5 ms·
What about a "Both Respirator"? [1] In the 1930s polio epidemic there was a shortage of "iron lung" respirators, which were expensive to produce. Edward Both
by femto 7y ago
What about a "Both Respirator"? [1]
In the 1930s polio epidemic there was a shortage of "iron lung" respirators, which were expensive to produce. Edward Both invented a plywood version, which was cheap and easy to produce. A re-purposed car factory then churned them out by the thousand.
Is a negative pressure ventilator relevant for COVID-19 treatment? (Any knowledgeable medicos here who can offer a critique?) If so, couldn't they be churned out by the thousand in a short space of time (ie. days)? My understanding is that the tooling is comparable to that used to produce a kitchen cabinet. They can even be manually operated in the absence of a motor or control system.
[1] https://en.wikipedia.org/wiki/Both_respirator https://en.wikipedia.org/wiki/Both_respirator
- thornjm 7y agoMed student here - so I know some of the theory only. The most relevant "law" is Fick's Law of Diffusion (https://d2jmvrsizmvf4x.cloudfront.net/CTU792sKR2evT2ezizQp_ficks-1498D1741D90BC0C7D21.jpg https://d2jmvrsizmvf4x.cloudfront.net/CTU792sKR2evT2ezizQp_f...). Doctors can increase diffusion by increasing the partial pressure of oxygen. In a diffuse infection a patient begins to lose both lung area (due to shunting) and the thickness of the diffusion barrier increases (due to inflammation). To help overcome this you want to increase pressure and oxygen concentration. An iron lung helps ease the work of breathing by reducing thoracic pressure and thus creates a larger pressure gradient for inspiration. However, it does not cause an absolute partial pressure of oxygen change compared to the atmosphere. Unfortunately, to bind haemoglobin in physiological lung conditions we need partial pressure of oxygen around 100mmHg. My guess is that an iron lung does not help increase the partial pressure of oxygen so it will do little but ease the work of breathing (which is better than nothing!).
- FreeFull 7y agoYou could always combine the iron lung with a mask that supplies oxygen.
- totalZero 7y agoIt's too bad we can't put sick people in an airplane, put oxygen masks on them, shut the door, and pressurize the cabin. Like a hospital, but at the airport.
- jpmoral 7y agoWhy not? Maybe not in an airplane and not at an airport, but the same general idea.
- _bxg1 7y agoWe've got all those 737s...
- totalZero 7y agoAlmost 800 of the 737 Max are just sitting around collecting dust. Not to mention all the grounded wide-body aircraft. Take out the seats, equip the cabin with ventilators, and when one outbreak gets under control, send the aircraft to the next outbreak zone. They even have their own generators lol.
- james_s_tayler 7y agoWould give all those pilots something to do and I'm sure it couldn't hurt fuel prices.
- bobthepanda 7y agoThe ones that have already crashed, and are totally grounded because they propose a risk to the public? Not sure if this is supposed to be better. And who would fly all these people? Access to the cockpit is through the rest of the plane.
- mdturnerphys 7y agoNo flying needed--just need to pressurize the aircraft while on the ground.
- ars 7y agoCould we build a huge hyperbaric building and place all the patients in there? Would that accomplish the same goal as a ventilator?
- dredmorbius 7y agoThere's both partial pressure (O2 concentration and overall atmospheric pressure) and repiratory function. Forced-air respirators (most current models) and iron lungs (operating with partial vacuum) both address this mechanism.
- downerending 7y agoI've been wondering whether CPR breaths could be used in extremis. It'd be pretty hellish, but I could imagine doing this for 24-36 hours if it was the only option to save my wife, for example.
- dredmorbius 7y agoAt a certain point, external oxygenation (heart-lung machine) may be more appropriate. But hyperbaric chamber, elevated supplemental oxygen, and repiratory assistance might be an approach.