Open Source Ventilator Project

[premelec]

I noticed that there is work being done to produce plans for locally manufactured https://opensourceventilator.ie/ - there are many clever folks on this forum who might contribute to designs... the technical requirements would not likely be very difficult - perhaps pressure measurement and motor or solenoid control - maybe run with compressed air or electric drill etc... In current pandemic circumstances even basic designs could be useful. Hope this interests some of you!

 

[tommo_NZ]

What a good idea. The PicAxe is the perfect controller for such a project, low power consumption, completely customisable, cheap and simple to implement. The range of sensors available covers all the basic requirements, and the output options equally useful. This was some way down my list of projects but still on my horizon. Let's see what the group can come up with.

 

[PhilHornby]

There's some information on a slightly less ambitious project here: https://github.com/jcl5m1/ventilator

 

[hippy]

CPAP devices do seem to be a more realistic option for DIY creation. Even a blower fan, battery, plus switch could be useful.

These devices sit between nasal cannulas and ventilators, are said to be quite good at keeping patients from progressing to needing ventilation.

The main challenge appears to be, not so much control, but mask design. Because it's providing forced airflow, it needs a good face seal to prevent it blowing contamination away from the patient and spreading that. But the design also has to allow a patient to exhale.

In practical terms of coming up with a design to save the planet; it's likely universities and commercial R&D teams are well ahead of the curve, have money and better resources, and will likely take preference over DIY offerings. That said they are probably all tracking what others are doing and a cheap DIY version can be useful when other channels cannot or do not deliver.

 

[MikeM100]

Interesting Oxford University project here:

OxVent - Low-cost mechanical ventilator for Covid-19

Rapidly deployable and scalable low-cost mechanical ventilator specially designed for Covid-19

oxvent.org

 

[hippy]

Interesting Oxford University project here:

I am not sure that deserves to be labelled a ventilator. It seems to me that it's actually a manually operated CPAP device which is normally carried in an ambulance and manually operated by paramedics.

The clever thing they have done is to automate the manual operation by putting the air reservoir 'bag' in a sealed box and varying the pressure in that box to compress it. That means the equipment itself is already certified for medical use. The only regulatory hurdle is to convince that squeezing the reservoir automatically is the same as a paramedic squeezing it manually.

 

[premelec]

I found this interesting URL on some of the complexities of breathing systems in medical use - more complicated than I had thought... and an interesting illusion shown. https://www.howequipmentworks.com/circle_breathing_system/

 

[hippy]

One solution currently being suggested as useful for Covid-19 treatment is ECMO ( Extra-Corporeal Membrane Oxygenation ) where blood is taken out, oxygenated, and returned to the body. It is effectively a lung bypass machine

 

[Buzby]

... where blood is taken out, oxygenated, and returned to the body. It is effectively a lung bypass machine.

Hmm ?

I don't think I'll try building one.

Got in enough trouble splashing water around from my drip generator, hate to think what the missus would say if it was blood !.

 

[premelec]

FWIW:

If You’ve Heeded the Rallying Cry for Ventilators, Here are the Government Regulations You Should Know - News

Learn about which government regulations have been dropped or modified to speed up design approval for ventilators.

www.allaboutcircuits.com

 

[Hemi345]

It's interesting to see how Tesla is using parts from their cars to design a ventilator:
MSN article

I gotta be honest, when I watched that video after previously seeing some of the open source ventilators, I couldn't help but think Tesla's design looks way over engineered (some of the open source designs I've seen look like they'd fit in a shoe box). Is Tesla just trying to show off or is it a case of additional complexity by trying to use parts that weren't initially designed for this function?

 

[hippy]

I would guess a lot of the parts are over-engineered simply by virtue of being car components, needing to be reliable for many years under extreme conditions and a lot of abuse.

Some of the valves and sensors are probably designed for handling a lot more pressure than one would ever need for a ventilator, and tend to end up as large milled aluminium blocks than something small and compact.

I expect something built from JCB pneumatics would create something akin to a Mr Kreosote event