Figure 1

Setup of the phantom experiments using string and rotating phantoms. (A) String phantom to obtain a controlled linear motion pattern. Angle α indicates the deviation of the motion direction from the ultrasound beam direction. Note the controller unit with the connection to the ultrasound system for tachometer signals and the possibility for exact velocity measurements. (B) Rotating phantom to mimic a vortex-like structure with a comparable setup. See text for details.