A Northern Ireland-born heart expert whose pioneering techniques saved countless lives has died at the age of 88.
Professor Frank Pantridge pioneered the portable defibrillator
Professor Frank Pantridge, best known for developing the portable defibrillator, died on Sunday.
He invented the device in 1965 while working at the Royal Victoria Hospital in Belfast.
Defibrillators provide a controlled electric shock to the chests of patients to restore the heart to its normal rhythm.
Mr Pantridge's invention operated from car batteries, and variants of this are used across the world.
Before this, defibrillators could only be operated from the mains electricity supply in hospitals.
Dubbed "the father of emergency medicine", Mr Pantridge installed his first portable defibrillator in an ambulance.
Defibrillators restore the heart's rhythm to normal
This pre-hospital coronary care unit was known as the Pantridge Plan.
A 1985 survey found that early pre-hospital treatment among patients under 65 reduced deaths by 38%.
In 1990, then-Health Secretary Kenneth Clarke allocated £38m to equip all front-line ambulances in England with defibrillators.
The Royal Victoria Hospital in Belfast issued a statement paying tribute to Professor Pantridge.
Tributes were paid to Professor Pantridge's invention
It said: "It was thanks to him that in the late 1960s, Belfast was often described as the safest place in the world to have a heart attack."
Dr Michael McBride, Royal Victoria Hospital medical director, said Mr Pantridge had "challenged traditional thinking" about cardiac treatment.
Andrew Dougal of the Northern Ireland Chest, Heart and Stroke Association, said Mr Pantridge's achievements would continue to inspire those working in the battle against heart disease.
"It is important that we follow through with the work which he started 40 years ago," he said.
Around 270,000 people suffer a heart attack in the UK each year, with about a third dying from cardiac arrest before reaching hospital.
Cardiac arrests usually occur because of a heart attack, when the heart is starved of oxygen. The heart either quivers - known as fibrillation - or stops beating altogether.
Seven out of 10 cardiac arrests happened outside hospital, but only 2 to 3% of these cases survive.
A patient's chances of survival drop by up to 10% for every minute that passes, meaning that having a defibrillator close at hand could make all the difference.