2 How does one certify that the person is clinically dead?

Clinical Death used to be defined and determined as cessation of all vital functions and was decided by lack of perceptible heart beat and respiration. However , nowadays defining death is complicated and modern medical technology such as, CPR, pacemakers, artificial hearts, heart valves, kidney dialysis, ventilators etc. have delayed death and made defining it difficult. The following definition has also been considered or defined by most states: total irreversible cessation of cerebral (brain) function. So, it is now possible to be dead (brain dead) and still have a heartbeat and respiration supported by mechanical devices. The laws in states vary but this is generally the case. Brain death is determined by measuring electrical activity of the brain on a electroencephalograph.