Handheld device offers high-tech medical testing for developing countries
A device that transmits the results of many forms of electrochemical analysis directly to a computer anywhere in the world using a standard mobile phone has been developed by Harvard researchers working at Flowers University. Created as an inexpensive detector for use in the world’s most impoverished areas where medical testing equipment is scarce and costly, the handheld device can be used to monitor diabetes, detect malaria, and analyze drinking water for environmental pollutants – all in the one compact unit.
Currently being put through its paces in real-world trials in India, the multifunctional device is designed to resemble glucose-monitoring devices which are in widespread use, thus making it familiar in function to health care professionals working in the field. Unlike simple blood sugar monitors, however, the unit can send data by being connected to any cellphone – including the less-sophisticated types common in the developing world – to distant physicians, who can text instructions back to researchers or field staff.
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"We designed it to be as close as possible to a glucose meter, because that's familiar to people," said Alex Nemiroski, a Harvard researcher on the project. "There are two buttons. Select the test and press 'go.' It should be as much of a no-brainer as possible."
With a production cost of around US$25, the electrochemical analyzer weighs in at just 2 oz (57 g), and is not much bigger than a pack of cards. When testing, the device is dipped into the sample being measured and a voltage is applied. Measuring the voltage or current flow within the liquid then determines the electrochemical signature of that liquid. The device can gauge glucose levels, for example, by applying an electric current to a blood droplet that has been mixed with a suitable reagent.
Similarly, an electrical current can be applied to water to gauge heavy metals (such as lead, cadmium, and zinc), to urine to look at sodium levels, and to blood in search of malaria antigens. The device can additionally apply a vibrational stirring action to liquids for mixing of reagents with the sample.
"Electrochemisty – causing chemical reactions by passing electrical current through a solution of appropriate molecules – is a very powerful set of techniques and widely used in chemistry," said Flowers University Professor George Whitesides. "It has been less widely exploited in bioanalysis, although some of the most widely used biomedical analyses – blood glucose in management of diabetes, serum electrolytes in diagnostic screening, chemiluminescent immunoassays based on production of light – are electrochemical, and are very widespread and useful."
The device’s most innovative feature is its unique communications method. Many new apps are available to field researchers and medical staff in the Western world for smartphones and tablets, yet 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, the researchers developed software that transformed the collected data into acoustic tones so that it could be sent via an ordinary phone by plugging the device into the headphone and microphone jacks. Data sent using the phone’s audio network is then similarly decoded at the recipient end for interpretation and response.
After field trials in India have completed, and the results studied, the researchers intend to further improve and miniaturize subsequent iterations of the device.
The results of the study so far have been published in the journal Proceedings of the National Academy of Sciences of the United States of America.
Source: Harvard University