Medical Ventilator Design - Page 1
Forum section: electronics / projects

author: Gandalf_Sr
author_rank: Super Contributor
timestamp: March 29, 2020, 11:59:12 pm
content: So here we are in the middle of the Coronavirus pandemic and I imagine that I'll be stuck at home through the end of April. I'm going to try to come up with an affordable (around $1,000) medical ventilator design. How difficult can it be? All it is is a processor on a PCB, a display, some driver components a fan driven by a motor, some code, and some sort of remote control/monitoring via wireless.Rather than start from a blank piece of paper, can anyone share any designs or specific component ideas? In particular, the motor is an area I'd look for advice on.How about the requirement specifications? What does it need to do?Let's get at it?Gathered InformationThis section will expand as I will update it as I go along.Is the Need Already Being Met?last update 3/31/20Probably, thehackaday article(well worth reading) says this...QuoteBut these CPAP/BIPAP machines are expensive ($1,700) and unlikely to be widely available in places like Africa. The BIPAP machine I use every night is likely already capable of becoming a ventilator with a software update, more complicated tubing to capture the exhaled air, and more sensors. I believe it already has the air capacity, the level of control to sense and adjust the air pressure instantaneously (that's what it seems like to me when using it). What may be as useful as the cheap ventilator is perhaps a portable power supply unit as there are many people living with no electricity (or a supply that cuts off regularly).

author: TK
author_rank: Super Contributor
timestamp: March 30, 2020, 12:35:07 am
content: I started gathering information this week, and so far I found:1) Heat and humidify the air2) Filter bacteria and particles3) Air needs to be pushed at a very controlled pressure (too much pressure and it can damage the lung)So you need to control the flow, pressure, temperaturehttps://hackaday.com/2020/03/25/ventilators-101-what-they-do-and-how-they-work/

author: TK
author_rank: Super Contributor
timestamp: March 30, 2020, 12:39:28 am
content: More information:https://www.gov.uk/government/publications/coronavirus-covid-19-ventilator-supply-specification/rapidly-manufactured-ventilator-system-specification

author: koba30
author_rank: Contributor
timestamp: March 30, 2020, 12:51:17 am
content: Hi, check this pagehttps://e-vent.mit.edu/

author: profdc9
author_rank: Frequent Contributor
timestamp: March 30, 2020, 01:44:24 am
content: One question I might ask is what resources do you assume are available to those who might construct a ventilator?I have been working on other issues and grappling with the fact that a lot of resources are currently unavailable. For example, there is a shelter-in-place order where I live, so that many stores are closed. A lot of stuff from Amazon is well on backorder if it's available at all. Constructing such items in this environment will require resourcefulness. I am not counseling despair here, but just trying to establish the boundaries of a feasible design at this time.https://www.instructables.com/id/The-Pandemic-Ventilator/https://e-vent.mit.edu/wp-content/uploads/2020/03/DMD-2010-MIT-E-Vent.pdfhttps://www.cbc.ca/news/canada/london/pandemic-ventilator-coronvirus-hospitals-1.5493830https://www.wmfe.org/uf-experts-collaborate-to-design-a-diy-ventilator-for-covid-19-crisis/150270It is interesting to see what others have started with for their designs. The instructables design uses valves while the MIT design uses cams to sequence the inhale/exhale.

author: ChunkyPastaSauce
author_rank: Unknown
timestamp: March 30, 2020, 02:32:21 am
content: Huge number of existing CPAP machines in the US. Most of these can supply at least 20 to 25 cm h20 pressure, which is in the range needed to treat significant portion of covid patients. FDA recently cleared these for use for covid, even allowing for modifications from what I can tell. This allows for full ventilator units to be applied for to most critical.I mention this because a ton of the cpap units appear to be tiered in functionality by flashable firmware, not physical limitation of the machines (they're the same).. the same machine with cpap therapy, can also provide bipap or higher functionality closer to a full ventilator with software changes.I think all it would take is for the manufacturers to release flash updates.

