flatline

A flatline is an electrical time sequence measurement that shows no activity and therefore, when represented, shows a flat line instead of a moving one. It almost always refers to either a flatlined electrocardiogram, where the heart shows no electrical activity (asystole), or to a flat electroencephalogram, in which the brain shows no electrical activity (brain death). Both of these specific cases are involved in various definitions of death.

View More On Wikipedia.org