Happy Health, a mental health-focused tech company, has announced a US$60m series-A round, led by ARCH Venture Partners, for its stress-detecting wearable Happy Ring.

Described by the company as a smart ring that can “measure the whole person – brain and body”, the team claims that the quality of the proprietary sensors and breadth of guidance in the accompanying app, give the wearable an elevated level of accuracy.

Tinder founder Sean Rad founded the company with medical doctor and entrepreneur Dustin Freckleton (founder and former CEO of biotech company LVL Technologies); Sue Smalley (co-founder of PTK Capital); Paul Berns (chairman); and Robert Nelsen (MD at Arch Venture Partners).

The ring has been primarily designed to measure a user’s stress levels and sleep patterns. To do this it features four proprietary EDA (Electrodermal Activity) sensors that measures the activation of the sympathetic nervous system (nerve network that activates fight or flight stress response). Other elements include four wavelengths of light (medical-grade PPG or photoplethysmogram), three-axis movement tracking and two temperature sensors.

“We're all experiencing more stress than ever before, yet we lack the tools to better understand and improve how we feel,” said Berns. “While there are many wearables that help you on your fitness journey, they widely ignore the mind and its effect on your overall well-being. The ability to measure and understand our emotional state will help us identify the habits that result in better health.”

According to the team, Happy Ring's “custom-designed biometric sensors and proprietary adaptive AI” capture brain signals from the peripheral nervous system and translate those into real-time objective measures of mood state.

Dustin Freckleton, CEO of Happy Health, said: “We all use our camera phones to record the important moments in our lives. Now, with the Happy Ring and the companion app, your phone can also show you what's happening inside of you, and the impact of each one of life's moments.”

In terms of how the data helps users to understand and manage their stress levels, their mood is scored from 1-100 throughout the day. They can share these results with the Happy Ring community, which it describes as a social network that is based on empathy, not likes.

As well as gaining a snapshot of their stress level in real time, users can also zoom in on a certain part of the day to view their physical response in context with a physical situation they encountered. The sleep tracker records and releases bedtime guidance, and breathing exercises are also recommended to alleviate stressful moments. The AI integration should mean that the experience becomes more accurate and personalised over time.

A monthly membership is US$30 (£25) per month (12-month min); the annual option is US$25 (£21) per month, US$300 (£259) up front; and 24 months priced at US$20 (£17) monthly, US$480 (£415) up front.

Interested parties can now join a waiting list (US only) and reserve the Happy Ring for US$5 (£4).