Connecting the Non-Brownian Dots: Increasing Near-Neighbor Particle-Tracking Efficiency by Coordinate System Manipulation.

The nearest-neighbor algorithm (N-N) for single particle tracking (SPT) is widely employed for studying the deformation and mechanics of soft materials, or to detect flow in microfluidic systems. However, this algorithm may not perform well under certain conditions of oscillatory or directed motion of the studied tracers. Here, a method is presented with the goal of improving the performance of NN-SPT algorithms when studying directed and oscillatory motions. Specifically, the approach applies a change-of-basis matrix to the detected particles positions, prior to the calculations made by the NN-SPT algorithm. The presented results demonstrate the superior tracking efficiency when analyzing these systems, manifested via lower tracking mismatches and less spurious results than the original N-N algorithm.