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E-VENT: Emergency ventilator design toolbox (e-vent.mit.edu)
188 points by zdw on March 30, 2020 | hide | past | favorite | 102 comments



I can't find it at the moment, but I recall seeing a report from China that 80% of COVID-19 patients placed on ventilators still ended up dying. I assume that's not the case in the US? (does anyone have stats on this yet?)

I also recall seeing (again, can't find it right now) a scientist concerned about the potential for widespread usage of ventilators to rapidly increase the prevalence antibiotic resistant bacteria.

My point is, having as many ventilators as we need is good, but it's even better to not need the ventilators in the first place. I hope we don't fixate on ventilators too much at the expense of mitigation and other treatments.


The number of people dying on ventilators is not meaningful question because patient dying from COVID-19 almost always becomes critical before dying. If there is ventilator, they get hooked into them for a some time.

The real question to ask is how many people who would survive with ventilator die without it.


From a scientific perspective you are right. It is also important that people realize ventilators only have a moderate impact, and act accordingly.


> because patient dying from COVID-19 almost always becomes critical before dying

Actually I read the opposite. That the patients in ICU's are younger 40-70 with the bulk in their 60's, while those dying are mainly 75-100, mostly over 80 years old.

That is: many if not most of those who die never pass the ICU. Obviously people in ICU wards die too, a significant fraction. But the age of the group that die mostly (80+) means it's mostly non-ICU patients. Doctors know a 80 year old with some comorbidity isn't going to survive being tubed. By "survive" they mean survive for X months afterwards too (This number can be e.g. 6 or 12 months to use as a guideline for survivability, to consider ICU treatment).


This is what makes discussions on this subject infuriating. Most people only have access to the absolute death numbers, and yet try to draw conclusions from them.

If it is the case, as you say, that a significant fraction of young people need to go into intensive care to have a chance to recover, that makes this pandemic much worse than most people think.

I do know that the number of hospitalizations is high (and possibly should be higher still, if hospitals were not turning away patients)


Then here are the numbers: https://www.statista.com/chart/amp/21173/hospitalization-icu...

COVID-19 still requires very high hospitalization rates, even among young people.


Not sure about coronavirus, but my grandfather was intubated after a heart surgery and has survived for a few years now despite flatlining on the bed and having some fingers amputated due to tissue death.

The health care system and market system are broken. More ventilators is the only solution.

The people in charge chose not to buy the correct number of ventilators because of profit.


There isn't a country in the world with enough ventilators right now, that's an awful lot of systems and not all of them are run for profit.


Then why will it only take 3 months and 2 companies to make 40,000 when a normal hospital has 5.

How can people possibly defend any system that is going to let, in their words, hundreds of thousands of people die, when x% of them could have been saved if money had been spent on equipment instead of buybacks and admin salaries.


> How can people possibly defend any system

People vote for politicians who allocate funds to the healthcare systems (generally). Either people don't expect the disaster to strike, or they are more interested in the lower taxes you can have if you don't prepare for peak demand. I suspect it's a consequence of both.

Any politician who says "When I'm in power, I'll raise taxes 10% to fund preparedness for a disaster that comes every 100 years", will not see office. Short sightedness isn't the same as evil. Humans are bad at imagining worse case scenarios and good at optimizing for short term goals. This is the same in industry. Companies now suffer because they optimized for efficiency not resiliency. Where are the companies that optimized for resiliency so they now continue production becuase they had larger stocks of parts, parts sourced from multiple locations etc? The answer: They are dead because they were out competed by companies who could undercut their prices because they order all their parts from China and keep only 1 day worth of production in their parts warehouse.


Number I’ve seen is that twice as many people die without ventilators when needed.


Yes. 86% globally, 70% from Seattle currently at the moment.

Here's a report on the state of things from a New Orleans ER doctor:

https://www.reddit.com/r/medicalschool/comments/fpwc1y/front...


It is a small study out of China, but yes, the #'s here are not good. 19/22 patients (~85%) put on 'invasive mechanical ventilation' died (read:intubation)

https://www.thelancet.com/journals/lanres/article/PIIS2213-2...


