A machine that will call 9-1-1 for you

More than 1 in 3 heart attacks happen at home. If you have a heart attack during the night and you’re alone or your partner doesn’t wake to call 9-1-1, your chances of survival may be slim to none.

Researchers at the University of Washington wanted to tackle this problem. They developed a prototype run using smart devices that monitors people for cardiac arrest without touching them. This machine detects agonal breathing, a type of disordered breathing that occurs in approximately half of cardiac arrest cases reported to 9-1-1. Sometimes called “gasping breaths,” agonal breathing results from a severe lack of oxygen and occurs shortly after arrest.

Researchers used agonal breathing recordings from 9-1-1 emergency calls to train the machine, and found it detected agonal breathing 97% of the time from up to 6 meters away. When they tested the machine using ambient household noises and audio from sleep studies and volunteers asleep in their bedrooms, the tool incorrectly identified agonal breathing 0.14-0.22% of the time. However, when three distinct agonal breathing events less than 10-20 seconds apart were required, the false positive rate fell to 0%. Additional testing is needed, but researchers are hopeful this tool could give first responders enough time to treat these patients who would have previously been unreachable.

This study was published online by Chan et al. in Digital Medicine. https://www.nature.com/articles/s41746-019-0128-7.pdf