High efficiency rare sperm separation from biopsy samples in an inertial focusing device.

Immotile and rare sperm isolation from a complex cell background is an essential process for infertility treatment. The traditional sperm collection process from a biopsy sample requires long, tedious searches, yet still results in low sperm retrieval. In this work, a high recovery, high throughput sperm separation process is proposed for the clinical biopsy sperm retrieval process. It is found that sperm have different focusing positions compared with non-sperm cells in the inertial flow, which is explained by a sperm alignment phenomenon. Separation in the spiral channel device results in a 95.6% sperm recovery in which 87.4% of non-sperm cells get removed. Rare sperm isolation from a clinical biopsy sample is performed with the current approach. The chance of finding sperm is shown to increase 8.2 fold in the treated samples. The achieved results highly support this method being used for the development of a rapid biopsy sperm sorting process. In addition, the mechanism was proposed and can be applied for the high-efficiency separation of non-spherical particles in general.

An automated instrument for intrauterine insemination sperm preparation.

Sperm preparation is critical to achieving a successful intrauterine insemination and requires the processing of a semen sample to remove white blood cells, wash away seminal plasma, and reduce sample volume. We present an automated instrument capable of performing a sperm preparation starting with a diluted semen sample. We compare our device against a density gradient centrifugation by processing 0.5 mL portions of patient samples through each treatment. In 5 min of operating time, the instrument recovers an average of 86% of all sperm and 82% of progressively motile sperm from the original sample while removing white blood cells, replacing the seminal plasma, and reducing the volume of the sample to the clinically required level. In 25 min of operating time, density gradient centrifugation recovers an average of 33% of all sperm and 41% of progressively motile sperm. The automated instrument could improve access to IUI as a treatment option by allowing satellite doctor's offices to offer intrauterine insemination as an option for patients without the clinical support required by existing methods.

Microfluidic-based sperm sorting & analysis for treatment of male infertility.

Microfluidics technology has emerged as an enabling technology for different fields of medicine and life sciences. One such field is male infertility where microfluidic technologies are enabling optimization of sperm sample preparation and analysis. In this chapter we review how microfluidic technology has been used for sperm quantification, sperm quality analysis, and sperm manipulation and isolation with subsequent use of the purified sperm population for treatment of male infertility. As we discuss demonstrations of microfluidic sperm sorting/manipulation/analysis, we highlight systems that have demonstrated feasibility towards clinical adoption or have reached commercialization in the male infertility market. We then review microfluidic-based systems that facilitate non-invasive identification and sorting of viable sperm for in vitro fertilization. Finally, we explore commercialization challenges associated with microfluidic sperm sorting systems and provide suggestions and future directions to best overcome them.