A doctor on the twiv podcast in America said that about 50% of his patients died after getting put on ventilators. https://podcasts.google.com/?feed=aHR0cDovL3R3aXYubWljcm9iZX... It's about 15-25 minutes in if you want to hear the full quote.


That figure is meaningless because he can't account for the people who are still on a ventilator on the moment and will eventually die.


Presumably you can compare people who die vs those recover and no longer need the ventilator. The number that recover after being on a ventilator (for say, 2 weeks, or something) would seem to provide more information (though I suspect it may be a little harrowing to hear the number).


yeah, I wish i had a study or something, but I happened to be listening to the podcast right when I saw the parent question. the guy was an immunologist iirc, so he has some statistical background. He probably was counting patients who either died or got off the ventilator, but I don't know for sure.


My partner has been treating COVID patients. The numbers she's seeing for COVID patients on ventilators surviving are better, but not by much.


Likewise. In SF at the moment, they're having pretty good outcomes but that's due to half-full ICUs and dedicated care. I could see how bad things would get if they were to be overwhelmed though.


As I'm sure you and she are aware, the gut-feel regression has a very poor historical track record at separating confounding variables, particularly outside of controlled studies. The decision to vent or not is being made by an expert physician, taking many variables into account, so it's very difficult to tease out a meaningful conclusion just by comparing the two survival rates.


At +1 year post ventilator survival rate is 30% pre-COVID19

https://www.ncbi.nlm.nih.gov/pubmed/8404197


To be more exact, (in that study) the total percentage of patients who were initially put on the ventilator who survived for at least a year was 30%.

Of the approximately 50% of patients who were on a ventilator and survived long enough to be released from the hospital, 60% of those survived for at least a year.


>widespread usage of ventilators to rapidly increase the prevalence antibiotic resistant bacteria.

I'm curious how that would work out. I think it would have to do with the drugs that are given along side the ventilator, not from the ventilator itself?

>I hope we don't fixate on ventilators too much.

It feels to me like we might be. It'll definitely be needed, but I think there are other issues that aren't getting as much attention; problems that might not seen as solvable by someone in their garage with a 3d printer and some pneumatic valves.



From a quick overview I don't think VAP will be a more serious issue for the proposed device than the commercial ones.

The microbes would come from two sources: Inside the system (from a prior patient), and from the air supply.

The former can be mostly prevented by replacing the bag and the tracheal tube, because both are cheap and disposable. Then there are probably some connection pieces and those need to be sterilized or replaced between patients.

The air supply can be run through a relatively low-tech filter if absolutely necessary.


I was under the impression these bag mask valves have a filter to prevent contamination from getting back in the bag but seems like its safe to just dispose, given adequate supply.


I think the concern was about the widespread use of ventilators in general, whether they are commercial or not.


cheap and disposable like the N95 masks? Does anyone manufacture these bags and tubes in your country at scale?


Not quite that disposable, but one per patient isn't really a big ask.


Kudos to the MIT group, but I think the problem of ventilator shortages has nothing todo with technology (this is old, well understood tech), but the lack of leadership in mobilizing industrial production to supply this lifesaving equipment. Since the early days of this crisis this country should had mandated companies to produce record levels of ventilators, masks, vests, and other equipment that are now needed to save lives. On the contrary, the federal government is up to this point dilly-dallying about how to procure and produce ventilators, without a clear solution in sight.


There are multiple university projects out there: https://www.coresponse.rwth-aachen.de/cms/~gqged/Coresponse/...

Currently also at least the 3d prototyping facilities of automotive manufactures are being used for such purposes.

However, I really want to see those devices saving lives instead of generating news reports.

We already have shortages of intensive care in the grand est and in Italy. I don't think people there have the time to read tech reports and try out all the design.


As far as I understood it, the commercially available ventilators are too complicated to ramp up production quickly. Patents and regulation also complicate things.

