Closed airflow system, CUSP, for preventing SARS-CoV-2 infection, promoting health care, and achieving Sustainable Development Goals

Thorough analytical investigation is made on an open airflow system, on which conventional clean rooms are based, and on a closed airflow system realized by a clean unit system platform (CUSP) combined with a gas exchange membrane (GEM). The air pressure inside the CUSP is exactly the same as that outside. Thanks to this equal pressure in and outside of the room, there is no airflow coming and going across the GEM, resulting in a closed airflow system. In the CUSP/GEM system, fresh air is introduced, not by mechanical ventilation that conventional clean rooms are based upon, but by diffusion-based molecular ventilation, in which O₂, CO₂, and other molecules come and go across the GEM depending on the molecule concentration gradient across the GEM. Since there is no airflow exchanged between the inside and outside, together with the fact that microbes, having roughly two orders of magnitude larger size than molecules, are too large to diffuse across the GEM, the CUSP/GEM system can be an ideal, extremely safe place in which to protect people from SARS-CoV-2 or any other viruses floating in the air outside. The CUSP is an ideal place in which patients can be treated while staying in very clean air - importantly, with zero risk of any harm coming to people outside of the space. Based on this system, we have succeeded in demonstrating that CUSP can provide the opportunity of correlation analysis in sleep assessment with CO₂ production while patients are sleeping in the CUSP. The unique features of the CUSP/GEM system, that make the inside of the room completely decoupled from the outside, mean that it can effectively be used for various applications. In the near future, diffusion-based molecular ventilation, or molecular ventilation in short, will prevail with CUSP systems wherever fresh clean air is needed for any closed space.