According to Cardiogram, heart rate sensors can detect both conditions, because your body's autonomic nervous system connects your heart with the brain, stomach, esophagus, liver, intestines, pancreas and blood vessels. The company needed data to be able to train its AI to recognize heart rate patterns that denote the presence of the conditions, though, so it recruited 6,115 of its app's users to participate in an online study with the UCSF Health lab.

Cardiogram managed to collect 30 billion sensor measurements composed of the subjects' heart rate and step counts, which it then fed to its AI. Since 37 percent and 17 percent of the participants have hypertension and sleep apnea, respectively, the AI got the samples it needed to be able to say whether someone has either condition.

According to the World Health Organization, 1 in 5 people with hypertension are undiagnosed -- perhaps even more now that the American Heart Association has redefined the condition's treatment guidelines. At the same time, 80 percent of people with sleep apnea -- a disorder that disrupts your breathing during sleep -- don't even realize they have it. A wearable that can detect them could compel you to seek medical attention and ultimately save your life.

The app-maker's studies still have to undergo peer-reviewed clinical research, and that includes its previous experiment, wherein it trained its AI to detect the signs of a stroke. It promises to "start translating these research results into actual care" these next few months, as well as to expand its AI's abilities and give it the power to detect diabetes.