| To quote an earlier comment of mine: So there are four main ways for breathing machines to be powered:
1) By compressed air from a wall port (majority of ICU machines) 2) With bellows (anesthesia machines) 3) Turbine, either dynamic or constant speed with a proportional valve (home use or patient transport) 4) Piston Let's assume that we use a pneumatic device driven by centrally purified air as that is simplest. The parts then are: -Gas blending to mix O2 and HP air. In many designs this is done using two solenoid valves. -A fast, precise, and accurate proportional solenoid valve. This turns the constant pressure into the desired waveform -another valve for controlling exhalation pressure. Can be another proportional solenoid, alternatively a manually adjustable valve to ensure constant minimum end exhalation pressure (PEEP) -Flow sensor (range of options, typically variable orifice or hot wire anemometer but other type exist) -Pressure sensor (silicon waver transducer) -Overpressure valve -O2 sensor (highly desirable, arguably you can estimate from O2 blending settings but that will work better on a very well characterised design which this would not be. Anyway O2 sensors are widely used so this will never be a constraint. -Piping to connect it all together -A control and alarm system to drive desired waveform based on user settings and sensors -Patient circuit: Humidifier / heat exchanger, patient valve (one time use), viral filters for intake and exhalation air (one time use), ET tubes (one time use)
Probably the limiting factor as far as parts go are the valves since this is a niche application.
Here's the problem: as a civilisation, if we had to make a hundred million vents by the end of the year it would be easy. Expensive, sure, but not that hard in an emergency.
It is much harder to make an extra 50,000 in a few weeks because it just takes time to turn the machinery of mass production in a different direction. Let me know if you want me to send my list of ventilator reading. I'm not an expert either, just trying to soothe my Corona-madness by thinking about building things. |