'Siri, does my baby have an ear infection?' An app does medical diagnosis
A new smartphone app can detect the presence of fluid in the middle ear, a sign of infection
A new smartphone app can use a phone's built in microphone and speaker to test for ear infections.
Ear infections are a common ailment in children that can cause a buildup of fluid in the middle ear, resulting in pain and fever. Using a smartphone and a piece of paper rolled into a cone, parents may soon be able to test their children for ear infections before making a decision about whether to head to the hospital.
The system works by playing a chirp of sound from the phone's speaker. This enters the the paper cone and is directed into the ear. The sound then bounces off the eardrum back to the phone's microphone. The app analyzes the sound reflections and can discern from them whether there is fluid in the middle ear - the presence of which indicates that the child likely has an ear infection.
"I think it'll have a major impact in hopefully reducing the amount of urgent care visits for ear infections," said Sharat Raju in conversation with Quirks & Quarks host, Bob McDonald. Dr. Raju is a resident in head and neck surgery at the University of Washington in Seattle, and helped develop the app.
Looking or listening for ear infections
Doctors traditionally diagnose ear infections by looking at the eardrum to try to detect the presence of fluid. However, Dr. Raju explains that some middle ear fluid is thin and translucent making it difficult to diagnose an ear infection visually.
New methods of detecting ear infections assess the mobility of the eardrum. If there is fluid behind the eardrum, it will not move as well as a healthy eardrum.
"Existing devices, known as tympanometers, … essentially use the power of sound in order to test the movement of the eardrum," explained Raju. "So we thought we could do the same thing with a smartphone."
The smartphone app sends a series of chirps into the ear and the echo reflected back off the eardrum is received by the smartphone's microphone. If there is fluid in the ear, the eardrum is much more rigid, and the sound reflects more powerfully back to the smartphone.
The app's algorithm analyzes the interference pattern between the sound leaving the phone and the sound reflecting back to the phone. With an infected ear, a large acoustic dip in the interference pattern indicates that there is likely fluid in the ear.
Raju and his colleagues trained the app's algorithm by performing the test of 49 patients, about half of whom experienced chronic ear infections. The app detected the presence of fluid with an accuracy of 85%, which is comparable to results from specialized equipment.
At home smartphone test
The smartphone app acts as a screening tool to help parents evaluate their child's condition, similar to taking their temperature with a thermometer.
"One of the main advantages of this is you don't have to go out and get a separate device. You have all the materials that you need at home," said Raju.
The app was successfully tested on iPhone, Samsung and Google Pixel phones, and seemed to work well with all of the devices.
In trials, parents who used the app on their children got similar results as the trained technicians in predicting ear infections successfully.
Don't go to the App Store just yet
The University of Washington team is seeking approval from the Food and Drug Administration to commercialize the app.
Raju hopes it will help parents monitor their children's ear health and reduce the number of unnecessary urgent care visits. He says it may even be useful in places where doctors don't have access to specialized equipment.
"I think this would be a great tool in those countries where smartphones are becoming increasingly ubiquitous."