Using polynomial modeling for calculation of sperm quality parameters in CASA

Abstract

Measurement of sperm velocity parameters takes an important place in sperm analysis. Today, computer-assisted sperm analysis (CASA) systems are used to detect motility measurements such as VCL (Curvilinear Velocity), VSL (Linear Velocity) and VAP (Average Path Velocity). The path length of sperm cells is necessary to calculate the motility parameters and it is calculated using video processing. However, this path length is obtained by the discrete-time processing of video frames, which can lead to unrealistic results. In CASA systems, the frame rate of the videos is increased to obtain the natural path length, but in this case, it is necessary to increase the hardware cost as well. Polynomial modeling applied to measure the natural path length in discrete-time structures can solve this problem. In this study, Lagrange interpolation which is an effective polynomial modeling method was used to obtain the natural path length and velocity parameters of the sperm. The results of the study showed that, when applied the polynomial modeling to calculate VCL and VAP parameters, it was found that especially in the low frame rate, more effective data were obtained than the classical method. As a result of this study, it is recommended to use polynomial modeling in the sperm velocity calculations of CASA systems, although there is an increase in calculation time.