TORONTO —
A wearable device that detects signs of an opioid overdose and injects a drug to reverse the event could be a lifesaving tool, according to a newly published paper by U.S. scientists who researched and helped develop the prototype.

The device, which is worn on the stomach, similar to an insulin pump, can detect when a person is experiencing an overdose and administer naloxone to reverse the event. Naloxone is an opioid antagonist and is considered very effective. It works by blocking the effects of an opioid, quickly restoring a person’s breathing back to normal.

Opioid overdoses have been a leading cause of death in places like British Columbia, and have increased during the COVID-19 pandemic. In the first nine months of 2021 alone, more than 1,500 people died of illicit drug overdoses in the province — the most officials have ever seen within that time frame and a 24 per cent increase from the same period in 2020.

In the U.S., fatal overdoses hit an all-time high as well, with the Centers for Disease Control and Prevention estimating that 100,300 Americans died of drug overdoses from May 2020 to April 2021, based on the latest available death certificate data. Researchers noted that opioids accounted for the majority of deaths. Left untreated, overdoses from the non-medical use of opioids can lead to respiratory failure, heart attacks, and death.

“The opioid epidemic has become worse during the pandemic and has continued to be a major public health crisis,” lead author and University of Washington (UW) doctoral student Justin Chan said in a statement.

“We have created algorithms that run on a wearable injector to detect when the wearer stops breathing and automatically inject naloxone.”

The algorithm can detect the life-threatening symptoms and patterns of an overdose, including when a person’s breathing and movements slow or stop. The prototype wearable naloxone injector system uses sensors, including accelerometers, to measure breathing, and a processor to gauge one’s movement, and sends the data via Bluetooth on breathing rates and motion to a nearby device. Accelerometers are commonly found in smartphones and fitness tracking devices to measure motion.

The system designed in this study builds on prior existing work, the authors said, but noted this design was unique in that it was evaluated on real-world participants who would be at risk of an overdose.

Scientists found that the sensors could track breathing rates with accuracy among opioid users and were able to tell changes in respiration that typically precedes a potentially deadly overdose.

This small study, conducted by a team from UW and published on Monday in Scientific Reports, involved two trials. One used the device on 25 volunteers from a supervised injection facility in Vancouver, B.C., to evaluate if the sensors were able to accurately track breathing changes and a halt in movement from opioid use in a real-world setting. The trial was used to help develop an algorithm and was not designed to actually administer naloxone. None of the volunteers overdosed or required any medical intervention.

The drug was only injected during a second trial that was conducted within a hospital setting with 20 healthy volunteers who did not take opioids. After measuring their normal breathing, participants mimicked the signs of an overdose by holding their breath and halting movement for at least 15 seconds, triggering an injection of naloxone. Blood samples were taken to confirm that the device could properly deliver the drug into the circulatory system. Only 18 participants were injected with naloxone as the device was not positioned close enough to the skin on the first two volunteers.

“Increasing access to naloxone is a necessary component of harm reduction. However, it does not address instances when there is no bystander to administer the antidote or when the event goes unrecognized by a witness,” the authors wrote in the paper, noting that up to 51.8 per cent of fatal overdoses occur when the individual is alone. In more than a quarter of cases, bystanders react too slowly because they do not immediately recognize the signs of an overdose, according to this study.

Researchers have been working on the prototype device in partnership with West Pharmaceutical Services for a number of years and are hoping to make the device, which is not yet approved by regulators, widely available. The research was funded by the U.S. National Science Foundation.

“This wearable auto-injector may have the potential to reduce fatalities due to opioid overdoses,” said co-author and UW professor Shyam Gollakota in a statement.

The authors said that more research is needed to gauge the usability and comfort of the device over longer periods and in unsupervised settings with volunteers who would be at risk of an overdose.