A splittable medical valve is disclosed that is configured with a interfacing region that permits the valve to be placed over or inside of a tubular medical device, such as a splittable introducer sheath, to prevent loss of bodily fluids andor reduce ingress of air-borne pathogens. A transmitter emits light rays, and a receiver receives the light rays. The shutoff ball has a passage in an area facing toward the pivot drive, and a chamber extends through the passage from the pivot drive into the interior of the shutoff ball. The memory includes a row decoder that controls a voltage on each of the word lines and controls a voltage on each of the voltage supply lines.