Smartphone for the diagnosis of infectious diseases
Researchers at Columbia University, working under the guidance of Dr. Samuel K. Sia, have developed a cheap smartphone accessory that allows for 15 minutes to simultaneously detect three markers of infectious diseases in a drop of blood obtained by pricking a finger pad.
For the first time, the device reproduces all the mechanical, optical and electronic functions of laboratory equipment traditionally used for blood tests. Its action is based on one of the methods of enzyme immunoassay, namely solid-phase enzyme immunoassay, known as ELISA (from the English enzyme-linked immunosorbent assay). There is enough energy stored in the smartphone battery to perform the analysis. Moreover, the triple analysis format embedded in the device is currently unavailable for laboratory equipment. Namely, it allows you to simultaneously detect antibodies to HIV, treponemal antibodies in syphilis, as well as non-treponemal antibodies in active syphilitic infection.
The diagnostic device is so small that it fits in the palm of one hand. For its operation, disposable plastic cartridges with reagents are needed, on which disease-specific zones give clear results similar to those obtained during ELISA. According to the developers, the production of one device will cost about $ 34, which is disproportionately less than the cost of equipment for ELISA, exceeding $ 18,000.
The developers managed to achieve extremely low energy consumption with the help of two innovations. First, they replaced the energy-consuming electric pump with a vacuum pump. To initiate the current of reagents loaded into the cartridge, the user must mechanically activate the negative pressure compartment.
The user presses the button of the device to start the reagent current.
This mechanism is reliable, requires only a little preparation and is easy to manufacture. The second innovation is that the device does not need a nutrient element, but uses a headphone jack to transmit energy and data. Thanks to the standardization of this element, the device can be connected to almost any smartphone.
Demonstration of the device operation. In this case, the HIV test was positive.
The experimental device has successfully passed the first pilot clinical trial in Rwanda. As part of the study, whole capillary blood samples were analyzed from 96 patients recruited through clinics specializing in the prevention of mother-to-child transmission, voluntary consultations and testing centers. The overwhelming majority (97%) of participants said they would recommend the new device to others, as it provides fast results, allows simultaneous analysis for several diseases and does not require complex manipulations.
Article by Tassaneewan Laksanasopin et al. A smartphone dongle for diagnosis of infectious diseases at the point of care is published in the journal Science Translational Medicine.
Evgeniya Ryabtseva
Portal "Eternal youth" http://vechnayamolodost.ru based on the materials of Columbia University
School of Engineering and Applied Science: Smartphone, Finger Prick, 15 Minutes, Diagnosis—Done!
09.02.2015