A laryngeal mask airway has a curved tubular guide for insertion through the patient’s mouth and oropharynx. An expendable material and more particularly a filter means or an additive for such a servicing device, which is renewable and is able to be utilized by the servicing device for the preparation of the pressure medium and bears a capacitively detectable code means, on the basis of at least one operational parameter of the servicing device is detected. The baseline rhythm includes a baseline atrial event and a baseline right ventricular RV event from an implanted cardiac lead or a leadless device, a pre-excitation interval determined from the baseline atrial event and the baseline RV event, and a plurality of activation times determined from a plurality of body-surface electrodes. Any number of algorithms may be implemented to determine the amount of added yellow light into each pixel of an image, based on, for example, the saturation of a pixel, the amount of other colors in the pixel, a selected brightness level, and various factors related to the design andor performance of the prism assembly, kernel, andor any of the individual components therein.