Surgery can be painful and expensive, with long recovery times and powerful painkillers to get you through it. The most common surgery, gallbladder removal, requires at least four incisions on the abdomen.

One Silicon Valley company is changing all of that by using an old technology in a new way. Levita Magnetics reduces the need for multiple incisions by inserting powerful magnets through the belly button, and controlling them with magnetic arms on the outside of the body. It's been used in more than 500 procedures in the U.S.

Watch to see how it works, and how the magnetic arms may soon be robotic.