[A simple test procedure for detection of micro-bubbles in extracorporeal blood circulation]

A new contrast medium for the ultrasonic examination of the human heart was recently approved by the German medical authorities. It has proved useful for investigating the sensitivity of air detectors in detecting microbubbles measuring only a few microns in the extracorporeal line. Although the contrast medium, originally intended to be injected undiluted into the human blood circulation, was considerably diluted, microbubbles were detected by the ultrasonic air detector far below the danger limit.