Harnessing Consumer Smartwatches for Heart Rate Streaming in Unity Game Engine

Heart rate sensing has become a standard feature of many consumers wearable devices, including smartwatches such as Google Pixel Watch. Meanwhile, many Unity games integrate heart rate as an indicator of players’ excitement and engagement levels, for which consumer smartwatches are very well-suited due to their widespread use. However, heart rate measurements of consumer smartwatches are not readily accessible in real-time, as Web APIs only provide data aggregated over intervals of 30 or 60 seconds, rather than high-resolution raw data. To address this limitation, this study designs and develops a system that integrates the Google Pixel Watch for heart rate streaming in the Unity game engine. The hardware components of the system include a Google Pixel watch, an Android handheld device (e.g., smartphones, tablets), and a computer running Unity applications. Heart rate readings are initially transmitted from the Google Pixel smartwatch worn on the wrist to the Android hand-held device using the Data Layer API of wear OS. The handheld device then packages the heart rate readings to comply with the lab streaming layer (LSL) framework and streams them to a corresponding stream inlet in Unity. This paper outlines the architecture and design of the system, and discuss the feasibility of alternative system architecture designs to inform future studies.