A transmitter transmits ultrasound signals towards a region to be imaged. The reflected ultrasound signals from the region are detected by a receiver. The transmitter and/or receiver is or are moved relative to the region to create Doppler phase shift. The time compression/expansion caused by the Doppler...http://www.google.de/patents/US5501222?utm_source=gb-gplus-sharePatent US5501222 - System for imaging a region
