Researchers have developed a cheap and compact electrochemical detector for medical testing:
The device, already in field trials in India, costs about $25 to produce, weighs just two ounces, and is about the size of a pack of cigarettes. It was modeled after the latest generation of inexpensive glucose monitoring devices, which are in widespread use, but whose function is limited to testing blood sugar. In addition to conducting the tests, the new device can send data over the lower-tech cellphones common in the developing world to distant physicians, who can text instructions back to researchers, government officials tracking outbreaks, and others.
He focused on an electrochemical detector, which measures the voltage or current generated in liquids for characteristic signatures of the liquid’s contents. For example, by applying a small amount of electricity to a drop of blood mixed with a reagent, the device can gauge glucose levels. The same goes for heavy metals in water, malaria antigens in blood, and sodium in urine.
They created software that converted the data to audible tones so it could be sent — after plugging the device into the phone’s headphone and microphone jack — just as if it were someone’s voice. The data is then sent over the phone’s audio network to a physician, database, or other recipient.