Apparatus, systems, and methods for monitoring a sensor module mounted in a sensor platform, wherein the sensor platform includes an adhesive side and a pocket, wherein the pocket is designed to receive the sensor module, to facilitate sensing by the sensor module of physiological attributes, and to allow insertion and removal of the sensor device from the pocket. The carbonaceous protective layer is formed by a Filtered Cathodic Arc process, and contains nitrogen distributed therein. The scaling factor can be tuned by monitoring a function based on the cumulative probability distribution function of the scaled soft decisions. The first ends engage a stop surface, and the second ends extend outwardly from the bores.