Each device group is further classified as continuous or discrete, according to the amplitude resolution of the input variables sensed. This classification is available from the GDGM the page at:
http://www.ircam.fr/equipes/analyse-synthese/wanderle/ Gestes/Interne/Capteurs/introf.html
Another approach could be, for example, the separation of systems according
to the relative position of the source and the sensing element, as proposed
by Mulder in [6] and discussed above.