When Marc Regimbal lost his three-year-old child for 20 minutes – in what he called the "hairiest experience" of his life - he was determined to make sure it would never happen again.
He spent the next four years combining global positioning system (GPS) and cell-phone technologies to make a tracker - called Childtrac - that could be easily attached to a child's clothing or backpack. Parents can set virtual boundaries and locate their children on their smartphones.
Just one year on from the launch of the product, however, and Regimbal said he is seeing growing demand from an unexpected demographic.
"People started asking about using the tracker on elders – especially people with Alzheimer's and dementia," he told CNBC.
(Read more: Wearable tech: a victim of its own hype?
There were an estimated 44.4 million people with dementia across the world in 2013, according to Alzheimer's Disease International, with this number expected to rise to 75.6 million in 2030, and 135.5 million in 2050. The condition often causes patients to get disoriented or lost -- even in familiar places – so the use of GPS technology to locate them can provide greater peace of mind to carers and family members.
"When it comes to locating elderly people, it's a fairly small market today and there are opportunities for significant growth going forward," André Malm, senior analyst at telecom industry analysts Berg Insight, told CNBC.
He stressed that tracking people with dementia was different to children – when often a mobile phone complete with tracking app would suffice.
(Read more: Telemedicine keeps seniors out of nursing homes)
"People with dementia might forget the phone - or in the case of an emergency might not be able to use it," Malm said. "So you really need a dedicated device - a wristwatch or a pendant - so you can make sure the person actually has it on them."
In response to this problem, Louis-James Davis, director of KMS Solutions, created the KMS Wristband. If the device's only button is pressed by the wearer, it automatically dials one of a nominated number of carers who can speak to the wearer while tracking their location.
"If someone with dementia says they are going to the shop, you can't always trust that they'll get there," he told CNBC. "This means that if they go off-route you check they're ok."
The cost of a KMS Wristband is currently being negotiated between the company and network providers (it is due to hit stores in October 2014), while Canada-based Childtrac's device costs C$299.95 ($272.70) and then $15 per month.
(Read more: Wearable smartbands set for 350% growth in 2014)
Davis described the tracking of vulnerable adults as a "key market" for the company, which was only launched in January this year.
"I took the communication technologies that were already out there in homebound assisted living and put it onto the wrist," he said.
Wearable tech game-changer?
Berg Insight's Malm says this shift from more traditional assisted-living systems towards wearable tech could be a game-changer for the market.
There are currently around 5.9 million "telecare" alarms – in-house safety systems that raise an alarm if a user gets into difficulty - in Europe and North America, according to Berg Insight. By contrast, there were only just under 100,000 mobile telecare users in mid-2013.
"But across the world – and in Europe specifically – the older systems are being replaced with digital systems and so there's the possibility to move to these next-generation, wearable devices," he said.
Malm forecasts around 3.5 million mobile telecare systems to be in use in Europe and North America by the end of 2018 – with roughly half of these being used on people with dementia.
As a result, he expects revenue from the sector to grow from around 35 million euros ($48.5 million) per year in 2013 to 500 million euros ($692 million) in 2018 in Europe, and from $40 million in 2012 to $550 million in 2018 in the U.S.
Another growth trigger point for the market would be the widespread adoption of the technology in nursing homes – an area from which Childtrac's Regimbal has reported growing demand.
"Nursing homes don't want to become prisons. They want to let the elderly go for walks, but sometimes they get lost – this device means they have peace of mind," he said.
Despite the relatively high cost of these devices, Malm said their implementations could actually save nursing homes – and even the state – money.
"There is less need for around-the-clock surveillance," he said. "In fact, these devices could be the only way our society will be able to afford the care of an aging population."
(Read more: The pros and cons of long-term care insurance)
In the U.K a number of local councils already provide tracking devices for some dementia patients, with a device called Mindme Locate especially popular with authorities. Mindme has supplied over 400 devices to councils across the U.K., and reported growing demand for its devices.
Meanwhile in April last year, Sussex Police said it had paid for GPS tracking devices in the hopes of saving money spent searching for missing dementia patients.
"The GPS will be very cost-effective to the police… It will reduce anxiety for the family and really reduce the police time spent on this issue," Tanya Jones, who was chief inspector at the time, said last year.
But not everyone is convinced that the use of GPS tracking devices on the elderly is always a good thing.
Neil Duncan-Jordon, national officer at the U.K.-based campaign group the National Pensioners' Convention, expressed reservations about the use of the technology, arguing that it can't replace human care.
"Sometimes the only person an elderly person sees is the person who comes in to check on them – if that's going to be replaced by new technology, what happens to that elements of personal contact?" he told CNBC.
"And GPS trackers don't actually provide better care. It might help you find people – and quicker – but it doesn't stop them going outside, and potentially falling over. It's quite a grey area."
The U.S.-based Alzheimer's Association, however, disagrees, arguing that the use of tracking devices provide assurance and confidence to a carer regarding their loved one's safety.
"Programs and services such as (these) are not a way to relieve one of responsibility, but to enhance a caregivers' ability to provide comprehensive and high quality care for their loved one with Alzheimer's," Beth Kallmyer, vice president of Constituent Services at the association, told CNBC.