A high school student at Forest Heights Collegiate in Kitchener Ontario is building “Norman”. It will be entered in the Waterloo Wellington Science and Engineering Fair to be held on April 1 2008.
Norman Pandemic Ventilator
Rockwell Allen Bradley Micrologix 1500
Jug of Water on the Bellows Plate
“Norman” is built from readily available components that can easily be obtained or re-purposed from other uses during a pandemic. It was constructed using the original design (link here) and is similar to “Max”, but with a few changes and improvements.
- The bellows is a vertical slider instead of a hinged bellows. The slider is constructed from Bosch struts (link here) and plastic panels. It is an innovative design that does not jam, yet is easily constructed and forgiving of slightly out of tolerance assembly.
- It uses an integral compressor so that it does not need to rely on pressurized air being available, but only electricity.
- It has a pressure transducer instead of a manometer. A restrictor valve has been added in the “to patient” line, so that the inspiration time can be adjusted.
- The bellows bag is a 2-liter PVC peritoneal dialysis bag. This is a very strong bag and has run many hours with no breakdown or apparent wear.
- The PLC is an Allen Bradley Micrologix 1500.
Here is a video of Norman running.
You can see that there is a jug of water on the bellows plate. Adjusting the amount of water in the jug on the bellows plate controls the maximum pressure generated by the bellows. The Checkmate pressure gauge behind the ventilator shows the maximum pressure is about 22 cm water. The Boeringer spirometer is recording a tidal volume of about 400 cc and a minute volume of about 7 liters.