Localized Ventilation Method for Providing Clean Air to Hospitalized Patients

Abstract

Three novel air terminal devices (ATDs) for localized ventilation were designed (ATD with perforated inner plate, ATD with honeycomb diffuser, and ATD with lobbed nozzle). The ability of the ATDs to provide clean air to the breathing zone of a person lying in a hospital bed was studied. Experiments were performed in a simulated full-scale hospital patient room. A thermal manikin was used to simulate a patient. The ATD was located above the head of manikin. Heated dummy simulated a doctor standing beside the bed. Tracer gas was used to simulate contaminated air exhaled by the doctor. The supply and the exhaust flow rates were controlled at 15.3 L/s and 14.8 L/s, respectively. The supply air temperature and room temperature were kept at 23 °C and 25.3 °C, respectively. Increase of the supply air speed resulted in a cleaner air supply to the breathing zone but also increased the risk of draught. The ATD with a lobbed jet nozzle was able to reduce contaminants by more than half in the breathing zone and to provide the lowest draught risk at the face. This ATD is a better solution to supply clean air in practice comparing to the other two ATDs.

Experimental studies on airborne transmission in hospitals: A systematic review

“…The position of the apparatus relative to the source patient and the susceptible will require further research to optimize the efficacy and minimize discomfort. 89,92,100…”

“…The position of the apparatus relative to the source patient and the susceptible will require further research to optimize the efficacy and minimize discomfort. 89,92,100 Dispersion. Understanding the dispersion of aerosols under the influence of ventilation is crucial to some epidemiology studies.…”

“…67,[72][73][74]83 Under this category, 11 studies investigated the use of personal or localized ventilation units. [85][86][87][88][89][90][91][92][93][94][95] The remaining eight discussed the use of air purifiers and air cleaners with a high-efficiency particulate air (HEPA) filter [96][97][98][99][100][101][102][103] to minimize exposure to infectious aerosols. These experimental studies showed that add-on portable ventilation devices could effectively contain and remove aerosolized particles.…”