Dr. Steven Brooks once used the promise of tasty appetizers to entice his neighbours over to his home so he could teach them how to save lives.
"They all came over and we had wine and cheese and a few mannequins on the back deck, and we learned CPR together and how to use the defibrillator," he said.
The Kingston, Ont., emergency room physician has made it his life's work to figure out the best way to equip communities with defibrillators — which he says can dramatically improve a person's odds of surviving cardiac arrest.
It's become increasingly common to install the devices in rinks, community centres and airports. But there remains a major challenge — finding them in an emergency.
"When the unexpected happens and someone collapses, it's unusual for somebody on the scene to be instantly be able to pull up in their brain where they last saw a defibrillator," Brooks said. "In the panic of the moment, it's just not very often that a defibrillator is accessible."
A CBC News investigation has shown that many defibrillators in Atlantic Canada are not registered with provincial authorities, and even 911 dispatchers often don't know where the life-saving devices are located.
And across the country there is a patchwork of policies around registering defibrillators. How information about their locations is shared with bystanders who could help someone in cardiac arrest varies from place to place.
To make sure a defibrillator is always on hand in his Kingston neighbourhood, Brooks installed a portable one outside his home in weather-resistant casing more than a year ago.
So far, his device hasn't been used. But it's estimated by the Heart and Stroke Foundation that 40,000 Canadians die from cardiac arrest a year.
People's chance of survival drops by 10 per cent every minute, unless someone starts chest compressions or uses a defibrillator, which gives an electric shock that can help restore a heart to its normal rhythm, Brooks said.
"Many of those people are saveable," he said. "Many of those people have cardiac arrests within a few metres of a PAD [public access defibrillator] and the defibrillators are not used. That is a tragedy."
Brooks's research has found that coffee shops, bank machines and recreational facilities such as rinks and pools are ideal places to install the portable devices.
At a couple thousand dollars per device, they aren't cheap. Brooks said communities need to consider how to position them in places they will be used and to make sure people and emergency dispatchers know about them.
But he said 80 per cent of the time people experience cardiac arrest outside hospitals, they are at home.
"Defibrillators just sitting out in the community are not going to be very useful," he said.
Seven provinces currently have voluntary registries in which people and organizations can record the location of their devices. Of them, Nova Scotia has the fewest registered, with 230. By comparison, Saskatchewan, which has a slightly larger population, has logged 10 times that many.
CBC News mapped locations of devices in New Brunswick, after obtaining their locations through freedom of information legislation.
Brooks said national guidelines would create some consistency and help ensure defibrillators are used.
The Nova Scotia government said it is implementing new software that will eventually allow emergency dispatchers to direct callers to portable defibrillators registered in their area, and plans to promote the new system to increase registration.
In Canada and internationally, there are a variety of approaches to equipping communities with defibrillators and ensuring people know where to find them.
"Finding them and getting the community involved in games and using apps to take pictures of defibrillators they see out there have been successful in some cities in increasing the number of defibs registered in the community," Brooks said.
There are also phone applications that can alert people who own defibrillators when there is a crisis nearby.
The software Nova Scotia acquired earlier this year is already used in Regina and will eventually allow Emergency Health Services responders to text or leave a voicemail for people who have registered devices, in hopes they might bring them to an emergency.
Brooks is conducting federally funded trials in British Columbia and Winnipeg on an app called PulsePoint, which alerts people to a nearby emergency and sends them directions to both the person in cardiac arrest and the nearest defibrillator.
The app is already used in Seattle and other parts of the United States. Kingston has used the technology since 2015 and "it's been a very successful pilot," Brooks said.
"People who are willing to help are empowered with that knowledge of where this person is who needs chest compressions, and also where the nearest PAD with detailed instructions, so they can go and get it and hopefully save a life," he said.
In New Zealand, a volunteer-run app has mapped 8,000 defibrillators across the country.
The phone application is not linked to local emergency systems so 911 personnel can't access the information. Its administrator, Gareth Jenkin, said initially he got pushback from people who questioned whether it would work but he said it's popularity continues to grow.
Jenkin, who works as a resuscitation co-ordinator, volunteers his time to add new devices to the map. There are no guarantees the devices are well-maintained or working, but he said it's better than nothing.
"Although people want a completely bulletproof system," he said, "you can never work out what a human is going to do in a crisis."
Having the address of defibrillator location isn't the only barrier either. When there are meetings about defibrillator access, Brooks said often he hears people debating whether there are privacy or liability issues.
When organizations list their device on a public registry, he said the reality is they have to be OK with someone running in to grab it and take it elsewhere.
"What is liability with that if defibrillator doesn't work, if battery haven't been maintained or the pads have expired, who is responsible for that?" he said.
"In my experience, I've never heard of that being a real barrier."
With files from Susan Allen and Karissa Donkin