Dead when the doctor says you are

We sometimes treat people as already dead once they are deemed terminal. Organ donations most often take place after brain death, a concept articulated 40 years ago at Harvard University and meaning the irreversible end of all brain activity. In a brain dead patient, the brain no longer tells the body to keep living, so machines do that, instead. Brain dead soon came to replace the historic understanding of death – the heart stopping. After all, a stopped heart no longer seemed relevant when machines could keep a heart beating indefinitely. However, the increased popularity of donation after cardiac death, or the harvesting of organs from patients whose hearts have been allowed to stop beating, has once again got the medical community looking at how to define death according to the functions of the heart. The Star