Related Experiment Video
Updated: Dec 24, 2025

A Novel Inhalation Mask System to Deliver High Concentrations of Nitric Oxide Gas in Spontaneously Breathing Subjects
Published on: May 4, 2021
Microorganism-ionizing respirator with reduced breathing resistance suitable for removing airborne bacteria
Miri Park1, Ahjeong Son1, Beelee Chua2
1Department of Environmental Science and Engineering, Ewha Womans University, 52 Ewhayeodae-gil, Seodaemun-gu, Seoul, 03760, Republic of Korea.
Abstract:
In this paper, we have demonstrated the feasibility of using microorganism-ionizing respirators with reduced breathing resistance to remove airborne bacteria. Using a miniaturized corona ionizer and two pairs of separator electrodes, airborne bacteria were ionized and removed from the airflow. Two microorganism-ionizing respirator designs were experimentally evaluated with flow rates ranging from ∼10 to 20 L/min and yielded airborne bacterial removal efficiencies of ∼75%-100%. Further, they were in close agreement with the analytical airborne particle removal efficiencies, at a similar range of flow rates. These flow rates also correspond to the breathing rates of standing and walking adults. More importantly, the breathing resistance could be reduced by more than 50% for flow rates of ∼200 L/min. Using manganese (IV) oxide coated mesh, the ozone concentration in the air outflow was reduced to less than 0.1 ppm, at a flow rate of ∼20 L/min, thus enabling safe use. The power consumption was less than 1 W.
Related Concept Videos
Transmission-based Precautions II: Airborne and Protective Environment
Airborne precautions:
Use airborne precautions when treating patients known or suspected to have diseases that spread through the air—for example, tuberculosis or measles. These organisms are present in smaller droplets expelled by an infected person and...
Physical Methods for Controlling Microbial Growth: Radiation and Filtration
Mechanical Ventilation II: Invasive Ventilation
Negative-Pressure Ventilators
Negative-pressure ventilators create a vacuum around the chest or body to draw air into the lungs, simulating breathing. This method does not require an...
Mechanical Ventilation III: Noninvasive Ventilation
Noninvasive Positive-Pressure Ventilation...
Oxygen Delivering System I: Nasal Cannula and Face Mask
Nasal Cannula
A nasal cannula is a lightweight tube split at one end into two prongs and placed in the nostrils. It is typically used to deliver low to medium levels of oxygen.
Suggested flow rate: The suggested flow rate for a nasal cannula typically ranges between 1 and 6 L/min.
Oxygen percentage setting:...
Oxygen Delivering System II: Venturi Mask and Transtracheal Oxygen
Venturi Mask
The Venturi mask, named after the Venturi effect, is designed to deliver precise oxygen concentrations. It consists of a large tube with an oxygen inlet that narrows down, causing a pressure drop that pulls air in through adjustable side ports. The mask is a lightweight,...

