April 3, 2008, Berkeley, CA--What began as a relatively simple class project in Prof. Dan Fletcher's undergraduate optics and microscopy course at the University of California at Berkeley has resulted in the development of a handheld microscopic imaging and transmission device that may have implications for healthcare in Third World, rural, and other underserved communities.
When Fletcher challenged his students to combine current readily available technologies with a potential application that could improve healthcare in underdeveloped countries, little did he know that his students would respond with such enthusiasm and ingenuity. They took a standard cell phone and modified it with a series of off-the-shelf lenses to achieve 5x-60x magnification of a blood or tissue sample, utilizing the phone's internal camera to capture and transmit the resulting images (see Figure).
"I was trying to give them something relevant to think about," says Fletcher, who is associate professor of bioengineering. "In developing world-health efforts there is a growing realization that smart phones can do a lot for healthcare."
The initial prototype of the cell-phone microscope--dubbed "Cellscope"--utilizes a Nokia cell phone with an embedded 3.1 megapixel camera. The phone's pocket holster provides the mount for the optical train. Illumination is provided by several white-light LEDs in a ring-illuminator design, and the detection sensors are based on standard CCD/CMOS chips. Once captured, the images are transmitted to a laptop using a Bluetooth attachment to the phone. Total cost of the first prototype, built from off-the-shelf components, was $75.
"It's really not much more than a fancy magnifying glass," Fletcher says. "We were able to use relatively cheap optics with relatively good sensors and apply that to microscopy. But it is the combination of elements that makes it interesting and potentially useful."
The second iteration of the phone boosted the magnification to 60x, making it possible to image single cells in a blood smear. The first application that Fletcher and his collaborators are targeting is the diagnosis of blood-based diseases such as sickle-cell anemia and malaria. This summer, in conjunction with UC Berkeley's Blum Center for Developing Economies, the device will be tested in Kampala, Uganda specifically for malaria diagnosis.
In addition, Fletcher's group is gearing up to collaborate with a telemedicine program at the University of California Davis to test the utility of the cell-phone microscope for home-bound leukemia patients. They are also working to improve the image resolution by customizing the magnifying optics to account for aberrations, and to better manage the transmission of the images with more advanced custom software.