First Smartphone App that Detects Pediatric Ear Infections

A new smartphone application can detect ear infections in children, according to researchers from the University of Washington who published their findings in Science Translation Medicine.

The app can identify fluid behind the eardrum by using a system that includes simply a piece of paper and a smartphone’s microphone and speaker. The piece of paper can be folded into a funnel that rests on the outer ear, and conductors sound waves in and out of the ear canal. Subsequently, once the smartphone plays a 150-millisecond sound, which resembles a chirping, the sound waves bounce off the eardrum, through the funnel and once traveling back via the funnel, are detecting by the smartphone’s microphone along with the chirping sounds. The app discerns fluid inside the ears depending on how the reflected sound waves interfere with original chirp and sound waves.

“It’s like tapping a wine glass,” said co-first author Justin Chan, a doctoral student in the Allen School, in a press release. “Depending on how much liquid is in it, you get different sounds. Using machine learning on these sounds, we can detect the presence of liquid.”

In assessing their algorithm’s efficacy, researchers tested 53 children (between 18 months and 17-years-old) at Seattle Children’s Hospital. Approximately half of the children tested were scheduled to undergo ear tube placement surgery for chronic or recurrent ear infections while the other half were scheduled to undergo non-ear related surgeries. Following parental informed consent, the researchers recorded chirps and sound waves in the child patients immediately before surgery. “What is really unique about this study is that we used the gold standard for diagnosing ear infections,” said co-first author Dr. Sharat Raju, a surgical resident in otolaryngology-head and neck surgery at the UW School of Medicine. “When we put in ear tubes, we make an incision into the eardrum and drain any fluid present. That’s the best way to tell if there is fluid behind the eardrum. So, these surgeries created the ideal setting for this study.”

High Accuracy in Fluid Detection

Results of the testing showed that among the children having ear tubes placed, 24 ears had fluid behind the eardrum, while 24 ears did not. For children undergoing non-ear related surgeries, two ears had bulging eardrums characteristic of an ear infection, while the other 48 ears were unobstructed. The findings suggested efficacy, as the algorithm correctly identified the likelihood of fluid 85% of the time, which is comparable to current methods implemented to detect ear infections. Moreover, when tested on 15 ears belonging to younger children between nine and 18 months of age, the algorithm displayed all five ears that were positive for fluid 90%, that did not have fluid.

“Even though our algorithm was trained on older kids, it still works well for this age group,” said co-author Dr. Randall Bly, an assistant professor of otolaryngology-head and neck surgery at the UW School of Medicine who practices at Seattle Children’s Hospital. “This is critical because this group has a high incidence of ear infections.”

The algorithm has been tested on a various smartphone’s and with different types of paper, and the results have remained consistent. The research team aims to commercial this app through a spinoff company before launching it to the public.

“Fluid behind the eardrum is so common in children that there’s a direct need for an accessible and accurate screening tool that can be used at home or clinical settings,” Raju said. “If parents could use a piece of hardware they already have to do a quick physical exam that can say ‘Your child most likely doesn’t have ear fluid’ or ‘Your child likely has ear fluid, you should make an appointment with your pediatrician,’ that would be huge.”