ventilator

grabcad

This design is for a ventilator and it is open source. Note that this is an initial design without any medical certification. This device provides ventilation for one human only, driven by one stepper motor (NEMA) and four solenoid valves, along with two balloons. If the balloons are not available, you can use a 1.75L Pepsi bottle which fits perfectly. The working principle is as follows: when both balloons are being compressed, the oxygen-containing red balloon prevents oxygen from reentering the tank by closing its solenoid valve at one end. It forces oxygen into the patient's lungs through the open valve at the other end of the red balloon. The inlet solenoid valve for the green balloon is closed to provide a single path for oxygen from the red balloon into the patient's lungs, while the outlet solenoid valve is open, allowing used air in the green balloon to be pumped outside. When both balloons are decompressing, the oxygen tank's solenoid valve opens, allowing fresh oxygen to flow into the red balloon. The other end of the red balloon's solenoid valve is closed to prevent used air from mixing with fresh oxygen. The inlet solenoid valve for the green balloon is open to create a negative pressure that sucks used air out of the patient's lungs and into the green balloon, while its outlet solenoid valve is closed to keep outside air from entering the green balloon. For suggestions or improvements, please contact me so I can develop the second edition.