A support surface includes a foam base layer including a foam bottom layer and a pair of foam side edges disposed adjacent sides of the foam bottom layer. The invention is essentially characterized in that the device is suspended in space such that it can move without any direct contact being established between the supporting area and the seat, thereby maintaining the vertical position of both the head and the neck. In various embodiments the techniques employ a cross-trace similarity model, which is defined to hierarchically cluster problems detected in the learning based issue detection via butterflies of trigram stacks. At least one operating parameter of the device is adjusted to direct at least a portion of the emitted electrons. The search points obtained from the searches on the upper level frame data and upper level field data are used as frame and field motion vectors.