Each year, more than 40,000 out-of-hospital cardiac arrests (OHCA) occur across the UK, but fewer than 10 % of people survive. Early intervention—especially CPR and the use of an Automated External Defibrillator (AED)—can at least double the chances of survival. While AEDs are designed for public use and don’t require training, locating and retrieving one quickly remains a major challenge during emergencies.
To address this, a team from the University of Warwick partnered with the Welsh Ambulance Services University NHS Trust and drone specialists SkyBound for a study funded by the National Institute for Health and Care Research (NIHR). Their goal was to assess whether drones could deliver AEDs faster than traditional emergency services in remote or rural areas.
They ran a series of simulated 999 emergencies in countryside locations where ambulance crews typically face delays due to distance or difficult terrain. In these tests, drones were launched to deliver defibrillators directly to the scene.
Ambulance services work as swiftly as possible to get to patients who have suffered cardiac arrests. However, it can sometimes be difficult to get there quickly. AEDs can be used by members of the public before the ambulance gets there, but this rarely happens. We’ve built a drone system to deliver defibrillators to people having cardiac arrest, which could help save lives.
Dr. Christopher Smith, Chief Investigator, University of Warwick
“We have successfully demonstrated that drones can safely fly long distances with a defibrillator attached and maintain real-time communications with emergency services during the 999 call. We are in a position where we could operationalize this system and use it for real emergencies across the UK soon,” added Smith.
In the study, the team used a DJI M300 drone equipped with a winch system to lower an AED to a bystander after a 999 call. SkyBound’s autonomous software managed the drone’s flight path, while ambulance call handlers provided live instructions to the person on the ground, guiding them as they used the AED on a CPR mannequin.
Eleven participants took part, with researchers observing how the drone pilot, emergency call handler, and bystander coordinated in real time. They also recorded how long it took to reach the simulated patient and administer care.
Among those supporting the research is 74-year-old retired surgeon Steve Holt, who survived two cardiac arrests in remote parts of Northern England. In 2019, while walking in the Lake District with his son Mark, he collapsed outside a rural pub. Mark immediately began CPR and used a nearby defibrillator, but heavy weather delayed an air ambulance. Paramedics didn’t arrive by road until 25 minutes later.
Now involved as a patient representative in the study, Mark sees clear value in drone-delivered AEDs.
He added: “While I was resuscitating dad it felt like an eternity waiting for help. Ambulances can be delayed, especially when trying to get to remote areas like those we were in. But in the future a call handler may be able to explain that help is on the way with a drone which can arrive much quicker. Without clinical research, healthcare advances would not come to fruition. It has been a privilege to be involved with the NIHR and the University of Warwick’s work.”
Early results from the study are promising. Drone launch procedures were efficient—taking just 2.18 minutes from the emergency call to takeoff. The drone flew safely and autonomously, maintained a stable connection with emergency services, and delivered the AED effectively. Participants reacted positively to the experience.
However, some delays occurred after the AED arrived. It took 4.35 minutes from the drone’s arrival until a simulated shock was delivered. Only 0.16 minutes were spent retrieving the AED, but hands-off CPR time totaled 2.32 minutes, highlighting a need for clearer guidance on using the device.
Researchers concluded that while bystanders interacted well with the drone, more support is needed to ensure AEDs are used quickly and correctly. The next step will be to secure funding for larger-scale studies and evaluate how drone delivery could be integrated into NHS emergency response systems.
Cardiac arrest, as the Secretary of State highlighted, is one of the biggest killers, claiming tens of thousands of people’s lives a year. In an emergency situation, time is of the essence and it’s crucial that bystanders can help before ambulance crews arrive.
Mike Lewis, Professor and Scientific Director for Innovation, NIHR
He concluded, “That’s why it’s so exciting, this innovative study is investigating if enabling emergency services can harness drones to deliver defibrillators to help improve survival. This demonstrates how health and care research can deliver high tech solutions to improve health and care services, and powers the country’s life sciences sector and technical advantage.”
Journal Reference:
Smith, C. M., et al. (2025) The use of drone-delivered Automated External Defibrillators in the emergency response for out-of-hospital cardiac arrest. A simulation study. Resuscitation Plus. doi.org/10.1016/j.resplu.2025.101045