A drone which could deliver a defibrillator to a person suffering from a cardiac arrest is being tested by the Karolinska Institute in Sweden.
Trial flights have the shown the drones can arrive at a destination four times faster than an ambulance.
After cardiac arrest, the chances of survival decrease by 10% for every minute that an individual goes without cardiopulmonary resuscitation (CPR) or defibrillation.
Some 300,000 people die of cardiac arrest in Europe each year.
BBC Click finds out more.