investigate side port design

[mmroden]

Blocked on #183, then potentially on #184
For a passive respirator, we want:

1. a clear front piece to talk through
2. side mount points for 22mm ports for the hose(s) coming from the papra
3. a filtered 1-way exhalation port
4. "good" mounting straps that evenly distribute weight and allow for heads to turn, look up/down, etc (also important for the mounting ports in 2).
5. Comfortable face fit that allows for passive N95 filtration on a non-bearded individual (ie, blocked on design a silicone face gasket for a tetra respirator design #184, potentially)

Communication is necessary for final NIOSH passing, unclear if the clear frontpiece is sufficient or we require something more (a microphone/speaker combination, perhaps?)

This ticket addresses the design of a mask that addresses the above requirements.

Aggressively placed into the Jan 2022 milestone, may require being moved out.

[mmroden]

Design Review:
proper seal: not really handled in these concepts
strap on the back of the skull
OSHA is particular about stress on the skin
no real stress on the bottom, weight of the mask hangs down
where straps connect to the mask is an issue to determine the equal pressure loading across the face
determine the mask shape & seal, calculate it to distribute force across the face (later design stages)
conceptual issues from Darryl:
not sure if we can get enough airflow off of one side
3M respirators at minimum have two inlets for air, one outlet for air
outlets aren't filtered, don't believe that their filter outlet is n95
asymmetrical tube-- not sure if we can get enough filtered air through one side
resistance is pretty low with 2, may be an intentional choice with 2
little filter would be N95?
problem is filter is way too tiny for flow, question is one of flow resistance
Mark Porter might know some stuff, could connect with someone who makes ventilator filtration material
Darryl hasn't seen that particular filter on the activemask
reviewing the activemask
assuming we could make a filter that is somewhat similar, we're in a much bigger project
custom N95 filters as part of the manufacturing
mask should go under the chin, which is more akin to how you wear a CPAP mask
a lot of people wear it under the chin (Mark is on the chin, Darryl is over)
issue of talking is taken up by the elastomeric nature, sealing edge will likely be large
the clear rigid part should not flex, transition between clear rigid and conforming softer portion needs to be thought out
when talking & move the jaw, there's no gap
concern is about the airflow, not sure about testing where can pull enough air through the filter
if the pucks are n95 filters also, then less worried about that
one filter in place in front, one in the back, should be enough airflow even with it off
where's the exhalation?
all respirators are 1 way through everything
disposable use ones don't have those regulations, but surface area is much larger
NIOSH standards for resistance and 1 way valving
Mark to review and contact Daniel
final thing: not sure if the one sided design is good or bad, will cause pressure loading on one side (will cause head tilting, even distribution is important)
t connector is floating, need to be anchored, will move around
weight on one side vs the other is overloading

[mmroden]

Putting in #187 in order get the designer the step files