Abstract: Embodiments disclosed herein are directed to ventilation devices, systems, and methods for applying positive end expiratory pressure (PEEP) to the lungs of a patient. For example, applying above atmospheric pressure to the lungs of the patient may mitigate alveolar collapse in the lungs and/or may have other health benefits for the patient.

Abstract: Embodiments disclosed herein are directed to devices, systems, and methods for mixing and/or blending two or more fluids, such as gases, to produce suitable mixed or blended fluids, such as a breathable gas. For example, the system may control and/or regulate flow from of first fluid from a first source and/or flow of a second fluid from a second source. The system may include a controller that may operate or direct operation of one or more valves to control the flow of the first and second fluids, thereby producing a blended or mixed fluid that has selected concentrations or proportions (or ratios) of the first and second fluids.