Modern microscopes, like this one from Zeiss,
are remarkably powerful. But they're also rather large
and expensive. Wouldn't it be nice to have one that you could
take around with you? What I want to talk about today is
a project that is aimed at making microscopes more mobile.
Or taking advantage of things you already are carrying
with you to do microscopy. I'll set this up with a brief
history of microscopes, where they came from, how they
ended up like they are now. And then I'll talk a little bit about
why mobile microscopes might be useful and then I'll give you
an example of one that we've built to do microscopy
with a mobile phone. So looking back, the versions of
the Zeiss microscope before the one I showed you in the
last slide, these microscopes were works of art.
As you can tell from the pictures here, they were ornate,
they came in many different shapes and sizes, and these were all
parts of the Golub collection at UC Berkeley.
And they show how the design of microscopes has evolved
over many years. But you can tell right away that they are
much smaller, they had many fewer parts, and in some cases,
they were even made to be portable. One of the earliest
microscopes was the device developed by Antony van Leeuwenhoek.
And it was so simple that it had just a single lens. And that
small lens, right here at the top of the device, is mounted
on a metal plate, and the sample was positioned on that little
stick right there. And the screws at the bottom of the device
were used to position the sample in front of this little bulb lens.
And Antony van Leeuwenhoek was able to use this to
observe a wide range of different structures, and he was also
the first to identify microorganisms. And he called them
animalcules. Because, if you see them first, you can
call them whatever you want to call them.
So this is an example of a very powerful microscope.
He was able to see microorganisms and see them move.
And he was able to do that with a single lens system that
easily fit into his pocket. So why did things get so large?
Well, one of the reasons why they got so large is that there
are a wide range of different diseases that need studying.
And as we continue to study more diseases, imaging
is a critical part of many of the disease diagnosis processes.
But they also help us to learn about the life cycle to be able,
more recently, to label specific proteins and to observe
how therapies might be impacting the development of these
diseases. But imaging is something we still need to do.
And even though there are many different ways to do imaging,
many new contrasts, modalities, many improvements, and
cameras. Many diseases still need to be imaged, in order to
be diagnosed. Or at least imaging can be used for diagnosis.
So here are some bloodborne pathogens that if you take a
blood smear, and you look at it under a microscope, you can
confirm that in fact, you have this disease. Similarly,
with various gastrointestinal parasites, if you take a sample
and you're able to observe either the organism itself
or a cyst form of the organism, you can positively identify
that you have this disease. Now oftentimes, this isn't the fastest
way to do diagnosis in well-developed countries, but
in many parts of the world where these are more realistic
problems for the average person, microscopy is still a
central method for diagnosis. A good example of this is
tuberculosis. So tuberculosis continues to be a serious
problem, kills over 2 million people per year, and microscopes
are among the central most diagnostic tools available.
Even though there are a variety of alternate methods
that we would use in a developed hospital, in order to diagnose
the disease, microscopy is still very important in a number of
regions. And oftentimes, those are the regions without
access to high quality doctors, or high quality microscope
equipment that would be necessary. So as a way of emphasizing
that point, maybe I'll step off here for a moment.
This is a map that shows the distribution of tuberculosis
cases that were recorded across the globe. And you'll see
that the size of the countries are scaled for the incidence
rates of the disease. And so you'll notice that North America
and much of South America is virtually nonexistent, because we
don't have many cases. But Africa and Asia, and Southeast Asia
have significant caseloads. So let me contrast where
the cases are with where the doctors are. So now
all of a sudden, Africa is much, much smaller. Asia
as well, has reduced in scaling. But Africa -- but U.S.
North America and Europe are rather bloated. So we have
many doctors and with those doctors are well-equipped
hospitals. But the places where many of these infectious
diseases are, do not have the physicians capable or the
equipment available to do the diagnosis. So how can
mobile microscopy help? Well, it's become clear over the last
many years that mobile phones are becoming ubiquitous.
In countries across the globe, individuals have cell phones.
They're able to use them for a wide range of purposes.
