A team of researchers from the University of California, Davis has transformed everyday iPhones into medical-quality imaging and chemical detection devices. Though they are not the first to tweak the smartphone in this way, this represents a simpler and more affordable method. Using materials that cost about as much as a typical app, the decked-out smartphones are able to perform detailed microscopy and spectroscopy, which could help doctors and nurses diagnose blood diseases in developing nations with limited or no access to laboratory equipment.
To build the microscope’s lens, the researchers inserted a ball lens into a hole in a rubber sheet, then simply taped the sheet over the smartphone’s camera. At 5x magnification, the ball lens is no more powerful than a child’s magnifying glass. But combined with the camera of a smartphone, the microscope could resolve features on the order of 1.5 microns, small enough to identify different types of blood cells.
Even though cell phone micrographs are not as sharp as those from laboratory microscopes, they are able to reveal important information, such as the reduced number and increased variation of cells in iron deficiency anemia, and the banana-shaped red blood cells characteristic of sickle cell anemia. The team may add features such as larger lenses to diagnose skin diseases and software to count and classify blood cells automatically in order to provide instant feedback and perhaps recognize a wider range of diseases.
The spectrometer that the researchers added to the iPhone is easy to build. It starts with a short plastic tube covered at both ends with black electrical tape. Narrow slits cut into the tape allow only roughly parallel beams of light from the sample to enter and exit the tube. It is this grating that smears, or spreads, the light into a spectrum of colors that scientists can use like a fingerprint to identify various molecules. Though the spectrometer is still in its early stages, the researchers believe it could measure the amount of oxygen in the blood and help diagnose chemical markers of disease.
