Bernhard Zagar, Florian Maier,
"Ultrasonic Flow Measurement in Small Periodically Excited Capillary-Phantoms"
: Proceedings of the 21th IEEE Instrumentation and Measurement Technology Conference, Como, Italy, Vol. 2, Seite(n) 1569-1573, 5-2004, ISBN: 0-7803-8248-X
Ultrasonic Flow Measurement in Small Periodically Excited Capillary-Phantoms
Sprache des Titels:
Proceedings of the 21th IEEE Instrumentation and Measurement Technology Conference, Como, Italy
The improvement of accuracy in ultrasonic flow measurement scanning-systems is still a goal to be worked on, especially if it is intended to be used for scanning of small blood vessels. For the development of signal processing algorithms it is necessary to have available a well defined flow characteristic within a flow phantom that can also be excited to mimic tissue motion stemming for example from heart-action, tremor and respiration. In our paper we present an experimental ultrasonic measurement set-up combined with a blood flow mimicking phantom and show results. The phantom was designed and produced in our lab and is capable of simulating periodic vessel jitter, that influences the accuracy of blood flow measured in the phantoms capillary. This flow is produced by an infusion pump. The tissue simulating body is made of glycerol, water, agar-agar and aluminium oxide, the acoustic properties of which such as speed of sound (c=1540 m/s) and attenuation coefficient (approximately 1.5 dB/MHz/cm) are adapted to human tissues.
The electronics is used to store the digitized signals scattered off the interrogated phantom volume.
The signal processing comprises: alignment to reduce unwanted tissue motion related artefacts, filtering of stationary and non-stationary clutter components and velocity estimation to estimate magnitudes and spatial distribution of the assumed flow. Concluding some image processing is necessary to generate a time sequence of 3D-flow data for a total simulated heartbeat period.