No one likes to go to the doctor, and it’s even worse leaving the clinic empty-handed—even if you get to skip class, it’s certainly not worth a wait and a lollipop if you can’t be treated. Well, this is exactly the case for ear infections, which are the leading cause of pediatric healthcare visits yet are mostly resolved without a prescription.

Now, researchers have unveiled a system that detects middle ear fluid using just a smartphone and an ordinary piece of paper folded into a cone working as a funnel-like attachment to be used at home. This app-based diagnostic technique can be easily worked by adults and outperforms expensive, hard-to-use, specialized medical equipment for detecting middle ear fluid in children’s ears. The concept for an app-based screening tool on a smartphone could facilitate reducing the number of trips to the pediatrician as well as practical, cost-effective diagnosis of ear infections across the world.

Earitating Symptoms

The presence of fluid in the middle ear is key when detecting and diagnosing ear infections. Fluid in the middle ear can build up without signs of an infection of short duration. Although there are few obvious symptoms, which makes diagnosis more difficult, the presence of middle ear fluid affects nearly 4 out of 5 kids and is linked to speech delay, sleep disruption, poor school performance, balance issues, and a greater chance of progressing to and developing a true ear infection.

The classic “ear infection” means that there is infected fluid in the middle ear that causes fever, ear pain, and other symptoms. Although ear infection is the leading cause of pediatric healthcare visits, many cases can be resolved without the prescription of antibiotics and come with the possibility of complications. These include eardrum puncture, loss of muscle control on one side of the face caused by an irritated or damaged nerve (i.e. facial nerve palsy), or inflammation of the brain and spinal cord membranes (i.e. meningitis).

A Call for Ear Infection Detection

Currently, the diagnosis of ear infections calls for using specialized medical equipment. These expensive, commercialized healthcare tools are hardly used and sit around collecting dust because they are not designed for home screening purposes and require a referral to an audiologist—a healthcare professional who diagnoses and treats hearing and balance problems.

As a result, there is a need for a screening technique to detect middle ear fluid that does not use costly equipment and requires minimal expertise. That’s why, in 2016, the American Academy of Otolaryngology made a call for inquiries into an easy, practical, and impartial means to spot middle ear fluid. On top of that, they sought novel in-house diagnostic strategies to aid parents and caregivers in monitoring middle ear fluid after an initial or follow-up visit to a doctor.

Enginearing a Digital Solution

To detect fluid in the middle ear by assessing the mobility of an eardrum, new research describes an app-based technique. The technique exploits the microphone and speaker of everyday smartphones and a piece of paper shaped into a funnel that serves as an attachment.

How it works is that the app sends a soft beep into the ear canal using the smartphone speaker, detects the beep’s echo from the eardrum using the smartphone microphone, and uses some sophisticated computer programming on these echoes for predicting the status of middle ear fluid.

“The technology works the same way a bat uses acoustic signals to see in the dark,” says Dr. Gollakota, senior author of the research article. “Like a bat using echolocation, we send out ‘chirps’ generated by the speaker of the phone. These chirps bounce off the eardrum and back to the microphone for processing. How the chirps deflect off the eardrum will change depending on how much fluid is present.”

Dr. Gollakota explains that this works similarly to how sounds will bounce differently off of a wine glass depending on how much liquid is in the glass—as with singing glasses, the more water added to the glass, the pitch gets lower.

The smartphone-based system beat out a commercial medical system in detecting middle ear fluid in nearly 100 kid’s ears and was easily operated by patient parents without any formal medical training. In all, this app-based system performs similarly across the smartphone platforms tested as well as when used by parents compared as compared to clinicians.

Icon design ear scan in flat line style. Symbol about health check up and medical concept.
solar22 / iStock / Getty Images

Smartphones Here, There, and Everywhere

The whole thing runs on an app, both the testing and data processing, that is compatible with all versions of iPhone, Samsung Galaxy phones after the S5, and other Android phones, including the Google Pixel. No additional attachments are required beyond a paper funnel that can be constructed from paper and tape using a pair of scissors.

Since smartphones are now everywhere, this app-based system may hold promise as a middle ear fluid screening tool for parents as well as health care providers in regions limited in medical resources. The value of a low cost, smartphone-based screening tool lies in that it is accessible and familiar. Currently, the authors are working to market the system as a DIY product.

Dr. Gollakota elaborates, “There are other developing solutions in this space, such as expensive smartphone attachments. We aim to offer a DIY solution that doesn’t require anything additional besides a piece of paper. We’re really excited about not needing any additional hardware and using something as familiar and available as a smartphone.”

This smartphone-based system has a few limitations. As with many diagnostic tools, analyzing and understanding the results calls for the right clinical context, such as what symptoms the patient is experiencing and for how long. This system also does not tell apart different types of middle ear fluid. Knowing middle ear fluid type could possibly be helpful for identifying the presence of middle ear fluid or classic ear infection, even though this difference is made on the foundation of clinical history and symptoms.

An App a Day Keeps the Doctor Away

Since smartphones can be found essentially anywhere on the planet, this proposed system may be clinically useful in developing regions and rural communities where smartphone accessibility is swiftly growing. Also, it can be used in primary care settings as an add-on tool for tests with existing medical devices or for home screening by parents for a reduction of health care costs. Future studies are needed to prove the system’s potential impact on these and other potential situations.

“The number of problems related to health and the human body is enormous, so there are many opportunities for finding technical solutions that are grounded in science,” says Dr. Gollakota.

The next steps for these digital diagnostics are to receive approval as diagnostic devices in the US, Europe, and around the globe to be used on patients. Before we know it, they may become the new norm for diagnosis.

Dr. Gollakota certainly thinks so. “An analogy is like the introduction of the thermometer in the hospital. Before the thermometer, clinicians used to touch the patient to figure out what was happening. But, when the thermometer was invented, clinicians were hesitant because it was something new. Now, the thermometer is so common, it’s mundane. I would imagine that in the next 5 to 10 years, these smart healthcare technologies will be all around us.”