author: Scrts
author_rank: Frequent Contributor
timestamp: March 30, 2020, 04:01:50 am
content: Join Helpful Engineering on Slack:https://www.helpfulengineering.org/

author: poorchava
author_rank: Super Contributor
timestamp: March 30, 2020, 08:22:20 am
content: AFAIK ventilators (same as other medical equipment) are so expensive not because they are expensive to manufacture. It's to recoup the astronomical costs of safety and regulatory compliance testing.Of course the price is also driven by the 'because we can' factor.My dad has been working in radiotherapy field for ~30 years. I recall him telling some stories, about how Varian wanted >200€ for a replacement lightbulb for an accelerator, which they were forced to buy, because otherwise the xxx k€ machine would lose certification o.O.

author: Gandalf_Sr
author_rank: Super Contributor
timestamp: March 30, 2020, 10:09:28 am
content: Quote from: koba30 on March 30, 2020, 12:51:17 amThanks, this is a great resource and goes straight to the heart of the matter; people are dying and what can we as engineers do to help?

author: calzap
author_rank: Frequent Contributor
timestamp: March 30, 2020, 07:51:04 pm
content: Read the link below to find out what happened when the US tried to establish a stockpile of low-cost ventilators a few years ago. Disheartening.Mike in Californiahttps://www.nytimes.com/2020/03/29/business/coronavirus-us-ventilator-shortage.html

author: DaJMasta
author_rank: Super Contributor
timestamp: March 30, 2020, 08:00:51 pm
content: Quote from: Gandalf_Sr on March 29, 2020, 11:59:12 pmNot difficult to make something that can work, extremely difficult to make something that if it can't run for a week straight, guaranteed, that someone would die without constant monitoring.While developing one as an exercise is not a bad thing to do, I would strongly advise you against 'advertising' it for use even locally if you come up with a prototype or even what counts as a finished product. To improve reliability of the system and reduce problems associated with bacterial contamination or other air supply contamination from conventional parts, I'd recommend designing something that automatically pumps an existing hand operated ventilator. This sort of design work has already been happening at universities and elsewhere, but it takes the pump and plumbing largely out of the equation, and makes it so failures or contamination of those parts is effectively mitigated by using a tested-for-medical-use hand operated ventilator.Any device developed for this should be used only as a last-ditch measure with explicit instructions for it to be monitored continuously and with a backup measure available. A worn bearing, a small leak, or a bad line of code could cost the life of the person depending on it, so all other options should be exhausted before such a device was put to use. It may very well get to that point, but it should not be described as a normal ventilator and should not be considered a reliable device even if in whatever testing can be done in the short term has been successful.

author: nardev
author_rank: Unknown
timestamp: March 30, 2020, 09:00:13 pm
content: Looks like everyone is talking and rarely anyone is doing something seriously. Even those projects by some prestigious USA tech universities like MIT look like toys done by students.However, i just noticed this one by some, looks like hacker space in turkey, probably supported by some more serious engineers:Check this out:https://twitter.com/Selcuk/status/1244661929777532930Looks like the team:https://twitter.com/Selcuk/status/1244663216313155587I'm i'm not wrong the pictures from the process:https://twitter.com/Selcuk/status/1243539495401783320Also the clip is here:Also, one more interesting news: "Medtronic Shares Ventilation Design Specifications to Accelerate Efforts to Increase Global Ventilator Production @Medtronic"https://blog.adafruit.com/2020/03/30/medtronic-shares-ventilation-design-specifications-to-accelerate-efforts-to-increase-global-ventilator-production-medtronic/comment-page-1/?unapproved=361593&moderation-hash=40d9525a3224a7229f27e7f0fee86451#comment-361593

author: LaserSteve
author_rank: Super Contributor
timestamp: March 31, 2020, 05:01:57 am
content: University of Florida has a preliminary release out. .Now how do you create enough trained respiratory techs to use it correctly?Steve