This device doesn't have that problem. I can recognize most components as either off-the shelf or easily manufactured.


>>As far as I understood it, the commercially available ventilators are too complicated to ramp up production quickly.

Very true, but USA, China, EU, Russia, India etc have their militaries ready to go with Plan A, B and C, they don't order bullets once invaded.

We all knew that pandemics are part of life, so we should have had warehouses full of this stuff. USA is spending about $700 BILLION a year in military matters and untold trillions in Afghanistan and Iraq. So, at least USA does not need an open source one, we can afford to pay whatever price they sell it for. They neglected this and of course now it's too late. 100K ventilators at, say,$25K each = $2,500,000,000 unless I made a mistake. What's $2.5 Billion to USA?


$2.5 Billion is a lot to the US, especially if it's taxpayer money for a public health issue.

But actually pretty much all countries have stumbled into the same problem. A respiratory pandemic of this magnitude wasn't anticipated by anyone, for reasons that should be investigated further. Now it's very easy to say there should have been a bigger stockpile, but a lot of the voters, especially in the GOP are quite sensitive to government spending, especially for healthcare.

And it's important to remember that there are probably other things countries need stockpiles of, with a similar anticipated risk. For example dialysis machines for a kidney disease pandemic. These things add up quickly, and all you can do is make an educated guess of how far to anticipate any such threat.


No, $2.5Bi is not a lot of money to save thousands of lives. The US wastes untold billions of dollars with war equipment that will probably NEVER be used, on a yearly basis.


Again, politically, for this particular purpose, and on a risk that was considered extremely low, this kind of amount is a lot. And it wouldn't be enough to solve or avert the crisis.


Actually it is not a lot, considering. But looks like prices are down, Pentagon bought 8000 of them for $84M. https://apnews.com/1fd6413c9615da74d44d971075ebf4ff You'd stagger the purchases so not every possible thing is bought at once. Or offer 50% of cost to states if they commit to buy xxxx machines over y years.

For scale: Hospitals got some $100 BILLION from Congress for CoronaVirus.


> A respiratory pandemic of this magnitude wasn't anticipated by anyone, for reasons that should be investigated further.

Right, we had close calls in the near past, but why did they not spread like this one?


Due to combination of enormous containment effort and luck. And of course a crisis averted becomes a source of Internet jokes rather than a lesson in preparedness.

But you can't be lucky all the time.


I'd say the "near-misses" were a few orders of magnitude less severe.

This virus is extremely uncommon in that it is both severe, highly transmissible and a completely new type of virus.

I really don't think most people in developed countries would have agreed to spend a couple Billion Dollars to have reserves in the healthcare system, including ventilators, hospital beds and personnel, in order to prevent a problem a couple of magnitudes bigger than anticipated.


Plenty of people anticipated this given the many near misses we've had since the 1918 pandemic. But there's no money in preparing for pandemics.


> I think the problem of ventilator shortages has nothing todo with technology

isn't the problem economy of scale? at peak, the US needs 25k-30k ventilators for a few days, and then 90 days later we don't need anywhere near that number. where do we store them? how do we justify the expense? etc.

especially if 70-80% of people who still get a ventilator die [1] https://news.ycombinator.com/item?id=22730622


> where do we store them? how do we justify the expense?

You either store a large surplus of them in warehouses, or ensure you can rapidly manufacture them even if the world around you goes to hell. That should be the responsibility of governments, and it's one of the main reasons to even have one - a government doesn't have to justify everything in terms of costs, it can evaluate some non-profit metrics like, I don't know, saving lives in case of emergency. Alas, something happened after the Cold War, all western nations went collectively insane, and got rid of most emergency surpluses and any kind of buffer in the system.


> at peak, the US needs 25k-30k ventilators for a few days, and then 90 days later we don't need anywhere near that number.

Those numbers are way off. NYC alone needs 30k machines.


How exactly do you mandate companies produce something which they don't even have the parts to make? The problem is not manufacturing capacity or will, it's that supply chains for medical devices are global and those supply chains have been broken. Increasing production of something like ventilators purely domestically requires increasing (or building from scratch) production of the components, which requires new or re-tooling, sourcing of raw materials, etc.

