A machine and method for forming containers from preforms. The method may further include pivoting the first door to the closed position, and pivoting a second door about a second pivot axis from a closed position to an open position when the first door is in the closed position such that the second door acts as an outlet facing in a direction opposite the first door. The first radius of curvature is substantially greater than the second radius of curvature. The number of mixer stages as well as the design architectures and topologies for each stage can be varied according to the needs of the application. The oscillator is operable to generate oscillation signals having a frequency dependent on an equivalent impedance of the waveguides such that the equivalent impedance corresponds to intraocular pressure.