Detection and tracking of low contrast human sperm tail

Tracking sperm tail movement provides important information for clinical sperm research. It is also a crucial step for sperm immobilization in Intracytoplasmic Sperm Injection (ICSI). However, the low visibility of the sperm tail under optical microscopy, coupled with the sperm fast motility, render sperm tail identification and tracking challenging tasks to execute. This paper presents two approaches for sperm tail tracking: (1) the Maximum Intensity Region (MIR) algorithm, and (2) the Optical Flow (OF) algorithm. The algorithms were evaluated by calculating the Euclidean distance error between each tail tracking algorithm´s computed tail location and a user´s manual input via mouse click of the tail´s image location. Experimental results demonstrate that the OF algorithm and MIR algorithm are both capable of tracking the sperm tail with minimal error when viscous liquid is added to the sperm culture medium, which is the present clinical standard practice for slowing down sperm movement. The MIR algorithm outperforms the OF algorithm by 52% in tail tracking accuracy in situations where the viscous liquid is absent.