[Continuous Doppler sonography: a new method in the monitoring of the cerebral circulation in very small premature infants].

Disorders of cerebral circulation, which are a major risk factor of intracerebral haemorrhage in the preterm baby, can be recognized by Doppler sonography. The development and clinical application of a small miniature Doppler transducer (13 x 9 x 20 mm) is presented which can be fixed onto the infant's fontanel. It is suitable for continuous measurements with a low energy output of only 13 mW.