Skip to page content Mission Information


Doppler Ultrasound (Echocardiography)
Hardware Type
Imaging Systems
Measurement Devices, Cardiovascular

A Doppler ultrasound uses reflected sound waves to evaluate blood as it flows through a blood vessel. It helps doctors evaluate blood flow through the major arteries and veins of the arms, legs, neck, and heart. It can show blocked or reduced blood flow through narrowing in the major arteries.

During the ultrasound, a handheld instrument (transducer) is passed lightly over the skin above a blood vessel. The transducer sends and receives sound waves that are amplified through a microphone. The sound waves bounce off solid objects, including blood cells. The movement of blood cells causes a change in pitch of the reflected sound waves (called the Doppler Effect). If there is no blood flow, the pitch does not change. Information from the reflected sound waves can be processed by a computer to provide graphs or pictures that represent the flow of blood through the blood vessels. These graphs or pictures can be saved for future review or evaluation.

Versions of this Hardware
+ Version Used During Ground-based Experiments
+ Version Used During Space Shuttle Missions