TRI a New Kind of Spectrometer
An inexpensive, smartphone-based device could offer a wide range of point-of-care tests
Michael Schubert |
Everyone’s vision of the “laboratory of the future” is different – but most agree that it should be reliable, versatile and efficient. And if those attributes don’t come with huge costs or space requirements – even better. Enter the US$550 spectral transmission-reflectance-intensity (TRI)-Analyzer (1), which can perform an array of tests on the spot by harnessing clever optics and the power of a smartphone. But is it the future?
“Several years ago, we completed an early demonstration of a smartphone as a spectrometer. The spectrometer itself was handheld, but to interface with any sort of meaningful biological sample, it needed to be attached to some benchtop optics. The next step was to produce a truly handheld device with everything inside, including the light source and sample interface.” To that end, the research team condensed three general optical techniques – transmission, reflection and intensity, each of which uses a different optical path – into a compact package to minimize size and cost. Best of all, the system wasn’t designed for a specific test. “So many recent advances in the point-of-care testing realm focus on miniaturizing a test for a single condition. The TRI-Analyzer is a handheld instrument capable of measuring thousands of commercial tests.”
The TRI-Analyzer was developed from the ground up. “We wanted to design a device that maximized spectral resolution (and therefore sensitivity) and versatility,” explains Long. He and his colleagues began with optical simulations to develop the ideal light path, and then substituted in commercial optical components. First, they designed the custom fiber-optic assembly and the 3D-printed cradle in which the optics are mounted; then, they built a prototype and tested each of the three modalities with basic samples, such as food coloring. “We also wanted to run some proof-of-concept experiments using biological samples from a context where a portable device would be beneficial,” says Long. To that end, the team assessed the TRI-Analyzer’s performance with an ELISA assay to detect an indicator of pre-term birth (fetal fibronectin protein) and a fluorescent assay to measure phenylalanine, an indicator for phenylketonuria.
The regulation of new medical technologies is stringent, so it will be some time before the TRI-Analyzer is approved for routine clinical use. In the meantime, though, veterinary pathologists take note: “The best patient right now would be a cow or horse. Just like people, they catch diseases and are highly mobile. ‘Clinic access’ is often challenging, and getting results back to patients after laboratory analysis can be difficult when they’re out in the pasture. Having a device that could perform a test on-site would obviously be beneficial.”
Personally, though, Long says he is incredibly interested in global health applications. “I’d love to see the TRI-Analyzer used by clinicians in rural or remote places where there might be clinics, but not clinical laboratories. Perhaps a doctor who travels to a dozen clinics on a regular basis could take the TRI-Analyzer with them as a portable lab system instead of collecting clinical samples, sending them off to a lab, and then trying to reconnect with a patient a couple of days later.”
Long and his colleagues hope that the TRI-Analyzer will help free many diagnostic tests from the centralized laboratory. Their ultimate goal? A tool that researchers and clinicians can use to quickly translate both existing and novel biomedical tests from the benchtop to the bedside. Better yet, they anticipate that the decreased logistics of sample collection, shipping, tracking, and follow-up will save time for physicians and laboratory professionals alike.
“I’d hope that we move away from having a separate gadget for each test we want to perform and toward a future where a single device can serve as a more universal portable laboratory capable of measuring many different types of tests,” concludes Long. “I hope our work helps nudge the field in that direction.”
- KD Long et al., “Multimode smartphone biosensing: the transmission, reflection, and intensity spectral (TRI)-analyzer”, Lab Chip, [Epub ahead of print] (2017). PMID: 28752875.