Table 3. . Displays the 3D-imaging technology and key findings of several studies used to create N95 mask seals.

3D Technology	Research design/key findings	Ref.
3D laser-scanning method	Used a high-precision hand scanner, zgHandScan H100 captured up to 480,000 points per second	[27]
3D face scanner	Created three differently face models (small, medium and large) using a 3D face scanner and developed three corresponding respirators through digital modeling; designed three silicon respirator models via rapid prototyping method	[21]
SPG	Used to collect 3D images of subjects with and without wearing a molded, cup-shaped N95 FFRs; recorded geometric data from photographic images	[23]
3D face scanner	Used a minimal set of landmarks to derive contact area for a half-face mask on individual human faces	[22]
3D real-time surface-pressure mapping system	Mapping system simulated contact between six N95 FFRs and five digital headform models to understand contact pressure	[19]
MATLAB computer-based algorithm	Developed a computer-based algorithm to determine the contact area between the headform models and N95 FFRs	[20]
3D laser-scanning method	Recorded contact pressure between a respirator and a digital headform	[25]

N95 FFR: N95 filtering facepiece respirator; SPG: Stereophotogrammetry.