Many experimental medical procedures are being attempted using 3D printing. One of these is that cells are printed directly onto a wound of the patient. First the wound is scanned and analyzed, and then the printer chooses the right kind of cells for the layer currently being printed. As the layers build the cells used are changed to match the natural cells of the body at that depth. Another medical advancement is the printing of organs. 3D imaging is used to map an organ such as a kidney. The file is then processed so that the printer can begin to work on the organ. As medicine improves the lifespan of people is getting longer. However organs are still in short demand given how difficult finding and match organ donors can be. This technology could revolutionize medicine in the future.