Open AccessDetermination of the In Vivo Cavitation Nuclei Characteristics of Blood
Author(s) -
Sean Chambers,
Robert H. Bartlett,
Steven L. Ceccio
Publication year - 1999
Publication title -
asaio journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.961
H-Index - 66
eISSN - 1538-943X
pISSN - 1058-2916
DOI - 10.1097/00002480-199911000-00007
Subject(s) - cavitation , in vivo , venturi effect , chemistry , syringe driver , radius , bubble , materials science , biomedical engineering , biophysics , mechanics , syringe , physics , biology , medicine , computer science , engineering , inlet , mechanical engineering , microbiology and biotechnology , computer security , psychiatry
Cavitation has been documented in the in vitro testing of blood-handling devices. To predict whether cavitation will occur clinically, the nuclei content of blood and the threshold pressure for activation of the in situ nuclei must be characterized. A single-pass flow apparatus is described for determining the nuclei characteristics of blood. The flow apparatus consists of a syringe pump and a venturi-geometry hydrodynamic device, called a cavitation susceptibility meter (CSM). Blood is accelerated through the throat of the CSM, thus exposing the nuclei in the blood to a well-defined pressure profile. The apparatus was used in an ex vivo sheep model for the determination of the in vivo nuclei characteristics of blood. The active nuclei concentration of in vivo blood was measured to be at most 2.7 nuclei per liter of plasma at a minimum throat pressure of -1610 mm Hg gauge (i.e., tension of 900 mm Hg). At this pressure, bubble stability theory predicts the active nuclei to have a radius on the order of 0.3 microm. Based on these results, in vitro studies to determine the cavitation potential of blood-handling devices must utilize test fluids that contain a minimum nuclei size distribution and concentration. It cannot be assumed that in vivo blood is nuclei rich, such that it will cavitate at or near vapor pressure.