Design concept: unknown

[racleave]

@hammockman, can you come up with a concept, quite different to #3, and fill in here? Would ideally like to choose between them on 26th.

[hammockman]

Some really loose concept fragments:

• share air sources/sinks between many ventilators rather than one per patient
• reciprocating beam pumps
• treadle sewing machines
• super-plentiful, less-than-perfectly effective better than opposite
• air tunnel - rotating patients - no masks

[hammockman]

Righto, #4a (no idea how different from #3 this is as #3 description sketchy):

• thin bag pairs with volume being increased/decreased equally powered by choice of electric motor, human power
• incoming air drawn through appropriate filters, similarly exhalation
• providing high-p and low-p rails
• patient fed with flapper valve at Y centre, +ve actuation on exhalation side only
• possibly shared between more than one patient
• breathing rate controlled by red/infrared oximeter
• no allowance for o2 enrichment

[racleave]

Cheers. Does the diagram in #3 need to be clearer? there was no diagram at the time

As I understand these ventilators we are talking forced ventilation, ie with a tracheostomy tube. I guess masks might be an option for early treatment, but the main focus is a tube down the, er, gullet. my poor terminology: mask=human-tube interface

The requirement sheet stipulates that setting of FiO2 is a must, so we need O2 enrichment.

Are these (infra)red sensors cheap? years ago i worked with a guy who was working on laser/camera based sensors for doing this sort of stuff. my current understanding is you can get away with pretty crappy gear so (a) i've no idea if there's an OTS sensor at our price point, (b) we sould be able to cobble something together from cell phones/webcams/...

Where does the new air come in?

[racleave]

Further to the mask/tube bit, the latest FAQ has a good set of links, including a tech guide on Covid-19. FAQ is here:

https://www.agorize.com/en/challenges/code-life-challenge/pages/faq?lang=en

[racleave]

Whoops, looks like my O2 enrichment comment above is wrong - the requirements sheet says

8. Oxygen concentration NOT mandatory, recommended

but also that

2. FiO2 from 20% to 100% in discreet steps of 10%

The FiO2 is simply how much O2, as a percentage, is in the air that is inhaled. So when breathing air we have an FiO2 of 21%. So, if the ventilator cannot enrich oxygen itself then we require an O2 supply.

Right?

[hammockman]

I read those two bits of info as "O2 enrich not mandatory" but if you do "allow for 10% steping from 20 to 100%"

[hammockman]

Turns out more knowledgeable ppl have been looking at multi-patient ventilation:

• https://emcrit.org/pulmcrit/split-ventilators/
• https://emcrit.org/wp-content/uploads/2020/03/Ventilator-Sharing-Protocol-Dual-Patient-Ventilation-with-a-Single-Mechanical-Ventilator-for-Use-during-Critical-Ventilator-Shortages.pdf