A Dependable Diagnostics Dongle


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A smartphone dongle for HIV and syphilis testing. Image: Tassaneewan Laksanasopin, Columbia University

After eight years and several versions, a team of researchers at Columbia University's Fu Foundation School of Engineering and Applied Science is getting close to a large-scale trial of a small, portable, and inexpensive ­­- yet highly accurate - diagnostic device that tests blood droplets for HIV and syphilis in just 15 minutes.

Powered by a smartphone, the device consists of a dongle that connects to the audio jack and a disposable plastic cassette preloaded with test reagents. As part of the dongle, the team developed a mechanically activated pressure chamber that “pumps” the blood sample into the cassette. The device, developed especially for developing nations, replicates for the first time all mechanical, optical, and electronic functions of a lab-based blood test.

“Our work shows that a full laboratory-quality immunoassay can be run on a smartphone accessory,” says Dr. Samuel K. Sia, associate professor of biomedical engineering at Columbia Engineering, who is leading the team.

Tassaneewan Laksanasopin, a Ph.D. candidate and lead author of a paper describing the work published in the Feb. 4 issue of Science Translational Medicine, has been working in Sia’s lab since 2008, soon after the project was underway. Awarded a Royal Thai scholarship to pursue her M.S. and Ph.D. degrees, she chose his lab to earn her degrees focusing on microfluidic technology because she is interested in global health and liked the idea of working on a diagnostic for prevention of disease, particularly for the developing world.

The device diagnoses diseases in just 15 minutes using finger-pricked whole blood. Image: Tassaneewan Laksanasopin, Columbia University

“Treatment is very important,” she says. “But anything we can stop early on will have a greater impact. That’s why I think this is very important.”

The first device the team developed had simple hardware and technology, but it required a lot of user training, Laksanasopin says. The next version was user friendly but costly. This last one is smaller and uses considerably less power so can be powered by a smartphone instead of a battery. This is because a power-consuming electrical pump in the previous version has been replaced by the pressure chamber. It takes only about 30 minutes to train healthcare workers how to use it. A user-friendly interface takes the user through each test, has step-by-step pictorial directions and timers to alert the user to next steps. It also stores records of test results for later review.

“We saw that people in developing countries were using mobile phones much more than we expected so it became feasible [as a source of power] since they already have them,” Laksanasopin says. Those changes cut manufacturing costs to an estimated $34, compared to the $18,000 that lab equipment runs. Portability, simplicity of use and maintenance are also important in developing countries because electricity is not always available 24/7, and healthcare is often best delivered outside of a medical facility and even in patients’ homes.  

“Coupling microfluidics with recent advances in consumer electronics can make certain lab-based diagnostics accessible to almost any population with access to smartphones. This kind of capability can transform how healthcare services are delivered around the world,” according to Sia in a Columbia Engineering School release.

The current version was recently tested by healthcare workers in Rwanda among 96 pregnant women. Laksanasopin admits that she was very nervous before the trial because ease-of-use is so important. Prior to the trial, only the development team had tested it. “We hadn’t had anyone without a technical background use it,” she adds.

The team will conduct a trial on a larger scale later this year and start talking to possible collaborators, with the hope that it will be ready for developing markets within two years. Some of that depends on how long the approval process takes, Laksanasopin said.

She is optimistic that the technology has broad applications, some for developed markets as well, such as Lyme disease. “We are exploring lots of other areas. Once we get this out to the market, we hope we can use the same technology for other markers and diagnose other diseases,” she says. “The platform is very flexible.”

In addition to looking at other sexually transmitted diseases, Laksanasopin says they may even go after cancer. Other possibilities are measuring hormone levels or vitamin deficiencies. “We want to have as many applications as we can,” she says.

When Laksanasopin receives her doctorate, expected in May, she plans to return to her native Thailand and is interested in teaching and research in the area of diagnostics. “When you travel to other countries [as Laksanasopin did to Tanzania], you see what people really need for healthcare devices,” she says. “I am very grateful that I picked this [area to work in].”

Nancy S. Giges is an independent writer.

Learn about the latest trends in medical diagnostics at ASME’s Global Congress on NanoEngineering for Medicine and Biology.

Coupling microfluidics with recent advances in consumer electronics can make certain lab-based diagnostics accessible to almost any population with access to smartphones.

Tassaneewan Laksanasopin, Ph.D. candidate, Columbia University

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July 2015

by Nancy S. Giges, ASME.org