Wearable injector can detect and reverse opioid overdose

Nov. 23, 2021

A research team at the University of Washington (UW) has developed a wearable device to detect and reverse an opioid overdose. The device, worn on the stomach like an insulin pump, senses when a person stops breathing and moving, and injects naloxone, a lifesaving antidote that can restore respiration.

The results of the proof-of-concept device were reported in Scientific Reports.

The UW team is looking to make these devices widely available, which would first require approval by the U.S. Food and Drug Administration (FDA). The FDA is currently working to accelerate efforts to address this critical public health problem and has recently released special guidance on emergency-use injectors.

In a multiyear collaboration, the UW investigators worked on the prototype with West Pharmaceutical Services of Exton, PA, which developed a wearable subcutaneous injector that safely administers medications.

The research team combined this injector system with sensors and developed an algorithm to detect the life-threatening pattern of respirations that occur when people experience opioid toxicity.

The pilot device includes a pair of accelerometers that measure respiration and an onboard processor that detects the halt of motion associated with breathing. The wearable system, which has received regulatory approval in the United States, activates the injector in the presence of prolonged apneic events.

The device also can transmit data about breathing rates and apneic motion to a nearby smartphone via Bluetooth.

To test the device, a clinical study was conducted with volunteers in a supervised injection facility in Vancouver, BC, and a parallel clinical trial was conducted in a hospital environment among volunteers who manifested signs of apnea by holding their breath.

Twenty-five participants were recruited at the Vancouver site. The sensors were able to accurately track respiration rates among people with opioid-use disorder. Further, the device was able to detect non-medical, opioid-induced apnea, a breathing pattern that commonly precedes a potentially fatal overdose. The testing in Vancouver measured breathing patterns only to develop the respiratory algorithm and did not involve injection of naloxone, which was administered only in the second study involving healthy human volunteers who did not take opioids.

In the second study, 20 participants simulated overdose events in a hospital setting by breathing normally, then performing a breath hold for 15 seconds to mimic an apneic event. When the wearable system detected that the subject had not moved for at least 15 seconds, it activated and injected naloxone into the participant.

Following device actuation, blood draws taken from study participants confirmed that the system could deliver the antidote into the circulatory system, showing its potential to reverse opioid overdoses.

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