Sleek and white, the machine looks like a cross between a refrigerator and a phone booth. It’s about seven feet tall and four and a half feet wide—so large that movers broke the doorway squeezing it into this nondescript room at Crescent Regional Hospital, in suburban Lancaster, just south of Dallas. The damage was worth it, hospital CEO Raji Kumar told me, because this device will revolutionize health care.Kumar invites me to take a seat, while she stands alongside. Soon a holographic image appears on the machine’s face, a screen with 4K resolution. At nearly life-size, Dr. Olayinka Adepitan appears to be sitting on a stool and is wearing black scrubs. I can see the three dimensions of the anesthesiologist’s head, legs, and torso in…