Apparatus for performing an assay to detect the presence of an analyte in a test sample. The cerium-based hydrate fiber can be synthesized by aging under the boiling point of water for 10 hours to 50 hours by the addition of a chemical modifier. The apparatus further includes a unit for acquiring the supplied image data after a certain time from generation of the sync signal, and a unit for controlling operation of the laser oscillator by a driving signal which is generated based on the acquired image data. The control module performs a method for simultaneously monitoring a voltage on the capacitor and a morphology of the cardiac signal during the charging and controls the therapy delivery circuit to deliver a shock pulse at less than a programmed shock energy in response to both the voltage reaching at least a minimum voltage and the morphology being monomorphic.