Medical Apparatus, Namely, Tissue Stimulators, Portable and Non-Portable Programmers for Tissue Stimulators, and Surgical Tools and Apparatus for the Implantation of Tissue Stimulators; an electrical stimulator for treatment of intractable pain syndromes, the posterior spinal cord, or other spinal cord stimulation (SCS); medical devices, namely, an interferential current generator and implantable electrodes; medical apparatus for spinal cord stimulation; dynamic interferential spinal cord sti...