High-precision absolute cell counting with curved sample chamber

Abstract

We propose a wide field-of-view fluorescence imaging system with a curved sample chamber that corrects the field curvature caused by a simple lens. We describe a simple optical imaging system for absolute counting of white blood cells (WBCs) in a large-field with our alternative approach to reduce field curvature effect in a flat image plane by replacing the conventional planar sample chamber with a curved one while using a single lens. We designed a curved substrate with a lens-dependent curvature and evaluated imaging performance through ray tracing analysis and image system simulation. The distortion of image taken with a conventional planar detector is greatly reduced by the curved sample substrate, which is also demonstrated by a proof-of-concept experiment. A field-of-view of 10.66, mm, ×, 8, mm was analyzed to count the WBCs and the imaging system’s magnification factor was 0.66. The absolute counts of WBCs, between commercially available conventional microscopy and proposed single-lens imaging system, were found to be matched reasonably.