Proc. SPIE. 10333, Optical Methods for Inspection, Characterization, and Imaging of Biomaterials III
KEYWORDS: Holograms, Holography, Microfluidics, Real time imaging, Digital holography, Ultrasonography, Microscopy, Particles, Phase imaging, Lab on a chip, Acoustics, 3D image processing, Automatic tracking, Digital image correlation and tracking
We demonstrate a 3D holographic tracking method to investigate particles motion in a microfluidic channel while unperturbed while inducing their migration through microfluidic manipulation. Digital holography (DH) in microscopy is a full-field, label-free imaging technique able to provide quantitative phase-contrast. The employed 3D tracking method is articulated in steps. First, the displacements along the optical axis are assessed by numerical refocusing criteria. In particular, an automatic refocusing method to recover the particles axial position is implemented employing a contrast-based refocusing criterion. Then, the transverse position of the in-focus object is evaluated through quantitative phase map segmentation methods and centroid-based 2D tracking strategy. The introduction of DH is thus suggested as a powerful approach for control of particles and biological samples manipulation, as well as a possible aid to precise design and implementation of advanced lab-on-chip microfluidic devices.