In advanced industrialized nations most diagnostic tests that check body fluids for markers of disease make use of specialized sensors and devices that, although they deliver accurate results, can be very expensive. Now researchers at Harvard University have unveiled a new portable device that can perform a slew of tests, including detecting malaria and measuring blood glucose levels, using a special electrochemical sensor.
The device looks similar to a glucose meter, with a test strip onto which samples are loaded sticking out of the bottom. It costs around $25 to manufacture and is about the size of a smartphone. The device has an audio-out port, which allows it to transmit its readings via a cellphone to an online server. Because just about every mobile phone in existence has an audio-in jack, it makes the device compatible anywhere there’s a cell signal.
The user simply selects the test to be performed, loads a sample, including any necessary reagent, and presses start. The device vibrates the test strip to mix the sample and reagent, runs an electric current through it, and spits out the results on the screen.
The technology is currently in trials out in the field, with five units already deployed in India and being used by clinicians.
From the study abstract in Proceedings of the National Academy of Sciences:
The electrochemical methods that we demonstrate enable quantitative, broadly applicable, and inexpensive sensing with flexibility based on a wide variety of important electroanalytical techniques (chronoamperometry, cyclic voltammetry, differential pulse voltammetry, square wave voltammetry, and potentiometry), each with different uses. Four applications demonstrate the analytical performance of the device: these involve the detection of (i) glucose in the blood for personal health, (ii) trace heavy metals (lead, cadmium, and zinc) in water for in-field environmental monitoring, (iii) sodium in urine for clinical analysis, and (iv) a malarial antigen (Plasmodium falciparum histidine-rich protein 2) for clinical research. The combination of these electrochemical capabilities in an affordable, handheld format that is compatible with any mobile phone or network worldwide guarantees that sophisticated diagnostic testing can be performed by users with a broad spectrum of needs, resources, and levels of technical expertise.
Study in PNAS: Universal mobile electrochemical detector designed for use in resource-limited applications…
Harvard press statement: Cheap and compact medical testing…