COVID-19 Face Mask Sizing System Mannequins (XS, S, M, L, XL)

[ToonHuysmans]

I have been getting several requests regarding representative mannequins for protective face mask development for the COVID-19 virus. Therefore, I have decided to make an example set of manikins for a sizing system (extra small / small / medium / large / extra large) available here for download. You can easily create other sizing systems using the DINED Mannequin tool. However, do not hesitate to start a discussion here on alternative sizing systems, e.g. taking nose prominence into account.

I’m using a simple five size system, define as:

Size	min	mean	max
XS	P01	P10	P20
S	P20	P30	P40
M	P40	P50	P60
L	P60	P70	P80
XL	P80	P90	P99

I have used as key measures Bigonial Breadth and Face Length. First let’s have a look at the percentile values of these key measures using the 1D Database Tool:

I entered these values in the Mannequin tool to get the corresponding 3D head shapes:

Note that the percentile values do not match perfectly since a 1mm step in the measure covers multiple subjects.

You could start the design of each size from the mean mannequins (e.g. P10), but then make sure to always test the size also on the boundaries of the size (e.g. P01 and P20).

Here you can find the STL-files of the P01, P10, …, P99 manikins: dropbox

[SylvieSchD]

Hello Toon, and everybody!
Thanks for this post!
I’m newly registered on this blog, even if using sporadically DINED database (and recommending it) for some years, when giving basic anthropometry training.

This year, I’ve asked my students to analyze face masks of many kinds… I find it incredible that usual “cloth” facemasks are sold without indicating sizes, or with poor regulation systems. For those who do indicate measures, I’m really surprised that nobody mentions corrections/allowances so their product fits when we open our mouth to speak!! As a result, after opening the mouth making “Ah” sound x 3 times (small test I created ), the mask will be under your nose (I must say that the worst situation would occur when singing, but we cannot anymore!). As a nurse, I’m also very keen on the fitting and closure around user’s face, so the mask is efficient, and when I see people replacing their mask on their face continuously, holding it by the (possibly) contaminated front area… I’m quite worried.

So my question is: If people generally open the mouth 3 to 4 “fingers high” (35 to 55 millimeters)…, which would be a good correction to the use of static dimensions in this dynamic setting of facial expression and movements?
Thanks!!
Sylvie

[ToonHuysmans]

Welcome to the DINED Forum, Sylvie!

The issue that you are raising has also been discussed here at the TU Delft. I’m not sure whether the answer is as simple as “adding a correction to the mask dimensions”. Adding some slack to the mask dimensions, to allow the jaw to move freely, would result in a bad fit with air leaking around the sides. One possible direction would be to redesign the mask to include a flexible or harmonica structure (as in surgical masks), much the same as the soft tissue of our cheeks, that articulates together with the jaw. Another option, would be to entirely encapsulate the lower jaw inside the mask and to provide room within the mask for jaw movement (the mask would be a lot bulkier though).

This doctor took a different road to solve the problem: Face mask hack

I certainly agree that there remains a lot to be done for face masks in order to become comfortable and safe.

Kind regards, Toon.