Computing device and method for determining primary and ghost components from recorded P-waves. In one example, the disclosed method includes forming a trench in a surface of a substrate to define a field area, forming a first conductive type well in a first active area of the substrate, forming a second conductive type well in a second active area of the substrate, and filling up the trench with a dielectric. The control of the expiration valve can be implemented by means of a software product for the breathing apparatus embodying programming instructions as control rules, which, when executed in the apparatus, enable control of the expiration valve during manual ventilation. The decodable indicia reading system can further comprise a decoding program executable by the microprocessor, which can be configured to input an encoded information item the imaging device andor the EIR device.