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Airbreak.dev: Jailbreak your CPAP machine to turn them into ventilators

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Re: Airbreak.dev: Jailbreak your CPAP machine to turn them into ventilators

#81

Post by ars »

favorited wrote: post #23

The CPAP jailbreak community was eye-opening when I first learned of it. I never expected something like that, but with the draconian policies it's not surprising. For example, my CPAP has a CDMA radio inside, which transmits usage data back to the manufacturer & my doctor. Insurance won't pay for it unless the machine tells them I'm using it – so a medical device company has a record of when I sleep and wake, which…

The CPAP world is a microcosm of what's wrong in the medical world, i.e. why things cost so much.

A CPAP machines costs about 10x as much as it should, and a part of that is insurance companies wanting to make sure they are not paying for a device you are not using.

Which then increases the price, which makes insurance companies even more worried about them.

Then you are paternalism where only a Dr. is allowed to change the settings on the machine. So they lock them down, which adds even more to the cost.

And then they are prescription only, so they have to go through specialized distributors because heaven forbid someone actually buy one without a Dr. letting them.

The end result of all this is lots of people making money, and higher costs for the patient in the form of higher insurance premiums.

Re: Airbreak.dev: Jailbreak your CPAP machine to turn them into ventilators

#82

Post by VectorLock »

hangonhn wrote: post #35
rootusrootus wrote: post #20

Earlier quoted context omitted.

A typical modern CPAP also takes measurements, and makes limited adjustments based on what it sees. It doesn't just pump air. Not that it's as capable as a real ventilator, but it's not just a simple air pump, either.

You also need to warm and humidify the air because ventilators are inserted past the part of your respiratory system that does that.

Most CPAP machines have built in humidifiers.

Re: Airbreak.dev: Jailbreak your CPAP machine to turn them into ventilators

#83

Post by VectorLock »

Very great. I was really really curious if this was possible and how much work it would be. As you said a lot of CPAP machines are very close in functionality to BiPAP machines. I could see this being very helpful to people who are having a hard time with CPAP therapy but are having difficultly getting their insurance provider to approve a BiPAP machine which are more expensive (something I've experienced)

Re: Airbreak.dev: Jailbreak your CPAP machine to turn them into ventilators

#84

Post by robterrell »

justicezyx wrote: post #72

Talking about cpap machine, I did some research on it, and found that they are regulated medical device and cannot be purchased without prescription. I suffer chronicle dry nose, moderate empty nose syndrome on the right side (due to surgery done 20 years ago in China), and Deviated Septum (due to injury as kid). One thing often happen to me is during middle of nigh sleep, my left nose duct will be extremely dry, cau…

You can find CPAPs on eBay, but my understanding is that you'd want a sleep study to validate the correct pressure settings. Are you sure you can't just set up a room humidifier?

Re: Airbreak.dev: Jailbreak your CPAP machine to turn them into ventilators

#85

Post by jschwartzi »

TylerE wrote: post #77
fwip wrote: post #62

Earlier quoted context omitted.

CPAP machines are usually used when you're asleep, right? Since sleep apnea can sometimes be fatal, it seems like screwing up your CPAP machine could conceivably lead to your death.

For most, yes, but there are people who use them while awake... for instance, people who suffer from conditions like ALS or COPD. Even as someone with just vanilla sleep apnea I'll occasionally strap mine on for a while when suffering from a head cold...certainly helps open things up.

Yeah, you're basically using Positive End-Expiratory Pressure(PEEP) to keep the alveoli from sticking together or developing stiffness. The problem it solves is under normal conditions your lung compliance goes down and with it your Tidal Volume. My understanding is that PEEP works for COPD patients by maintaining enough alveolar pressure that at the next inspiration all of the alveoli in the lung are recruited to store gas instead of only some which both increases surface area and also volume of gas. Both of these factors improve blood oxygenation. I think it has the same effect with pneumonia too for the same reasons.

I am not an RT but I worked for a ventilator company for like 4 years.

Re: Airbreak.dev: Jailbreak your CPAP machine to turn them into ventilators

#86

Post by Ericson2314 »

gruez wrote: post #41
fortran77 wrote: post #29

Earlier quoted context omitted.

What's scary is that CPAP machines are allowed on airplanes. If they really aerosolize virus particles, maybe they shouldn't be.

The parent commenter only mentioned that it exhausts aerosolized virus particles, not that it produces any. Do they emit/amplify aerosolized virus particles themselves? If so, by what mechanism?

If anything, more tubing would might condense humid lung air in the walls so whatever leaves the tubes is drier.

Re: Airbreak.dev: Jailbreak your CPAP machine to turn them into ventilators

#87

Post by DanBC »

fowkswe wrote: post #15

Also worth understanding that a ventilator is not always the best option - there have been findings recently that a tactic called 'proning' is often enough to increase blood oxygen: https://www.nytimes.com/2020/04/14/nyregion/new-york-coronav...

Here are two useful videos about proning to explain why it works:

https://twitter.com/libbyg9/status/1243813444689821696?s=20

https://www.youtube.com/watch?v=FS4t5w1eCYw

Proning can be done to intubated patients too.

Re: Airbreak.dev: Jailbreak your CPAP machine to turn them into ventilators

#88

Post by Ericson2314 »

gowld wrote: post #76
reaperducer wrote: post #47

Earlier quoted context omitted.

These are not normal times, and I can certainly see a doctor with tinkering skills modding his office's CPAP stock in order to save lives.

Not likely a doctor in a US hospital. Too much liability risk.

The idea is manufacturers don't want to loose money and do this stuff themselves, so somebody donates their time to bring this hack to the FDA, and then the hospitals can use it.

Re: Airbreak.dev: Jailbreak your CPAP machine to turn them into ventilators

#90

Post by jschwartzi »

reaperducer wrote: post #47
IdoRA wrote: post #36

There is a reasonable chance that this will not be as useful as the team hopes: 1) They are increasing maximum pressure and pressure rate changes beyond the built-in design parameters. If these new parameters are outside what the engineering requirements document spec, these changes are a problem in seeking EUA. 2) In regulatory affairs, authorized , cleared , and approved have very specific (and enforceable) meaning…

These are not normal times, and I can certainly see a doctor with tinkering skills modding his office's CPAP stock in order to save lives.

The problem is that high pressures can cause barotrauma. So you might end up increasing PEEP beyond what a patient's lungs can survive, and because you're using a CPAP machine instead of a ventilator there's not really any facilities to measure pressures that high. Or there are but they were never characterized because the machine doesn't measure pressures that high. And because they were never characterized you may not actually be delivering the pressure that the machine says you're delivering. So this is pretty crazy.

The other thing ventilators typically include is pressure alarms and high pressure limits. Under routine use the high pressure limits keep you from popping patient lungs in volume-controlled modes. A pressure-controlled mode like BiPAP may be okay in this case since it provides those limits. The downside of pressure-control is that the patient's lung compliance and alveolar recruitment may change, so you can start off delivering a certain tidal volume at a certain pressure and then because of compliance changes the patient's alveoli lose the ability to contain the same volume of air, so the patient is losing oxygenation unless you change the settings.

My point is that there are a lot of considerations beyond simply delivering a fixed pressure of gas into a patient's lungs and hacking a CPAP may not meet those requirements.

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