The eye-face shield is composed of four parts: goggles, lenses, face shields, and elastic bands. The goggles protect the eyes and support the face shield with a special connection structure. The requirements for goggles used in clinical settings are presented in Table 1.
Table 1 Properties of a nice goggle
A
|
Excellent airtightness
|
B
|
Ultimate comfort for long time wearing
|
C
|
Ease of assembling/disassembling
|
D
|
Ease of lenses fabricating
|
E
|
Aesthetic appearance and tomographical smoothness
|
We designed goggles with three different sizes (dimensions are shown in Table 2). The size was based on the Chinese GB 14866-2006 standard, which mainly refers to ISO 4849:1981, as well as the goggles on the market. According to the requirements and dimensions of the aforementioned goggles, we created a 3D model of the goggles using SolidWorks, NX, 3Dmax, and other 3D modeling software programs. We found defects through sample try-on and repeatedly modified the model to improve the airtightness, comfort, and aesthetics.
For satisfying requirement A in Table 1, the goggles do not have any holes except for the lens holes (see Fig. 1) and the elastic-band holes (see “3” in Fig. 1). We adjusted the arc of the goggles to fit the face and improve the airtightness. We designed an inverted “V” shape at the nose wings (see Fig. 1) to fit the slope of the nose bridge.
For satisfying requirement B in Table 1, the edges that fit the face are designed with flanging. The outward flanging (see “4” in Fig. 1) is 12 mm wide and approximately 90° from the horizontal plane. The inward flanging at the nose (see “5” in Fig. 1) has a width of 5 mm. The flanging improves the airtightness, increases the stress area, and reduces the number of pressure sores.
For satisfying requirement C in Table 1, we designed anchors on both sides of the goggles (see “7” in Fig. 1) to connect the face shield. There are four anchors: two on the left and two on the right.
For satisfying requirement D in Table 1, we designed two types of lenses: a single-lens and a double-lens (see Fig. 2). The single-lens has a wider field of vision, but the cutting process is more complex. The double-lens shape is square, which can simplify the lens cutting process. Four slots on the interior of the front panel (see “2” in Fig. 1) were added to reinforce the lenses.
For satisfying requirement E in Table 1, we avoided sharp edges and corners in the design process and designed the nose cover for the exposed part of the nose (see “6” in Fig. 1).
Table 2 Dimensions of the three size goggle face
Size
|
Dimensions of goggle face /mm
|
Large size
|
Length× width =164×70
|
Medium size
|
Length× width =150×70
|
Small size
|
Length× width =110×50
|
We designed six types of goggles: 3DP-S-L, 3DP-S-M, 3DP-S-S, 3DP-D-L, 3DP-D-M, and 3DP-D-S. In the labels, “3DP” indicates that the manufacturing method is based on 3D printing. Regarding the middle letter, “S” represents “single-lens”; and “D” represents “double-lens”. Regarding the last letter, “L” represents “large” ; “M” represents “medium” ; and “S” represents “small” (only for children). Details are presented in Fig. 2.