IEEE Spectrum June, 2015 - 74

Part 3: Changing the Code

the aRgument

Robotics

kevin Fu

Will BioniC
Bodies GeT
HaCked?
the u.s. food and drug administration
issued the first cybersecurity guidelines
for medical devices. what's in them?
They're the equivalent of hand washing in
medicine-they're the basics. Cybersecurity
hand washing means you enumerate the risks,
put in place technical controls to mitigate the
risks you've identified, and make sure you
have the ability to determine if those controls
are working effectively. To security professionals this isn't surprising, but to a biomedical
engineer it really is groundbreaking.

as patIents welcome
neurostimulators, medical microbots,
and other hardware into their bodies,
they're welcoming potential security flaws
too. Kevin Fu, an associate professor
of electrical engineering and computer
science at the University of Michigan, says
the medical device industry needs to get
serious about cybersecurity now to ensure
that life-saving technologies remain safe
and trusted in the future.
ieee sPectRUM: are medical device
manufacturers considering security
early enough in the design process?
KevIn fu: Yes and no. Some
manufacturers show up to meetings about
improving medical device security and
participate in good faith. The real problem
is that some manufacturers still aren't
showing up.
yet you and others have shown how
medical devices can be compromised.
I don't see any maliciousness. If you're a
manufacturer and some hacker comes and
says the sky is falling, you'd probably laugh it
off. The sensationalism has a negative impact.
It distracts from the serious engineering.

what's the biggest security threat to
medical devices today?
The main risk is conventional malware
that accidentally breaks into a medical
device. That is not your sinister hacking plot.
For example, the FDA got a report that a
pharmaceutical compounder [a machine that
makes liquid drugs] had Conficker, a rather
old worm. It turns out the compounder was
running Windows XP Embedded, a 10-yearold operating system. It was completely
susceptible. This is classic hand washing:
Imagine you haven't washed your hands for
10 years and then you decide to pick your nose.
-Interview by Eliza Strickland

20 m or so of fast, directed motion, he
says, so it's likely that external guidance will be needed to get the device
most of the way to its destination.
One of Nelson's targets is the retina.
Today, drugs designed to treat the retina can be injected into the eye, where
they slowly diffuse, but only a fraction
of such a dose may reach its target.
Microbots laden with drugs, Nelson
says, could potentially deliver them
74

jun 2015

north american

in a more targeted manner, reducing
doses as well as side effects.
One obvious strategy for guiding a
robot to the right spot is to build it out
of magnetic materials and then steer
it externally with magnets. Researchers have used MRI machines to do this
in animals. But Nelson, Sitti, and others are pursuing less powerful electromagnet configurations capable of
even greater control.

SPectrum.ieee.orG

Moving a microrobot with magnetic fields turns out to be surprisingly tricky. "We're still learning about
the mathematics and physics of that,"
Nelson says. To move an object with a
robotic arm in any arbitrary way, he
explains, you need six actuators for a
full six degrees of freedom: movement
in the x, y, and z directions, and rotation around each of those axes. When
he and his colleagues worked out a
way to finely control a simple magnetic microrobot with five degrees of
freedom, they found that eight separate external magnetic coils were
needed. Adding in the sixth degree,
Nelson says, requires that the microrobot have a more complex magnetic
profile than a simple bar magnet.
Nelson's team can use its magnets
to control a helical microrobot with
magnetic fields of less than 10 millitesla, a fraction of what's created in
an MRI. "We can twist these helices
and cause them to corkscrew and move
forward," he says, much in the same
way that E. coli bacteria propel themselves by rotating their flagella. Earlier
this year, his team reported that it had
successfully used coated versions of
these artificial bacterial flagella in the
laboratory to deliver genetic material
to human cells.
In the near term, Nelson is looking
to see how his magnetic control technology could be used by doctors in
a tethered fashion, as a way of finely
guiding the tips of catheters through
the cardiovascular system. But in the
long term, he's exploring what might
be done once this physical connection
to the outside world is severed. For him
and many other researchers, the possibilities seem vast-as big as the human
body itself weighed against the complex,
ever-moving world of the microscale. n
post youR CoMMents at http://spectrum.
ieee.org/microbots0615

illustRation by

Jacob thomas

http://http:// http://www.ieee.org/microbots0615 http://SPectrum.ieee.orG

Table of Contents for the Digital Edition of IEEE Spectrum June, 2015