Portable semen analyzer for automated, rapid measurement of sperm motility and concentration

Abstract

Semen analysis is the cornerstone of male infertility testing but many men tend to find the process of producing a sample at a lab uncomfortable and are reluctant to being tested. Our earlier work suggested that the integration of advancements in consumer electronics and microfabrication could be a powerful solution for developing a home-based male infertility screening [1]. Here, we report a versatile portable semen analyzer that can automatically perform the test and is not dependent on the smartphone camera for data acquisition, which makes it more adaptable to all of the smartphones in the market. The optical system can qualitatively classify semen samples (positive/negative) based on the World Health Organization guidelines (15 million sperm/mL and 40% motility) for seminal quality estimation [2]. When paired with any smartphone, it can also quantify sperm concentration (SC) and motility (SM). The hardware of the standalone device includes a 3D printed case, a miniaturized computer (SBC), a digital image sensor (CMOS), and DVD lenses to record videos and transmit data to a paired smartphone wirelessly. The smartphone application is designed to measure sperm concentration and motility using the transferred video from the stand-alone device. We evaluated the system using 30 semen samples and compared the smartphone-based results with manual analysis. Our custom-designed microfluidic devices enable simple, power-free semen sample handling. The loaded disposable microchips were inserted into a slot on the stand-alone device for data acquisition and analysis. The quantitative and qualitative sperm concentration and motility measurements were compared against the results obtained by manual analysis. The overall agreement between the two methods was evaluated using Bland-Altman’s absolute difference method of analysis. The accuracy of the system in normal/abnormal classification of the semen samples based on the WHO guidelines on SC and SM was calculated. Bland-Altman analysis revealed -3.3 million sperm/mL (LoA: 24.01 to -31.06) and 1.6 % (LoA: 9.6 to -6.1) mean biases for SC and SM, respectively. The accuracy of the device in classifying semen samples based on the concentration threshold of 15 million sperm/mL and the motility threshold of 40% was 100% for our tested sample set. These results suggest that the developed stand-alone device is able to measure sperm concentration and motility of an unwashed semen sample without any dependency to the smartphone camera. Such a device can be used with any smartphone model in the market without requiring any physical modification in the system. The mean processing time for transmission and analysis of a video on-phone is <10 seconds.