Objective: Investigating a model arm
Doppler sonography uses the Doppler Effect to assess whether structures (usually blood) are moving towards or away from the ultrasonic probe, and its relative velocity. By calculating the frequency shift of a particular sample volume, for example a jet of blood flow over a heart valve, speed and direction of this sample volume can be determined and visualised. Doppler frequency shift is the difference in ultrasonic frequency between transmitted signal and received echoes, i.e. the echo frequency minus the transmitted frequency. The Doppler frequency is proportional to the blood flow velocity. Doppler sonography is particularly useful in cardiovascular studies (sonography of the vasculature system and heart) and essential in many areas such as determining reverse blood flow in the liver vasculature in portal hypertension. In the experiment, blood flow measurements are made with Doppler ultrasound. A realistic arm model is used to show the differences between continuously (venous) and pulsatile (arterial) flow and between normal blood flow and a constriction (stenosis). The Doppler information is displayed graphically using spectral Doppler or as an image using colour Doppler.
Notes:
Ultrasound coupler gel recommended, not included in the scope of delivery. Alternatively, water can also be used.
Detailed experiment instructions (only available in German and English) are included with the experiment.
![Experiment: Doppler sonography, 8001225 [UE9020400], Ultrasound](/imagelibrary/UE9020400/UE9020400_01_Experiment-Doppler-sonography.jpg)
![Experiment: Doppler sonography, 8001225 [UE9020400], Ultrasound](/thumblibrary/UE9020400/UE9020400_01_1200_1200_Experiment-Doppler-sonography.jpg)
