Affiliations: [a] Graduate School of Engineering, Tohoku University, Sendai, Japan | [b] Institute of Fluid Science, Tohoku University, Sendai, Japan | [c] Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan | Department of Bioengineering and Robotics, Graduate School of Engineering, Tohoku University, 6-1-1 Aoba, Aramaki, Aoba, Sendai 980-8579, Japan
Correspondence:
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Address for correspondence: Dr. T. Hayase, Institute of Fluid Science, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577, Japan. Tel./Fax: +81 22 217 5253; E-mail: hayase@ifs.tohoku.ac.jp.
Abstract: Detailed information of real blood flows is essential to develop an accurate diagnosis or treatment for serious circulatory diseases such as aortic aneurysms. Ultrasonic-Measurement-Integrated (UMI) simulation, in which feedback signals from the ultrasonic measurement make the simulation converge to the real blood flow, is a key to solving this problem. However, aliasing in the ultrasonic blood velocity measurement causes UMI simulation to converge to an erroneous result. In this paper, we have investigated the detection and the correction of aliasing in UMI simulation. The artificial force in the feedback of UMI simulation can be used as an index to detect the aliasing. We have proposed two ways for the correction of the aliasing. Correction A, in which measurement velocity is replaced with the computational one at the monitoring point where the aliasing is detected, substantially improves the accuracy of UMI simulation. Correction B, in which measurement velocity is replaced with an estimated Doppler velocity, can provide exactly the same result as that of UMI simulation using the nonaliased standard solution. Although correction B gives the most accurate result, correction A seems more robust and, therefore, a beneficial choice considering the other artifacts in the measurement.
