Researchers at the University of Washington have developed a device to replace spirometers. What are spirometers? They are used by doctors to measure lung capacity and diagnose respiratory conditions. Spirosmart is an app tat costs thousands of dollars less than dedicated hardware, so much that its even affordable enough for patients who can monitor their conditions at home by exhaling into their phones.
SpiroSmart uses a different approach to avoid the need for any other hardware. The researchers created a model of a human trachea and vocal tract and used it to generate an algorithm which can analyze the sound of someone's breath as it resonates inside their lungs. What happens after is that the resonance changes when the flow of air is restricted letting the app detect this.
The app is just as accurate as dedicated spirometers. Check out the video below: