Multielectrode Sensing for Extraction of Signal From Noise in Impedance Cytometry

We demonstrate a novel multielectrode sensing method for extracting signal from noise in a microfluidic impedance cytometer through introducing redundancy in our measurements and coding the signal. We use a pair of coplanar interdigitated electrodes (IDEs), where we can sense the change in impedance between any two neighboring fingers of the IDE pair. In the context of impedance cytometry, the passage of beads or cells over each two neighboring fingers partially occludes the current measured between the IDE pair. Therefore, as each particle enters and leaves the electrode area, we measure a train of pulses. By applying the equivalent matched filter we can exploit this train of pulses to proportionally increase the signal-to-noise ratio in our measurements.