Mobile app for detecting opioid overdose

Second Chance is a smartphone app developed by University of Washington engineers to detect an opioid overdose. The researchers tested the app at a public supervised injection facility in Vancouver, Canada with encouraging results. From Science News:

Second Chance, described online January 9 in Science Translational Medicine, converts a smartphone’s speaker and microphone into a sonar system that works within about a meter of a user’s body. When the app is running, the phone continuously emits sound waves at frequencies too high to hear, which bounce off a user’s chest. Tracking when these echoes reach the phone allows the app to detect two possible signs of an impending overdose: slow breathing or no breathing at all...
For real-world use, the researchers envision the app notifying a user if it detects breathing problems and sending for help only if the user doesn’t respond to that notification, says study coauthor and computer scientist Shyam Gollakota. The scientists still need to ensure that this setup could reliably alert emergency contacts or medical personnel in time to resuscitate a person.