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PandaDad22 t1_ithwn87 wrote

Reply to comment by randxalthor in MIT engineers develop sensors for face masks that help gauge fit by derpPhysics

The article says

>Currently, there are no simple ways to measure the fit of a mask,

When really the aspartame test works really well.

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Ace_Dystopia t1_iti340g wrote

While aspartame and bitrex can be used for fit testing, you’ll still need a nebulizer and a hood to test the fit.

If there were masks or even N95s that could tell you the fit upon putting it on, I’d consider that a simpler solution.

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PandaDad22 t1_itibhbv wrote

I’ve done it many times. The test is simple and tests exactly what needs to be. Its cheap and easy.

MIT is not solving a problem here.

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Ace_Dystopia t1_iticzgv wrote

I live in Canada and the costs for a mask fitting test kit or even a homemade one can be more than $100. I’m not sure if it’s just me, but all the nebulizers I see sold are over $50+, which I wouldn’t consider cheap.

The 3M mask fitting test kit is a couple hundreds of dollars.

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E_Snap t1_itk6het wrote

Okay so let’s build costly circuitry into disposable masks then? Oh, and don’t forget to make sure your mask has batteries, otherwise it won’t be able to tell you whether it fits or not.

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RebelWithoutAClue t1_itk8brk wrote

Bitrex is is disgusting stuff. A trace amount of it on your face can easily get to your mouth when you have lunch.

Aspartame is a pretty good option but it's detection limit will be higher in that we'd need to have more leaking in to detect it.

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derpPhysics OP t1_itigtmr wrote

I suggest people actually read the paper itself (I linked it earlier). The goal of the work goes well beyond just finding an alternative mask-fit testing method. It seeks to link mask fit with user behavior and environmental conditions - to find out why/when people use masks incorrectly and give them a real time, ambulatory feedback. That's not possible using currently existing methods.

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PandaDad22 t1_itj0ahv wrote

It all sounds dumb. /r/science should ban anything with “MIT” in the title. It’s alway click bait.

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randxalthor t1_itirf3m wrote

If you want simple, you can do the glasses check. If you huff and your glasses don't fog up (presuming they're not anti-fog coated), it's an alright seal.

For professionals, that's not good enough, and the aspartame test is expensive and time-consuming, as well as not a continuous evaluation.

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HoobieHoo t1_itjo3r2 wrote

Glasses fogging isn’t reliable as even N95 masks allow water vapour to pass. With the huff test, a well sealed mask will collapse and expand slightly as you inhale and exhale, respectively. If it doesn’t do that, then it isn’t sealed properly.

Regular surgical masks aren’t designed to fit with a seal like N95s are.

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randxalthor t1_itkbtj4 wrote

You seem to have ignored my comment about how surgical masks aren't designed to seal.

Also, the fog test for N95s was the quick and dirty solution. It does, in fact, work, though it's not a good substitute for the aspartame test, as I pointed out. If your nose bridge fits properly and your straps are properly placed over your head, breathing out will not create enough positive pressure to push the mask away from your skin. The nose bridge is also the most critical part of the mask for fit because of the tight curvature, which is why it's a decent rule of thumb.

The water vapor you breathe out with a good seal will thus be forced to travel more evenly through the mask and not concentrate on your glasses. Many medical professionals wear glasses with N95s without worrying about fogging precisely because their masks fit well around the nose.

And in case you're wondering why I know all this, it's because I worked before and during the pandemic in bioweapons defense designing vapor and aerosol filters, and my SO worked as one of the aforementioned medical professionals treating COVID-positive patients.

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Lives_on_mars t1_itoeay0 wrote

I didn’t know aspartame could be used (Splenda). I thought it was only saccharine (sweet n low). As a sub for Bitrex that is.

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PandaDad22 t1_itofq2a wrote

I don’t remember. One or the other.

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Lives_on_mars t1_itorp3q wrote

I was going to buy some Bitrex anyway. I taste “sweetness” too easily in my mouth…after one or two tests it’s hard for me to tell, taste wise, if I’m tasting sweet or not. It’s a bummer the test can’t really be done with odors. Barring a nuisance-filtering mask, anyway.

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