Abstract: A system is provided for use in measuring the cardiac output of a living being. The system includes at least one sensor for measuring the lung carbon dioxide elimination rate of the living being and a processor for predicting the cardiac ouput level of the living being as a function of the current value of the lung carbon dioxide elimination rate based upon the predictive increase in cardiac output as the lung carbon dioxide elimination rate of the living being increases. Structure is provided for determining the cardiac ouput of an intubated living being and a non-intubated living being.

Abstract: The present invention relates to gas mixing devices for use with breathing circuit assemblies for use with breathing devices, such as respiratory therapy devices and ventilators and to methods for administering gases, such as breathable gases, like nitric oxide, in combination with other gases in a manner which facilitates the establishment of reliable delivery standards for the gases, which facilitates adequate mixing of the gases, and which reduces exposure time of the gases to one another so as to eliminate or minimize the production of toxic byproducts generated from such gas mixtures.