Temporal Variation Characteristics of Analysis Accuracy in Two-Dimensional Ultrasonic-Measurement-Integrated Blood Flow Analysis

2016 ◽  
Author(s):  
Hiroko Kadowaki
Keyword(s):  
Blood Flow ◽  
Temporal Variation ◽  
Flow Analysis ◽  
Measurement Data ◽  
Ultrasonic Measurement ◽  
Doppler Velocity ◽  
Feedback Gain ◽  
Cfd Analysis ◽  
Variation Characteristics ◽  
Blood Flow Analysis

A two-dimensional ultrasonic-measurement-integrated (2D-UMI) blood flow analysis system was developed for easy acquisition of an intravascular hemodynamics, which feeds back Doppler velocity obtained by an ultrasonic measurement to a numerical blood flow simulation for clinical application. In previous study, ultrasonic measurement and 2D-UMI simulation were performed to clarify the analysis accuracy for real flow field. Additionally, spatial variation characteristics of analysis accuracy was clarified by comparison of velocity vectors between 2D-UMI and 3D-CFD analysis results corresponding to an experimental flow. However, temporal variation of analysis accuracy of 2D-UMI analysis result has not been examined in spite of essential information for reduction of experimental measurement error due to speckle noise. The aim of this study was to clarify temporal variation characteristics of analysis accuracy of each velocity component obtained in 2D-UMI blood flow analysis. Comparisons of Doppler velocity V and (u, v) velocity profiles between measurement data, 2D-UMI, and 3D-CFD analysis results were performed, and their time variations were discussed. As a result, it was clarified that temporal variation of Doppler velocity error for measurement data became larger with increasing feedback gain. Temporal variations of u and v velocity component errors for 3D-CFD analysis result showed the same tendency as that of Doppler velocity in feedback gain.

Feasibility Verification of Blood Viscosity Estimation by Two-Dimensional Ultrasonic-Measurement-Integrated Blood Flow Analysis

2021 ◽  
Vol 4 (2) ◽  
Author(s):  
Hiroko Kadowaki ◽  
Takuya Kishimoto ◽  
Takeshi Tokunaga ◽  
Koji Mori ◽  
Takashi Saito
Keyword(s):  
Blood Flow ◽  
Flow Field ◽  
Blood Viscosity ◽  
Flow Analysis ◽  
Ultrasonic Measurement ◽  
Doppler Velocity ◽  
Two Dimensional ◽  
Blood Flow Analysis ◽  
Analysis System

Abstract Although blood viscosity has attracted much attention for its effect on hemodynamic parameters related to atherosclerosis, quantitative method for evaluating blood viscosity in vivo is not currently established. The purpose of this study was to verify the feasibility of blood viscosity estimation by a two-dimensional ultrasonic-measurement-integrated (2D-UMI) analysis system that computes an intravascular blood flow field by feeding back an ultrasonic measurement data to a numerical simulation. A method to estimate blood viscosity was proposed by reproducing the flow field of an analysis object in the feedback domain of ultrasonic Doppler velocity in a 2D-UMI blood flow analysis system, and evaluating the variation of the Doppler velocity caused by the analysis viscosity in the nonfeedback domain at the downstream side. In a numerical experiment, a viscosity estimation was performed for numerical solutions of sinusoidal oscillating flows analyzed as a blood flow model in a human common carotid artery at four different types of blood viscosities. The estimation viscosities were made to correspond to those of all analysis objects by giving proper conditions on the feedback gain and feedback domain to optimize the accuracy of the 2D-UMI blood flow analysis. In conclusion, the feasibility of blood viscosity estimation by 2D-UMI analysis was established. Simultaneous measurement of the in vivo blood viscosity and flow field can be easily performed in many clinical cases by its widespread use at clinical sites, thereby clarifying the relationship between hemodynamics and vascular pathology for various blood flow fields.

Effect of Feedback Conditions on Blood Viscosity Estimation Method in Two-Dimensional Ultrasonic-Measurement-Integrated Blood Flow Analysis

2019 ◽  
Author(s):  
Takuya Kishimoto ◽  
Hiroko Kadowaki ◽  
Takeshi Tokunaga ◽  
Koji Mori ◽  
Takashi Saito
Keyword(s):  
Blood Flow ◽  
Shear Stress ◽  
Blood Viscosity ◽  
Flow Analysis ◽  
Estimation Method ◽  
Ultrasonic Measurement ◽  
Estimation Accuracy ◽  
Feedback Gain ◽  
Two Dimensional ◽  
Blood Flow Analysis

Abstract Wall shear stress from blood flow is particularly considered to be a factor that promotes atherosclerosis, and is expressed as the product of blood viscosity and velocity gradient of blood flow. If in vivo wall shear stress can be evaluated by simultaneously measuring blood flow velocity and blood flow velocity gradient in real time, it is thought that blood viscosity estimation leads to elucidation of mechanism of arteriosclerosis and early detection. In previous study, a blood viscosity estimation method was proposed by applying two-dimensional ultrasonic-measurement-integrated (2D-UMI) blood-flow analysis reproducing an intravascular blood flow field by feeding back an ultrasonic measurement to a numerical fluid analysis. The estimation accuracy was examined by a numerical experiment under specific conditions. However, the effects of analysis conditions on this method are not verified. Accordingly, we investigated the effects of the feedback domain and the feedback gain on the estimation accuracy, and examined appropriate feedback conditions by a numerical experiment for a blood flow field of a straight blood vessel assuming a common carotid artery. As a result, it was suggested that the estimation accuracy generally improves as the feedback gain is increased in a specific feedback domain.

2F42 Validation of Accuracy of Velocity Vectors in Two-Dimensional Ultrasonic-Measurement-Integrated Blood Flow Analysis

2016 ◽  
Vol 2016.28 (0) ◽  
pp. _2F42-1_-_2F42-5_
Author(s):  
Hiroko KADOWAKI ◽  
Toshiyuki HAYASE ◽  
Suguru MIYAUCHI ◽  
Kosuke INOUE ◽  
Tadashi SHIMAZAKI ◽  
...  
Keyword(s):  
Blood Flow ◽  
Flow Analysis ◽  
Ultrasonic Measurement ◽  
Two Dimensional ◽  
Blood Flow Analysis
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