Highly Sensitive Detection of Red Blood Cell Aggregation with Ultrasonic Peak Frequency

Abstract

A novel technique of detecting the peak frequency of an ultrasonic reflection spectrum was proposed, with the aim of enhancing the sensitivity and accuracy of estimating the aggregation size of red blood cells (RBCs). Peak frequencies for stagnant and running suspensions prepared with monodisperse particles of graphite and acryl that were used to mimic aggregated RBCs were acquired. As a result, the relationships between particle diameter and peak frequency, which were independent of the material of the particles and flow rate, were obtained. For bidisperse samples, i.e., mixtures of two different sizes of particle samples, quantitative relationships corresponding to changes in the mixing ratio were observed.

Experimental Compensation for Difference between Small‐Particle Aggregates and Substitute Large Particles in Ultrasonic Spectroscopy

“…In this investigation, we used monodisperse samples with a single particle diameter peak. However, when using bidisperse specimens, it has been found that the peak frequency can be estimated from the two particle diameters and their mixing ratio . In combination with the present research, we may conclude that the relationship between the aggregate diameter and the peak frequency can also be measured for bidisperse or polydisperse aggregate samples.…”

“…In our earlier research , experiments on materials including acrylic particles with diameters of 6 μm to 46 μm and graphite particles with diameters of 5 μm to 20 μm showed that the peak frequency is dependent only on the diameter. In addition, Figs.…”

Introduction of measurement techniques in ultrasonic electronics: Basic principles and recent trends

“…Scattering [359][360][361][362][363][364] Ultrasonic transducers (piezoelectric effect) and its attachments [375][376][377][378][379][380][381] Acoustic field measurement and control [382][383][384][385][386] Blood flow measurement [394][395][396][397] Tissue characterization Velocity [125][126][127][128][129][130][131][132][133][134][406][407][408]420,422) Displacement 409,413,425) Thickness 399,418) Viscoelasticity 398,[401][402][403][404][405][410]…”

Maximum likelihood estimation of red blood cell aggregation degree based on calculation of local flow vector in blood circuit

“…Aiming at key indicators of patient conditions such as drug dosage by means of real‐time monitoring of blood viscosity, we previously applied optical and ultrasonic methods to blood viscosity measurement during extracorporeal circulation treatment . The measurement principle is based on close relationship between blood viscosity and red blood cell aggregation degree; the focus is put on behavior of red blood cells on blood flow surface observed through a blood circuit made of transparent polyvinyl chloride tubes.…”

“…Aiming at key indicators of patient conditions such as drug dosage by means of real-time monitoring of blood viscosity, we previously applied optical and ultrasonic methods to blood viscosity measurement during extracorporeal circulation treatment. [2][3][4][5] The measurement principle is based on close relationship between blood viscosity and red blood cell aggregation degree [6][7][8][9] ; the focus is put on behavior of red blood cells on blood flow surface observed through a blood circuit made of transparent polyvinyl chloride tubes. Red blood cells in an aggregate are bonded together via a coupling mechanism called cross-linking; thus in this study, we assume that positional relationship between red blood cells in an aggregate is steadily maintained over time, and that correlation between time-difference images observed at a fixed point depends on the degree of aggregation.…”