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New Life-Saving Medical Imaging Tool: The Mobile Phone

Basic health care technologies that help people live longer and better can’t be used in much of the developing world because of a simple lack of infrastructure.

National Geographic Emerging Explorer Aydogan Ozcan is helping to change that. The electrical engineer has shunned expensive medical technologies to tap a ubiquitous tech device, the mobile phone, and turn it into a sophisticated medical imaging tool that could help save countless lives.

Equipped with Ozcan’s tiny digital microscopes, mobile phones can analyze samples of blood and other bodily fluids and enable the early diagnosis of diseases like tuberculosis, HIV/AIDS, and malaria.

By instantly linking test results to online databases, or boasting their own sophisticated diagnostic algorithms, such phones are even able interpret and diagnose tests–a critically important task in areas where medical technicians may be poorly trained or absent altogether.

Nat Geo News Watch contributor Brian Handwerk interviewed Ozcan about his work with the mobile phone as a medical technology, and how the growing platform’s many new applications are outgrowing simple communication.

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Aydogan Ozcan has the Ph.D., the expertise, and the engineering acumen to perfect the world’s most complex medical diagnostic technology. Instead, he’s solving global health issues–with a cell phone. Read more about him on his National Geographic Emerging Explorer profile page.

Photograph by Phil Channing

Aydogan Ozcan interviewed by Brian Handwerk

How does your training as an engineer guide your thinking about how to repurpose existing technologies like mobile phones for new scientific tasks?

The important thing isn’t how elegantly you solve a problem, it’s how practical your solution is. I think that’s what sometimes differentiates engineers from scientists. Engineers consider their limitations in terms of things like budget. Yes the solution has to be clever, but you also have to make it work within your constraints–that’s the thinking of an engineer.

And the mobile phone appealed to you as an inexpensive and common device?

Yes. Today we have close to 5 billion cell phone subscribers and every year we are manufacturing about a billion new phones. By 2015 close to 90 percent of the world’s population will have at least one cell phone subscribed to a network. This volume has created an incredibly complex and advanced device in our pockets.

If instead of billions of phones we were only talking thousands then the cost of your iPhone, with the same kinds of advanced hardware and software components, would probably be more than $20,000.

If you look at scientists researching in labs today, that’s exactly what they do. They buy advanced instruments with their grants that literally cost us tens of thousands of dollars because of the lower scale of volume.

One can do so many things today with a smart phone. The cell phone is an amazingly advanced instrument that now comes with 8 and 10 megapixel cameras and very nice hardware that can process like a computer. This is bringing scientists a platform that we’ve never used before. It’s very cost effective, it works everywhere, and it can be used by anyone. A phone connected to a network is also easy to scale up and spread.

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Close to 5 billion people subscribe to mobile phone services every year, putting advanced computer technologies in the pockets of most people worldwide.

NGS stock photos by Jodi Cobb 

You’ve made cell phones double as microscopes. But to do that you had to make them work differently than the scopes we remember from our biology labs.

The most important component of a microscope and the one that you’ll be paying a lot for is the lens. With a microscope or a camera you need a good lens to create a nice image. Our microscopes are entirely digital. We replace the lens with digital codes that can magnify images of cells.

It’s a lens-free technology that works entirely in the digital domain so it doesn’t even change the weight of a cell phone. And, at the same time, in the digital environment of the cell phone it can be connected easily with a computer network

Just how does it work?

Essentially these microscopes attach through the USB or camera unit of the cell phone to create images of cells, or pathogens, or whatever samples that you have by processing the shadows of the object.

If you walk on a sunny day you see your shadow on the street, but that shadow for us is dark and not very interesting because we are opaque to light. It turns out that cells and small objects like bacteria are partially transparent to light, which means that light can penetrate through them and get refracted.

So if you look at their shadows, they contain a unique texture that represents that type of cell and its key features. Using a digital computer code you can process these shadows to construct an image of the cell [that looks as if] you were looking through a regular microscope.

“The entire microscope, including the magnification, is running on a digital platform. So on a cell phone it’s connected everywhere in the world.” 

The entire microscope, including the magnification, is running on a digital platform. So on a cell phone it’s connected everywhere in the world and within seconds you can send it to any computer and bring the [diagnostic] expertise of people all over the world to any remote location to [analyze the images].

