A device to study the degradation of blood in a shear field with controlled wall effects

A technique is described for studying shear‐induced degradation of blood with near‐uniform shear exposure to walls of a single material. The device used is a specially designed coni‐cylindrical viscometer with essentially all blood‐contacting surfaces constructed of a single test material. The technique developed permits exposure of blood only to this material under such conditions that significant shear occurs only in the viscometric region of the device. Contact with air is prevented. Preliminary data are reported for blood taken from fasting dogs and tested in a prototype device constructed of polycarbonate (Lexan). Venous blood was found to hemolyze much more than arterial blood and the extent of hemotysis increased with time. Changes were also observed in the electrophoretic pattern of the plasma proteins.