| Radio Controlled Birth Control for men?
A radio-controlled contraceptive implant that could control the flow
of sperm from a man's testicles is being developed by scientists in
Australia.
The device is placed inside the vas deferens ? the duct which
carries sperm from each testicle to the penis. When closed, it
blocks the flow of sperm cells, allowing them to pass again when it
is opened via a remote control. The valve could be a switchable
alternative to vasectomy, the researchers say.
Although women can choose from several long-term contraceptive
methods, for men vasectomy is really the only option. With this
procedure, the vasa deferentia are cut or blocked, a process that
requires surgery and can require a week of recovery. The procedure
cannot be reliably reversed, leaving some men to later regret their
decision.
Now, a team from the University of Adelaide, Australia, may have
come up with a more easily reversed alternative. They have designed
a small radio-controlled valve that would "push-fit" snugly inside
the vas deferens and block the passage of sperm.
The silicone-polymer valve can be flipped between open and closed
positions with a pulse of radio waves. A set of conducting "fingers"
on the valve act as antennae and convert the signal's energy into
sound waves that travel through the polymer and create stresses
inside the device.
Remote control
"Since it is flexible, the polymer either contracts or expands as a
result, and this movement allows the valve to be opened or closed as
needed," explains team leader Said Al-Sarawi.
"It will be like turning a TV on and off with a remote control,"
added team founder Derek Abbott, "except that the remote will
probably be locked away in your local doctor's office to safeguard
against accidental pregnancy or potential misuse of the device."
To secure the device against accidental activation, the device works
in a similar way to a car's remote key-fob. Each valve responds only
to a radio-frequency signal with a unique code.
Another advantage of the microvalve is that would not require open
surgery, unlike a vasectomy. The 800 micron-long device could simply
be inserted using a hypodermic needle. "The procedure could be
performed in a special clinic rather than in a hospital," says Abbott.
The researchers have finished the design of all parts of the valve,
and are convinced it will work effectively. The next step is to test
it in the lab with a tube of pressurized water. After that, trials
could begin in live sheep and pigs, they say.
'Grace period'
One potential problem, however, is that after a while the valve may
clog with protein and remain shut, rendering the man permanently
infertile.
"We would only propose the device to men who were thinking of having
a full vasectomy anyway," said Abbott. "But, unlike in an actual
vasectomy, he would have a 'grace period' where the procedure can
easily be reversed." How such a device affects gender politics would
also make a fascinating social study, he added.
Men who regret a vasectomy can often only have children using donor
sperm, says Natalie Gamble, associate with UK law firm Lester Aldridge.
"Although the law protects families conceiving with the help of a
sperm donor, this type of conception has significant legal and
emotional implications," she adds. " I am sure men will welcome the
chance to control their fertility more flexibly, and to preserve the
chance to have their own genetic child."
Joe Hofmeister is president of US firm Shepherd Medical Company,
which is also working on male contraceptive devices. "Consumer
market research performed by an independent third party for Shepherd
confirms a strong patient desire for a permanent-yet-reversible male
contraceptive such as the microvalve or other such system."
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