The Stimulus Router System (SRS) is an externally controlled neuroprosthesis that has only one component implanted (passive lead, pick-up terminal) under the skin and the other end (delivery terminal) is tunneled to a target nerve. A surface electrode is placed over the implanted pick-up terminal and a second electrode is placed nearby. Current pulses are passed through the skin between the electrodes. The basic properties of the SRS were explored in two animal experiments (Gan et al. 2007; Gan & Prochazka 2010) which showed that the SRS was reliable as a long term neuroprothesis and was able to selectively activate deep-lying nerves in a graded manner over the full physiological range. A case study of the first implant of the SRS in a person with tetraplegia with bilateral hand paralysis was completed (Gan et al. 2012) which showed initial success of the system.