Walking rehabilitation assistance devices that facilitate mobility in users that are rehabilitating for walking. The access blocking device is movable from an access blocking condition in which access to the block valve through the access port is blocked, to an access permitting condition in which access to the block valve through the access port is permitted. These values are low pass filtered and a search is carried out for candidates for an eye. The AD converter further includes an adder for supplying the analog input signal to an input of the quantizer. The processor 220 is further configured to provide an output signal 228 to an output device 240.