Researchers Enable Lab-Grade Medical Tests on Smartphones

The spectral transmission-reflectance-intensity (TRI)-Analyzer
The spectral transmission-reflectance-intensity (TRI)-Analyzer in use (Credit: University of Illinois at Urbana-Champaign)

In a major step towards creating a tricorder, University of Illinois at Urbana-Champaign researchers have invented a device that allows smartphones to perform the kinds of lab-grade medical diagnostic tests that previously had to be done on large and expensive instruments.

The device, called a spectral transmission-reflectance-intensity (TRI)-Analyzer, plugs into a smartphone and is able to run tests on a patient’s blood, urine, or saliva as reliably as clinic-based instruments that cost thousands of dollars. The researchers say their TRI Analyzer costs only $550.

“Our TRI Analyzer is like the Swiss Army knife of biosensing,” said Prof. Brian Cunningham, the Donald Biggar Willett Professor of Engineering and director of the Micro + Nanotechnology Lab at Illinois.

“It’s capable of performing the three most common types of tests in medical diagnostics, so in practice, thousands of already-developed tests could be adapted to it.”

In a paper published in the journal Lab on a Chip, the researchers demonstrated that their TRI Analyzer was able to carry out two commercial assays–detecting a biomarker associated with pre-term birth and the PKU test for newborns that indirectly detects an enzyme essential for normal growth and development.

The results from TRI Analyzer matched the accuracy of those from clinic-grade spectrometer instrumentation costing thousands of dollars.

“The TRI Analyzer is more of a portable laboratory than a specialized device,” said Kenny Long, an MD/PhD student and lead author of the research study.

The wide range of diagnostic tests the TRI Analyzer can conduct include an enzyme-linked immunosorbent assay (ELISA), that detects and measures proteins and antibodies in blood. The TRI Analyzer is also able to analyze the output of any test that uses a liquid that changes color or generates light output.

The TRI Analyzer turns a smartphone’s camera into into a high-performance spectrometer. The smartphone’s white LED is used to illuminate a sample fluid. The light from the sample is collected in an optical fiber and guided through a diffraction grating into the phone’s rear-facing internal camera. These optical components are held together with a 3D-printed mount.

The TRI Analyzer is able to analyze multiple samples simultaneously with a microfluidic cartridge, allowing it to quickly and reliably provide results for patients without access to a clinic or hospital with a diagnostic lab or for patients that require rapid results.

“Our Analyzer can scan many tests in a sequence by swiping the cartridge past the readout head, in a similar manner to the way magnetic strip credit cards are swiped,” said Long.

Cunningham says that the TRI Analyzer can also be applied to point-of use applications such as animal health, environmental monitoring, drug testing, manufacturing quality control, and food safety. The researchers are now licensing the TRI Analyzer.