A method of sharing inductors for inductive peaking of an amplifier includes calculating a single stage inductance of a single stage for inductive peaking in order to have a stable impulse response. The helical reinforcement member has a configuration to resist kinking and crushing of the tubular body that would close-off flow of the breathing gas. In a leakage search mode, the capillary line having the larger cross section is open. A back reflector is disposed adjacent the back surface. The recess defines a gap between the side walls of the adjacent grate blocks. In one preferred version of the invention, device functions are automatically or manually combined with an installation structure.