The microarrays of the present invention are prepared by using a separate fiber for each compound being used in the microarray. The method entails use of feedback in which the patient views andor hears a signal related to the intensity of electromyographic activity the patient produces in the appropriate muscles while attempting to move the paretic or plegic joint. Each of the proxy modules is a light weight version of a corresponding precise module in a server application. In the primer layer, a portion having the conductive layer formed therein has a thickness larger than the thickness of a portion without the conductive layer. The reference spectrum I0 is compared to a known target spectrum I0soll, which is associated with the measuring cuvette, comparison parameters being obtained, it being decided automatically whether a contamination of the measuring cuvette exists as a function of predefined threshold values of the comparison parameters.