The medical term non-invasive is used to describe any procedure where neither the skin is cut nor surgery is required. Therefore, non-invasive ventilation is a procedure where the throat has not been cut to insert a tracheal breathing tube. For people who suffer from chronic obstructive pulmonary disease (COPD), asthma, emphysema, or a degenerative muscular disease, non-invasive ventilation mechanically assists in breathing until either the inflammation of the airway is reduced or it is determined that more drastic measures are required to continue breathing.
Generally, the earliest known non-invasive ventilator, called the body ventilator, was created by John Dalziel in 1838. It was an airtight metal box that a patient would sit in while a manual bellows generated negative pressure that provided some breathing relief. In 1928, the first widely used iron lung was developed by Philip Drinker.
The 1930s saw the advancement of non-invasive ventilation applications when Alvan Barach discovered continuous positive airway pressure (CPAP) could be useful in the treatment of acute pulmonary edema, thereby replacing the body tanks with more mobile systems. Between 1947 and the early 1980s, the most common form of mechanical breathing used was intermittent positive pressure breathing (IPPB), and was administered via a mouthpiece. IPPB is a form of assisted breathing where air or gas is pushed into the trachea, much like how an anesthesiologist administers anesthetic.
Sometime in the 1960s, non-invasive positive pressure ventilation (NPPV) began to be administered at night and as needed during the daytime, and successfully treated patients with muscular diseases across the United States. The big breakthrough came in the 1980s with the introduction of the nasal piece. Until then, the non-invasive ventilation systems required patients to wear large masks over their mouths; many patients reported discomfort with the fit of the mask and unease at wearing them in public.