The Impact, a laproscopic surgical tool from Covidien, Boulder, Colo. (www.coviden.com) lets doctors cut and fuse tissues using the same instrument. It can also be used to grasp and divide tissues, reducing the need to change instruments during surgery. It is often used to sever blood vessels and then fuse them so they do not bleed. It can handle blood vessels up to 7 mm in diameter, along with vasculature, lymphatics, and tissue bundles of the same diameter. It fuses tissues using pressure along with a voltage one-fifth to one-twentieth that of standard electrosurgical instruments but with four times the current. By monitoring current and voltage, the device “knows” what physical changes vessels are going through and alters its output to match the circumstances, thereby eliminating guess work on the part of doctors. When a vessel is sealed, the device sounds a tone and shuts off power to the fusion element. It takes an average of two to four seconds to seal a vessel.