A computational simulation of a cough shows the airflow velocity of droplets moving through a simple face mask. Credit: Jung-Hee Seo
What if you could see viruses and bacteria with your own eyes?
In these challenging times with the COVID-19 pandemic across the world, I am sure that many wish they could see bacteria and viruses with their own eyes. It may be scary, but you could then better know how to protect yourself and those around you. You may know if it makes sense to wear a mask, or not? And you would know if the ventilation helps you, or just whirls everything around in the room. And you would know if your cleaning was done properly, even your handwashing.
Researchers are working hard to help us reach better understanding of how viruses and bacteria move in the air. Some of them have made very useful visualizations based on advanced computational fluid dynamics (CFD) and it is intriguing what you can see.
A first step is to see how we as humans transmit viruses and bacteria into the air. I learn from visualizations from Bauhaus-Universität Weimar (Germany) and MIT (USA) that show what happens when we cough, sneeze or even when we just talk. I even see what happens when wearing masks and observe that there will still likely be lots of potentially contagious droplets expelled.
Video produced by researchers at Bauhaus-Universität Weimar
A team at Johns Hopkins University have investigated the airflow from a person wearing a mask. It clearly shows that not all masks are the same. In their article they are looking ahead and wondering how life can return to normal while still minimizing new transmissions? They continue to argue that science can teach us a lot. “Think about students returning to a university campus. If we know more about the aerodynamics of droplet movement, we could potentially redesign HVAC systems to reduce the dispersion of droplets in a dorm, for example,” says multiphase flow expert Rui Ni, an assistant professor of mechanical engineering. “The same idea could work with nursing homes. If we all wear masks, how does that affect the practice of social distancing? If we put more science behind this line of thinking, we can open the country in a safer way.”
Furthermore, we also see what happens when there is just a modest airflow in the room. Research from Finland reveals how the aerosolized viruses and bacteria remain floating in the room for a long time, which has also been confirmed by other research teams via measurements.
The study included researchers from Aalto University, the Finnish Meteorological Institute (FMI), Technical and Innovation Centre VTT and Helsinki University.
In order to see the bigger picture, several research teams look at the airflow in the whole room and try to model and visualize it. Among the most interesting are the ones from the Royal Institute of Technology in Stockholm, Sweden, where they have modelled operating rooms using supercomputers and CFD for many years. They are also a research partner of ours. I will come back to their work later as it gets published.
VisBac, Royal Institute of Technology, Stockholm Sweden
As I am sure that you all know, Avidicare has been committed to help healthcare towards zero infections and we are focused on the airborne pathway to contamination. Our technology, TcAF, has been developed for this very purpose and it ensures a downward movement of the air in the room, as seen in this clip:
Taking all this together, it seems that we will gain an ability to really “see” bacteria and viruses moving around in the air, even if we will need to wear virtual reality goggles for the next couple of years. I hope this will make life safer for all of us.