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New Male Birth Control Device Can Be Turned On and Off Like a Light Switch

To prove he was serious, inventor Clemens Bimek decided to experiment on his own body.

Imagine male birth control that could be flipped on and off like a light switch. If German inventor Clemens Bimek has anything to say about it, his small, valve-like device, the Bimek SLV, will allow men to take sperm in and out of their ejaculatory system at will. And to prove he’s serious about it, Bimek decided to experiment on himself—he’s already implanted the valve in his own body.

The basic idea of SLV, as Bimek tells GOOD, is almost 20 years old now. Back in 1998, when he was living in Berlin, he wondered why the decision to have a vasectomy had to be so final.

“The idea came while I was watching a health advice program on television,” Bimek says. “It showed a segment about vasectomies, something I had never heard before. The first thing that came to my mind was, ‘Why not just insert a valve instead of simply cutting it?’”


The only problem was that Bimek was neither a doctor nor a surgeon—he worked in construction. But the daily walk from his home to the job site took him past the Berlin-Kreuzberg patent office. On a whim one day, he stopped in to see if any patents for similar devices already existed.

“I decided to do some research on the topic and discovered that a few developments had already been attempted in this direction,” Bimek says. “But to me, these methods seemed overly complicated and therefore impractical. That was the day I began to develop my ideas and to work on a first prototype.”

“I didn’t know about the size of a spermatic duct nor about its structure,” Bimek explains. “I spent hours, day, weeks, months, years reading, studying the subjects of andrology and urology, gaining extensive knowledge about the complex processes of male genitalia and contraception. I conducted interviews with specialists and scientists, met with many experts and, more often than not, was faced with skepticism and disregard.”

Undeterred, Bimek began his preparatory work for the device’s design, which involved watching videos of vasectomies and reverse vasectomies to understand the male reproductive system. Starting with technical drawings, Bimek ultimately settled on a design that involved transecting the vas deferens (the sperm duct), just as in a vasectomy.

When the vas deferens is cut, it’s no longer connected to the seminal vesicle, which produces the ejaculatory fluid and also serves as the place where this fluid and sperm are mixed to produce semen. When the device—which, again, functions like a light switch or castle gate—is implanted, the severed ends of the vas deferens are fitted into the valve, then held in place by a connector, similar to the way a garden hose might fit into a spout. Switching the device on prevents the introduction of sperm into ejaculatory fluid, effectively sterilizing the user. Switching it off lets the sperm flow back into the fluid, once again producing semen.

As a vegetarian, Bimek ruled out animal testing from the get-go, opting instead to go straight to the human body—or, in this case, his own scrotum. This step in and of itself proved difficult because he had to find someone to approve the surgery, which he eventually did through his local hospital’s ethics committee.


“[At] first I wasn’t too keen on it—test it on myself? Really?” Bimek says. “But, on the other hand, did I have any other option? No. How could I find out if it works? How should I know about the operation, possible pain, possible complications? How could I tell anyone anything about living with the SLV every day, how life changes or not? How would I know what still had to be changed? I didn’t want to do any animal testing.”

“So there was no other option other than testing it on myself,” he adds. “Isn’t that something most inventors do?”

While the device has worked for Bimek, he still has to put the SLV through clinical trials. For this, Bimek is looking for older males who already have children and are seriously considering a vasectomy. The idea is that even if something were to go wrong—like the device failing to work in a candidate, creating a permanent vasectomy—then the resulting situation wouldn’t be as bad as it would for a man who truly wants the flexibility of undoing the procedure in order to have children.

Helping Bimek take the SLV to clinical trials is Peter Schnückel, an entrepreneur who agreed to financially back the device’s development. Schnückel isn’t a medical doctor, but like Bimek he shares a desire to disrupt the contraception industry. And like Bimek, Schnückel rejects the idea, proffered by doctors and surgeons they’ve spoken to, that males won’t opt for an implant that gives them this kind of flexibility in their reproductive lives.

Peter Schnückel

Schnückel quickly helped Bimek bring the idea to the public. Philipp Renger, who’s also working on the Bimek SLV project, says that after its unveiling three months ago, German news outlets started covering the device, which led to positive emails from thousands of men willing to take part in clinical trials. Other men who had vasectomies years ago, but who had since met partners who wanted children, told Bimek they would have opted for his device had it existed.

Because of the device’s manufacturing costs, Renger says the switch is probably going to be more expensive than a vasectomy, which can cost as much as $1,000 in the United States. But Bimek believes that this is a cost men will be willing to absorb if it means they can change their minds down the road. Renger says the SLV is definitely a product for people who have a fixed relationship and children, and want a better option than the condom, which isn’t 100 percent effective.

“The only twist is that if the device is turned on and the sperm cells are held back, then you’re supposed to be sterile, but some sperm cells are left in the spermatic duct,” Renger says. “It takes 12 weeks or more until all of those sperm cells are dead, or it takes 20 to 30 ejaculations for all of the sperm cells to be flushed out.”

Renger tells GOOD that if the device is approved after clinical trials, men would have to wait three to six months for the sperm to be fully evacuated from the seminal vesicles to be safe. But the process of turning the device off, allowing the sperm to once again enter the ejaculatory fluid, would be far quicker.

“You’re fertile probably within a couple of minutes or hours,” Renger says. “As soon as you turn it off, the sperm cells can flow through [the device] and get mixed with the ejaculatory fluid, and that’s it.”

Bimek’s team is awaiting ethics committee approval of a clinical trial. If approval is granted, he plans to go ahead with trials in the second half of 2016, concluding the following year. If all goes well, Bimek hopes to have medical certification to begin manufacturing the Bimek SLV device by 2018. And then there just might begin to be more equality in birth control amongst the sexes.

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