A novel method for designing and fabricating low-cost facepiece prototypes

Area of Science:

• Occupational Safety and Health
• Biomedical Engineering
• Industrial Design

Background:

• The National Institute for Occupational Safety and Health (NIOSH) updated respirator fit-test panel in 2010 with new digital head form models.
• The updated panel includes two new sizes (Short/Wide, Long/Narrow) based on 2000 census data to represent the contemporary workforce.
• Commercially available elastomeric facepieces typically come in three or four sizes, necessitating the development of custom-fit options for new head form designs.

Purpose of the Study:

• To develop a novel method for designing and fabricating elastomeric facepieces tailored to new National Institute for Occupational Safety and Health (NIOSH) head form designs.
• To enable effective fit-testing using custom-designed facepieces that accommodate updated head form dimensions.
• To create prototypes for future fit-testing studies using advanced manufacturing techniques.

Main Methods:

• Utilized computed tomography (CT) scanning of a solid silicone facepiece.
• Employed multiple computer-aided design (CAD) programs (VolView, ParaView, MEGG3D, RapidForm XOR) to develop a facepiece model.
• Fabricated the facepiece model using three-dimensional (3D) printing (stereolithography - SLA).
• Created a silicone mold from the 3D-printed model to cast elastomeric prototypes.

Main Results:

• Successfully developed a digital model for an elastomeric facepiece designed to fit the NIOSH Short/Wide head form.
• Produced a physical prototype of the custom facepiece using stereolithography 3D printing.
• Created a silicone mold from the prototype for casting multiple elastomeric facepieces.
• Cast prototype facepieces in two distinct silicone materials for subsequent fit-testing.

Conclusions:

• The developed method offers a viable approach for creating custom-fit elastomeric facepieces for respirator fit-testing.
• This technique addresses the need for facepieces that accommodate the expanded sizing of the new NIOSH head forms.
• The custom-fabricated prototypes are ready for use in fit-testing studies to evaluate respirator effectiveness.