Yes, the current federal mismanagement of the whole crisis is awful, but even if everyone had acted quickly, there would still be shortages. Covid spreads faster than device production.


The federal government needed to act as a facilitator, connecting manufacturers with ventilator companies or other experts in medical device manufacturing.

With the supply chains broken, work could have started to bring up new domestic part manufacturers. If all medical device manufacturing was prioritized, lead times would probably shorten to weeks, not months. This is happening by industry already, but again the federal government's facilitator role could definitely speed it up.

Even in a crisis, there are business interests that need to be looked after. A company can't simply decide to stop making parts for its customers and shift to making medical device parts. It would probably soon run out of money and not be able to pay its workers. Here the federal government could eliminate business risk by giving out loans/grants for retooling and guaranteeing the purchase of parts that are made.


This is, in fact, something the federal government is historically quite good at. The Apollo program was (from the NASA side) primarily an organizational project. The feds have traditionally been in a unique position to do global information-brokering.


I can guarantee you that this country has the industrial capacity to produce any kind of parts, especially for a well known technology like ventilators. The fact is that they are not doing it because nobody alerted and told them to do so three months ago.


I'm not convinced that it would have been reasonable to do so three months ago. Three months ago there were rumors that there was something brewing in some part of China most people had never heard of.

I point this out to suggest that your expectation might be a little unfair. If such an order had gone out one month ago it would have been controversial. But if you want to say that the administration is a month behind in their reactions it would be more fair.

You seem to have observed that a giant beauracracy is reacting weeks behind a crisis and this seems to upset you.


3 months ago 5K people were infected in a single day in China. The current administration was completely trained on how to handle a pandemic right after the inauguration. Unfortunately most of those folks have been fired and 3 months ago we were distracted by yet another scandal this time ending in Impeachment.

However 2 months ago this was the message from the White House: 'When you have 15 people, and the 15 within a couple of days is going to be down to close to zero.'

That un-fucking-believable 'head in the sand' moment happened at peak infection in China; 80K people infected. This administration isn't a month behind; they simply don't deal with things unless they are forced to.

The US stockpiles ventilators for emergencies like this for a reason. Someone was asleep at the switch in our Federal Government and the reaction is to lie about how well they are doing and blame everyone else.

I'm fed up, aren't you?


3 months ago the first four cases walked into a hospital in China.

I don't want to defend the current US political powers. I'm highly discouraged about a lot of things. But it doesn't help to make unfair accusations based on bad facts. If your criticisms are based on fiction they get tossed out.

Just rebase on truth and you might have some much more supportable criticism. There's plenty to legitimately criticize. When you drown out legitimate criticism with baseless criticism, the noise to signal suppresses real criticism. It is unclear whether this is intentional.


> Three months ago there were rumors that there was something brewing in some part of China

I disagree. Anyone paying attention knew, in the first weeks of January, that something very dangerous was happening. Moreover, we cannot equate the US government to a common person. They have the most expensive intelligence apparatus in the world. And we have an expensive government exactly to protect the population against real threats like this.


Congress was even briefed as such. They then went and sold their stocks, while downplaying it to the rest of us.

AOC is right, it's time to make stock trading flat-out illegal for members of congress. They hold index funds or nothing.


They should also be restricted to buying/selling with a 1-2 quarter lag on the buy/sell order to prevent them from dumping the indexes when they learn of something that will move the entire market like the current situation.


They could have dumped their index funds for cash for a huge profit.


"The giant bureaucracy" isn't the problem, in itself.

The current administration in the white house, however, is.

A lot of factors came together, hampering the response. Trump has fired lots of experts, many others left for other reasons and Trump has problems hiring Replacements. He disbanded that office in the White House. On top of that he didn't take the issue seriously at all.

I would say that in early January it wasn't yet clear this would become a serious respiratory pandemic. Maybe not even to US intelligence services or the Chinese government. But late January and early February it dawned on most people (including me).


