A Negative Pressure Isolation Head Chamber to Protect Health Care Workers from Airborne Transmission of Aerosolized Viruses

At a Glance

COVID-19 had infected more than 2 million people worldwide by April 2020, including more than 9,000 health care workers who had inadequate access to standard personal protective equipment. As a result, health care workers developed their own equipment and guidelines to protect themselves from infection though all of these devices lacked proof of effectiveness. The goal of this project was to test the effectiveness of the Badger Box, a novel portable negative pressure isolation box that can act as both a physical barrier and containment unit for aerosolized viruses. Preliminary results indicated the Badger Box’s capability to capture over 95 percent of particles.

The Challenge

COVID-19 had infected more than 2 million people worldwide and killed more than 133,000 people by April 2020, including many in Wisconsin. The health care professionals who cared for and treated patients with COVID–19 were at high risk for airborne transmission, and at that time, more than 9,000 health care workers had been infected. Infection control precautions for health care professionals included the use of N95 respirator masks, gloves, isolation gowns and face shields although there had been widespread reports of inadequate access to the standard personal protective equipment. As a result, health care workers developed their own equipment and guidelines to protect themselves from infection, though all of these devices lacked proof of effectiveness.

Project Goals

The overall goal of this project was to test the effectiveness of the Badger Box, a novel portable negative pressure isolation box that can act as both a physical barrier against the spread of aerosol droplets and serve as a containment unit for aerosolized viruses. This goal was addressed through two specific aims:

1. Determine the effectiveness of the Badger Box in containing aerosol dispersion during aerosol generating procedures such as airway intubation, extubation and non-invasive respiratory support.
2. Determine the effectiveness of the Badger Box in containing aerosol dispersion in the standard hospital room.

Results

The researchers recruited healthy volunteers to measure their aerosol generation rates during normal breathing, talking, heavy breathing and episodic sneezing and coughing. Notably, sneezing exhibited the highest particle emission per incident, followed by talking. Leveraging these findings, the team developed an algorithm that matched the aerosol generation rates of healthy volunteers with machine-generated aerosols to simulate these conditions inside the Badger Box. Preliminary results demonstrated the Badger Box’s ability to capture over 95 percent of particles generated under common conditions.

The researchers plan to use this data in the future to provide reference on how much aerosol particles are generated under interventional procedures and to develop and test additional aerosol isolation devices and strategies to mitigate their spread.