The present disclosure provides devices for supporting pelvic floor tissues to decrease the incidence of pelvic floor injuries during child birth. The reference pH sensor is an extended gate field effect transistor structure and comprises a metal oxide semiconductor field effect transistor on a semiconductor substrate, a sensing unit comprising a substrate, a solid-state conductive sensing layer on the substrate, and a polypyrrole layer on the solid-state conductive sensing layer, and a metal wire connecting the MOSFET and the sensing unit. An enclosure may be used as the heat sink or heat spreader. The robot is controlled to effect predetermined movements of the instrument or tool relative to the work piece. The catheter may include a biodegradable tip, which when absorbed by the body would enable the catheter to be removed.