When performing in vitro fertilization, it's important to use the "best" sperm possible – this will increase the patient's chances of getting pregnant, reducing the number of treatment cycles required. And while there are already sorting methods that select the fastest-swimming sperm, a new microfluidic device also ensures that they're the healthiest.

Known as SPARTAN (Simple Periodic ARray for Trapping And IsolatioN), the gadget was designed by a team from Worcester Polytechnic Institute and Stanford University. It measures only about 4 mm wide by 12 to 16 mm long, and contains an array of tiny three-dimensional posts that serve as a mini obstacle course.

The process starts with donor semen being injected into one end of the device. As it flows to the other end, the sperm in the semen have to make their way through that obstacle course. Before the inferior sperm can complete the course, the top performers are collected at the "finish line."

You can see animation of such a sperm race, in the following video.

Although swimming speed is certainly an issue, SPARTAN also selects against malformed sperm that would have difficulty navigating the course, such as those with bent necks or abnormally large heads. The whole process takes between 5 and 30 minutes to complete, and can be performed on-site at a fertility clinic.

"With SPARTAN, we not only get sperm with excellent motility, but also with normal morphology and better DNA integrity, helping families worldwide by reducing the stress of multiple IVF procedures, while potentially increasing pregnancy rates," says Worcester's associate professor Erkan Tüzel, who led the research along with Stanford's Prof. Utkan Demirci.

The technology has been licensed to Maryland-based company DxNow, which plans to release a product commercially in July.

A paper on the research was recently published in the journal Advanced Science.

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