improvised ventilator

February 2006

Do you still use a ventilator that a friend built for you? I was thinking about making a web page about simple ventilator design, so I was doing some research on the web about early vent design and I remembered you mentioning that you had a couple of units built.

Hi j

Yes I sure do.

My ventilator is not dissimilar to the design of the earliest vent. It uses a Mitsubishi windscreen wiper motor, that has been rewired to slow down the speed to suit our application. The speed is further regulated with a rheostat so I can dial the speed per minutes I require. (Between 15 and 12 breaths per minute.)

When I go to bed I turn it up, and when I am rested and before I drift off to sleep, I turn it down a few minutes later.

The volume is set but adjustable with a spanner, The volume doesn't need to be regularly adjusted, so this arrangement is fine.

The bellows are made of flexible air conditioning ducting and had been exceptionally durable, not needing and replacement over ten or so years.

It works on a 12 volts system, and I use a 110v or a 220v transformer you can buy from people like radio shack.

The advantage area;

  1. Cost, mine was made by a retired engineer and he only charged me $3,000.00
  2. Easy to repair wherever you are. A car mechanic or maintenance engineer can fix it if ever it required repair. Try and get a Bi Pap or off the shelf one fixed on the road.
  3. It is as light as a Bi Pap
  4. It is sturdy and pretty bullet proof. I used to strap mine to my off road motor cycle and head off into the wildernesses of Australia, PNG, Mexico, Honduras, China etc.
  5. It is highly efficient on power, it consumes less than 1 amp/hour. and I have been able to sleep the night using my motor cycle battery, then to be able to start the bike the next day. Try doing that with a Bi Pap. A full sized car battery does before the night is out.
  6. It has approval to be used using air craft power with Qantas. All other will accept using battery power.

The problem is that my retired engineer is getting on a bit and may not be able though I am sure is still willing to make any more.



That sounds like a really great design. What kind of interface do you use with it? How does it handle exhalation? Does it have a return hose, or a valve at the interface?

The reason I thought about making a web page about simple vent design was because of a story I heard on the radio. They were talking about what might happen if there was a flu pandemic. With the severe respiratory distress that can occur with flu, vents would be required for a lot of patients. Most hospitals have a limited number of vents and they were talking about how they might have to ration them, and make decisions that would cause some patients to live, and some to die.

I thought about your vent, and some of the earliest vents which were relatively low-tech and imagined that patients' families, or even hospital maintenance departments might be able put build vents as needed. Of course they wouldn't have all the features that hospitals are used to, but they'd probably be good enough to keep people alive. I figured if I made a web page and put the idea out there, people might think about how to really do it if the need ever arose.

I read about an early vent design that used the output of a Hoover to supply air to an air powered vent. A single Hoover vacuum cleaner could generate enough air to power up to 10 vents. That might make for a pretty noisy hospital room.


Hi J

This respirator might be simple but it takes a lot of time to make one. It would not be a short term fix by any means. It requires the wiper motor to be rewired to suit the breathing rate of the individual user, ie 12 to 15 breaths/minute in my case.

The interface is a full face mask, I made up using a Leardal bubble mask as a basis. I couldn't get an off the shelf one to give me the required seal to stop air leaks.

The valve system is at the mask itself.

Thanks for your interest


other improvised, open source or home-made ventilators

MIT Emergency Ventilator (E-Vent) Project

Open Source Ventilator Project

The Pandemic Ventilator

Improvised automatic lung ventilation for unanticipated emergencies.

A single ventilator for multiple simulated patients to meet disaster surge.

An Improvised Oxygen Supply System for Pandemic and Disaster Use

Chinese farmer keeps son alive with £20 homemade ventilator

An old article from 1936 referencing early design of a ventilator

Poulton PE. Left-sided heart failure with pulmonary oedema: its treatment with the “pulmonary plus pressure machine”. Lancet 1936; 231:981–3. An early improvised design of ventilator.