Washington: A compact, inexpensive handheld device that monitors diabetes, detects malaria and environmental pollutants is being trialled in India by Harvard scientists.
The device costs about USD 25 to produce, weighs just two ounces, and is about the size of a pack of cigarettes.
It was modelled after the latest generation of inexpensive glucose monitoring devices, which are in widespread use, but whose function is limited to testing blood sugar.
The new device can also 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.
"We designed it to be as close as possible to a glucose meter, because that's familiar to people," said Harvard University researcher Alex Nemiroski.
"There are two buttons. Select the test and press 'go'. It should be as much of a no-brainer as possible," said Nemiroski, a postdoctoral fellow in the lab of Flowers University Professor George Whitesides and lead author of the paper.
Nemiroski 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.
Nemiroski recently sent off five units to be field tested in India, and is already working on the next generation of the device, which will have more features and be able to conduct more tests.
The equipment currently used in a typical Western lab is large, bulky, and costs around USD 50,000, according to Nemiroski and Whitesides.
Procedures also require other types of laboratory equipment, including mixers, beakers, and expensive reagents.
Though reagents, which are substances used in chemical analysis, are also needed for some of the tests done by the device, samples measured in drops need just a small amount of reagent for each test. The device also uses vibration to mix samples.
The device's most innovative feature is its unique communications method. The cell phones used in the developing world are largely those that tend to be "low-tech," and without data capability.
To overcome these problems, researchers created a 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.
The research was published in the journal PNAS.
