Acoustofluidic phase microscopy in a tilted segmentation-free configuration

TL;DR

This paper introduces a cost-effective, registration-free quantitative phase microscopy method using acoustic focusing and tilted geometry to image flowing cells without segmentation, suitable for biological applications.

Contribution

The paper presents a novel tilted segmentation-free configuration for quantitative phase microscopy that simplifies imaging of flowing cells without the need for segmentation or moving parts.

Findings

Successfully images red blood cells in flow

Recovers phase maps without segmentation

Cost-effective and robust implementation

Abstract

A low-cost device for registration-free quantitative phase microscopy (QPM) based on the transport of intensity equation (TIE) of cells in continuous flow is presented. The method uses acoustic focusing to align cells into a single plane where all cells move at a constant speed. The acoustic focusing plane is tilted with respect to the microscope's focal plane in order to obtain cell images at multiple focal positions. As the cells are displaced at constant speed, phase maps can be generated without the need to segment and register individual objects. The proposed inclined geometry allows for the acquisition of a vertical stack without the need for any moving part, and it enables a cost-effective and robust implementation of QPM. The suitability of the solution for biological imaging is tested on blood samples, demonstrating the ability to recover the phase map of single red blood cells flowing through the microchip.