A lab the size of a postage stamp George Whitesides
the problem that I want to talk with you
about is really the problem of how does
one supply health care in a world in
which cost is everything how do you do
that
and the basic paradigm we want to
suggest to you I want to suggest to you
is one in which you say that in order to
treat disease you have to first know
what you’re treating that’s Diagnostics
and then you have to do something so the
program that we’re involved in is
something which we call Diagnostics for
all or zero cost Diagnostics how do you
provide medically relevant information
at as close as possible to zero cost how
do you do it let me just give you two
examples the rigors of military medicine
are not so dissimilar from the third
world poor resources a rigorous
environment of a series of problems in
light weight and things of this kind and
also not so different from the home
healthcare and diagnostic system world
so the technologies that I want to talk
about is for the third world for the
developing world but it has I think much
broader application because information
is so important in the healthcare system
so you see two examples here one is a
lab that’s actually a fairly high-end
laboratory in Africa the second is
basically an entrepreneur who is set up
and doing who-knows-what in a table in a
market I don’t know what kind of health
care is delivered there but it’s not
really what is probably most efficient
what is our approach and the way in
which one typically approaches a problem
of lowering cost starting from the
perspective of the United States is to
take our solution and then to try to cut
cost out of it no matter how you do that
you’re not going to start with a hundred
thousand dollar instrument and bring it
down to no cost it isn’t going to work
so the approach that we took was the
other way around ask what is the
cheapest possible stuff that you could
make a diagnostic system out of and get
useful information
add function and what we’ve chosen this
paper what you see here is a prototypic
device it’s about a centimeter on the
side it’s about the size of a fingernail
the lines around the edges are a polymer
it’s made of paper and paper of course
wicks fluid as you know paper cloths
drop wine on the tablecloth and the wine
wicks all over everything I’ve put it on
your shirt it ruins the shirt that’s
what a hydrophilic surface does so in
this device the idea is that you dip the
bottom end of it in a drop of in this
case urine the fluid wicks its way into
those chambers at the top the brown
color indicates the amount of glucose in
the urine the blue color indicates the
amount of protein in the urine and the
combination of those two is a
first-order shot at a number of useful
things that you want so this is an
example of a device made from a simple
piece of paper now how simple can you
make the production why do we choose
paper there’s an example of the same
thing on a finger showing you just
basically what it looks like
one reason for using paper is that it’s
everywhere we have made these kinds of
devices using napkins and toilet paper
and wraps and all kinds of stuff so the
production capability is there the
second is you can put lots and lots of
tests in a very small place I’ll show
you in a moment that the stack of paper
there would probably hold something like
a hundred thousand tests something of
that kind and then finally a point that
you don’t think of so much in developed
world medicine it eliminates sharps and
what sharps means is needles things that
stick she was takin a sample of
someone’s blood and the someone might
have hepatitis C you don’t want to make
a mistake and stick it and you just you
don’t want to do that so how do you
dispose of that it’s a problem
everywhere and here you simply burn it
so it’s a sort of a practical approach
to starting on things
now you say if paper is a good idea
other people have surely thought of it
and the answer is of course yes those
half of you roughly who are
and at some point may have had a
pregnancy test and the most common of
these is in a device that looks like the
thing on the left it’s something called
a lateral flow immunoassay and in that
particular test you’re in either
containing a hormone called HCG does or
does not flow across a piece of paper
and there are two bars one bar indicates
that the test is working and if the
second bar shows up you’re pregnant this
is a terrific kind of test in a binary
world and the nice thing about pregnancy
is either you are pregnant or you’re not
pregnant you’re not partially pregnant
or thinking about being pregnant or
something of that sort so it works very
well there but it doesn’t work very well
when you need more quantitative
information there are also dipsticks but
if you look at the dipsticks therefore
another kind of urine analysis there are
an awful lot of colors and things like
that what do you actually do about that
in a difficult circumstance so the
approach that we started with we’ve
