A New Hyperelastic Lookup Table for RT-DC

TL;DR

This paper introduces two new hyperelastic lookup tables for RT-DC that improve cell stiffness measurement accuracy by accounting for complex material models and geometries, supported by finite element simulations.

Contribution

The paper develops and provides two novel hyperelastic lookup tables for RT-DC based on finite element simulations, extending beyond simple linear models and cylindrical geometries.

Findings

New LUTs account for neo-Hookean hyperelasticity in square and cylindrical channels.

Shear-thinning medium influences cell deformation in RT-DC.

Proposed LUTs enhance accuracy and applicability of cell stiffness measurements.

Abstract

Real-time deformability cytometry (RT-DC) is an established method that quantifies features like size, shape, and stiffness for whole cell populations on a single-cell level in real time. To extract the cell stiffness, a lookup table (LUT) disentangles the experimentally derived steady state cell deformation and the projected area, yielding the Young's modulus. So far, two lookup tables exists, but are limited to simple linear material models and cylindrical channel geometries. Here, we present two new lookup tables for RT-DC based on a neo-Hookean hyperelastic material numerically derived by simulations based on the finite element method in square and cylindrical channel geometries. At the same time, we quantify the influence of the shear-thinning behaviour of the surrounding medium on the stationary deformation of cells in RT-DC and discuss the applicability and impact of the proposed LUTs regarding past and future RT-DC data analysis. Additionally, we provide insights about the cell strain and stresses, as well as the influence resulting from the rotational symmetric assumption on the cell deformation and volume estimation. The new lookup tables as well as the numerical cell shapes are made freely available.