An intelligent FFR with a self-adjustable ventilation fan

ABSTRACT This article presents an intelligent Filtering Facepiece Respirator (FFR) with a self-adjustable ventilation fan for improved comfort. The ventilation fan with an intelligent control aims to reduce temperature, relative humidity, and CO2 concentrations inside the facepiece. Compared with a previous version of the FFR, the advantage of this new FFR is the intelligent control of the fan's rotation speed based on the change in temperature and relative humidity in the FFR dead space. The design of the control system utilizes an 8-bit, ultra-low power STC15W404AS microcontroller (HongJin technology, Shenzhen, China), and adopts a high-precision AM2320 device (AoSong electronic, Guangzhou, China) as temperature and relative humidity sensor so that control of temperature and relative humidity is realized in real time within the FFR dead space. The ventilation fan is intelligently driven and runs on a rechargeable lithium battery with a power-save mode that provides a correspondingly longer operational time. Meanwhile, the design is simplistic. Two experiments were performed to determine the best location to place the fan.

[1]  Heow Pueh Lee,et al.  Objective assessment of increase in breathing resistance of N95 respirators on human subjects. , 2011, The Annals of occupational hygiene.

[2]  Stacey Benson,et al.  N95 Filtering Facepiece Respirator Deadspace Temperature and Humidity , 2012, Journal of occupational and environmental hygiene.

[3]  Hui Li,et al.  Investigation of the flow-field in the upper respiratory system when wearing N95 filtering facepiece respirator , 2016, Journal of occupational and environmental hygiene.

[4]  Hui Li,et al.  An Improved FFR Design with a Ventilation Fan: CFD Simulation and Validation , 2016, PloS one.

[5]  Jeffrey B. Powell,et al.  PRESSURE DROP OF FILTERING FACEPIECE RESPIRATORS: HOW LOW SHOULD WE GO? , 2015, International journal of occupational medicine and environmental health.

[6]  Stacey Benson,et al.  Thermal burden of N95 filtering facepiece respirators. , 2012, The Annals of occupational hygiene.

[7]  Jeffrey B. Powell,et al.  Effect of exhaled moisture on breathing resistance of N95 filtering facepiece respirators. , 2010, The Annals of occupational hygiene.

[8]  Raymond J Roberge,et al.  Are Exhalation Valves on N95 Filtering Facepiece Respirators Beneficial at Low-Moderate Work Rates: An Overview , 2012, Journal of occupational and environmental hygiene.

[9]  Nobutomo Matsunaga,et al.  Experiment of Measurement and Control using Embedded System for Undergraduate Students , 2009 .

[10]  Erik Birgersson,et al.  Reduction of Carbon Dioxide in Filtering Facepiece Respirators with an Active-Venting System: A Computational Study , 2015, PloS one.

[11]  Madhurima Chattopadhyay,et al.  A new scheme for reducing breathing trouble through MEMS based capacitive pressure sensor , 2016 .