Aeromask: Assessing Aerosol Distribution in Augmented Reality

Abstract

Understanding the behavior of aerosol particles remains a key concern especially during the corona pandemic times. In this paper, we present a method for visualizing the distribution of aerosol particles in augmented reality (AR) using the Microsoft HoloLens device. We use this technology to obtain better spatial perception of particles in the real world which are invisible to the naked eye. As a case study, we show the flow behavior of exhaled aerosols without any mask, with a medical mask, and with an acrylic glass shield.

In a first step, we measure the flow field under laboratory conditions. Then, starting at the mouth, a certain number of exhaled particles have been traced through this flow field. Finally, the traced particles are visualized over time on a Microsoft HoloLens using the particle system component of the Unity game engine. To tackle the limitations of a HoloLens device, three different particle visualization approaches have been evaluated to render as many particles as possible without compromising visual quality and interactivity. The most convincing implementation achieves a simultaneous rendering of nearly 80,000 moving particles at average rate of 35 frames per second. This implementation allows us to investigate virtual particle flows in the real world from different angles. Our case study emphasizes that the flow propagates forward without a mask. With a mask, the particles ascend. And using a Plexiglass shield, they flow forward, collide with the shield, and spread around afterwards.