Design of a fluidic circuit-based microcytometer for circulating tumor cell detection and enumeration

Portable devices have been introduced to provide companion diagnostics in many applications such as personalized healthcare monitoring since several decades ago. Recently the polydimethylsiloxane (PDMS)-based microfluidic chip enables a cost effective platform for point of care diagnostics. In this paper, we present a systematic theoretical and experimental study of a novel fluidic circuit-based microcytometer. The working principle of this device is based on the characterization of the bandwidth and amplitude of the bias-voltage pulses induced by the microparticle's physical blockage of the sensing aperture. In the simulation, the amplitude and bandwidth of the bias voltage change is simply related to the microparticle translocation time and resistance change in the sensing aperture. In the modeling part, we simulate the two parameters (peak and translocation time) by considering 7 μm and 16 μm, which is used to approximately characterize the Red Blood Cells (RBCs) and Circulating Tumor Cells (CTCs). In the experimental setup, microparticles of different sizes are used to demonstrate the chip performance. Furthermore, RBCs and CTCs are detected and enumerated by the proposed chip. The microcytometry chip is presented and is expected toward the point of care clinical diagnostics.