I'm not sure I understand this comment. I don't know if this suit will really offer protection, but I don't see the problem with the choice of filter.
A HEPA filter has a stricter rating than the N95 masks that healthcare workers use.
"HEPA, which stands for High Efficiency Particulate Air, is a designation used to describe filters that are able to trap 99.97 percent of particles that are 0.3 microns"
N95: Removes 95% of all particles that are at least 0.3 microns in diameter
And whether the seal around the HEPA filter that the HEPA filter is put inside is airtight.
E.g. I've seen some vacuum cleaners which have HEPA filters reviewed as a bit useless at filtering because the particles flow through small gaps around the filter.
Some places it is illegal to cover your face. (Banks, Government Buildings, etc...) I would probably put a "Hi my name is BLANK" sticker on my shirt to kinda offset that.
I'm not trying to get anything banned, but it's obvious that what you wear has an impact on the people around you. If you walk into a gas station with a ski mask and a pistol I'm pretty sure everyone around you is going to calculate what your next move is. Similarly if I see a group of people put on gas masks at the CVS, I'm going to be pretty scared. If I saw a dude in a full hazmat suit just casually walking around, I'd be terrified!
Why? Because hazmat suits are for, well, hazardous situations. Hazmat suits invoke thoughts of radiation, of deadly gas, of immense pain and long term disability. In short: they're scary, and wearing one could scare people. Thus, I figured they might already be banned in some areas.
Part of why I used a blower rather than another type of pump is that you can still breathe in. You have to force the air through with your chest, which is tiring, but there's no danger. the idea is that you go out and get the blower replaced, at that point
I wonder whether hospitals could use something like this. Pipe in air from outside to the helmets of healthcare workers. Everyone needs to be tethered, which is pretty annoying, but maybe doable?
In the 1971 film The Andromeda Strain, the biological containment lab has these cool suits which have a tunnel you crawl through to get into the suit. The suit never leaves the containment chamber. I keep thinking back to that design, and wondering if that's the future of COVID hospitals. Something like that wouldn't be that hard to mass produce at all.
That's exactly what we were trying to do! Since the system is positive pressure, the "snorkel" can be as long as you like. It can even leak a little bit, with no ill effect to the wearer (since the air will puff out).
One time I biked to work (~5 miles) on a summer day (80+ F) wearing nothing but underpants and a PPE suit from childrens' hospital Boston. The only thing exposed to air was my face.
When I got to work, I was swimming in my own sweat. I remember taking it off and draining buckets of sweat out of the 'sock parts'.
If this thing is air tight, I expect it would work about the same. That little blower wont be enough to cool you down on a warm day and you will be enjoying a sweat bath.
If you really want to go all the way, you can either DIY or buy one of the existing ice backpacks. These come with a vest with water tubes to cool down your skin and blood. The ice supply lasts a few hours.
Of course, it means there will be more to worry about contaminating when doffing.
In some sports this is kind-of normal procedure to reach a weight class before a major competition. You go into a sauna or do sports in air-tight clothes and lose a few kg of water. After getting weighted and assigned a weight class you drink lots of water again
- Source of clean air: HEPA filter will get contaminated and needs to be changed. UV sterilization might do it, but bulky and power intensive. Otherwise carry your own gases -- extremely technical, likely to asphyxiate yourself.
- As soon as you go I to a red zone the exterior of the suit is contaminated. Basically you need a disposable suit/gown outside the positive pressure suit.
Only other issue is that this is bonkers. Stay at home, wash your hands, wear a face shield when out to prevent touching your face if need be.
Unless you are in a room with 20 infected people the filter won’t matter that much.
A few layers of cotton is usually enough to filter 95%> of all 0.3 micron particles this is because the filtration is based on the fact that the thickness of the filter is orders of magnitude larger than the size of the particles so the size individual holes at any given layer don’t matter that much.
That said the majority of the benefit from this suit wouldn’t come from air filtering but from the fact that you won’t get contaminated droplets on your face and you won’t be able to touch your face with your hands after touching contaminated surfaces.
I think that study is testing the opposite what what this suit provides -- it's not testing protection of the wearer, but testing whether or not the mask protects others:
The median-fit factor of the homemade masks was one-half that of the surgical masks. Both masks significantly reduced the number of microorganisms expelled by volunteers, although the surgical mask was 3 times more effective in blocking transmission than the homemade mask.
It’s called a powered respirator they’ll cost around $200-250 for the ones that just offer more comfort than full/half mask respirators to $500 that also offer chemical/hardcover protection to $1000> for special uses like welding/smelting work.
