An On-Chip RBC Deformability Checker Significantly Improves Velocity-Deformation Correlation

Area of Science:

• Biomedical Engineering
• Cellular Mechanics
• Microfluidics

Background:

• Red blood cell (RBC) deformability is crucial for evaluating cellular health and is linked to various human diseases.
• Conventional methods assess RBC deformability by correlating cell velocity with deformation through microfluidic constrictions, but often yield moderate correlations due to limited deformation ranges.

Purpose of the Study:

• To develop an on-chip deformability checker that overcomes the limitations of conventional methods by extending the range of RBC deformation.
• To significantly improve the correlation between RBC transit velocity and deformation for more accurate RBC evaluation.

Main Methods:

• Implementation of an on-chip checker featuring three microfluidic constrictions of varying widths to induce distinct RBC deformation levels.
• Simultaneous evaluation of RBC responses across the three deformation regions to obtain a comprehensive dataset.
• Testing of RBCs from five volunteer subjects using the developed checker.

Main Results:

• The proposed on-chip checker significantly enhances the correlation between RBC deformation and transit velocity, increasing the absolute correlation coefficients from an average of 0.54 to 0.92.
• The extended range of deformation applied by the multi-constriction design effectively addresses the limitations of previous approaches.
• Experimental results also provide insights into the influence of cell size, shape, and orientation on the evaluation.

Conclusions:

• The developed on-chip deformability checker offers a robust and accurate method for evaluating RBC deformability.
• This technology has the potential to significantly benefit medical practices by providing more reliable diagnostic information.
• The improved velocity-deformation correlation facilitates better understanding of RBC mechanics in relation to health and disease.