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Principle of Echo-Dynamography
Doppler effect is the phenomenon in which the frequency of sound becomes higher when the sound source is approaching to the observer and the frequency becomes lower when the sound source goes away. In clinical Doppler echocardiography, whether blood flow is approaching or going away by using Doppler effect. However, blood flow in the heart chamber is not always along the ultrasound beam direction. Development of EchoDynamography was started here applying some laws on fluid dynamics.
In the left figure, blood flow is separated into fundamental flow component and eddy component.

Flow-Distance Function
Flow function at the distance xn from ultrasound transducer is described as flow-distance function Qn. Comparing Qn and Qn+1, the inflow point from other plane is estimated to locate at the largest difference point of Qn and Qn+1.

Example of EchoDynamography
Right figures show conventional color Doppler echocardiography, blood flow vector and stream line obtained with EchoDynamography. Experienced sonographer can assess flow direction by conventional Color flow, but EchoDynamography can quantitatively express blood flow, vector and eddy.

Expansion to 3D Blood Flow
EchoDynamography is based on 2D color Doppler echocardiography. 3D data was obtained with trans-esophageal echocardiography (TEE) and 3D blood flow is reconstructed for assessment of 3D blood flow.
By collaboration with Professor Toshiyuki HAYASE and Dr. Kenichi Funamoto, 3D blood flow simulation in aortic aneurysm is on going.
Blood flow analysis by MRI data is recently started.

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