I suspected the machines were this simple in concept. The complications are what are difficult to design for. I have all the parts so now need the description of the various details that are necessary. Especially how the ventilator tube is fixed to the patient.
ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-V8VIw0fk4X0.html This video shows the Intubation process and how the ventilator should be connected to the patients tubing. I am not a med professional but this should give you a basic idea.
With compressor, preasure regulator to achive 20cmH2O preasure for inspiration, air filter, 3way 2position valve and on, off time delay to control the valve you can make a simple inspiration and expiration mechanism.
I have a prototype running using a drone motor and speed controller to drive a simple centrifugal fan capable of pressures up to 100cm.H2O, two slide valves operated by standard RC model servos and an Arduino for a controller. I have a +-50millibar differential pressure sensor being read by the Arduino in order to synchronise the ventilator to the patient's breathing and allow control of the inspiration and expiration pressures. It's very crude (all made from 2mm HIPs plastic sheet) and the sketch in the Arduino is only about 200 lines but it works.
@@ColinMill1 Hello. Ofcourse there are many ways to do it. I am not very familiar with Arduino. Ofcourse is more sofisticated through Arduino because you have to deal with sftware and microcontrollers. Some day I will trye it. Take care
@@gjergjkastro9404 Many thanks for the reply. Yes, I think there are so many ways to do this. I'm just using the things I'm familiar with (I have been playing with RC models since the 1950s!) . The Arduino is a fun thing to use as (like the Raspberry Pi computer) there are so many users out there you can find example code to help you do almost anything. In this case there is a library that makes it really easy to control servos and speed controllers.
@Rahul Soni I'm passing on all the design information and results to a friend who has contacts in the medical equipment field in the hope that some of it might be of use to others. I have been prompted to do this work by the possibility that, if our health service gets over-run by the number of cases we may be in a situation where older people in their 60s and over will not be helped as there would be many younger patients that would be more likely to survive if ventilated. Since I, and many of my friends and family are in this age range I plan to build a few as some kind of insurance against this eventuality. I would be very happy to pass on any information to others if it can help. I still need to do more work on the fan design as the current design becomes rather inefficient (and noisy!) above about 20cm.H2O pressure. I will be designing a new one today.
@Rahul Soni OK - I'll try to sort out the info as I have it so far and get it to you. I think the most difficult component to source is the pressure sensor. I am using some that I bought some years ago from a company called SensorTechnics (part number HDIM050DBEP3) - any differential transducer with a suitable pressure range (10kPa which is 100mBar or 1.5psi would be ideal). I'm going to design the new fan around a 2212 size 1400kv outrunner motor as this is a common type that is available on ebay etc. The servo could be almost anything. I am using some standard size servos (HobbyKing 15288A) as I just have a lot of these on the shelf.
Simple diy ventilators are very possible. They were simple and effective until 1970 . Then manufacturers found it profitable to sell more complicated and expensive units. Now they cost thousands of dollars and are difficult to make (but are absolutely better than any diy one, unless they are not available. It is essential to have a high pressure vent. This pressure control tube connected to the air feed line. It is held under 5-20 cm of water. Excess pressure vents out the water tube. Overexpanded (overpressured) lungs will cause permanent damage or death. Air can be forced into the lungs with a bellows. As the video shows a couple of synchronized valves are needed. I used ping pong balls in 1.5" pvc water pipes as non return valves in my prototype. The valves are connected so the exhaust closes when inlet opens, and exhaust opens when inlet opens. The bellows(or 6" diameter piston) would be best operated with a cam and electric motor. but many options are possible for power- humans, compressed air, etc. Thousands of volunteer DIY manufacturerers could produce large numbers of these quickly and cheaply for anyplace hospital ventilators are not available. Is anyone interested in plans on how to make these? jaksha at mac.com
Coronavirus is from droplets but can someone get it too from accidental inhalation of air from ventilator exhaust or is the unit filtering the air as it flows out?
Yes, you can be exposed from the patients exhaled volume from the expiratory limb of a vent circuit. It requires a virus/bacterial rated HEPA filter on the inspiratory limb and expiratory limb. You don't want to contaminate you or the vent for the next patient use.
Been wondering that. Especially with viral cases such as the Covid-19, serious cleaning and intermittent sanitization of the system amid usage is necessary.
@@NjugunaBK that ..and also...ACE2 is how this chimeric virus is entering the cells. Why are we not talking about all the ACE2 Homologues in use for therapeutics, diagnostics, prognostic ect. ...how do we know which ACE2 the virus is using? This virus is lab made. And so the receptors for it are also lab made. All this can't happen in an immunoncompetent person. Immuno deficiency is how foriegn receptors and viruses and have their day in the human body. Only under suppression, oppression, can anything take hold where it's not supposed to be. Think how war invasions are accomplished.
Here is a simple DIY electric ventilator air pump with volume control, pressure control, peep, and cycle control. Built with hardware store parts and a wiper motor for $25. A simplified version will be posted on youtube April 23 (1) simple ventilator pump - RU-vid
have i enough knowledge make for this machine? Probably yes... but i'm not enough to use. I realized that we do not need only doctors... We need intensive care doctors and nurses. To use the machine our need a high degree of medical expertise and we haven't time for education. This would look like to produce millions of aircraft. But you haven't enough pilots to fly the planes... Stay home... Our only insurance is to stay away from people.
