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brentjackson / OpenRespirator

A shortage of intubation devices is a critical concern for the COVID-19 pandemic. The purpose of this open source hardware project is to develop designs whereby makers can assist with the fabrication of intubation devices that could be used by medical personne.
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Low-Cost Open Source Ventilator #5

Open morriswinkler opened 4 years ago

morriswinkler commented 4 years ago

https://github.com/jcl5m1/ventilator

Please have a look at that, if you can rebuild that setup it would be a good starting point.

brentjackson commented 4 years ago

Thanks Morris... that's an excellent find.

I'm not quite sure what you mean by "rebuild that setup". Do you mean build this device, somehow replicate the GitHub setup? (Sorry if I'm being dense and not grasping the obvious.)

morriswinkler commented 4 years ago

Hello Brent,

i have actually moved on from that design, did a bit of research last few days.

Based on the requirements of a ventilator that is needed for patients that suffer from a medium to severe case of the COVID-19 infection the goal should be oriented on a model that is used in intensive care units (see:https://www.openanesthesia.org/modes_of_mechanical_ventilation).

I found some documentation on the requirements, my current bet is that a leave blower will provide a good starting point. Usually motors used in the ICU units are around 40000 rpm with 400l/min volume. Most small leave blowers fit volume specs ( they have bigger blades so rpm is around 25% of ICU unit motor). The leave blower have 20-40 dB more noise on average, but my bet is that you will never have to run them on full power.

https://www.amazon.com/gp/product/B00AXTO41E?pf_rd_r=2HTM1Q9C54393A2PAAX6&pf_rd_p=2d1ab404-3b11-4c97-b3db-48081e145e35

I was planning to get one tomorrow, i am currently stuck in a very small country between Europe and Asia so i ran out of luck getting one online. I am planning in hijacking the motor controls, i hope that the design allows for a somewhat easy setup that can be translated to other units, since this round blower design is fabricated a lot.

It has an adapter shaft on in and outlet that would be perfect for attaching a intubation tube and a filter. And most leave blower that fit that specific design have those (they even look mostly compatible to each other).

I read up a bit on the requirements of the ICU ventilators and they have a lot of modes and settings which they are used in. But all of them require a feedback loop that measures the pressure within the intubation tube (also used if a mask is attached). So if i would be able to get control over the leave blower and the specs look somewhat promising i plan on getting a pressure sensor and creating a small setup to start creating a working first version.

My biggest concerns are the durability of the leave bower, they are not designed to run 24/7 for weeks at a time. So i guess this has to be tested first. The motors on the ICU units run in duty cycles. So they ran between 20 to 100 cycles a minute, which gives me hope that a leave blower can handle that.

I guess if that all would work out i would try to find a person that can explain me what modes are the most important for covid-19 and add those modes to the setup.