You're designing a wearable for emergency situations; some things are obvious from the get-go. It must be simple to use. It should be discreet. It mustn't ever be 'off'. And of course, should the time comes to use it, there can be no risk it will fail.
Some considerations are perhaps less glaring. Like how the body reacts in a moment of panic. Why in some cases, a victim setting off an alarm will put them in greater danger. Or even some of the people who will make up the user demographic - like estate agents.
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There's already a handful of wearables on the market solely for emergency situations, some of which we've covered in our roundup of the best personal safety wearables. They come in many different forms and are becoming more capable, more discreet, and more reliable.
But what goes into making one? As it turns out, more than you'd probably think.
Step one: Doing the research
According to NISVS research from 2010, nearly one in five women and one in 71 men have experienced rape or attempted rape in their lives. It's obvious why many of the safety wearables on the market are targeted at women, but plenty consider both sexes, and all manner of scenario. Cab drivers are a notable subsection of users, as are estate agents - not a demographic we'd thought about before but one that's brought up multiple times when speaking to device makers. Of course it makes sense: these people are frequently meeting strangers in unfamiliar places.
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"Here you have a family of four who all had smartphones and they were all taken away, and phone lines were cut," says Wearsafe co-founder Dave Benoit. "You know what smartphones are awful at? Being good communication tools during times of distress." The idea was conceived for a wearable, easy-to-use panic button for emergency scenarios.
In the case of company Roar, founder and CEO Yasmine Mustafa had been traveling part of South America where she was warned of the risks of doing so alone. When she returned, one of the first things she heard about was of a woman in a nearby neighbourhood who was raped after leaving a bar, and decided to do something about it.
The Roar team spent time speaking to campus students, police officers and even self-defence instructors for ideas. "When you're grabbed, you're most likely to be grabbed by the arm," says Roar's Hunter Vargas, explaining why they decided to not making something for the wrist.
Wearsafe also looked to university students, as campus assaults are significantly high."We tried to test the market in 2012," says Benoit. "We went through four university programs, we got to sit shoulder to shoulder with students over entire semesters who told us what they wanted in the product."
Mark Hardy, creator of the Mangos smart ring, says the company's research indicated there was a strong desire among females in the 18-24 year-old bracket. "Then there's a gap for women in their 30s," he says, "then it picks up again for another age group of 45 to 54."
Step two: Making it wearable
With women being a big focus of emergency devices, smart jewelry is finding ways to combine SOS features with discreet, fashionable design. But there are plenty of safety wearables built for both sexes.
Vargas describes how Roar originally came up with the idea of a "macelet", a portmanteau of mace and bracelet, before it evolved into Athena. The new wearable is a unisex pendant with a magnetic clasp, and with a three-second hold of the button it will emit an alarm and send your location to your loved ones, giving them a prompt to check you're OK. Alternatively you can press the button three times for it to send a silent distress call including your location to your pre-selected contacts.
The Mangos smart ring (seen just above) showed up last year, but after a not-so-successful crowdfund campaign seemingly vanished off the map. The ring would work much like the Athena, and its creator Mark Hardy tells Wareable he's preparing to have another run-up this year - currently looking for private investors - with an aim to make it available by the end of 2017. This time, however, he is turning to outside help to improve on the design.
"It's something I did myself and I kind of regret that," says Hardy on Mangos 1.0. "There was a lot of room for improvement on the aesthetics". The company is looking to partner with jewelry makers for the revised wearable, but wants to keep the price down to $40. "I think our ring blends in really well, but [people] want it to look even more inconspicuous."
The Wearsafe doesn't camouflage itself as a ring or wristband, but works as a clip-on with a button designed to be easily press-able through clothing. Benoit highlights how our fight-or-flight response often causes our muscles to tense up, so even the simple act of pushing a button muse be interrogated.
Step three: Taking signal from the noise
In a state of panic, information disseminates unreliably. Often, the person on the other end of the phone must piece together the story with just a few strands of information relayed from a single person's perspective. Stripped of context, a distress call can be worryingly ambiguous, and it's essential that any safety device doesn't risk merely adding to the noise.
Wearsafe is trying to get around this problem by delivering some of the information itself. First, users fill out a profile with any medical conditions they have and other need-to-know facts. Second, the device buffers live audio for 30 seconds, and when the button is pressed, this is captured and added to the package of information that's relayed, via a link, to the recipients. It also places the selected contacts into what Benoit describes as a "virtual situation room" where they can communicate with one another.
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"The biggest problem for the first responder community is that it's like a reverse funnel," says Benoit. "If I see something and I didn't see the entire picture, and I provide only snippets of information, what I didn't see could be detrimental."
The Wearsafe team consulted with ex-Navy Seals and even ex-CIA for guidance on how to build their device. "The number one bit of advice was keep it simple," says Benoit. "Don't overload with information that isn't entirely relevant. You need to provide certain types of data.
"One thing they said to us is that you have to provide assurance to the person that something is happening." In the case of Wearsafe this happens by a small vibration that lets you know that someone has got your call for help.
Ripple, a penny-sized clip-on wearable, takes a different approach. While three pushes of its button will put you straight through to 911, one push will get you a call from a member of the Ripple response team, who can either assist you further or just be a voice to talk to on those occasions you're walking through a dodgy part of town after dark.
As for Roar, Hunter Vargas says the company has thought about other ways to help provide that added context, such as the optional tracking feature. "If they're walking from class to their house they can heave their friends watch over them," describes Vargas. It's also looking at integrating a way to directly contact emergency services down the road, but in a way that, again, can provide more information than simply a set of GPS coordinates.
Step four: No room for failure
It's imperative that an emergency device never fails - otherwise what's the point? The connection must be 100% reliable and fully responsive at any given moment. The problem is that many devices still rely on on a smartphone, although the sound alarms will often function on their own. But whether half the internet goes or or it simply starts raining (most of these wearables are waterproof) it mustn't matter.
Mark Hardy says that the new Mangos ring will up the use count from 400 to 1000 pushes. You'd hope that this wouldn't be a problem for anybody, but users need full confidence that they'll never be caught out by a dead battery in a life-threatening situation. "That device is going to outlive most of its users," says Hardy.
There's a lot to think about, which is why it's not easy for companies like Apple and Fitbit to just slip this type of technology into their existing wearables. Wearsafe's Mark Hardy reveals the company is working on an Apple Watch app, to be released in a matter of weeks, and that the company is in conversations with companies about how it can bring its technology to their devices, but there's a glaring problem here: battery life.
While it might seem inevitable that general wearables from the likes of Fitbit or Apple will start offering more features around safety, they lack many of the things that make a good dedicated lifeline. To build one of those, it must be much more than a mere afterthought.