From the University of Washington, researchers have developed a way to use smartphone photos to identify potentially harmful bacteria on the skin and mouth. Microbes on the skin can be visually determined by this method that contributes to acne and causes gingivitis and dental plaques. Ruikang Wang, a University of Washington professor of bioengineering and ophthalmology, lead the team.
A group of researchers combined a smartphone modification with a set of image processing methods to show bacterial images taken by a conventional, standard smartphone camera. According to the researcher, the result is a relatively low-cost and fast method to assess harmful bacteria that could be used at home.
According to Wang, “Bacteria on the skin and in our mouths can have wide impacts on our health — from causing the tooth to decay to slowing down wound healing. Since smartphones are so widely used, we wanted to develop a cost-effective, easy tool that people could use to learn about bacteria on skin and in the oral cavity.” He explained bacteria is not normal to see using conventional smartphone photos because they capture in RGB. In the visual spectrum, images captured are from different wavelengths, but many bacteria emit colors beyond that spectrum and hence are invisible to it.
The researchers augmented a smartphone camera to get around this problem with a 3D-printed ring with 10 LED black lights arranged around it. According to lead author Qinghua He, a UW doctoral student in bioengineering, “The LED lights ‘excite’ a class of bacteria-derived molecules called porphyrins, causing them to emit a red fluorescent signal that the smartphone camera can then pick up.”
Porphyrins are produced by many bacteria as a byproduct of their metabolism and growth. Porphyrins can accumulate in the mouth and the skin where bacteria are found in high numbers, said co-author Yuandong Li, a UW postdoctoral researcher in bioengineering. On the skin’s surface, if more porphyrins are there, the greater chance there is of acne to form.