I'd love something like this for doing remodeling work in the summer. Sweat and fog on the inside of my safety goggles is a serious risk to my safety and sanity.
Oh ffs were not dealing with the andromeda strain here.
If you need to go outside and you’ll be in occasional contact with other people gloves and a face shield will do.
If you’ll be in constant contact with other people or in situations where air circulation will be limited e.g. public transport or small offices then a respirator / face conforming mask needs to be added.
The "laser microscope" only goes halfway. You can deconvolve the diffraction pattern and get a fully volumetric image! Resolution is an issue. One setup, if your target is not moving, is to aim the projection at a desktop scanner.
If you had an expanded budget and were going to make some design changes for longer-term wear, or more versatility/durability, what would they be? How close to Quarian envirosuits can we get, exactly?
If I had an expanded budget I'd get something designed for this purpose. This was a bit of a McGyvering for hospitals that ran out of regular PPE suits.
If I was to change anything, I'd have more air go between the two layers, for comfort. Or use a less noisy air source than an air bed blower.
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[ 3.1 ms ] story [ 115 ms ] threadNow, how much if I wanted to buy one? :)
The idea was to use parts that are still available easily, although I worry about the scuba masks for it.
Our other builds are at https://robots-everywhere.com/re_wiki/pub/web/Cookbook.SaltM...
A HEPA filter has a stricter rating than the N95 masks that healthcare workers use.
"HEPA, which stands for High Efficiency Particulate Air, is a designation used to describe filters that are able to trap 99.97 percent of particles that are 0.3 microns"
N95: Removes 95% of all particles that are at least 0.3 microns in diameter
There's what it says it does, and the probability that it actually does what it says it does. Those are two different considerations.
E.g. I've seen some vacuum cleaners which have HEPA filters reviewed as a bit useless at filtering because the particles flow through small gaps around the filter.
Why? Because hazmat suits are for, well, hazardous situations. Hazmat suits invoke thoughts of radiation, of deadly gas, of immense pain and long term disability. In short: they're scary, and wearing one could scare people. Thus, I figured they might already be banned in some areas.
https://smile.amazon.com/Rubies-Adult-Jurassic-Inflatable-Co...
Try it: Turn off the motor, and take shallow breaths, see how much air you get.
Maybe you could make one out of a snorkel mask (like one of the dodgy full-face ones: https://smile.amazon.com/dp/B07BP6CTBQ/) and a vacuum cleaner?
Random picture from Google: https://www.google.com/imgres?imgurl=http%3A%2F%2Fwww.txbiom...
https://questionablecontent.net/view.php?comic=1315
When I got to work, I was swimming in my own sweat. I remember taking it off and draining buckets of sweat out of the 'sock parts'.
If this thing is air tight, I expect it would work about the same. That little blower wont be enough to cool you down on a warm day and you will be enjoying a sweat bath.
Of course, it means there will be more to worry about contaminating when doffing.
- Source of clean air: HEPA filter will get contaminated and needs to be changed. UV sterilization might do it, but bulky and power intensive. Otherwise carry your own gases -- extremely technical, likely to asphyxiate yourself.
- As soon as you go I to a red zone the exterior of the suit is contaminated. Basically you need a disposable suit/gown outside the positive pressure suit.
Only other issue is that this is bonkers. Stay at home, wash your hands, wear a face shield when out to prevent touching your face if need be.
A few layers of cotton is usually enough to filter 95%> of all 0.3 micron particles this is because the filtration is based on the fact that the thickness of the filter is orders of magnitude larger than the size of the particles so the size individual holes at any given layer don’t matter that much.
That said the majority of the benefit from this suit wouldn’t come from air filtering but from the fact that you won’t get contaminated droplets on your face and you won’t be able to touch your face with your hands after touching contaminated surfaces.
The median-fit factor of the homemade masks was one-half that of the surgical masks. Both masks significantly reduced the number of microorganisms expelled by volunteers, although the surgical mask was 3 times more effective in blocking transmission than the homemade mask.
The idea is that you can keep throwing out the outer suit but keep the rest.
Source: have used one for welding.
If you need to go outside and you’ll be in occasional contact with other people gloves and a face shield will do.
If you’ll be in constant contact with other people or in situations where air circulation will be limited e.g. public transport or small offices then a respirator / face conforming mask needs to be added.
https://civilpedia.org/p/?pid=101&t=p&h=Basics+of+IEC+Fusion
or this
https://civilpedia.org/p/?pid=30&t=p&h=Laser+Microscope
I've never seen that before...
If I was to change anything, I'd have more air go between the two layers, for comfort. Or use a less noisy air source than an air bed blower.