Cardiostimulator is a 23rd century Federation medical device used to reactivate a stopped heart. Doctor Leonard McCoy used a portable version of the device aboard the USS Enterprise during an operation on Ambassador Sarek, after the power to sickbay had failed and the operation table's own cardiostimulator had failed. This implies that operation tables (and possibly sickbay tables as well, in future designs) are routinely equipped with the device. The device is a descendant of the modern-day defibrillator. (TOS: "Journey to Babel")