This is a race against time. If we can somehow produce good working respirators within 1-2 months then everyone can win, but this seems unlikely. Right now there are companies with paid full time (and overtime) employees working on this who have the active guidance from the original manufacturers. I don’t think they are doing significant amounts of pcb design.
I think that for this effort to succeed we will need:
Project management who knows how to manage a crash project and is willing to take command.
Everyone would need to commit to long hours. Everyone would need to commit to follow the direction of the project manager. In the beginning we may all choose the part we want; that is OK. But once this gets going, it would have to look much more like a military operation than a democracy. Commitment and pain
I am pretty sure we will need people (at least consulting) who already understand how this whole thing works. There are probably some or many of us who can figure it out but the learning curve takes time which is not available.
Someone will need to get this together physically, get it working, and build them en masse. The factory will be the key, and why would a factory build our redesign rather than something proven from an existing manufacturer?
Who/how to finance the needed expenditures?
I think our discussion involves re-engineering for which there is probably no time. For example we are discussing schematic revisions and new pcb; I do not think there is time for that. I think the winning operation will be only an expansion of an existing operation to build an existing product that is 99% fully designed.
One possible great exception would be one of us has some very clever original way to take something like a common vacuum cleaner (my wild example of a cheap existing product) and add $10 in parts and make a respirator. I don’t think that starting now to re-engineer this respirator can get us what is needed in volume fast enough.
And if I had taken more time I would better compose my argument…
We’re not redesigning. We’re only updating components that cannot be sourced.
If you want to help, great. If you don’t, that’s fine as well. The internet is great for cynicism but it is also useful for organizing people toward a common goal. You get to pick which part of if you want to contribute to but it can never be both.
If you want to say that I am skeptical, I guess I will accept that. But “cynical” means I question the motives and that is simply not true. I just want everyone to have what I see as a clear eyed understanding of the problem at hand.
Many people are donating from money to all kinds of materials or providing their services with the machines they have selflessly. Some are also fraudulent campaigns.
Yesterday I saw more than 10 complaints in the CoronavirusMakers Telegram group that the police are investigating.
I’m printing faces shields and the PLA or PETG are it’s provided by donations from companies or people, the police collaborate in the distribution. Tons have already been distributed.
PLA/ABS or PETG could be used to make the enclosure box.
Yesterday, when I was commenting on the idea in the Telegram group, some electronic engineers volunteered for the final assembly if it were to be done. They have no experience with KiCAD or EDA but can collaborate on other parts of the project.
The PB560 was assembly by jabil.com, you can see it in the BOM file. The idea here is that any electronic engineer or company can mount it.
About the display I know someones display manufactures in Shenzhen that they can build any kind of display. LCD, TFT, OLED, with touch (capacitive or resistive), parallel 24-bit RGB or SPI interface in 4.3",5",7",10", etc…
I’m working in a brazilian version, because we have a lot of people interesting to help and recreate this ventilator.
1 - Built some devices to prove that it’s posible.
2 - Start to research how to replace some obsolete parts ( memory, valve proportional, turbine, display LCD, pressure sensors from honeywell).
I think that device is actually a CPAP controller - it is simply a flow generator that relies on a venturi to generate a flow of gas of variable oxygen concentration. It is purely mechanical and has no electronic components. Moreover it seems to require a flow rate of oxygen which exceeds the UK recommended maximum so I’m not sure why it is being so widely touted.
The device we produced, called UCL-Ventura, has gained regulatory approval and the Department of Health and Social Care has now placed an order for up to 10,000. We have conducted successful patient trials at UCLH and sister hospitals, and are now working to produce and dispatch our devices to the NHS hospital network. We have also refined and modified the device to create a Mark II version, which has shown up to 70% reduced oxygen consumption in healthy volunteer assessments. To help meet international need, we have released the designs and manufacturing instructions for free to governments, industry manufacturers, academics and health experts across the globe. https://www.ucl.ac.uk/healthcare-engineering/covid-19/ucl-ventura-breathing-aids-covid-19-patients
Hi Maurice - don’t get me wrong, I’m pleased that we have more respiratory support but I have been a bit cross about the way this project has been spun. This device is not a ventilator - it’s a flow generator that I have been using for over 15 years - here is a manual from 2008. https://www.opweb.de/english/company/Respironics/WhisperFlow
I recognise that they have managed to do the re-engineering quickly which is impressive but the press make it sound like it’s a fantastic new invention. In the UK we have been very slow to respond to corona and we do not have enough ventilators. The brexit disaster has meant that we have not been involved in a EU ventilator procurement process but have signed up to buy ventilators from Dyson that don’t yet exist. The media have been desperate to latch onto a good news story and have pushed this into undue prominence. This is a good bit of engineering in normal times but we now have an oxygen shortage (My hospital O2 supply can’t supply the flow required to the hospital) and this type of device used lots of oxygen. The original requirements for cpap devices were 6lpm but when they announced this it was changed to 15lpm (this uses a minimum of 11lpm). So I’m very cynical about how this story has been promoted - not criticising your comments but there is a back story here that isn’t being told. Anyhow I’m not going to comment further - I am a bit fed up with every oxygen delivery device being called by our useless media a ‘ventilator’ and being apologists for serial and criminal lack of provision of PPE etc.
Anyhow, this is getting far from the original project which has excellent and laudable aims and many apologies for the rant.
The Puritan Bennett 560 Ventilator is a microprocessor-controlled ventilator consisting of
a low-inertia micro turbine (blower) used for flow generation.
The turbine is a low-inertia blower driven by a brushless DC motor that delivers gas by
responding to pressure and flow measurements that are processed on the CPU PCBA.
The turbine spins at a maximum of 50,000 rpm, and can deliver flows of up to 240 lpm
and maximum pressures of 70 cmH 2 O to 90 cmH 2 O. A resistive-type temperature sensor
resides in the turbine housing. The CPU monitors the temperature and will shut the
turbine down if the temperature rises above 70° C while the turbine speed is less than
1000 rpm.