full face masks for healthcare workers

[Cam Smith]

Hi,

My name is Cameron Smith. I'm an anesthesiologist at the University of Florida. With the current coronavirus crisis and the shortage of personal protective equipment in the hospital I have been thinking about how to better protect healthcare workers and I got thinking about SCUBA gear as an option, but some of the patient interactions, such as in the operating room, can be quite long - long enough to outlast the gas supply in a cylinder. That got me thinking about surface supplied gas systems.

Does anyone know if a full face masks cold be modified to use hospital piped gas supply lines rather than a compressor? The supply pressure is 55 psi, but the equipment would only need to operate at 1 ATA.

Thanks very much

 

[Searcaigh]

1 ATA is 14.7 psi (1 bar) so 55 psi should be fine, but if connecting to the hospital gas supply, you'll need to sort out regulators to reduce the pressure to the second stage on the system. Long trailing hoses might be an issue.

As for using normal dive cylinders, an AL80 should easily last a few hours on the surface.

On the hospital system what gas are you planning to use air or O2? The latter will require careful management.

How's the nurse gonna mop the sweat off your brow when wearing a FFM?

 

[saxman242]

Hi Cameron,
Typically, scuba 2nd stage regulators are designed to operate with a supply pressure in the 120psi region, so it definitely wouldn't be a plug and play system if you were trying to just hook up to house air, but it likely could be adjusted to work. Scuba "hookah" systems, which use a boat supplied air source use compressors that operate in the 50 psi range, so it's definitely doable. Battery Powered Built-In Boat Systems

 

[CuzzA]

Your efforts would be better applied to making your own masks until we can produce enough here in the US. As I'm sure you are aware, China produces the lions share of our masks (among other things) and the production was halted and they're hoarding them for themselves. #QuitChina

Here is one example. I'm sure there are many more out there on the net.

COVID-19 - How to make a reuseable respirator as a replacement for N95 mask | Boston Children's Hospital

 

[GJC]

Hi,

My name is Cameron Smith. I'm an anesthesiologist at the University of Florida. With the current coronavirus crisis and the shortage of personal protective equipment in the hospital I have been thinking about how to better protect healthcare workers and I got thinking about SCUBA gear as an option, but some of the patient interactions, such as in the operating room, can be quite long - long enough to outlast the gas supply in a cylinder. That got me thinking about surface supplied gas systems.

Does anyone know if a full face masks cold be modified to use hospital piped gas supply lines rather than a compressor? The supply pressure is 55 psi, but the equipment would only need to operate at 1 ATA.

Thanks very much

I have actually connected a balanced second stage to a 50 psi oxygen hose from an O2 regulator on the wall O2 supply. It didn't breath any differently than on a scuba tank at 135 psi supply pressure. You could probably connect it to wall air supply, but you will need an adapter because air and O2 connectors are different sizes.

The disadvantage of a scuba full face mask is that they are a lot more expensive than other alternatives (you can get a gas mask with a hepa filter for $30) and because the scuba market is small, the supply is small (the Army would have a lot more gas masks available if you wanted to try that).

 

[formernuke]

Fire fighters air mask would be another option, not sure about supply though.

 

[johndiver999]

I have actually connected a balanced second stage to a 50 psi oxygen hose from an O2 regulator on the wall O2 supply. It didn't breath any differently than on a scuba tank at 135 psi supply pressure. You could probably connect it to wall air supply, but you will need an adapter because air and O2 connectors are different sizes.

The disadvantage of a scuba full face mask is that they are a lot more expensive than other alternatives (you can get a gas mask with a hepa filter for $30) and because the scuba market is small, the supply is small (the Army would have a lot more gas masks available if you wanted to try that).

I would have expected that a regulator would work fine at such a low pressure, especially for a person who is not at the increased pressure at depth and who is not engaging in strenous activities. That would seem like a pretty safe way to ensure protection.

It should be simple to figure out whatever type of air line adapter that would allow a quick connect and disconnect. Something like this could save lives and if it worked well, it might give health care workers the confidence to not "call in sick" - which I am hearing is already occurring, due to the fear of catching the disease and skepticism about the availablity of Personal protection.

 

[Jcp2]

The problem with any PPE setup for an aerosol/airborne pathogen is not the donning, or even the wearing, but the doffing without inadvertent self contamination and self inoculation after leaving the quarantine area.