Development of an inexpensive programmable logic controller for clinical gases regulation

An inexpensive programmable logic controller has been developed to regulate the production of radioactive gases such as oxygen-15, oxygen-15 labelled carbon monoxide and carbon dioxide, and carbon-11 labelled carbon monoxide. The system controls the flow of the gases to a PET camera via a series of regulated flowmeters and switching valves with feed-back from the system coming from a small finger ionization chamber located inside a 10 mL loop of the gas. Total equipment cost is less than $1,500