The present disclosure generally relates to a manifold valve assembly engaged to an inflatable apparatus, such as a cushion to prevent pressure ulcers, for example. The manifold valve assembly is also in communication with a processing device to determine an optimal immersion level for a user seated on the inflatable apparatus. Additionally the processing device, in communication with the manifold valve assembly may save optimal immersion or air pressure levels for comparison to future checks of cushion pressure and send that to a user interface at the processing device. The assembly and processing device may also save and display a history of pressure checks.