cylindrical cone-cup structure made from the acrylic material. This chamber had 3 flow scales of 1.00, 1.25, and 1.5 mm according to the change of the inner stationary cone, at which the surface roughness was distributed into the several levels between 0.14 and 0.92 micrometers in arithmetic average roughness. Using this shear chamber, we examined what effect the flow scale and the surface roughness had on hemolysis. Results: Our experimental data showed the tendency of a positive correlation between the ratio of surface roughness to the flow scale and the induced hemolysis levels, validating our hypothesis. Conclusions: The ratio of the surface roughness to the flow scale should be the additional parameter for shearinduced hemolysis.

Original languageEnglish
Pages (from-to)205-210
Number of pages6
JournalInternational Journal of Artificial Organs
Issue number4
Publication statusPublished - 2016 Apr


  • Flow scale
  • Shear-induced hemolysis
  • Surface roughness

ASJC Scopus subject areas

  • Medicine (miscellaneous)
  • Bioengineering
  • Biomaterials
  • Biomedical Engineering


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