started with is to ask is it really
practical to make things of this sort
and that problem is now in a purely
engineering way solved and the procedure
that we have is simply to start with
paper you run it through a new kind of
printer called a wax printer the wax
printer does what looks like printing it
is printing you put that on you warm it
a little bit the wax prints through
sodus orbs into the paper and you end up
with the device that you want the
printers cost 800 bucks now
they’ll make we estimate that if you
were to run them 24 hours a day they’d
make about 10 million tests a year so
it’s a solved problem that particular
problem is solved and there’s an example
of the kind of thing that you see that’s
on a piece of eight by twelve paper that
takes about two seconds to make and so I
regard that as done there’s a very
important issue here which is that
because it’s a printer a color printer
it prints colors
that’s what color printers do I’ll show
you in a moment that’s actually quite
useful now the next question that you
would like to ask is what would you like
to measure what would you like to
analyze and the thing which you’d most
like to analyze were a fair distance
from its what’s called fever of on
origin someone comes into the clinic
they have a fever they feel bad what do
they have do they have TB do they have
AIDS do they have a common cold the
triage problem that’s a hard problem for
reasons that I won’t go through they’re
an awful lot of things that you’d like
to distinguish among but then there are
a series of things aids hepatitis
malaria TB others and simpler ones such
as guidance of treatment now even that’s
more complicated than you think a friend
of mine works in transcultural
psychiatry and he is interested in the
question of why people do and don’t take
their meds so dapsone or something like
that you have to take it for a while he
has a wonderful story of talking to a
villager in India and saying have you
taken your dapsone yes have you taken it
every day yes have you taken it for a
month yes what the guy actually meant
was that he’d fed 30-day dose of dapsone
to his dog that morning he was telling
the truth because in a different culture
you know the dog is a surrogate for you
you know today this month since the
rainy season there are lots of
opportunities for misunderstanding and
so an issue here is to in some cases to
figure out how to deal with matters that
seem uninteresting like compliance now
take a look at what a typical test looks
like prick a finger you get some blood
about 50 microliters that’s about all
you’re going to get because you can’t
use you know the usual sort of systems
you can’t manipulate it very well
although I’ll show something about that
in a moment
so you take the drop of blood no further
manipulations you put it on a little
device the device filters out the blood
cells let’s the serum go through and you
get a series of colors down in the
bottom there and the colors indicate
disease are normal but even that’s
complicated
because to you to me colors might
indicate normal but after all we’re all
suffering from and probably in excess of
Education what do you do about something
which requires quantitative analysis and
so the solution that we and many of
people are thinking about their and at
this point there’s a dramatic flourish
and out comes the universal solution to
everything these days which is a cell
phone in this particular case a camera
phone there everywhere
six billion a month in India and the
idea is that what one does is to take
the device you dip it you develop the
color you take a picture the picture
goes to a central laboratory you don’t
have to send out a doctor you send out
somebody who can just take the sample
and in the clinic either a doctor or
ideally a computer in this case does the
analysis turns out to work actually
quite well particularly when your color
printer has printed the color bars that
indicate how things work so my view of
the healthcare worker of the future is
not a doctor but it’s an
eighteen-year-old
otherwise unemployed who has two things
he has a backpack full of these tests
and a Lancet to occasionally take a
blood sample and an ak-47 and these are
the things that get him through his day
there’s another very interesting
connection here and that is that what
one wants to do is to pass through
useful information over what is
generally a pretty awful telephone
system it turns out there’s an enormous
amount of information already available
on that subject which is the Mars rover
problem how do you get back an accurate
view of the color on Mars if you have a
really terrible bandwidth to do it with
and the answer is not complicated but
it’s one which I don’t want to go
through here other than to say that the
communication systems for doing this are
really pretty well understood also a
fact which you may not know is that the
compute capability of this thing is not
so different from the compute capability
of your desktop computer this is a
