The app has been developed in collaboration with researchers at the University of California San Francisco's Health eHeart study, which aims to help end heart disease. The program wants to develop a way to detect atrial fibrillation – a medical condition that can lead to stroke – using innovations in everyday consumer technology.
By that token, the Cardiogram developer team have been refining an algorithm that attempts to detect abnormal heart rhythms using the Apple Watch's heart rate sensors.
The 1.0 version of the app at the center of its efforts brings that goal a step closer, introducing native watchOS 2 support that enables users to track and view recorded heart rate data without having to tether their iPhone. A new Apple Watch complication also allows users to quickly view their latest heart-rate readings.
Meanwhile, the iPhone companion app now includes comprehensive activity statistics and trending HRM data, along with a Metrics screen that brings together users' move, stand, and exercise goals.
In addition, iPhone 6s and 6s Plus device owners can use 3D Touch gestures to tag peaks in heart rate, while social media sharing and interface tweaks make up the rest of the update.
Anyone with an Apple Watch can take part in the eHeart study, since the algorithm learns from its users, whether or not they have preexisting heart conditions.
Apple's HealthKit framework debuted in 2014, allowing developers to build health monitoring software that integrates with Apple's Health app, while Apple's open source framework ResearchKit was made available to developers in April 2015, enabling them to create their own iPhone apps for medical research purposes.
Apple itself continues to have significant interest in making its Apple Watch part-medical health instrument. An Apple patent application recently came to light, titled "Care event detection and alerts", which envisions a hardware system with the ability to monitor the surrounding environment for events that would require assistance from medical professionals, police, fire rescue or other emergency services.
Cardiogram is a free download for iPhone on the App Store. [Direct Link]