EDIT: I am wrong and can't add. Jan 30th was two months ago. Leaving this here to remind me not to post on HN pre-coffee.

> Three months ago there were rumors that there was something brewing in some part of China most people had never heard of.

Three months ago was January 30th. The number of cases on that date was 7,711 and the number had been increasing at roughly 50% every day for WEEKS at that point.

https://en.m.wikipedia.org/wiki/Timeline_of_the_2019–20_coro...


Three months ago was December 30.

"On 29 December 2019, a hospital in Wuhan admitted four individuals with pneumonia and recognized that all four had worked in the Huanan Seafood Wholesale Market, which sells live poultry, aquatic products, and several kinds of wild animals to the public."

http://weekly.chinacdc.cn/en/article/id/e3c63ca9-dedb-4fb6-9...

Please please please don't make me defend people I don't want to defend.


Thank you. I can't add, at all.

I am going to edit the post to permanently enshrine my inability to do basic math. :)


That’s why we had people embedded in the health services in China. To get warnings on this kind of event far in advance.


The capacity is not fungible, even if with force of law. Further, even if this had been started 3 months ago, I sincerely doubt that the work would be bearing much fruit even now.

Ventilators, generally, may be "well known", but the design and operation of a modern ventilator is probably not something that is "well known".

Doing this kind of stuff is much more complex than our ability to scramble. The key is to think about this kind of crap before it becomes necessary. Without that, we won't have what we need on time. Things like this are just not solvable by throwing money at it after the fact.


Two months earlier means two months earlier, even if it's "not in time" to prevent all shortages.


You issue an emergency procurement. The Federal government has the added power of mandating action.

Will it ship Amazon Prime? No. But you'll be surprised how quickly people will deliver.


You don't mandate as much as you put out an offer. With the right incentive pretty sure many companies could switch to produce these items. And that's the point, it takes time to set up a production line, and the main reason why the government should have acted before.


It would've been nice if the thing the Government _did_ do before this had worked out. Instead, a large company bought the awardee and they requested the government cancel the contract, which resulted in a re-award and... no ventilators yet: https://www.nytimes.com/2020/03/29/business/coronavirus-us-v...


PLEASE, Let's collect all Open-Source Ventilator projects in single article on Wikipeda![0]

[0] https://en.wikipedia.org/wiki/Open-source_ventilator


And include data on which ones have been tested for safety.


What could do wrong if you use one that is not tested for safety?


Lung perforation. Inadequate ventilation. Aerosolization/Contamination. Suffocation. Death. You know, bad stuff.


I wonder if it will actually get built and used due to the critical nature of the Medical Field, even amidst this emergency.

The good thing; at least you'll have a working Ventilator.

On the other, your life depends on this frankenstein'd together machine made with hospital spare parts.


It's not as bad as you think. The ventilator is only one part of the solution. There are also sensors for heart rate and oxygen consumption, maybe even CO2 (though that's expensive) and Human beings involved in monitoring everything.

First, most of these patients are probably not completely breathing-depressed to the point they don't breathe on their own at all. That extends the time necessary to fix anything.

If indeed one of these ventilators malfunctions, it is probably visible at once. In case of loss-of-function an operator can immediately grab the bag and resume ventilation. In other failures he can disconnect the device and reconnect a non-mechanized manual bag in seconds.

This can even be done by volunteers with minimal training, in such emergency situations.


none of the hospitals in my area are accepting amateur-manufactured equipment or PPE, so I wonder a lot about these efforts.

I have a 3D printer, so I think I'm waiting until they get desperate.


In my area, they're burning through PPE like there's no tomorrow, and complaining about shortages. When the crisis really hits, that's when they'll need to go for amateur-made, reusing, and working naked.

The lack of foresight in this whole situation has been astounding.


Yeah, I agree. At best, I think it's people trying to help, but I doubt they'll get anywhere.

