A system for controlling the delivery of medical gases includes a digital signal processor that receives at least one ventilation parameter value change, calculates a fresh oxygen flow rate, total fresh gas flow rate into the breathing circuit, and a reference oxygen flow rate representative of a predetermined oxygen concentration delivered to a patient. The microwave ablation system includes a power source. An electronics module is provided that contains a light source. Tubular members extend through holes. The signal line of a liquid crystal display device is driven by the inductance element, whereby the power consumption is reduced. The interconnect lines in each group are modeled.