An essay for smartphones promises quick and cheap to identify disease – also in the third world.
AIDS and syphilis can cause lifelong problems, some patients will die of the disease. So far expensive laboratory tests are needed to prove the disease. This makes often unaffordable in poor countries, where also the power for larger laboratory devices is not always guaranteed. A small laboratory attachment for smartphones promises now to identify the disease quickly and cheaply. He will help in particular pregnant women because the harmful effects of diseases can significantly reduce an early diagnosis and treatment on mother and child.
The plastic extension will cost 34 dollar and used disposable cartridges for a few cents. In a pilot study in Rwanda, a few drops taken from the fingertip ranged blood, to detect disease-specific antibody in the Palm-sized device. Health workers could use it after a half-hour briefing – including step by step instructions on the screen. A health workers are in the blood sample. You mixes in the fine micro channels of the cartridge with proof of substances, in which gold nanoparticles are included. The desired antibodies are present in the blood, they are bound by the particles. Then accumulate more silver nano-particles around them. The silver coating blocks out light that is illuminated from the outside into the cartridge, and displays the result in this way in about 15 minutes.
The quick test works on a similar principle as the Elisa test (enzyme linked immunosorbent assay). Developed in the framework of a program for the U.S. Agency for development cooperation USAID maternal health. He has proved in the Rwandan study with 96 pregnant women almost as precise, says Samuel Sia from Columbia University in New York. The biomedical engineer has led the development of the essay and published the results of the study of early February in the journal ‘Science Translational Medicine’. Several groups are working on similar so-called Microfluidics chips. Ten years ago, SIA founded the start-up Claros Diagnostics, with whom he developed a detection test for prostate cancer. Meanwhile, he has sold the company to OPKO health in Miami.
In recent years, his group has further miniaturized technology and reduce their power consumption. SIAs group did not include electric powered mini pumps for liquids in the cartridge. Instead, they built up a mechanically activated vacuum chamber to move the detection reagents to the blood sample. Now she works so efficiently that it can be powered via the headphone output of daily used mobile devices. The fully charged battery in an iPod touch allows a total of 41 tests.
Sia Group wrote a program with which to save the test results to your mobile device and upload to a server can be. To a large dissemination “it could take some time and require larger studies”, says Sabin Nsanzimana, head of the Department “sexually transmitted diseases” with the Rwandan Ministry of health. Samuel Sia plans therefore already a big field study. The Smartphone-based diagnosis could have far-reaching effects the researchers according to. “We have developed for HIV and syphilis, but she can be used of course for a whole range of different applications,” he says. “She could change the health care system if the users get locally precise measurements.” (David Talbot)