Using software he developed and about $10 worth of off-the-shelf hardware, UCLA professor Aydogan Ozcan has adapted cellphones to substitute for microscopes:
In 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. For instance, 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, he said.
[...]
For this electronic system of magnification, inexpensive light-emitting diodes added to the basic cellphone 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,” Dr. Brady said, “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.”
Dr. Ozcan’s system may someday lead to a rapid way to process blood and other samples, said Bahram Jalali, an applied physicist and professor of electrical engineering at U.C.L.A. “It is potentially much faster than a microscope,” he said. “You don’t have to scan mechanically” as people must with a microscope with its small field of view.“Instead you capture holograms of all the cells on the slide digitally at the same time,” he said, so that it’s possible, for example, to see immediately the pathogens among a vast population of healthy cells. “It’s a way of looking quickly for a needle in a haystack,” he said.