A dual time sliced circular bus extending in opposite directions, and optionally interspersed so as to reduce noise. The seclectable bandgap reference has at a high current consumption when enabled and a low current consumption when disabled. The disc scaffold design may include an outer annulus that may contain desired structures and a central nucleus pulposus region that could either contain a designed microstructure or a contained hydrogel. The plurality of conductive traces includes a first conductive trace and a second conductive trace. The fluid pressure measurement assembly measures a first pressure of the fluid, a second pressure when the needle contacts tissue and a third pressure when the needle penetrates the tissue and the aperture becomes occluded.