A new contraceptive device that controls the flow of sperm at the flick of a switch will enter its trial phase this year and could hit the market soon. The device is the first of its kind in male contraception, according to The Local.

The idea first came to inventor Clemens Bimek, a German carpenter, 20 years ago while he was watching a documentary about contraception. Bimek saw how sperm flow can be stopped by vasectomy. He thought how a valve with an on-off switch can be mounted on each sperm duct to prevent the release of sperm, Spiegel Online reported.

Every day on his way to work, he would pass by the Berlin Patent Office in Kreuzberg and wonder if someone already had a patent for the sperm switch. After some time, he went inside and asked - and he discovered that no one had patented such a device.

"So it all started," he said.

The device, called Bimek SLV, is implanted on the vas deferens. One valve, measuring less than one inch, is mounted on each duct. The sperm switch is positioned at the scrotum and can be felt under the skin. Switching it on releases the sperm and switching it off stops the sperm from flowing.

The device can be mounted surgically in about 30 minutes. It does not require hospitalization, and the patient can go back to work the day after the procedure.

Dr. Hartwig Bauer, a urologist, said the invention is better than a vasectomy because vasectomies are not reversible.

"A third of all patients would like to have such operations reversed at a later date. But it doesn't always work," he said.

However, some experts do not share the same enthusiasm. Dr. Wolfgang Buhmann from the Society of German Urologists fears that the implant could lead to scar tissue in the vas deferens and eventually stop sperm from passing through.

Human trials for Bimek SLV will start this year. The device will be implanted in 25 volunteers. The manufacturer is still looking for more volunteers for the trial phase.