Unlocking the data in your breath with IOT technology

Project Details

Building a Breath-Powered, Bluetooth-Connected Fitness Tracker App

Calibre was founded by an engineer with the idea to use modern technology to democratize data previously only available through professional laboratories or hospitals. More specifically, by creating a smart mask that connects to a companion fitness tracker mobile app, Calibre uses breath calorimetry to provide live tracking of key biometrics like: respiratory exchange ratio (RER), VO2, VCO2, respiratory rate, breath volume, breath count and more. This opens up a world of possibilities when it comes to areas like health management and fitness tracking.


Biometrics Tracked

Calibre tracks over 30 unique biometrics, the only of its kind in the market.



To date, the platform has attracted users at a rate of 8 per day.


Sessions Tracked

Since launch, north of 10,000 "sessions" – aka activities, like a Run – have been tracked.

The Results

Paper Leaf was responsible for the software side of the project – not just the mobile app development and UX/UI, but also API development, firmware compatibility, and of course mask connectivity and integration. The mask itself was handled by a product design firm specializing in hardware.

Built on React Native, with a Laravel-based API, the fitness tracker app allows users to find and connect to their Calibre mask over Bluetooth, start and end “sessions” (activities like runs, bike rides, etc), compare data session over session, and more. Within each session, users can now learn key metrics like:

  1. Respiratory Performance. Previously only available in lab-based testing environments, data like Breath Count, Breath Rate, Respiratory Exchange Ratio (RER), Peak VO2 & VO2 average and more are now available.
  2. Fuel & Calorie Tracking. The app tracks most accurate calorie measuring method available, and combines it with ground-breaking metabolic visibility via a trademarked Keto-Gauge.
  3. Metabolic Tracking. Monitoring metabolism requires respiratory data and Calibre is the first device to deliver this in a convenient, functional and accurate way. The app uses indirect/breath calorimetry which is the Gold Standard according to organizations like the ACSM (American College of Sports Medicine) and the WHO (World Health Organization).

All data is saved to the cloud-based user profile, and after a successful Kickstarter campaign, initial batches are in the hands of early adopters.

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