Abstract: A specified concentration of oxygen in a medical gas delivered to a patient by a gas delivery system can be achieved through the use of pulse width modulation control of the flows of one or more component medical gases. The flow of component medical gases can be controlled to improve the resolution and concentration range of medical gas delivered at low flow rates. A first flow of a first medical gas is provided and a second flow of a second medical gas is introduced to achieve a desired average medical gas concentration. When the second flow of the second medical gas is introduced, the first flow of the first medical gas is reduced to maintain a desired total medical gas flow rate.

Abstract: A specified concentration of oxygen in a medical gas delivered to a patient by a gas delivery system can be achieved through the use of pulse width modulation control of the flows of one or more component medical gases. The flow of component medical gases can be controlled to improve the resolution and concentration range of medical gas delivered at low flow rates. A first flow of a first medical gas is provided and a second flow of a second medical gas is introduced to achieve a desired average medical gas concentration. When the second flow of the second medical gas is introduced, the first flow of the first medical gas is reduced to maintain a desired total medical gas flow rate.

Abstract: The present invention is a method and system for providing auxiliary power to an integrated anesthesia delivery and patient monitoring system. When AC main power is unavailable or inadequate to power a patient monitoring device of the integrated system, DC power from a battery in an anesthesia machine of the integrated system provides power to the patient monitoring device through a DC power connection. Distribution of the battery power is controlled by a first, normally closed solid state switch in the anesthesia machine and a second, normally open solid state switch in the patient monitoring device. The battery is also configured to provide DC power to the anesthesia machine when AC mains power is unavailable to the anesthesia machine. The method and system utilizes required DC auxiliary power from the anesthesia machine to provide DC auxiliary power to the other devices.