In the UK there are more than 40,000 out-of-hospital cardiac arrests (OHCA) annually, but fewer than 10% of people survive. Early CPR (cardiopulmonary resuscitation) and use of an Automated External Defibrillator (AED) to restart the heart can at least double the chance of survival. AEDs are safe for the public to use, even without training, but it can be difficult for bystanders to locate and retrieve one quickly during an emergency.
Researchers at the University of Warwick teamed up with the Welsh Ambulance Services University NHS Trust and autonomous drone specialists SkyBound for a National Institute for Health and Care Research (NIHR) study to test the feasibility of drone-delivered AEDs.
They tested using drones to fly defibrillators in response to 999 calls as part of emergency simulations in a remote countryside location where ambulance crews would usually be delayed in reaching by road.
Chief Investigator Dr Christopher Smith, University of Warwick, said: "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.
"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 operationalise this system and use it for real emergencies across the UK soon."
In the study, the researchers designed a system to deliver an AED attached by a winch to a DJI M300 drone following a 999 call. Skybound's automated drone software activated and controlled the drone's flight. The AED was lowered to a member of the public to help them carry out resuscitation on a CPR mannequin, all while receiving instructions from ambulance service call handlers.
The study, which recruited 11 participants, involved assessing real-time communications between the drone pilot, call handler and public bystander. Experts observed how those taking part behaved and interacted with each other. They also timed how quickly the mock cardiac arrest patient would be reached.
Steve Holt, who survived two cardiac arrests in remote Northern England beauty spots, says research into using drones to deliver Automated External Defibrillator (AEDs) to cardiac arrest patients may help to save lives.
The 74-year-old retired surgeon collapsed on a walking holiday in the Lake District with his 43-year-old son Mark in 2019 in a remote country pub near Coniston. Mark began CPR and used the defibrillator located outside the pub, but bad weather thwarted an air ambulance, so it took 25 minutes before paramedics arrived by road.
Mark, now a patient representative on the current NIHR study, sees the great potential of delivering defibrillators by drones and feels that it would be welcomed by people. 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.
Study findings show the technology is very promising. Drone start-up procedures were quick. It took 2.18 minutes from emergency call to drone take-off. The drone flew autonomously and safely, with good links to the ambulance service and effective real-time communication. Participants reacted positively to drone delivery of the AED.
However, there were delays once the drone had arrived on scene. It took a further 4.35 minutes after the drone had arrived before a shock was given to the simulated patient using the AED. Hands-off CPR time was 2.32 minutes, but only 0.16 minutes of this was spent retrieving the AED.
Researchers concluded that bystanders interacted well with the drone but struggled using the AED, showing that bystanders and call-handlers need more support to use drone-delivered AEDs for this to be effective. The next stage will involve funding larger studies to test the technology and evaluate whether it can be used in the NHS.
Professor Mike Lewis, NIHR Scientific Director for Innovation, said: "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.
"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."
