UCLA researchers have designed a portable imaging system that can diagnose gout.
The new system is compact and cost-effective, and it could allow many more primary care doctors to screen for the disease, which is the most common type of inflammatory arthritis.
The definitive test for gout calls for a doctor to draw joint fluid from a patient and then use a device called a compensated polarized light microscope to identify uric acid crystals in the sample. But recent studies have shown that primary care doctors usually opt to make their diagnoses without performing the procedure.
The UCLA-designed platform, based on a technology called lens-free on-chip microscopy, can perform wide-field imaging without the need for lenses. It uses holographic imaging to produce high-resolution images of the crystal-like objects—the telltale signs of gout—in the patient’s fluid sample.
The technology works by sending a stream of light through a polarizer, through a sample of the fluid on a microscope slide, and then through another polarizer before it reaches an image sensor microchip, a component also found in mobile phone cameras and webcams.
The image sensor captures the holographic diffraction pattern produced by the sample and feeds it to a computer with software that can quickly generate an image of the sample. The platform can use the entire active area of the image sensor chip—about 20 to 30 square millimeters, or approximately 100 times larger than standard optical microscopes can analyze at a similar resolution level—allowing for rapid analysis of larger volume of samples.
The UCLA technology could ultimately be used to diagnose other conditions that are caused by crystals forming in bodily fluids and that are currently diagnosed using conventional polarized light microscopes—kidney stones, for example.