In past factories were driven by a shaft that was spun using engine or other force outside building. The concept is similar.

A shaft spinning at a controlled rate using a server motor such as used in CNC machines.

Disk mounted on shaft in offset that as spinning will compress ventilator bag and release.

A bag holder under shaft that firmly holds bags with a path designed for disk to pass through when compressing.

The bag holders need to be adjustable height wise to make possible compression of ventilator bag partially for children or full breaths for adults.

Motor speed control capable of four revolutions a minute or higher.