From the July 2014 issue of Entrepreneur

Entrepreneurs: Rachel Emanuele and husband Arthur founded First Sign Technologies, a Scottsdale, Ariz.-based line of safety products. The company is launching with a hair clip that contains a mechanism capable of detecting sudden movements that may indicate that an assault or attack is taking place.

"Aha" moment: One dark night, Emanuele had an uneasy feeling when she arrived home. "The lights were out, and it was pitch-black outside," she says. "I realized then that our home security system protected only our house, not me coming home alone and facing a potential intruder."

Use your head: The couple spent more than two years researching their idea for a wearable safety device before landing on the concept of a barrette that could remain concealed and operate automatically. "We chose to create a hair clip since the head is the most commonly injured area during a violent assault," Emanuele says. "You can hold it in your hand when you're walking in a parking garage, or wear it under a ponytail. The idea is that if you're in danger, there's no way you'd have time to get out your cell phone and reach your app. Your brain doesn't react as you think it would during a dangerous situation."

Alert system: The clip contains an accelerometer and a gyroscope that detect sudden movements indicative of those commonly made by victims of beatings, muggings or rapes. The device uses Bluetooth to access the wearer's phone, transmitting GPS coordinates, audio and visual information to the First Sign monitoring station. Meanwhile, the phone emits an audible message--"Help is on the way and evidence collected"--in order to deter the attacker. The hair clip, which is half the thickness of a standard USB drive, also features a built-in microphone that immediately starts recording what's happening, an aid to investigators trying to track a suspect.

In the event of a false alarm, the wearer has 15 seconds to deactivate the device by entering a PIN into the First Sign mobile app (available for iOS and Android devices). "However, the moment the device detects an impact, our monitors are reviewing the situation in real time," Emanuele says. "If the device isn't deactivated, your emergency contacts will be notified as soon as that 15-second window is up."

Portable panic button: The device can be clipped in the hair (worn concealed, plain or with one of three decorative covers) or attached somewhere close, such as in a pocket or on a belt clip or purse strap. "The idea is that you have it on and forget it's there, but it never stops working for you," Emanuele says.

Defense funding: The couple raised more than $55,000 (on a goal of $50,000) via an Indiegogo campaign in the first quarter of this year. The clips will start shipping in the fall, priced at $50 (plus $25 for each snap-on cover). Monitoring will cost $5 per month.

Next up: First Sign plans to debut a home security system that plugs into a wall outlet; a user under distress need only say their "safe word," and the device calls for help and collects evidence. The company also plans to introduce a wrist-based heart-rate monitor that connects directly to medical emergency responders, as well as a Bluetooth headset that will work with the First Sign sensors and software.