Hacker News new | past | comments | ask | show | jobs | submit | more fifteenforty's comments login

Without these sorts of things, patients are dying.

This is not business as usual. We are already using various hacks to overcome the shortages, any improvement is worthwhile in the very short term.


Sorry to be the bad new bear, but most people die even with them. Go look at the respirator death rates.


As an anaesthesiologist, I’m fully aware of the published death rates. You will see that they vary from 50 to 95%. The former appears achievable.


As you say, we have many patients already in our ICUs who need ventilation, but aren’t /difficult/ to ventilate.

Perhaps they could get the split ventilators and the COVID-19 patients could get their own?


Yes, but the demand projected for ventilators seems to exceed the entire existing supply, and obviously dwarf the uses for all other conditions combined.


There are way too many different brands and types of CPAP machine for anyone to make any sort of sensible comment here. They aren’t all the same. Some of them do have a backup rate that could be used to mandatory mechanical ventilation, but that can’t be readily altered at the bedside in the models I have used. The use-case is radically different to the ICU.


We are talking about negative pressure mechanical ventilation. Positive end expiratory pressure is just one way of splinting open alveoli. Maintaining recruitment and V/Q matching in ARDS can be achieved in multiple ways, including negative pressure mechanical ventilation.


Interesting, I'd be curious to know more. My understanding of NPV is that it's primarily useful in cases when the lungs are generally "functional" and some other issue is preventing adequate ventilation.


Anyway, the ventilator hardware is relatively easy to make, a gas pump, reduction and humidifier, plus a few hoses. Literally your granddad's CPAP sleep apnea machine is (almost?) good enough, if it has tuned oxygen intake. I would wager intubating actually makes most problems worse in case of damaged lungs, but with low odds only.

The real problem will be getting actual oxygen (concentrators are not free) and people to tune the system.


Theoretically yes, in fact it may actually be better. We have largely abandoned negative pressure ventilatory support for a number of practical reasons. Not least is that once you have intubated a patient, they are less contagious!


On more than one occasion I have "broken the rules" or Macgyvered my way out of a life-threatening situation (for my patients), either with equipment or drugs. This is a crisis. Our systems aren't working fast enough to cope.


The flow direction issue is partly addressed by the unidirectional valves in many ventilators/anaesthesia machines. The bigger issue is staffing expertise, I fear.


True. Unfortunately, there may be a wide amount of practical experience shortly.


There are lots of problems with this, but I think it is possibly a better move than some of the home-built ventilators you see floating around.

I’m biased though: I’ve designed a 3D printed improvement on this idea that potentially allows you to ventilate multiple patients with different pressures: https://www.prusaprinters.org/prints/25808-3d-printed-circui...


Fellow MD trying to help with engineered solutions.

Perhaps check this out as well; someone used a common valve from a hardware store to titrate pressures up and down: https://www.youtube.com/watch?v=eSVbwWANqRI&feature=youtu.be.

I've been thinking about how we might increase ventilation to one part of the circuit if the pCO2 drops too badly--any thoughts there?


Thank you for pointing this out! I’m trying work out how to get in touch with this guy, unfortunately he has turned off all comments.

I’m not sure I understand your question: do you mean if the one patient is getting hyperventilated? My suggestion is to set the pressure settings to ventilate the poorly compliant compliant lung, then use the flow restrictor to compensate on the more compliant lung.


I was thinking as I read the article that there was a next step innovation in the wings to vary the treatment by patient.


Agreed.

Anaesthesia machine control should be air-gapped.

Unfortunately, in the modern world of electronic medical records, we do need access to a stream of measurement data. Historically this has been obtained using one-way serial port data streams, which is probably safer than having a network stack accessible to the web.

The users (anaesthesiologists and hospital administrators) don’t understand these problems. (I’m an anaesthesiologist)


Could still be achieved through low data rate UDP with manual acknowledgements of sent data, with inbound data blocked.


I think it's a systems issue not really a software one. You need some sort of gap between the control unit (which can kill people) and the monitoring system which shouldn't be able to.

Would be perfectly reasonable to pass monitoring data from the control unit via a tx only channel to a networked monitoring device. For instance using a digital opto-coupler to galvanically isolate the two units.


I believe it would be cheaper, and thus more likely to be adopted if tx only was implemented in software, such as a iptable rule.

Hardware tx only would only make sense if you avoid side channels as well.


manual ack udp? What?


You could buy a BenQ WiT for $180. Vastly more practical for most nerds, cheaper and has a replaceable DC transformer. The name isn’t as sexy though!

https://www.benq.com/en/lighting/e-reading-lamp/wit.html


Consider applying for YC's Summer 2025 batch! Applications are open till May 13

Guidelines | FAQ | Lists | API | Security | Legal | Apply to YC | Contact

Search: