Manual and Automatic Image Analysis Segmentation Methods for Blood Flow Studies in Microchannels.

Violeta Carvalho,João E Ribeiro,Inês M Gonçalves,Andrews Souza,Diana Pinho,Maria S Souza,David Bento,Rui Lima

doi:10.3390/mi12030317

Abstract

In blood flow studies, image analysis plays an extremely important role to examine raw data obtained by high-speed video microscopy systems. This work shows different ways to process the images which contain various blood phenomena happening in microfluidic devices and in microcirculation. For this purpose, the current methods used for tracking red blood cells (RBCs) flowing through a glass capillary and techniques to measure the cell-free layer thickness in different kinds of microchannels will be presented. Most of the past blood flow experimental data have been collected and analyzed by means of manual methods, that can be extremely reliable, but they are highly time-consuming, user-intensive, repetitive, and the results can be subjective to user-induced errors. For this reason, it is crucial to develop image analysis methods able to obtain the data automatically. Concerning automatic image analysis methods for individual RBCs tracking and to measure the well known microfluidic phenomena cell-free layer, two developed methods are presented and discussed in order to demonstrate their feasibility to obtain accurate data acquisition in such studies. Additionally, a comparison analysis between manual and automatic methods was performed.

Highlights

Blood flow in microcirculation is crucial for the normal function of tissues and organs.a detailed study of blood flow patterns and blood cells flowing in microvessels, microchannels and organs-on-chip is essential to provide a better understanding of the blood rheological properties and disorders in microcirculation [1,2,3,4,5,6,7]
The purpose of this work is to review the state of the art of techniques used in in vitro blood flow studies and two developed methods (i) an automatic method to track red blood cells (RBCs) flowing through microchannels and (ii) an automatic method to measure the cell-free layer (CFL) thickness in microchannels with bifurcations and confluences will be present and discuss
The present study indicates that the data obtained from the proposed automatic method significantly matches the data obtained from the manual method

Summary

Introduction

Blood flow in microcirculation is crucial for the normal function of tissues and organs. A detailed study of blood flow patterns and blood cells flowing in microvessels, microchannels and organs-on-chip is essential to provide a better understanding of the blood rheological properties and disorders in microcirculation [1,2,3,4,5,6,7]. One of the first techniques used for the study of flow patterns was the phase-contrast magnetic resonance imaging (PC-MRI). The technique requires long acquisition times and has low resolution [8,9]. Other techniques have been developed and combined to improve the acquisition and image processing.

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