COVID 19, CPAP, Ventilator MEGA THREAD...everything go here please

[Sleep87]

How feasible is it to convert CPAPs into ventilators?

A perhaps related question: how different is the hardware between a CPAP and BiPAP? Is the conversion from a modern CPAP merely a matter of software?

I imagine that our inventory of new and used CPAP machines and supplies is pretty solid, and the supply chains on these more equipped to scale up than, say, the supply chains for the ventilators.

Some references mentioning both sorts of devices, to inspire your answers:
https://www.ethics.va.gov/LST/Mechanica ... mation.pdf
https://newsmomsneed.marchofdimes.org/p ... entilator/

[arhdc]

Looking at APAP devices the difference is primarily software. The Resmed Lumis TX is basically the same, or exactly the same, hardware as a Resmed S9 AutoSet with the addition of an alarm module and more modes available in the software. I am not sure how prohibitive the process would be to upgrade software, maybe reflashing a chip, replacing a chip or perhaps changing a motherboard. Having said this, none of these converted machines would be FDA compliant and who knows what it would take for an emergency variance.

The other limiting factor would be that the highest tier that these machines could be upgraded. I am not sure the could ever be more than non-invasive ventilators. Normal BiLevel machines max out at 25mmH2O where full-on invasive ventilators are able to achieve pressures of 30mmH2O or more. The blowers may not be able to achieve higher pressures. Not saying that this is a bad idea or totally impossible, but modifying normal APAP/Bilevel machines is unlikely to be a real option unless you can get ahold of a motherboard for something like a Lumis TX.


https://www.resmed.com/us/en/healthcare ... is-tx.html

[palerider]

How feasible is it to convert CPAPs into ventilators?

About as feasable as converting the average family sedan into an 18 wheeler.

Ie, it's not happening, because the manufacturers won't let you.

[yrnkrn]

About as feasable as converting the average family sedan into an 18 wheeler.
Ie, it's not happening, because the manufacturers won't let you.

I do not understand: Is the issue technical (family sedan->18 wheeler) or legal/economic (manufacturers won't let you) ?

[jnk...]

issue technical . . . legal/economic

All three.

Imagine taking your family sedan into a mechanic and telling him you'd like him to convert it into an 18-wheeler. He will tell you that it would be cheaper and less time-consuming to build an 18-wheeler from scratch than to try to convert your car into one. And even that still wouldn't be road-legal after all that wasted time and money.

Technically speaking, plain old CPAP, particularly when used in a hospital setting, is already a form of non-invasive ventilation, NIPPV, just not the right form for certain conditions:

Noninvasive ventilation is a popular method of adult respiratory management in both the emergency department (ED) and the intensive care unit (ICU), and it is increasingly used in the care of pediatric patients. NIV is divided into two main types: negative-pressure ventilation (NPV) and noninvasive positive-pressure ventilation (NIPPV). NIPPV is further subdivided into several subtypes, including continuous positive airway pressure (CPAP), bilevel positive airway pressure (BiPAP), and volume-assured pressure support (VAPS).--https://emedicine.medscape.com/article/ ... -technique

When ventilation is spoken of in connection with COVID-19 complications, though, it is spoken in reference to the hospital setting and generally refers to someone in extreme distress who needs invasive ventilation to keep breathing at all. No rigged home CPAP machine is going to be considered by the docs useful for that, despite the fact that both approaches fall into the same broad medical category of machines that help fix something about how someone breathes.

If someone is sick enough to consider any form of PAP for something other than snoring, OSA, obesity hypoventilation, or other similar long-term breathing/heart/central conditions, that person is sick enough to be in the care of an emergency-medicine professional who will get that person the right machine for that person's condition and monitor that person through his life-threatening situation. No one should be encouraged to attempt that sort of thing on one's own. And no one should attempt to modify machines for that purpose. Ever. Period. Full stop. I disagree with the pros who mention home machines and possible use for COVID-19, even though I have heard it said out loud a few times. So yes, there are other opinions out there.

Fixing long-term breathing issues is one thing. Emergency medicine is another. Different realms. Different approaches. Best kept in their own lanes, in my opinion. After someone gets over COVID-19, they may benefit from long-term forms of PAP if breathing needs help. But that's a different ball of fish, or kettle of wax, or whatever. I personally don't see too much middle ground.

[JeanBernardMinster]

This link appears to be relevant. I tried to attached the contents of the article, and for that was banned from the forum under my original name for spamming. Had to register again.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4099596/

[JDS74]

Just a thought.
For non-invasive ventilation, the two classes of CPAP - ASV and S/T, can already operate in this mode.
Mine did for me a few years back.

I suspect that the conversion to one of these types would be cost prohibitive even if allowed by the FDA and/or the manufacturer.

[palerider]

This link appears to be relevant. I tried to attached the contents of the article, and for that was banned from the forum under my original name for spamming. Had to register again.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4099596/

no, something from 2004 is not relevant.

[palerider]

Just a thought.
For non-invasive ventilation, the two classes of CPAP - ASV and S/T, can already operate in this mode.

No, an ASV is unsuitable, and cannot operate in whatever "mode".

ST, yes, *VAPS, yes, ASV, no. S, no, auto, no.

[yrnkrn]

ST, yes, *VAPS, yes, ASV, no. S, no, auto, no.

Aren't ST and *VAPS software modes in the ResMed Airsense 10 series?
Couldn't ResMed make a lot of ventilators available in a short time just by distributing a software update to all Airsense 10 series machines?

[palerider]

ST, yes, *VAPS, yes, ASV, no. S, no, auto, no.

Aren't ST and *VAPS software modes in the ResMed Airsense 10 series?
Couldn't ResMed make a lot of ventilators available in a short time just by distributing a software update to all Airsense 10 series machines?

sure, they could turn all the machines into lumis tx machines.

[yrnkrn]

sure, they could turn all the machines into lumis tx machines.

I am not personally familiar with the Lumis TX machine.
Visually it looks just like any S9 machine.
What is the technical reason a regular S9 machine can't be updated to function same as the TX machine?

[palerider]

sure, they could turn all the machines into lumis tx machines.

I am not personally familiar with the Lumis TX machine.
Visually it looks just like any S9 machine.
What is the technical reason a regular S9 machine can't be updated to function same as the TX machine?

Because you can't put new firmware on it.

[chunkyfrog]

It would probably require pulling the motherboard and replacing it entirely,
Or at least replacing the ROM (or IC) wherein the programming resides.
Precision benchwork might be more costly that assembling a new machine from scratch.

[yrnkrn]

True, I can't put firmware on any ResMed machine as the firmware is closed source and unavailable to me.
For the S10 series, ResMed can update the relevant ventilator modes using over the existing air (cell) firmware distribution.
The update would not have to be free, they can charge for it and send it only to specified machines or countries.
Would make many more ventilators available immediately alleviating one of the bottlenecks.