Mobile Future

Turning cell phones into diagnostic tools

The
New York Times reported this
month
on an engineer who is converting cell phones into devices that diagnose
diseases. Dr. Aydogan Ozcan, an assistant professor of electrical engineering at
UCLA, has successfully adapted cell phones for screening in places far from
hospitals, technicians or diagnostic laboratories. Dr. Ozcan’s devices provide a
simple solution to a complex problem by replacing the need for a traditional
microscope with a basic cell phone camera. 

One prototype, a slide holding a finger
prick of blood can be inserted over the phone’s camera sensor. The sensor
detects the slide’s contents and sends the information wirelessly to a hospital
or regional health center. The phones can detect the asymmetric shape of
diseased blood cells or other abnormal cells, or note an increase of white blood
cells, a sign of infection.

Dr. Ozcan has formed a company, Microskia,
to commercialize the technology. Some of the company’s products would be
adaptations of regular cell phones. For phones without cameras, or phones too
compact to modify, the company has different designs, including a simple box
with a sensing chip that can be plugged into a cell phone or laptop with a USB
cord.

As explained in The New York Times article, the devices
are compact in part because they have eliminated the central element in a
microscope, its lenses. There is no need for lenses in these devices because
magnification can be done electronically. For this electronic system of
magnification, inexpensive light-emitting diodes added to the basic cell phone
shine their light on a sample slide placed over the phone’s camera chip. Some of
the light waves hit the cells suspended in the sample, scattering off the cells
and interfering with the other light waves. When the waves interfere, they
create a pattern called a hologram. The detector in the camera records that
hologram or interference pattern as a series of
pixels.

"The holograms are rich in information,"
Dr. Ozcan said. "We can learn a lot in seconds," he said. "We can process the
information mathematically and reconstruct images like those you would see with
a microscope."