Internal medicine and infectious disease specialist Isaac Bogoch and his colleagues turned an iPhone 4S into a fairly accurate microscope by attaching an eight dollar, three-millimeter ball lens to the smartphone's camera lens using double sided tape.
The DIY microscope was tested with 200 slides of stool samples from school children with different types of parasitic worms in Pemba Island, Tanzania. The slides were covered with cellophane strips and then placed up against the lens. A simple flashlight illuminated the slides from below. The doctors took photos of the samples and assessed them on the iPhone screen.
To check the accuracy of the iPhone microscope, the slide samples were also assessed using a conventional microscope.
The iPhone microscope was 70% accurate as compared to a conventional microscope. These results were promising, but not quite enough. The microscope will have to be at least 80% accurate in order to be clinically useful, according to the study which was published last March on The American Journal of Tropical Medicine and Hygiene.
The researchers are confident that the technology can still be improved.
Mobile phone diagnostic technology will likely contribute to the diagnosis of infections and non-infectious etiologies in resource-constrained settings. A first-generation mobile phone microscope using a ball lens had modest diagnostic yield for soil-transmitted helminth infections; however, newer technologies may further improve mobile phone diagnostic capabilities, but they require additional field testing in different epidemiologic settings.
Bogoth's DIY iPhone microscope is not the first time a smartphone was used as a microscope. A similar device was created by researchers from University of California, Davis in 2011.