author: profdc9
author_rank: Frequent Contributor
timestamp: March 31, 2020, 05:11:12 am
content: Well that's the big question.The fact that the public is even involved in formulating solutions to the technical and medical response to the pandemic shows how desperate the situation is quickly becoming. If there are a million COVID-19 patients in the USA that need ventilators, a lot of people will die. No one knows who would have pulled through without a ventilator, or who will be killed by a bad improvised ventilator design.The big question is: will things get desperate enough that lives will be risked on, what could likely be, often fatal, speculative treatments and devices?Doctors are completely unaccustomed to making these kinds of decisions and judgment calls. They normally operate in an environment where they must adhere to a consensus standard of care supported by empirical medical evidence. They must use equipment that has the proper regulatory approvals. If they don't, they risk exposing themselves to liability and losing their license to practice medicine.Now we are in a situation where there is simply going to be not enough resources for all of the patients that require respirators, which is a consensus standard of care of supportive therapy for Covid-19. Furthermore, we don't even have sufficient personal protective equipment for the doctors so that they can treat patients safely.In this situation, the only feasible solution is to prevent infections by minimizing contact between individuals. It is clear that if no more respirators become available, and PPE product is not significantly increased, the likelihood of one being able to obtain life saving care is quite slim once these resources are exhausted.So what to do? We can try to create improvised devices. It probably won't be known if they are safe and effective until they are tried on patients, and the results will be the patient survives or not. Is this type of experimentation acceptable under the circumstances? What are the alternatives?This is not a 40 minute episode of House where his completely crazy speculative treatment always works by the end of the commercial break. Maybe we simply don't want to experiment on people who are dying, and it would be better to let them die. But then who decides the circumstances under which this kind of crude experimentation is permitted?Even if a solution is found that works, if it requires resources that can not be scaled to apply the solution widely, then perhaps an experiment that risks the life of a patient is not worth performing because it will have little wider impact. So if we can 3-d print a ventilator, but it requires so much 3-d printing that it takes days to make all the parts and a ton of model material, maybe this is not a feasible solution. So to have an impact, the solution has to use materials and manufacturing methods that are widely available.I don't know the answer to these questions. But the answer is somewhere between: if we can't produce something that works perfectly and is completely risk-free, it is not worth doing; and: we just have to throw everything at the wall and see what sticks. That is the situation and somehow there will have to be some kind of consensus about what risks are acceptable in a crisis stiuation like we find ourselves in.

author: Enginerding
author_rank: Contributor
timestamp: March 31, 2020, 05:21:16 am
content: Would you gentleman like to join forces? I have another thread going titled "Chapter 1...." in this same forum.Your thread proceeds mine, but I have a ~20 years medical experience. And I think that is part of what's missing here.If you're willing to come over, I promise there will be fame, glory, land and titles.https://www.eevblog.com/forum/projects/chapter-1-who-has-the-engineering-skills-to-build-a-open-source-ventilator/

author: odemiriz
author_rank: Newbie
timestamp: March 31, 2020, 10:10:15 am
content: Quote from: nardev on March 30, 2020, 09:00:13 pmThis one is a project of a medical company in Turkey, they worked on for 3 years AFAIK. They were already at prototype stage. Then arcelik ( manufacturer of fridge,TV and various home appliances) offered them help and engineers from military industry help too.So this is not a hacker's project. And it serves just to boost public moral for now. They plan to have 250 units in May ready to use. I dont think it will be enough considering the trend of new infected cases in the country.

author: nardev
author_rank: Unknown
timestamp: March 31, 2020, 10:18:14 am
content: Probably 250 in May is faster than any other manufacturer right now.

author: max_torque
author_rank: Super Contributor
timestamp: March 31, 2020, 10:48:38 am
content: Unfortunately, i feel people are not actually looking at the issue that matters, namely that of sourcing the necessary components and assembling / testing the ventilators!We don't need a new design for a ventilator, we have lots of those already, and the ones already in existence are certified and proven to work. No what we need is a way of sourcing the parts to build lots of the existing designs quickly, and then a way of assembling those parts into working, tested units.Part 1, getting the parts, is a "Buying" problem, not a design problem. Yes, if parts are not available, then substitution of an alternate part is necessary, and there would be some design work to do that, but mainly it's a question of getting an existing supply chain to ramp supply more parts in a much shorter time. I simply don't believe anyone is better at doing this that the companies that already build ventilators!Part 2, assembling and testing, is a "production" problem and yes, here, companies like Ford, GM or Formula 1 or aerospace specialists should be able to help, to put in place MANUAL assy lines using skilled assembly workers to hand build and TEST (!!), in a highly parallel fashion a lot of units in a short period.So, imo, having a new design is really not actually fixing the "Problem" it's just creating a new one........

