With operating principles similar to a vacuum hood, the airborne infection isolation and removal (AIIR) device is initially targeted at the dental industry to improve the safety of both staff and patients. Many dental procedures generate aerosols, or small droplets of saliva and blood, that are ejected into the air. These aerosols float in the room and can contain dangerous particles that harbour viruses such as SARS-CoV-2, influenza, tuberculosis, human papillomavirus, and aerosolised mercury, explains Care Health Meditech managing partner Stephen Munro.

“To aid in the development of AIIR, we turned to UBC researchers for their expertise in multiphase flows and computational fluid dynamics, which will help evolve the design ensuring its effectiveness,” Munro says.

Transmission of the COVID-19 virus is thought to occur through breathing in respiratory droplets, touching contaminated surfaces or inhaling particles in the air. According to Munro, the key to controlling the transmission is to isolate and eliminate COVID-19 contaminated air and droplets, particularly aerosols.

While the AIIR device is currently being used by some dentists, UBCO researchers are now looking at ways to improve the design through computational fluid dynamics simulation and specific testing in Associate Professor Sunny Li’s thermal management and multiphase flows lab.

“Our team is looking at the device’s size and geometry in connection with its airflow dynamics, and the dynamics of droplets and particles to make it more accurate and efficient,” says Li, one of the lead researchers on the project.

Li is working with Assistant Professors Joshua Brinkerhoff and Sina Kheirkhah from the School of Engineering, and Associate Professor Jonathan Little from the School of Health and Exercise Sciences to provide design modifications and recommendations.

During testing, dental procedures will be mimicked in the lab with a dental mannequin connected to a breathing simulator. Particle imaging velocimetry and high-speed shadow photography imaging will be used to visualise airflow and track the motion of all droplets. Droplet motion and trajectory can vary depending on the droplet size and local airflow, explains Li.

While work is being done in the labs to optimise and improve the device for frontline acute healthcare settings, the initial AIIR device is already being delivered to dentists in both Canada and the USA, owing to high demand.

“Although we are targeting the dental industry, there’s an opportunity to expand into other areas where the risk of airborne infection is high,” says Munro.

“The AIIR has the potential to reduce the risk of patients and dentists being exposed to the COVID-19 virus, and will allow dentistry to return to near-normal procedures,” says Munro. “This is significant for Canada and the world as it reduces the need for production and the purchase of personal protection equipment (PPE), and in a few years, we aim to have the potential to reduce the need for PPE and N95 respirators for routine procedures in hospitals, doctors’ offices and care facilities.”

The research is funded by a Mitacs Accelerate Grant.