82 Nanomedicine storage tank, the area at right is the CO₂ tank, the black dot at the center is the computer, and the open volume around the computer can be a vacuum, or can be filled or emptied with water. This allows the device to control its buoyancy very pre- cisely and provides a crude but simple method for removing respirocytes from the blood using a centrifuge. When we can build respirocytes, they could be used as an emergency treatment at the scene of a fire, where the victim has  been  overcome  by  carbon  monoxide  poisoning.  In  an animation [11] from the PBS documentary Beyond Human, 5 cubic centimeters of respirocyte-containing fluid are injected into the patient’s vein. After passing through the pulmonary bed, the heart, and some major arteries, the respirocytes make their way into smaller, and smaller, blood vessels. After about 30  seconds,  they  reach  the  patient’s  capillaries  and  begin releasing life-giving oxygen to starving tissues. In the tissues, oxygen is pumped out of the device by the sorting rotors on one side. Carbon dioxide is pumped into the device by the sorting rotors on the other side, one molecule at a time. Half a minute later, when the respirocyte reaches the patient’s lungs, these same rotors reverse their direction of rotation, recharg- ing  the  device  with  fresh  oxygen  and  dumping  the  stored CO₂, which can then be exhaled by the patient. Only 5ccs of respirocytes, just 1/1000th of our total blood volume,  could  duplicate  the  oxygen-carrying  capability  of the  entire  human  blood  mass.  Each  respirocyte  transports hundreds of times more physiologically available oxygen mol- ecules than an equal volume of natural red blood cells. A half a liter of respirocytes, the most that could possibly be safely added to our blood, would allow a person to hold his breath at the bottom of a swimming pool for up to 4 hours, or to sprint at top Olympic speed for up to 12 minutes, without taking a breath.