Called Second Chance, the app sends inaudible sound waves from the phone to a person’s chest to sense breathing patterns. When a person is taking seven or fewer breaths per minute — a rate that commonly leads to bedside visits in hospitals — the app is triggered.
Researchers said the app still is being tweaked, but the goal is for it to then ask whether a person is OK. Absent a response, the app will instruct the phone to either call 911 or the emergency contact of a person’s choice.
“Our vision is that people, if they’re going to use, should use in the safest manner possible,” said co-corresponding author Dr. Jacob Sunshine, an assistant professor of anesthesiology and pain medicine in the School of Medicine. “A lot who end up dying are using alone. This is to help particularly those people, but could also be useful for people using with others as well.”
The Centers for Disease Control and Prevention said 70,237 people died by overdose in 2017. About 47,600 of them had at least one opioid in their system.
Rajalakshmi Nandakumar, a doctoral student in UW’s Allen School who took the lead in developing the app, said researchers chose to harness sound waves because they’re so widely available.
“The speakers and microphones present in off-the-shelf devices … can detect even minute motion,” she said. “One of the issues with new hardware is getting people to adopt it. If you use existing devices, it’s easier."
Second Chance, which works up to 3 feet away, also detects movement. Someone who’s moving likely hasn’t overdosed, researchers said. The opposite is true for someone whose head has slumped.
Nandakumar traveled with some colleagues to the Insite supervised injection facility in Vancouver, Canada, to test the app.
Ninety-four people agreed to participate, wearing monitors on their chests as they prepared their drugs and for five minutes afterward — the window when overdose symptoms typically occur.
Of the participants, 47 took seven or fewer breaths per minute, 49 stopped breathing, and two required oxygen, ventilation and/or naloxone, an overdose-reversal drug. The app correctly identified their breath rates 90 percent of the time, researchers said.
Nandakumar said the participants, once they understood the app used sonar rather than a camera, didn’t have privacy concerns.
“In general, people at the injection site were really excited and supportive of our app,” she said. “They were asked separately if they would use it when it’s available and most were interested.”
“If you look at addiction as a medical issue, these people generally want help — they come to safe injection sites because they can engage in medical supervision,” Nandakumar said. “The United States doesn’t have any such facility currently … but this app could provide similar protection.”
Nandakumar and Sunshine said they’re working with a California group to get approval from the U.S. Food and Drug Administration. They aren’t sure when that may happen but are hoping their application will be expedited because of the seriousness of the opioid epidemic.
Researchers said the app, while it only has been tested on those who inject, likely can be used for all forms of opioid use.
Sunshine said researchers, whose work was funded by the UW Alcohol and Drug Abuse Institute and the National Science Foundation, haven’t tested whether the app detects slowed breathing faster than a person could.
“But as a clinician I can tell you … it’s not as straightforward as you might think,” he said. “There’s literature on this that features medical staff of various levels of training trying to estimate the rate and, compared to a monitor, the performance is not as good as you might think.”
©2019 The Day (New London, Conn.). Distributed by Tribune Content Agency, LLC.
