Measurement of very low concentration of microparticles in fluid by single particle detection using acoustic radiation force induced particle motion

Analysis and characterization of microparticles suspended in fluid have important applications in various industries. In this work, a new ultrasound-based method is proposed that enables the measurement of very low concentrations of particles in fluid. By using single particle detection, the method provides particle counts and acquires backscatter signals from individual particles. The detection method utilizes the motion of the particle induced by the acoustic radiation force and acoustic streaming. The identification of an individual particle is enabled by detecting its trajectory using a line-by-line cross-correlation and modified Hough transform. The proposed method has the potential to be used as a laboratory or a clinical device for analyzing fluid samples and studying single-cell characteristics.