Hi, I worked on this project and have a couple comments to address the issues people are raising.

- There are established medical protocols to treat COVID-19 patients with BiPAP machines, including the addition of a viral filter to mitigate aerosolizing the virus. People are using these protocols now and we link to them from the site.

- There are two separate firmware hacks presented. The first one modifies ~20 bytes and provides UI access to BiPAP code left in the existing binary, which would allow the more common CPAP machines to fulfill the same limited function. The second is a PoC of a 'full ventilator' mode.

- The manufacturer's CPAP and BiPAP lines have identical mainboard designs and a near identical array of sensors, which provide realtime data including tidal volume calculations. This project exists as a PoC to show that it would be possible - simple, even - for the manufacturer to convert CPAPs to BiPAPs via an OTA update - or, with significantly more effort, to fully featured ventilators. It is likely that they are reluctant to acknowledge this is possible in fear of destroying the market for the BiPAP machines.

- If you are a SleepyHead/OSCAR developer, or have access to an AirCurve S10 and an ST programmer, I would love to talk.

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 is mildly unnerving.

Edit: I think sleepyhead[0] was the biggest project when I started looking into it, but it isn't under active development anymore. Apparently forked to OSCAR[1].

[0]https://gitlab.com/sleepyhead/sleepyhead-code

[1]https://gitlab.com/pholy/OSCAR-code

Here's what you should really know before you design a ventilator, by someone who works for a medical equipment company.

https://www.youtube.com/watch?v=7vLPefHYWpY

Not a doctor. But I am seeing growing evidence that ventilators are overused potentially. From ref [1]:

> But as doctors learn more about treating Covid-19, and question old dogma about blood oxygen and the need for ventilators, they might be able to substitute simpler and more widely available devices.

and

> "In a small study last week in Annals of Intensive Care, physicians who treated Covid-19 patients at two hospitals in China found that the majority of patients needed no more than a nasal cannula."

1 - https://www.statnews.com/2020/04/08/doctors-say-ventilators-...

Messing with vents if you don't know what you're doing sounds like a sure fire way to kill yourself.

Not a doctor. A major issue with using this type of CPAP machine on a Covid-19 positive person is the high amount of aerosolized virus particles it exhausts. Anyone using this should be extremely careful and know what they're doing. That being said, doctors in many countries are using positive air pressure machines with an air-tight helmet/bag with filtered exhaust.

ventilators don't just pump air. they also monitor and control the amount of air, and beep when something is wrong. plus a bunch of other features...

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...

Jailbreaking the CPAP machine might not be necessary. From what I understand, a CPAP, in certain circumstances, can be given to someone who has 'milder' COVID-19 symptoms. That would then free up a ventilator so the vent can go to someone who has more severe symptoms.

This is an informative video in what is involved in designing ventilators.

https://www.youtube.com/watch?v=7vLPefHYWpY

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, causing me to wake up and switch side (it seems my nasal cycle is completely gone).

One idea I wanted to try to fix is to use a cpap + humidifier to pump moisturized air.

And I found that I have to get prescription, which I tried with one lab sleep study causing $3000+, and concluded that I do not have sleep apnea, which is one of the symptoms to qualify cpap prescription.

Then I started to look for off market cpap machine on Craigslist. No luck, the machines are often old, and beat up after long usages.

I did not seriously research if cpap has risks to normal people. But it does not seem harmful, unfortunately it has to be regulated and possibly also become very expensive.

Edit: Thanks for the good recommendations. Buying from Chinese site (I often forgot this), nebulizer, etc.

"The breath extension replaces the function at 0x80bb734"

It sounds what Naughty Dog did to get RAM on the PSX for Crash Bandicoot ... they grabbed memory already allocated by the Sony runtime libs and would use it if it not do anything bad.

A crashing game console is not a ventilator but a good hack nonetheless.

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) meanings. If someone is loose with how they use these words, it suggests they don’t have someone with regulatory experience involved (a negative sign). The earlier the team can engage with someone with regulatory experience, the better.

The headline switches from singular to plural halfway through.

I love this idea though. The manufacturers should get onboard with “emergency BiPAP” mode to make this happen without users having to do an elaborate hack.

If the the only difference between company X’s CPAP machine and company X’s BiPAP machine is purely software, shouldn’t we just pay and/or force them to unlock the features via update?

CPAPs are known to be very closed systems, I remember a couple of articles about handy SleepyHead analysis software. If anyone interested, it was forked - new name is OSCAR.

Would these not be too simple to address the ventilation requirements of the coronavirus?

This was the case with the ventilators from a consortium in the UK, where the profile of corona requires more complex ventilation -

https://www.theguardian.com/world/2020/apr/13/uk-scraps-plan...

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)

It’s true, it is mostly a software change to upgrade a cpap into a bi-level device more like a ventilator. The barrier is really about procurement, and if they are proposing to reuse devices then it is all about shipping them to a location to be cleaned and tested, modified if necessary, repacked and shipped to a destination with new masks, hoses, and proper updated manuals.

This is very cool. I was wondering the other day if my CPAP machine (same model) would be capable of doubling as a ventilator and I'm surprised that someone has already thought of this and provided a solution.

if you vent your home cpap machine into an open room and the person using it is infected, congrats you just vaporized the infection onto anyone nearby

As a CPAP user who needs a new machine, I am now screwed by this. This will, by the time I have a new sleep study, cause all sorts of supply issues.

don't ventilators use intubation? how would this help in that case?