fantastic device which is only beginning
to be tapped I don’t know whether the
idea of a you know one computer one
child makes any sense that here’s here’s
the computer of the future because the
screen is already there and you they’re
ubiquitous right now let me show you
just a little bit about advanced devices
and we’ll start by posing a little
problem what you see here is another
centimeter sized device and the
different colors are different colors of
dye
and you notice something which might
strike you is a little bit interesting
which is the yellow seems to disappear
and get through the blue and then get
through the red how does that happen how
do you make something flow through
something and it hurts the answer is you
don’t you make it flow under and over
but now the question is how do you make
it flow under and over in a piece of
paper and the answer is that what you do
and the details are not terribly
important here is to make something more
elaborate you take several different
layers of paper each one containing its
own little fluid system and you separate
them by pieces of literally double-sided
carpet tape the stuff you use to stick
the carpets onto the floor and the fluid
will flow from one layer into the next
it distributes itself flows through
further holes distributes itself and
what you see in the lower right hand
side there is a sample in which a single
sample of blood has been put on the top
and it has gone through and distributed
itself into these 16 holes on the bottom
in a piece of paper basically it looks
like a chip two pieces of paper thick
and in this particular case we were just
interested in the replicability of that
but that is in principle the way you
solve the fever unexplained origin
problem because each one of those spots
then becomes a test for a particular set
of markers of disease and this will work
in due course and here’s an example of a
slightly more complicated device there’s
the chip you dip in a corner the fluid
goes into the center it distributes
itself out into these various wells or
holes and turns color and all done with
paper and carpet tape so it’s I think is
low cost as we’re likely to be able to
come up and make things now I have one
last two last little stories to tell you
and finishing off this business this is
one one of the things that one does
occasionally need to do is to separate
blood from blood cells from serum and
the question was here we do it by taking
a sample we put it in a centrifuge we
spin it and you get blood cells out
terrific what happens if you don’t have
an electricity
and the centrifuge in whatever and we
thought for a while of how you might do
this of the way in fact you do it is
what’s shown here you get a eggbeater
which is everywhere and you saw off a
blade and then you take tubing and you
stick it on that you put the blood in
you spin it somebody sits there and
spins it it works really really well and
we set that we did the physics of egg
beaters and self-aligning tubes and all
the rest of that kind of thing send it
off to a journal we were very proud of
this particularly the title which was
eggbeater a centrifuge and we set it off
and by return mail it came back I call
up the editor I said what’s going on how
is this possible the editor said with
enormous disdain I read this and we’re
not going to publish it because we only
publish science and it’s an important
issue because it means that we have to
as a society think about what we value
and if it’s just papers in phys Rev
letters we’ve got a problem here’s
another example of something which is
this is a little spectrophotometer it
measures the absorption of light in a
sample the neat thing about this is you
have light source that flickers on and
off at about a thousand Hertz another
light source that detects that’s light
at a thousand Hertz and so you can run
this system in broad daylight it
performs about equivalently to a system
that’s in the order of 100 thousand
dollars it costs $50 we can probably
make it for 50 Cent’s if we put our mind
to it why doesn’t somebody do it and the
answer is how do you make a profit in a
capitalist system doing that interesting
problem so let me finish by saying that
we thought about this as a kind of
engineering problem and we’ve asked what
is you know what is the scientific
unifying idea here and we’ve decided
that we should think about this not so
much in terms of cost but in terms of
simplicity the simplicity is a neat word
you’ve got to think about what
simplicity means I know what it is but I
don’t actually know what it means
so I actually wasn’t interested enough
in this to put together a several groups
of people the most recent in
involved a couple of people at MIT one
of them being an exceptionally bright
kid who’s one of the very few people I
would think of who’s innocent ik genius
we all struggled for an entire day to
think about simplicity and I want to
give you the answer of this deep
scientific thought so in a sense you get
what you pay for
thank you very much