Respirator with Air Blower and Air Quality Detector

This work is motivated by the challenges faced during the COVID-19 pandemic. Effective protection from the virus is needed. Masks is one way to protect from the virus. To support the efforots to control the spread of COVID-19 among the population, in this work we present an improved respiratory system consisting of a respiratory mask, air blower and a control system. Our design avoids some of the problems with available masks such as leak of unfiltered air and the irritation caused by these masks. To overcome this problem, the existing respirator is being modified to ensure user can breathe comfortably, no air gap on the side of respirator mask and respirator mask can measure air suction rate. Air blower will increase the air suction rate and sensor will detect the air quality and display it thru the monitor. User can monitor the air index surround them. A prototype is built. Testing of the prototype showed that the system functions as expected and achieves its objectives. On the downside, the prototype is heavier than existing products in the market. Further improvement in the design may lead to an improved version with reduced weight. © 2022 IEEE.

Automated Generation of Custom Fit PPE Inserts: For Respiratory Masks Using 2D and 3D Anthropometric Data

This research presents a machine learning-based interactive design method for the creation of customized inserts that improve the fit of the PPE 3M 1863 and 3M 8833 respiratory face masks. These two models are the most commonly used by doctors and professionals during the recent COVID-19 pandemic. The proper fit of masks is crucial for their performance. Characteristics and fit of current leading market brands were analyzed to develop a parametric design software workflow that resulted in a 3D printed insert customized to specific facial features and the mask that will be used. The insert provides a perfect fit for the respirator mask. Statistical face meshes were generated from an anthropometric database, and 3D facial scans and photos were taken from two hundred doctors and nurses on an NHS Trust hospital. The software workflow can start from either a 2D image of the face (picture) or a 3D mesh taken from a scanning device. The platform uses machine learning and a parametric design workflow based on key performance facial parameters to output the insert between the face and the 3M masks. It also generates the 3D printing file, which can be processed onsite at the hospital. The 2D image approach and the 3D scan approach used to initialize the system were digitally compared, and the resultant inserts were physically tested by twenty frontline personnel in an NHS Trust hospital. Finally, we demonstrate the criticality of proper fit on masks for doctors and nurses and the versatility of our approach augmenting an already tested product through customized digital design and fabrication. © Association for Computer Aided Design in Architecture Annual Conference, ACADIA 2021.

A fluid mechanics explanation of the effectiveness of common materials for respiratory masks.

OBJECTIVES: Face masks are an important component of personal protection equipment employed in preventing the spread of diseases such as COVID-19. As the supply of mass-produced masks has decreased, the use of homemade masks has become more prevalent. It is important to quantify the effectiveness of different types of materials to provide useful information, which should be considered for homemade masks. METHODS: Filtration effects of different types of common materials were studied by measuring the aerosol droplet concentrations in the upstream and downstream regions. Flow-field characteristics of surrounding regions of tested materials were investigated using a laser-diagnostics technique, i.e., particle image velocimetry. The pressure difference across the tested materials was measured. RESULTS: Measured aerosol concentrations indicated a breakup of large-size particles into smaller particles. Tested materials had higher filtration efficiency for large particles. Single-layer materials were less efficient, but they had a low pressure-drop. Multilayer materials could produce greater filtering efficiency with an increased pressure drop, which is an indicator of comfort level and breathability. The obtained flow-fields indicated a flow disruption downstream of the tested materials as the velocity magnitude noticeably decreased. CONCLUSIONS: The obtained results provide an insight into flow-field characteristics and filtration efficiency of different types of household materials commonly used for homemade masks. This study allows comparison with mass-produced masks under consistent test conditions while employing several well-established techniques.