Photoplethysmography and ultrasonic-measurement-integrated simulation to clarify the relation between two-dimensional unsteady blood flow field and forward and backward waves in a carotid artery.

Understanding the spatiotemporal change in hemodynamics is essential for the basic research of atherosclerosis. The objective of this study was to establish a methodology to clarify the relation between a two-dimensional (2D) unsteady blood flow field and forward and backward propagating waves in a carotid artery. This study utilized photoplethysmography (PPG) for blood pressure measurement and two-dimensional ultrasonic-measurement-integrated (2D-UMI) simulation for flow field analysis.

Effects of inflow velocity profile on two-dimensional hemodynamic analysis by ordinary and ultrasonic-measurement-integrated simulations.

Two-dimensional ultrasonic-measurement-integrated (2D-UMI) simulation correctly reproduces hemodynamics even with an inexact inflow velocity distribution. This study aimed to investigate which is superior, a two-dimensional ordinary (2D-O) simulation with an accurate inflow velocity distribution or a 2D-UMI simulation with an inaccurate one. 2D-O and 2D-UMI simulations were performed for blood flow in a carotid artery with four upstream velocity boundary conditions: a velocity profile with backprojected measured Doppler velocities (condition A), and velocity profiles with a measured Doppler velocity distribution, a parabolic one, and a uniform one, magnitude being obtained by inflow velocity estimation (conditions B, C, and D, respectively).

Development and feasibility study of a two-dimensional ultrasonic-measurement-integrated blood flow analysis system for hemodynamics in carotid arteries.

Prevention and early detection of atherosclerosis are critical for protection against subsequent circulatory disease. In this study, an automated two-dimensional ultrasonic-measurement-integrated (2D-UMI) blood flow analysis system for clinical diagnosis was developed, and the feasibility of the system for hemodynamic analysis in a carotid artery was revealed. The system automatically generated a 2D computational domain based on ultrasound color Doppler imaging and performed a UMI simulation of blood flow field to visualize hemodynamics in the domain.

Simultaneous analysis system for blood pressure and flow using photoplethysmography and ultrasonic-measurement-integrated simulation.

We developed a simultaneous analysis system for blood pressure and flow using photoplethysmography and ultrasonic-measurement-integrated simulation. The validity of the system was confirmed by analysis of blood flow field in a carotid artery and corresponding wave intensity (WI) values.