Investigation of Red Blood Cell Properties on Impedance Signatures Generated in a Coulter Counter.

The ability of red blood cells (RBCs) to deform is essential for microcirculation and oxygen delivery. Any changes in RBC deformability can lead to significant cardiovascular complications, necessitating timely detection. Although specialized microdevices can be designed to assess RBC deformability, leveraging instruments already used in clinical settings would enable easier integration and accelerate clinical translation. Coulter counter (CC) systems are routinely used to count, size, and analyze RBCs and the possibility to extend their diagnostic capabilities to RBC deformability is currently examined. In this study, the effects of RBCs' geometrical, morphological, and rheological properties on CC measurement have been investigated numerically, thanks to a simulation framework predicting the RBC dynamics in a CC and the associated impedance signature. Subsequently, a numerical parametric study has been performed, and the resulting pulses have been compared with experimental results, confirming the simulation's accuracy in predicting CC measurements. In addition to the RBC volume and the RBC trajectory in the sensing region, which had been investigated before, present results show that in our modeling framework, RBC sphericity, membrane viscosity, and cytoplasm viscosity are the main RBC characteristics contributing to the broad CC measurement spectrum observed experimentally when analyzing healthy blood samples.