I worked on an ML project for a hospital as late as last year. The FDA was clear - we could develop it in house and use it as a clinician tool, but productizing it outside the hospital it was nearly forbidden. One generic model for all patients and that model had to have FDA approval. Any changes at all required FDA approval. This was what our legal team and a partner vendor interpreted.

"The FDA doesn't want someone in a basement with no medical knowledge marketing a medical device," said one person. These amateur ventilators seem like the kind of stuff the FDA wants to prevent.


There were pictures out of New York over the weekend of hospital workers using trash bags as gowns.

The only people who dislike "amateur" equipment are the paper-pushers who are safe at home behind their keyboards and screens.


Kaiser is accepting donations of homemade masks

https://lookinside.kaiserpermanente.org/donate-ppe/


In my area (not in the US) we are making homemade face shields. Simple hand made construction, no 3D printer required. Hospitals are happy to get them because they go through them like crazy.


There is a ventilator concept(with pressure booster double acting) that's fully mechanical and very simple that can be plugged into an air supply or water supply to power the ventilator. It sould easily be made and used anywhere in the world at home, ICUs and ambulances. The ventilator could operate without any power source at all. It can be powered by water (even by any tape) You can easily add adjusting stroke length & volume of breath, cadence, ratio of inhale/exhale, connecting many ventilators to one system etc.. Let me know and feel free to develop the idea further !


Right now I'm doing a lot of research into GxP for a life sciences project I'm working on. Quoting something I found online...

"GxP is an acronym that refers to the regulations and guidelines applicable to life sciences organizations that make food and medical products such as drugs, medical devices, and medical software applications. The overall intent of GxP requirements is to ensure that food and medical products are safe for consumers and to ensure the integrity of data used to make product-related safety decisions."

I would guess that the GxP mindset is lacking in a lot of these projects, and in truth it would be a burden to progress to be full in on it.

But that said, I do hope people who are doing these things are at least aware of the importance of data integrity and a very good log of their work. Don't just record what works, but also record what doesn't work. If a motor, or an Arduino, or any other part fails on you or you find that using a cheap one leads to issues, this is REALLY important to record and note for the record. This is especially true for anyone attempting to duplicate your work.

That said, it's worth noting that the site specifically states that...

"We are working to submit a specific variant of the MIT E-Vent design to the United States FDA for review under the Emergency Use Authorization (EUA) authority."

and

"The Department of Health and Human Services (DHHS) has declared liability immunity for medical countermeasures against COVID-19."


Please look up medically recommended air clearance methods. These have a long history of being used by people with serious lung issues to help keep them alive. One news video indicated that Italian doctors are using them before people are so bad as to need a ventilator, but they don't seem to be getting anywhere near as much press as the "ooh, shiny" solution of mechanical ventilators.

Edited for clarity.


Can you provide a link? I did a search for "medically recommended air clearance methods" and nothing stood out.



Thanks. I'm not a doctor so I could be wrong (and happy to be corrected) but from my understanding the problem with those techniques in this situation is that they are for clearing mucus from the lungs (in the bronchi and broncioles) not from alveoli, because mucus isn't the type of fluid in the alveoli. Hence, they'd have little effect.

This video[1] goes into what happens when you have ARDS caused COVID and how it will be treated. It shows why machines like CPAP aren't appropriate too.

[1] https://www.youtube.com/watch?v=okg7uq_HrhQ How Coronavirus Kills: Acute Respiratory Distress Syndrome (ARDS) & COVID-19 Treatment


A. One news video indicated Italian doctors are using airway clearance in less severe cases. Not all cases end up needing ventilators.

B. I know ways to also treat inflammation. I've left remarks about that various places, but a few people were following me around and harassing me on the excuse that I'm not a doctor, I'm just someone who lives with serious lung issues.

C. I originally brought this up because people were asking "What can be done at home?" They are de facto rationing health care because there aren't enough medical supplies to go around. So I talked about what I know about managing serious lung issues to say "If medical care is unavailable and you find yourself in serious respiratory distress, there are things you can do on your own." Because no one else was really offering up solutions.