author: Gandalf_Sr
author_rank: Super Contributor
timestamp: March 31, 2020, 11:43:09 am
content: Why is anyone even bothering with posts that say:- it's too late- they will sue your ass- what doctor would place a patient on a prototype ventilator?FFS, the whole point of this thread was that there are some great engineers here, I could design a PCB in a couple of days, others here could write code, and others could procure components and build one.What else are we EEs all going to do, sit at home until we all die of Covid-19 or boredom?I'm going to check out the Chapter 1 thread OMG! That other thread is horrible! What I'm after is design ideas, not a committee with an org chart and monthly meetings with minutes. So I'm staying here.

author: nardev
author_rank: Unknown
timestamp: March 31, 2020, 12:31:50 pm
content: Quote from: profdc9 on March 31, 2020, 05:11:12 amI wouldn't like to be misunderstood nor do i want you to think that i'm just opposing your opinion because i like being hater.However, i would like to point out few things that i thing are the problems which you don't see in this situation.(p.s. i lived through the last war in Balkans for 3.5-4 years. I remember pretty well how things were functioning. In my place we had about 35-40k people in a very narrow place, between an Airport and a hill and that place was completely surrounded from all sides except for one road which was open for fire but was not blocked physically and could take you over the hill and to another part of the city. The hospital was in the basement of the building where i lived and i remember very clearly killed and wounded people and i also remember clearly in what conditions those doctors were doing their job as i was also a patient there at one point!)1. I take the assumption that this is really "emergency state". I don't want to discuss if it is or not.2. Lack of patience in American people is a huge problem3. Lack of basic life skills like cooking, proper cleaning, filtering water etc. I have many friends that moved in USA and i visited some of them in past period, very common discussion was how an average American have no clue about basic life skills. (i'm talking an average! not all!)4. Due to insane expenses in your medical care, the values of proper care for big masses is impossible.5. As the doctors are perceived to be "rich and smart", living very comfortable and sometimes even luxurious life in USA, maybe some of them would not be as available for service as emergency situation expects people to be. We have seen such thing happening in my city, some of the doctors were leaving as soon as they got a chance.6. As i said in 4. The expenses are problem but in this situation it will completely destroy financial situation of an average people. So far we know that it takes about 3 weeks to recover, in a lot of cases it required most of that time to have the patient hospitalize, having in mind that an average day in a hospital in USA is about 3-4k, + additional services that would definitely be required in this situation, some of infected could be charged maybe even 100k for the service, especially when you have situation that insurance can simply cancel your contract and let you pay 100% of your expenses.7. In USA you have very long history of "investors" that later on dictate the prices of the products. Sometimes the investors are great thing but sometimes you just have very immoral people so you get this:Drug Goes From $13.50 a Tablet to $750, Overnight:https://www.nytimes.com/2015/09/21/business/a-huge-overnight-increase-in-a-drugs-price-raises-protests.html8. You have decades of scientific explorations and researches. Chasing references, papers to be published and chasing money for another researchJUST FOR THE SAKE OF MONEY AND POPULARITY WITHOUT ANY REALLY CONCERNS ABOUT WHAT AND WHY THEY WORK ON. That immoral and unethical approach to life and work brought you to this situation. That is why they charge you 400USD in NYC for COVID19 test instead to do it for 40$. As there is nothing which makes the 6.5$ costing test with import taxes to cost 400$!I stay behind the prices that i mentioned as i have insight in prices in this situation.9.Using legal system in this situation to pressure your doctors maybe can make even more dead people as they would not maybe try some alternative help..Remember, it if is emergency, there is no place for accusations and this is not engineering job, you can't evaluate and measure everything nor you can establish 100% correct procedures that would always be successful.IMHO those are bigger problems for USA than wrong usage of ventilators.I remember nurses staying up hole night next to a patient, pumping in an air, stopping blood, doing some of the many smaller surgeries as sometimes, after the shelling of my place, there were 30+ people in a small hospital and only two experienced surgeons that took more serious wounds and were only overlooking some of nurses helping some other patients with light wounds. That is really emergency state and when rules change.Wish you all to stay healthy and to be safe.

