Sperm quality analyzer: A portable LED array microscope with dark-field imaging

Sperm quality analysis plays an important role in diagnosing infertility, which is widely implemented by computer-assisted sperm analysis (CASA) of sperm-swimming imaging from commercial phase-contrast microscopy. A well-equipped microscope comes with a high cost, increasing the burden of assessment, and it also occupies a large volume. For point-of-care testing (POCT) of sperm quality, these factors are confronted with the challenges of low-cost and portable instruments. In this study, an encoded light-emitting diode (LED) array illumination is employed to achieve a portable microscope with multicontrast imaging for sperm quality analysis. This microscopy has dimensions of 16.5 × 14.0 × 25.0 cm, and its dark-field (DF) imaging provides high-contrast sperm image data which is suitable for CASA. According to DF imaging, we developed a software of LabCASA, which can used to assess the motility characteristics of sperm. Compared with TrackMate, the difference in motility parameters from our software was less than 10% in the coefficient of variation (CV). The sperm motility parameters vary with the chamber temperature, which further confirms the reliability of our system with DF imaging. The DF imaging provides strong robustness for tracking sperm's motion under different microscopes. For assessment of the motility parameters, our system can work at a lower cost with a plastic structure. This system with DF imaging is suitable for portable POCT of sperm quality analysis, which is highly cost-effective in resource-constrained circumstances.