A New York woman is crediting FaceTime for saving her life during a stroke. Apple's video call service has been around for almost eight years (it was released with the iPhone 4 in 2010) but took some time to be widely embraced. Now, Opokua Kwapong says the feature is the main reason she is still alive today.

Midway through a video call with her sister, Adumea Sapong of Manchester, something went wrong. Sapong told her sister that her voice had become slurred and that Kwapong "didn't look quite right".

"My sister looked at me and said she could see that my face didn't look right," Kwapong said, according to the BBC. "She also said that I was slurring my words, but I thought she was just fussing and I didn't believe her."

Kwapong had just woken up from a nap when her sister called from the UK. The 58-year-old said she did not realise the gravity of the situation.

"When I called Opokua she said that she'd not been felling well and had been feeling tired and was also having some difficulty walking," Sapong said. "I said, 'perhaps you need to take some aspirin'. She tried to pick up a glass of water and wasn't able to."

"Then I noticed on the FaceTime video call that her face was drooping. I told her she needed to hang up and immediately see a doctor. She thought I was making a fuss so I then conferenced in one of my other sisters, who is a doctor, and she could hear her speaking and could also tell that her speech was slurred. We both told her to call for help straightaway."

After rushing to an emergency room, a scan revealed that Kwapong had a blood clot in her brain. "There is no doubt that FaceTime saved my life," she said. "If my sister had not noticed that something was not right, then things could have been so different."

Her sister said technology deserved praise in the life-saving ordeal. "If it had not been for FaceTime, then we would be having a very different conversation right now," Sapong said. "You hear a lot of negative stories about the internet and technology, but I think this is an example of how technology can be a force for good."

Kwapong is now permanently paralaysed on the left side of her body.