What kinds of things are you using these microscopes for?

My research group is trying to bring microscopy and imaging to this platform with a specific emphasis on disease diagnosis, and in particular infectious diseases. Manageable diseases like TB, malaria, and HIV cause more than 4 million deaths a year. When combined with poor water problems, like giardia and other simple parasites, there are more than 6 million annual deaths that might be prevented by antiviral therapies and other treatments–if they are properly diagnosed.

Computational microscopes on this platform can be used wherever people are to look at blood cells, or water samples, or whatever health care providers have used microscopes for over the centuries.

Are there conservation applications as well?

We’ve published a paper that talks about water-borne parasites and how they can be screened using our lens-free microscopes. In a remote village, for example, or if you are a camper and you want to look at some fresh water before you drink, you could potentially use the same dime-sized gadget.

The device [with analysis software] could be used for routine monitoring of water supplies to look for different pathogens or pollutants.

There’s a rush now to try to inventory species, especially plants and insects, before they disappear. But resources are limited–could these phones somehow play a role?

Taxonomy is [another] great example where our microscopes running on widely available cell-phones could potentially help to better organize our efforts to study biodiversity at different scales. For that end, we indeed need to create new microscopic imaging tools utilizing our existing cellphones.

On a related note we have recently demonstrated a new microscope on a cellphone that is this time capable of imaging fluorescent objects within the same compact body of the cellphone. This new cellphone microscope complements our previous efforts to create a bigger vision out of this platform in general.

This fluorescent microscope attachment is about the size of a matchbox–what additional capabilities does it add?

It achieves a very large imaging area that is 0.8-1.0 of a square centimeter [between 0.12 and 0.15 of a square inch]. This wide imaging area is very important to screen large sample volumes of, for example, blood or water to identify certain bacteria or pathogens which in real life almost always exist in rare quantities, requiring a large sample volume to be imaged.

We are aiming to use this new microscope for screening labeled pathogens in drinking water or food, as well as using it for imaging various bodily fluids (such as blood, sputum, urine, etc.) for searching disease markers. In these applications, aiming [at] resource poor countries, the ultra wide field of view of this inexpensive cellphone microscope would especially be of crucial use.

How did you first come up with this scheme?

When the microscope was invented centuries ago there were no computers, no algorithms, and our understanding of the physical properties of light was very limited. Yet the design of today’s microscopes follows the same design from centuries ago. Although their performance is much better, the main process of image formation remains essentially the same, and as an engineer that seems like extremely sub-optimal design.

“I wanted to almost forget how microscopes are constructed and try to come up with a new way to look at microscopic objects from the perspective of computers and digital components.” 

I wanted to almost forget how microscopes are constructed and try to come up with a new way to look at microscopic objects from the perspective of computers and digital components. [I had] the idea that, at least for certain applications, a fundamentally new design of microscopes could perform cheaper and more effectively.

This [concept] intersected with the cell phone as a perfect digital platform and merged into something bigger that can be connected to any person, computer or laboratory in the world.

The way technology is advancing, what you do now would seem to be only the tip of the iceberg?

A microscope is a big instrument with many different parts, so improving one part doesn’t necessarily improve the overall performance–standard microscopes from the 1990s had roughly the same image quality as those today.

With digital microscopy, every time a new imager comes out I can improve my performance without any trade-off. If you currently use 3 megapixels and next year use 5 megapixels you will almost double performance without any trade-off in resolution. Every time new components or sensors come out I will improve my performance.

Improvements to the mobile phone platform are being driven by consumers, not science, but science is reaping the benefits.

Absolutely, and things will get even better for a vision that tries to bring new technologies through the platform of the cell phone. The phone is not just for speaking, it’s an extremely cost-effective and sophisticated platform that is also extremely flexible. There are so many things it can do, and only one thing is voice communication. That will soon be a minor function of the cell phone.

And this [imaging] platform, for example, can be open source. It will likely be used for different purposes that my group hasn’t even considered.

Related blog posts in this series:

How the network of human minds can save Earth (Interview with Emerging Explorer Albert Yu-Min Lin.)

Solving eco challenges with grassroots messaging (Interview with Emerging Explorer Ken Banks.)

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