Patient Safety is a fairly new discipline in the field of healthcare that aims at finding ways to prevent medical errors that can potentially lead to adverse healthcare events. In other words, Patient Safety is the science of eliminating the risk to patient's health during medical treatment. "The background behind the emergence of this discipline: Patient Safety was first the science behind the struggle against nosocomial infection before expanding in the last decades also to the field of prevention of medical error in the act of performing care to patients." When doctors take their Hippocratic oath, they swear to not cause any harm to anyone. Yet at the end of the 19th century, as Pasteur proved that germs were at the origin of infectious disease, the scientific community understood that doctors, rather than curing patients, could also kill them through their hands and instruments if not washed properly. The first battlefield in the discipline of Patient Safety was then the one of hygiene and the struggle against the spread of nosocomial infections. This concept is the foundation for the WHO's "Cleaner Care is Safer Care" program. A new field area of this discipline came to light to the public in the 1980s and 90s when various reports were released on medical errors occurring during patient care such as incorrect drug use, incorrect diagnosis, or even the failure to remove instruments from the inside of a patient during surgery. Increased awareness of medical care errors came in 1982, when an ABC television program titled "The Deep Sleep" reported that every year 6,000 patients in the US die or suffer from permanent brain damage due to anesthesia errors.