D. I also spoke up to express my concerns that we are posting all these articles about homemade ventilators because ventilators are invasive and promote serious secondary infections that are more likely to be antibiotic resistant. I wish we were emphasizing other measures.

I have a form of cystic fibrosis. I deal daily with serious lung issues. This includes inflammation which is supposed to be chronic and progressive.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/ppul.24129

I have, anecdotally, found that it is possible to reverse the inflammation. If you really want to see my previous remarks, there is a link in my profile. I'm disinclined to link it here because of people following me around and harassing me.

I am not interested in having this turn into endless drama. Rest assured, lung clearance is known to help improve lung function, even when there is chronic and irreversible lung inflammation. If you have no other options because the medical system is overwhelmed, it's worth knowing about.

Please note that I am absolutely not suggesting this as an alternative to seeking medical treatment if it is available. I'm only suggesting it as an option in cases where you simply cannot get medical care due to overwhelming demand and find yourself in respiratory distress.


>with serious

without?


For people with serious lung issues. Yes, these are done without causing serious lung issues. They are far safer than ventilators, which can promote antibiotic resistant secondary infections.

I have edited the above for clarity.


Ah! I thought it was a typo. Thanks for the link to the video btw, my chest has been congested for over a month with a bog standard cold, going to give them a try.


There are a number of projects among recent ventilator threads, if anyone wants to compare:

https://hn.algolia.com/?dateRange=all&page=0&prefix=true&que...


A condensed recent Twitter rant of mine regarding this influx of DIY ventilators based on bag-valve masks (BVMs):

There are quite a few BVM-based ventilators being designed right now. However, there are a lot of caveats I have become aware of. In short: ventilators for use in intensive care need to be safe and adjustable. Oh, and it is not clear whether ventilators actually change the outcome.

Lungs of COVID-19 patients are often damaged, and ventilation causes additional damage. As the patients' alveoli no longer capture enough O2, you need to increase air pressure to force more O2 into them. More pressure = more damage to alveoli, so you need to be very careful. So you need to be able to adjust the pressure curve very finely. None of the BVM solutions I have seen so far has such a feature. COVID-19 already causes severe lung damage in some people - you don't want to damage them even more due to wrong ventilation.

Unlike emergency care (where BVMs are usually used), intensive care of COVID19 patients needs to play the long game. AFAIK, patients need constant care, supervision and medication over a period of 10+ days. Any damage you cause to the lungs early on will make it harder later on.

But won't it be better to keep people alive with a simple ventilator even if they will suffer lung damage? Maybe not. I am aware of the gut-wrenching situation doctors face in Italy and elsewhere - deciding whom to connect to the few available ventilators. It seems (I'm not really sure about it yet) that ventilators just delay inevitable death by a few days in most cases. A study from Wuhan notes: “32 patients required invasive mechanical ventilation, of whom 31 (97%) died.” [1]

"Not everyone is a good fit for ICU. Even outside of COVID, if you are of a certain frailty and you have certain underlying conditions, your chances of making it off a ventilator when you are deathly sick is close to 0%." [2]

So the question is indeed whether one should really extend a patient's suffering for a few days or whether one should instead focus on making their last few days as comfortable as possible, and give them the chance to stay conscious and say goodbye to family.

Even if there is a subset of patients who might benefit from a BVM-based ventilator (and I am not sure about this), I would be very hesitant to rely on them. If a motor burns out, a tube gets loose, or a microcontroller goes crazy, the patient might choke, panic, even die. None of the DIY ventilators has gone through rigorous testing yet. None of the ones I have seen has backup mechanisms (spare motor, continuous surveillance of all parameters, fail-safe power supplies, etc.) I would not want to inflict them on dying patients - or caregivers.

This leads me to the most important point: the most severe bottleneck are qualified professionals. Should we really hand these people some DIY Arduino-based ventilators that might fail any moment, that lack important features, and that need additional training? A ventilator that malfunctions at the wrong time (or does not reliably function at all) will take away time and attention from exactly those people whom we really don't want to get distracted or burnt out.