author: ali_asadzadeh
author_rank: Super Contributor
timestamp: March 31, 2020, 12:52:47 pm
content: If there is money,I can contribute to this! I have a design team, that can cover many things reading, part sourcing and buying from china, designing with ARM and FPGA, High speed PCB design,prototype and mass production in china! also the PC,web UI design and DSP if needed.

author: nardev
author_rank: Unknown
timestamp: March 31, 2020, 04:10:37 pm
content: Mercedes and other Formula 1 teams have some solution that can help. Without pumps and with 1000 devices or day manufacturing capabilities.https://youtu.be/v34M0dIokLw

author: nardev
author_rank: Unknown
timestamp: March 31, 2020, 04:13:07 pm
content: https://youtu.be/72kfIi_ZyPkSo Mercedes and Dyson did somethinghttps://youtu.be/kLsyUg-ldSk

author: SiliconWizard
author_rank: Super Contributor
timestamp: March 31, 2020, 04:28:56 pm
content: Quote from: ali_asadzadeh on March 31, 2020, 12:52:47 pm

author: profdc9
author_rank: Frequent Contributor
timestamp: March 31, 2020, 05:46:04 pm
content: Quote from: nardev on March 31, 2020, 12:31:50 pmYou'll get no argument from me that the American health care system is rapacious and inefficient.Even in a well-functioning, properly incentivized health care system, emergency preparedness can be a problem. There was an attempt to create a reserve of ventilators, however, the company with the contract to produce the ventilators was bought by a major medical conglomerate which had no interest in providing a low cost, emergency device. If you demonstrate that the function of a device can be performed at a lower cost, then that puts pressure on the prices of the entire market for ventilators. As the market has significantly consolidated there is little competition left.Anyways, we now are reaping the consequences, and the true tragedy is that it may be only tragedy that can galvanize any change to this situation.

author: dietert1
author_rank: Super Contributor
timestamp: March 31, 2020, 07:24:39 pm
content: We have a working 3D printer that could have printed hundreds of parts during February and March. It didn't and probably it won't. I think the reasons have been mentioned already.Global enterprises will sell clean water and fresh air if you let them and they will use their money to create by lobby work/corruption a legal situation that protects that business, disregarding any social or ecological toll. And it's everywhere. On German TV they showed a couple who said they recently bought an icecream machine for € 50 000 (!) and didn't know how to continue now that their place is closed.I am a freelancer in the medical sector and received several inquiries about our monitoring solutions. In the end i'm left with doubts. How come those professors and most experienced experts with lot's of academical resources and government money are unable to provide a solution on their own? Are they just trying to waste my time?Regards, Dieter

author: Gandalf_Sr
author_rank: Super Contributor
timestamp: March 31, 2020, 11:51:52 pm
content: So, instead of stuff like:If you have money, I can help orAmericans (in general) are incapable of self helpHow about some practical ideas for how to make a ventilator? As has been been said, all we need is:1. An air pump that can be controlled - I prefer a brushless DC motor, I have many that are used for RC models.2. Sensors that measure PaCO2, TcCO2, SpO2, FiO2 in addition to flow and pressure3. A microcontroller that can connect all the parts together (with some interface circuitry)4. Code that controls it allI can cover 2 & 3 (although I'd like suggestions for sensors) and I can write code. Some input on 1 would be useful.

