Wearable Technology

Rhea, Your Guardian Angel


Some Background

In the Spring of 2017, I had the opportunity to dedicate a semester to design a wearable. I looked outward at emerging technology, as well as inward, at what sort of problems people around me encounter in everyday life. 


On March 10, 2017, I read an article about a female jogger who was attacked by a man hiding in a bathroom stall. Fortunately, she used her self-defense skills to fight off her attacker. However, her fitness tracker documented her frantic movements and GPS location the entire time.

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It’s amazing how much data is already being collected by wearables and our phones. They can see, hear, and know so much about us–but her tracker couldn’t call for help despite her screams, increased heart-rate, and frantic movement. I wanted to create a wearable that would be able to help women during an attack. 

Defining the Problem

Communication is crucial in moments of crisis. With new advances in technology, I wanted to explore faster and more effective methods of activating relief efforts. While there are several personal safety apps and wearables on the market today, they are not very effective. Upon further research, I was able to find out why

Current personal safety wearables and apps all require touch or hand activation. These products exclude everyone who may need immediate assistance but cannot reach their phones to call 911 or press a panic button. 

Deeper Insights


Lack of Hand mobility (or not being able to touch/reach something) can be a temporary, situational, or a permanent disability. To illustrate this I began role playing different scenarios:

  1. Temporary: Broken arm or hands are busy fighting 
  2. Situational: Hands restrained or tied behind back
  3. Permanent: No hands

Regardless of the scenario, each of these users would have trouble calling for help. Even if the user did have use of their hands, they might not think to reach for their phone during an attack. Rather, their natural instinct would be to scream.

Voice Integration

What if we screamed for help and our devices automatically knew we were in danger? I proposed a wearable called Rhea-- a voice activated panic button that calls 911 when you say "Rhea Help!" Rhea allows people to call for help quickly and hands-free. 

Form + Function


The prototype shown above was used to explore how people might interact and communicate with the device. After explaining the concept, I asked a series of “How would you..” questions:

  • How would you call for help?
  • How would you know that Rhea has heard your call for help?
  • How would Rhea let you know that help is on the way?
  • In the case of a false alarm, how would you cancel a 911 call?

Their responses helped me boil own the necklace features to a set of inputs:

  • Use voice commands to call for help or cancel a call
  • In case of a false alarm, touch necklace to cancel a call

And outputs:

  • steady vibration once the necklace hears your call for help
  • a sharp pulsing vibration to let the user know that help is on the way

The Companion App

The companion app app provides visual cues to people through the onboarding process while also showing them how to maximize a device’s capabilities. 

In addition, the app allows people to set up Touch ID. A concern among people I interviewed was how they could discretely cancel a call in case of a false alarm. With just a touch of your finger, the necklace quickly reads your fingerprint and automatically cancels a 911 call. The use of Touch ID also prevents attackers from canceling a call if they knew what was happening. 


Lastly the app allows people to create their own custom phrases that Rhea will respond to. This feature was inspired by a true story where a domestic abuse victim alerted police to the danger she was in by calling 911 and pretending to ‘order a pizza’ (Source). 

Using codewords is crucial in emergency situations where people need to discretely call for help. 



How do we carry forward what we know from UX and product design to create meaningful personal safety wearables? Here’s my take, from my work on Rhea:

  1. Incorporate voice-activation technology: In emergencies, it is important that tasks can be completed hands-free and quickly. Voice-activation allows people to call for help even when they can’t reach for their phones.
  2. Interactions should be minimal: Haptic feedback is well-suited for safety wearables as it can be quickly and intuitively understood with little distraction.
  3. Wearables should be discrete: A wearable device should be stylish and blend seamlessly into people’s lives. When it comes to everyday wear, people prefer customized wearables that compliment their personal style.