Impedance-based assessment of blood samples

A method comprising:

• perfusing a fluid sample including red blood cells into at least one microchannel of a microfluidic device, wherein the at least one microchannel includes a plurality of micropillar arrays arranged in a direction of fluid flow through the at least one microchannel, and each of the plurality of micropillar arrays is located between a respective electrode pair;
• measuring an electrical impedance of at least one micropillar array between a respective electrode pair including at least one measurement before the fluid sample has entered the microchannel and at least one measurement after the fluid sample has entered the microchannel, wherein the perfusion of the fluid sample and the measuring of electrical impedance are performed in the absence of washing of the microchannel;
• determining a normalized impedance change for the at least one micropillar array based on the measurements of the electrical impedance;
• and
• determining an assessment of deformability and/or microcapillary occlusion of the red blood cells in the fluid sample based on the normalized impedance change determined for the at least one micropillar array.

A method of measuring efficacy of a therapeutic agent in modulating red blood cell adhesion and/or deformability, the method comprising:

• perfusing a fluid sample including red blood cells through at least one microchannel of a microfluidic device, wherein the at least one microchannel includes a plurality of micropillar arrays arranged in a direction of fluid flow through the at least one microchannel, and each of the plurality of micropillar arrays is located between a respective pair of electrodes;
• measuring an electrical impedance of at least one micropillar array in the at least one microchannel before and after perfusion of the fluid sample through the at least one microchannel, wherein the perfusion of the fluid sample and the measuring of the electrical impedance are performed wash-free;
• determining a normalized impedance change for the at least one micropillar array based on the electrical impedance measured before and after the fluid sample is being perfused through the microchannel;
• and
• determining the measure of efficacy of the therapeutic agent based on a comparison of the normalized impedance change for the at least one micropillar array to a control.