And several years ago, a group of undergrads in microscopy
course that I taught, we began to experiment with using
the cameras that were emerging on phones to do
microscopic imaging, rather than taking -- using the phone to take
a picture of large things, like people or trees, could we use
that same camera without modifying the camera itself,
can we develop a lens system that will adapt that camera
for use to do microscopy? And our early efforts were encouraging
and we developed a simple device which we call CellScope, which
put together some eyepiece optics together with some objective
lens, and mounted it on the camera phone and allowed you
to take images. And to this device is something that we have been
developing over the last number of years, and the whole point
of this is to take advantage of the cell phones that many, many
consumers are already buying, which is pushing the price down
and increasing the performance. Can we harness that
technology and use it to do imaging? The overall concept
is that a person with the ability to take microscopic images
of relevant samples, such as a blood sample or a sputum
sample, they would be able to capture an image. Potentially
do some amount of image processing on that handset itself,
and then potentially send the image to a clinical expert who
could provide either a second opinion or improve the
advice about diagnosis and treatment. And so by using the
compact highly capable handset that are becoming ubiquitous
together with clinical experts who could be anywhere in the world,
they don't need to be in the region where the diseases are
found. A mobile microscope could help to enhance or
spread quality healthcare to places it hasn't reached yet.
So based on that original device, we've developed a
number of different devices. And I'll give a brief demonstration
of how we use these different technologies.
The goal of our project is to turn a standard cell phone
into a multipurpose microscope. So let me show you a few
examples. The original one we worked with was a system
that was high magnification, and the goal was to be able to look at
blood smears and resolve white blood cells, red blood cells,
and platelets. So what we've built is a system that has a little
light source, has a small stage for a slide, and then some optics
and mirrors that bring -- that come to a point here where
we want to line up with the camera of our cell phone. So we take this
cell phone and simply stick it in, and then we can move our
slide around simply by hand. And we can focus with a small
ring underneath the stage. And if we do that, then we can see
a magnified image. This is an image of some bacteria
and some blood, and one can pan around, adjust the exposure
or the focus, and take a photo, or even take a video
if this were a live sample and something were moving.
So that's all possible, again, no change to the phone.
It simply sticks into the holder. Now because the
phone itself is simply an imaging system, we might as well
use it to do different kinds of imaging. So another simple
clip on attachment that we've made for the same phone
is an otoscope, so an otoscope is used by primary care
physicians to inspect the ear. And so, this device has a simple
lens over the camera and is designed so that it captures
the same sort of image that a physician would see when looking
into the ear with a traditional otoscope. But in this case, you can
capture the image, you can email it, you can send it and you could
look at the ear at any hour of the day or night.
And a third device is focused not on ears, but on eyes.
This is a device that has been used to diagnose or screen
for trachoma. And this is done by holding the device up to
the patient's eye, flipping the eyelid, and inspecting the base of the
eyelashes. And this can be done, as well, with additional
lighting. So adding some illumination increases the ability
to resolve the details that are necessary. So again, small
improvements, small changes to the optics outside of the
phone are letting us do imaging with standard technology
at a range of different length scales.
With the ability to take microscopic images with your cell phone,
there are a range of different ways you could use such a
mobile microscope device. One that we've talked about already
is how healthcare, being able to take images of relevant
disease samples. But there are a number of other places where
mobile microscopy could be very useful. For example,
agriculture. What is causing that crop to die? What is
the cause of the disease. Taking a microscopic image of
leaf samples are one way to help diagnose the problem.
Similarly, a number of samples we might want to study
scientifically, are not things we can culture in a laboratory.
And so doing imaging in the field is necessary for those cases.
Having microscopes that are more portable, that are lower
cost, that are easier to deploy, may be a way of getting access,
getting imaging into places where imaging hasn't gotten
yet. And similarly, education. These devices we've enjoyed
working with and have had the chance to introduce to some
classrooms, some middle school classrooms. And that
experience has been enjoyable for both of us, and we're hopeful
that mobile microscopes can be useful not just for researchers
or healthcare providers, but also for teachers and students.
One example of where we've tried to take these devices
out into the field and learn about how they're useful is in
India. Together with World Health Partners, we evaluated whether
an ability to take simple blood smears in remote healthcare
clinics would be a useful capability for those regions.
And we're continuing efforts to understand where can microscopy
go. Where is it needed? What are the diseases and conditions
that it can be used to diagnose in the field?
And that's really the next stage of work. Now that we know
that microscopes can be built and they can be built
simply, cell phones can be used to power those microscopes
and provide the image collection capabilities, do they actually
work in the field? And that remains an open question.
And one we're very excited about.
So with that, I'll end and thank all of the people who have
contributed greatly to advancing this project and the support
we've received.