There is a UK government guidance which gives a good overview of essential requirements for ventilators [3]. It states:

"A ventilator with lower specifications than this is likely to provide no clinical benefit and might lead to increased harm, which would be unacceptable for clinicians and would, therefore, not gain regulatory approval."

Disclaimer: I'm no expert on medical tech or intensive care. I have just followed a few of those projects over the past weeks and read reports of experts. It could be that I am wrong and those projects will save many lives. There could also be use cases where DIY ventilators may help (e.g. in home care). But overall, I am rather skeptical and would rather suggest focusing on stuff that might be more useful.

[1] https://www.sciencedirect.com/science/article/pii/S014067362...

[2] https://www.reddit.com/r/Coronavirus/comments/fnl0n6/im_a_cr...

[3] https://www.gov.uk/government/publications/coronavirus-covid...


Would you feel more accepting of these projects (the more-vetted ones at least) if hospitals start explicitly asking for any and all ventilator hardware?


Hmm, good question. Probably yes. After all, if medical professionals would see a benefit of simple devices, who am I to question them.

However, every single professional whom I've talked to, or whose comments I read, argued that well-trained professionals are the real bottleneck. None of them said they would try out a minimalist ventilator.

I can really understand the desire to do something in order to help those who work on the frontline. However, all this effort and ingenuity would be better spent on other projects:

- personal protective equipment (masks, face shields)

- simple replacement parts

- maybe some simple devices (e.g., CPAP, air filters)


I'm not surprised if you're right about that, but I would love to see some authoritative sources about specifically which DIY projects would be most effective.

I read some of your links from above, and I agree it's good to be skeptical. I'm basically waiting for hospitals to start announcing that DIY ventilators are the right move, but by the time that happens, it may be too late to start sourcing materials and get things built in time to make a difference.


One idea that is keep coming to my mind. Why ventilator are built to be used by individual at once?

Sorry, I am not subject matter expert, but was wondering is there is way to design ventilator that can serve X patients?


The real fallback for lack of ventilator machines is the use of the bag valve mask. This is a manually operated device, no motors or electronics.

https://en.wikipedia.org/wiki/Bag_valve_mask

I have to assume this is more reliable than whatever somebody hacked together in their garage. Your average builder may be able to make something that works OK in testing, but having it work 24/7 by people unfamiliar with its quirks is a different matter entirely.

The official word out of New York is that they are going to use bag valve masks when they run out of ventilators and train people how to squeeze the bag.


The proposed system uses exactly such a thing. But a mask doesn't work because you want to put pressure into the lungs, not inflate the cheeks. Masks only work temporarily to assist a patient that is still breathing relatively well on his own.

And there is nothing technically preventing the use of those bags right now. But you'd have to have one person standing beside each bed, 24 hours a day. Which means a hell of a lot of foot traffic, and those will get infected with a high probability. They also need to be trained to a minimal standard.

It's not practical.


Masks do and can increase pressure in lungs, the reason intubation is used is to provide fluid drainage, prevent choking. So that the critical patient does not drown. Other than that, they're equivalent. Cheeks can puff out only so far.


I have never used masks that way and I would worry about the fit. But it may be possible, temporarily, especially when you hold it down.

Procedurally most physicians seem to reach for the intubator as soon as there is any trouble breathing, even though that takes longer than putting on a mask.


My understanding is that squeezing the bag would have a high risk of covid infection. The only way this solution would help the curve is if covid survivors were doing the squeeze.


Ventilators are at the bottom of the COVID-19 infection funnel. The cost-benefit is not as good as mechanisms higher up the funnel. I'd advocate narrowing the infection funnel at the top by adopting a universal mask protocol. https://www.maskssavelives.org/


USA can chew gum and walk at the same time.


not seeing any value from MIT here other than an opportunity for them to ink a quick patent.

Heres something more feasible if you're looking to endorse or support an effort:

https://opensourceventilator.ie/


Students built this in 2010.




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