Automated Point-of-Care Semen Analysis Using Smartphone Imaging and Occlusion-Aware Multi-Object Tracking

This paper presents an automated point-of-care semen analysis method that uses smartphone imaging to visually measure sperm concentration and motility of semen samples. The proposed method follows the same visual tracking scheme as laboratory semen analysis systems, aiming to match clinical standards while being suitable for point-of-care use. A boundary-sensitive segmentation network is developed to identify and distinguish sperm from impurities in raw semen. A novel occlusion-aware multi-sperm tracking algorithm is proposed to tackle challenges posed by smartphone imaging and undiluted raw semen samples. For automated motility measurement, an occlusion-awareness module is proposed to robustly track multiple sperm during frequent sperm crossover/occlusion. The module combines the segmented contour and kinematic-based probabilistic modeling to determine the occlusion status of both targets and measurements, facilitating fundamental improvement to feasible joint event enumeration to enable robust data association. The proposed method achieved a high success rate of 95.14% for tracking occluded sperm, with low mean errors for sperm concentration (2.03 million/ml) and motility (1.58%), outperforming existing multi-sperm tracking methods. In clinical tests involving 50 participants, our method exhibited good agreement with clinical standards (Spearman rank correlation coefficients of 0.94 for concentration and 0.89 for motility) even when used by inexperienced users.