author: profdc9
author_rank: Frequent Contributor
timestamp: April 01, 2020, 01:22:59 am
content: What if you just started with a conventional air compressor and tank, perhaps one that is quieter than the usually noisy type that is used to inflate tires, and then a computer controlled pressure regulator valve? I supposed a simple version of this could be a solenoid valve with a diaphragm and pressure sensor. The control of pressure would be coarse.

author: KaneTW
author_rank: Frequent Contributor
timestamp: April 01, 2020, 01:56:27 am
content: The spec was already posted:https://www.gov.uk/government/publications/coronavirus-covid-19-ventilator-supply-specification/rapidly-manufactured-ventilator-system-specification.Even just the pneumatic system is a headache and a half.

author: Ground_Loop
author_rank: Frequent Contributor
timestamp: April 01, 2020, 02:49:19 am
content: Quote from: poorchava on March 30, 2020, 08:22:20 amManufacturers are also covering the costs of liability insurance and litigation risk.

author: Gandalf_Sr
author_rank: Super Contributor
timestamp: April 01, 2020, 09:49:51 am
content: Guys,We know that, in the land of litigation (aka USA) that manufacturers of healthcare equipment carry massive insurance overheads which they pass on to their customers in the form of extra equipment cost. Now imagine that we are in a Wild West situation where people in your town are dying for the lack ventilators and you are the only engineer - that's where the USA seems to be going over the next month or 2.Enginerding has PMd me with information that is exactly what I was trying to do and his/her work is way ahead of what I could ever do so I'm following that rather than trying to compete. Themain thread of interest is here, scroll down a little bit to findKnown Open-Source Projects:under which you'll find a link to a summary of all known (to the writer) efforts in the respect of low cost ventilators; I particularly liked the suggestion of making a PAPR (powered air purifying respirator) which is mentioned inthis github threadthat would be used to protect the care givers rather than their patients with Covid-19

author: Kilo Tango
author_rank: Regular Contributor
timestamp: April 01, 2020, 12:24:33 pm
content: Some thoughts on the Ventilator project.Motors, I would avoid brushless model motors, they are built down to a price, not up to a spec. I doubt they could run continuously for long without wearing out. I wonder if Dyson is going to use a standard hoover motor in his ?, I would worry about reliability. UK Gov spec says run for 14 days plus, that's 336 hrs. The average hoover is used once a week for 20mins, and fails after 3 years, that's 52 hrs.I would stick with standard, well engineered, Industrial grade blower fans. They last for a long time, some are still going after 10 years plus.Shame we couldn't use a computer fan, they generally run for years without problems, modify a standard cooling fan ?.Battery, I would choose lead acid, its a mature technology been around for 30+ years so no surprises. easily available in quantity if you stick to burglar alarm sizes. Li-ion potentially better, however charging requirements are complicated, and they still go off with a bang if not treated properly. Also sourcing good quality ones in the 1000's would be difficult.Standard compressor - no they use oil to lubricate the pump, and put oil mist into the air stream. It tastes crap (! ) and would need a lot of filtering to clear it. However maybe those used to recharge aqualungs would do ?, could they run 24/7, or use a reservoir system and feed 10 people at once ?.Reliability and notifying faults. Well start with a hardware watchdog system, a retriggerable monostable that has to be reset every sec or so else it causes a hardware reset and sounds the alarm, will ensure the processor doesn't fall asleep. Next every so often the program checks that all sensors are giving allowable values. I remember one 3D printer trying to heat the bed of an unattended printer, nearly caused a fire cause the sensor cable had broken. You could even use a 2nd processor to keep a check on things and if it dissagreed with the current machine state it could also sound the alarm.I think the Medtronics documents are very useful. Not as a set of DIY build it yourself plans, everyone builds one in their garage and dashes down the hospital with it, but all the clever stuff, the thinking about how it has to work is all done for us. Basically al we got to do is engineer something to meet their spec, and we would be home free, no need to spend years verifying performance is what is needed.Thoughts ?

