Creators of the mobile phone would have anticipated a few uses for it in the future, but they couldn’t have imagined it would become the versatile device it is now. Today, you can use a mobile phone to play games, take photos or a video, watch movies on the Internet, follow the news or send email. There is one application, however, no one would have imagined so far — its use as a microscope for clinical diagnosis.

The idea occurred to Dan Fletcher while he was working on a project for his graduate students. Fletcher is an associate professor of bio-engineering at the University of California in Berkeley and a mechanical engineer by training. His team often develops many of the instruments they use in research. Fletcher’s initial idea was to ask the students to add some lenses to a mobile phone camera, but it changed as he proceeded. Why not add an entire microscope instead?

Fletcher was motivated to pursue his idea because of the fact that a microscope added to a mobile phone would be extremely useful. He was thinking about a specific kind of instrument called a fluorescence microscope. It is widely used in research to monitor cell division or take images of the nervous system, among other things. In medicine, the technique can be used to detect pathogens causing infectious diseases. Remote areas in many countries, including developed ones like the US, do not have clinical labs but have connectivity through mobile phones. So it wouldn’t be a bad idea to develop a portable microscope and merge it with a mobile phone.

Last week, after a year of work, Fletcher and his students demonstrated a prototype device using off-the-shelf components. The device, called a CellScope (short for cell phone microscope), can take pictures of parasites that cause malaria and tuberculosis. Needless to say, it can also transmit the images using the mobile phone network to any place in the world, thereby promising to take clinical microscopy out of expensive laboratories into many remote areas. Says Fletcher, “The device will be cheaper than any other fluorescence microscope.” It will cost a few hundred dollars compared to a few thousand for a fluorescence microscope. The precise cost will be known later, when it is ready for commercialisation.

A fluorescence microscope, as the name implies, uses the phenomenon of fluorescence, where a cold body absorbs light of a specific wavelength (colour) and then emits light of a different wavelength. It is widely used in circumstances where a normal optical microscope will not work. For example, a fluorescence microscope can be used to picture and examine even a single molecule. In medicine, the specimen to be seen is tagged with a molecule that fluoresces, or exhibits fluorescence. A parasite, for example, lights up under the microscope when tagged properly.

A fluorescence microscope is a large device which is used in a clinical lab and looks like any normal microscope. It is often used in conjunction with a digital camera. The Berkeley CellScope looks more like a telescope that can be attached to a mobile phone camera. You can put the sample on a glass slide at one end of the tube, and see images on the mobile phone display attached to the other. A photograph of the image can then be taken and transmitted whenever there is a network connection.

The real innovation in the device is in the design and assembly of the microscope in a small form. The mobile phone is not a necessary part of the device except for the connectivity. “It was the connectivity of the mobile phone that inspired us to use it as part of the system,” says team member and Berkeley graduate student David Breslauer. Fletcher and his students are now trying to further miniaturise the device for a commercial version. “The challenges now are less technical and more operational,” says Fletcher.

“It is a useful innovation. Especially when doctors working in rural areas have to consult experts in other specialties for a more accurate diagnosis,” says Biswaroop Chatterjee, a microbiologist working at the Jan Swasthya Sahyog, a rural hospital near Bilaspur, Chhattisgarh.

The device will be beneficial all over the world because many villages in many countries have no clinical laboratories but have mobile network connectivity. But to be used in the field, the Berkeley team has to make changes other than miniaturisation. One problem is to increase the processing of the image within the mobile phone and reduce its size before it is transmitted. The other problem is to make the device easy to use so that it can be used by anybody. “Some amount of training is necessary to use the device now,” says Fletcher. Part of his challenge is to reduce it to a minimum.