Live data from Hacker News

Pandemic Ventilator Project

panvent.blogspot.com

41–50 of 111 posts

Re: Pandemic Ventilator Project

#41
Great idea. Simultaneous to these types of home-brew projects...we also need someone (President? eCelebs? etc) to promote and organize fund raising efforts to simply buy and distribute cheap but effective ventilators.

Imagine a WWII style "war bonds" effort, but instead to build and distribute say 5M ventilators over the next 6 weeks.

In addition to this, we must re-purpose closed schools (gyms, cafeterias, etc) into make-shift CoVid19 triage centers where affected patients can be put on cots with saline drip, drugs, and ventilation. This is doable, but we need to do it.

Re: Pandemic Ventilator Project

#42

Good idea using a large AC blower. I would think a small brand new or very clean wet dry shop, vac using the blower attachment might be even better. It would be noisy but would allow the design to incorporate negative pressure of the vacuum side to assist with exhaling. Maybe the shop vac could be plugged into a speed controller to improve duty cycle and reduce noise but controlling an AC motors speed is quite a bit…

What about using an air compressor? These should still be readily available and is an off-the-shelf air pressure solution. The air couldn't be used directly (oil in it) - there would need to be an isolation bellows or something similar.

Re: Pandemic Ventilator Project

#43

Earlier quoted context omitted.

CPAP stands for continuous positive airway pressure, one of the problem with SARS(Severe acute respitory syndrom) or Wuhan Fever is it stiffens the lungs making it hard to exhale. This in turn allows the lungs to fill up with fluid, a sort of viral pneumonia. I believe a ventilator uses a negative pressure or vacuum to assist with exhalation and air exchange.

Actually exhalation is passive, not active, in modern day ICU ventilation.

This infuriates me. It's cutting corners, reducing the quality of care.

There are now portable iron lungs that fit like a turtle shell. They do both inhalation and exhalation. That should be the only acceptable standard of care.

Re: Pandemic Ventilator Project

#44
post #20

Earlier quoted context omitted.

Someone dear to me needs a ventilator per tracheostomy (Trilogy 100). Her Consultant Aenesthesist who was in Italy four weeks ago and works on an Intensive Care Unit told me that 6 out 10 Covid-19 affected ITU patients require an ECMO ( https://en.m.wikipedia.org/wiki/Extracorporeal_membrane_oxyg... ). This is very bad. I could sense his unease, these are machines you don't come by easily. His ITU is preparing for wa…

> and the conservative's austerity program has put the NHS to breaking point. No such austerity has happened, and now is not the time for this petty bickering.

Bickering isn’t needed, but there is no doubt that many objective indicators of service quality and system stress in the NHS point to a decline. Vacancies in posts alone is a substantial concern and is directly linked to govt policies in training in recent years (withdrawal of the nursing student bursary for example).

Denying the fact that the NH is under pressure isn’t helpful either... we need to be realistic about what to expect when we underfund our healthcare system.

Re: Pandemic Ventilator Project

#45

4x resources delay a crisis by 2 doublings. If a doubling takes 7 days, that’s just 2 weeks. R0 (reproduction rate) overwhelms everything. The only way out safely is to greatly reduce R0: - social distancing: 6-9 feet away from everyone - avoiding crowds - Never share utensils; no buffets - hygienic routines: wash hands, use wipes, close toilet lid before flushing (see Amoy Gardens), etc. And convince others to do th…

I've got an idea for a way to reduce R0 with some voluntary people tracking. I could do with some other developers to plan it.

If anyone's interested, please drop me an email: rls at hwyl.org

Re: Pandemic Ventilator Project

#47

Earlier quoted context omitted.

> and the conservative's austerity program has put the NHS to breaking point. No such austerity has happened, and now is not the time for this petty bickering.

Bickering isn’t needed, but there is no doubt that many objective indicators of service quality and system stress in the NHS point to a decline. Vacancies in posts alone is a substantial concern and is directly linked to govt policies in training in recent years (withdrawal of the nursing student bursary for example). Denying the fact that the NH is under pressure isn’t helpful either... we need to be realistic about…

But the NHS is always 'underfunded' because demand for healthcare is infinite. Its funding has gone up continuously. There will never be a time when this isn't a political fight, that is, there's no level of funding that would end this bickering.

Re: Pandemic Ventilator Project

#48
post #36
post #14

Earlier quoted context omitted.

The issue is that with the kind of ventilation required you need to sedate the patient with gasses and you need to recycle those gasses and unused oxygen. With the length of time patients have to be on this you don't want to lose those gasses and also pump it out into the atmosphere. The Manley design could be a good starting point I suppose, you just have to replace the weight system with controllers and add a carbo…

FWIW: in the kind of disaster these kind of home brew devices are targetted at, they're unlikely to be used on sedated patients. I read this as "how to save a life with a vaccuum cleaner in extremis", and not "here's a good ventilator design". Is it a good idea? I dunno. I'll check on the vaccuum today just in case. Also FWIW: the air path doesn't seem like the critical piece here. My (amateur) intuition tells me tha…

If amateur ventilators are only used when ventilation is required and standard ventilators are not available, that still may be a good answer.. still, I am sure that there are better and worse designs for amateur ventilators, it would be best if someone who knew they were doing reviewed various designs and could recommend the best of the bad situations.

Re: Pandemic Ventilator Project

#49
post #41

Great idea. Simultaneous to these types of home-brew projects...we also need someone (President? eCelebs? etc) to promote and organize fund raising efforts to simply buy and distribute cheap but effective ventilators. Imagine a WWII style "war bonds" effort, but instead to build and distribute say 5M ventilators over the next 6 weeks. In addition to this, we must re-purpose closed schools (gyms, cafeterias, etc) into…

"we also need someone (President? eCelebs? etc) to promote and organize fund raising"

Fund raising won't help if too many people get infected. What you need right now is for those in charge to stop playing Rambo and pretend they have it in control (they don't) then grow up, tell people to stop behaving like there is nothing going on. Schools, stadiums, all non vital businesses should close and people should stay home. This virus propagates at very high speed; as for now there is no cure, and I'm sorry for believers but prayers won't work (ironically, "healing" pools at Lourdes are already closed since days). This is serious, folks. We can only slow infections to a level in which people recover at faster pace than those who get infected, otherwise ICU numbers won't be enough and a lot more people will die.

Re: Pandemic Ventilator Project

#50
I posted directly via the contact form on the blog, not sure if it made it through.

I'm way out of my lane even commenting on this, but maybe you can dramatically simplify the air delivery side of this design, if you're willing to under-engineer. A single air chamber with an inlet (blower in) and two outlets (patient out and return out). Low rpm motor slow rotating a sealed disc with holes in it balancing outflow between feed-to-patient and return. Put a blowoff mechanism inline around the flow meter. If the capacity is there and there's such a thing as a common or global delivery 'frequency', maybe it could support more than one person.

Again, I might as well be from another planet in terms of knowledge in this domain. I'm just confused at the apparent complexity around the servo, linkage, and waste-gating. I DO get that delivery can be tailored nearly entirely in software with this design. That's cool.

Post reply on HN