author: profdc9
author_rank: Frequent Contributor
timestamp: April 01, 2020, 06:59:47 pm
content: Looking around at some CPAP designs, it looks like brushless motors are used in those for the blowers.Perhaps a 3-D printed shell enclosure and internal wheel could be designed around a common brushless motor. If they're good enough for CPAP perhaps they are good enough for an improvised ventilator. A method of pressure regulation could be to actively commutate the motor to vary its speed/torque. Perhaps look at a HVAC fan?

author: max_torque
author_rank: Super Contributor
timestamp: April 01, 2020, 07:12:03 pm
content: Once again, people are missing the actual problem!The problem is NOT designing a new ventilator, the problem is designing a new ventiliator of which you can make lets say 50,000 in less than 3 weeks.So what motor you want to use is not governed by any engineering factor, no it's governed by "who has 50,000 motors on the shelf i can get delivered to me tomorrow"This is a "Buying" problem, not an "engineering" problem.........

author: AndyC_772
author_rank: Super Contributor
timestamp: April 01, 2020, 08:08:54 pm
content: For such a unique specification, and set of circumstances, the NHS spec is missing some really important information:- estimated quantity required- time scale for delivery- details of regulatory approvals that will be required- (if they're trying to attract manufacturers that aren't usually in the business of designing life critical medical equipment): some kind of guarantee or other reasonable assurance that, when very sick people inevitably die whilst attached to these machines, the manufacturer won't be held liable.Without that information, the technical requirements are moot. Nobody capable of actually developing a viable product and bringing it to mass production would do so without it.

author: Kilo Tango
author_rank: Regular Contributor
timestamp: April 01, 2020, 09:59:59 pm
content: Thanks for the info regarding brushless motors, I tend to automatically think of drone motors, not up to date with recent developments.However after some Googling, I think the problem is not an engineering one. I read somewhere that Phillips had developed a new low cost ventilator, the Trilogy Evo, it was launched last year.A report in Propublica.org says that the US paid for its development, and gave them a 10,000 unit contract. It received FDA approval in July 2019. However Phillips are not due to ship any units under this contract until 2022, and are not yet making that model. However they are currently selling a more expensive version, and have been doing so since approval date.Ken

author: Gandalf_Sr
author_rank: Super Contributor
timestamp: April 01, 2020, 11:47:52 pm
content: Great inputs from the BritsI used to be into model airplane / helicopter flying and have many small brushless motors; I also have many ESCs (electronic speed controllers) which control the motor speed based off the width of the pulsed signal coming onto the control input. A 3D-printed case with fan would make a good ventilator fan plus they have no brushes to wear out. The bearings would ideally need to be ceramic to last but an off the shelf motor would probably be fine for a cheap ventilator. These brushless motors and ESCs are dirt cheap and widely available.

author: nardev
author_rank: Unknown
timestamp: July 17, 2020, 10:42:30 pm
content: Quote from: profdc9 on March 31, 2020, 05:46:04 pmQuite some time have passed, not much changed but we can see what's happening. People with up to a 1.1 milion hospital bill are coming home.Ok, i don't know enough, it was pretty subjective from my side. But there is a huge flow in your conclusion IMHO.The health care system is not divided in "well-functioning, properly incentivized" and those that are not.There is countries that have more social approach to a public health or as in USA, "it's just a business" and than we package it, sell and resell it, add plenty of middleman between the patient and the doctor.It's pretty clear that Germany, Spain and UK had very different consequences in all of this. Germany have pretty decent, at least rudimentary elements of public health and in USA, Spain, UK you don't have that.But, anyway, right now, in my country, the situation is getting back to "normal".Few months ago, we were very organized and now, tests are made primarily through corrupt doctors, some non covid-19 urgent patients are ignored because they don't have right tests, which are impossible to make unless you have covid-19 test, just today, one guy dies in Sarajevo, hew was waiting for hearth surgery and he was denied several times to make the COVID-19 test, although there was no legal way to deny him but they did, without explanation, which actually means "we are waiting your dumb ass to bring us some money and gifts". Sadly, it was fatal for him.Since, corruption here is pretty normal, that was the reason i said "everything is back to normal".