In 1876 Ignez von Hauke from Austria experimented with both continuous positive pressure applied to the mouth via a mask and, initially, continuous negative pressure ventilation for up to 15 min intervals for the treatment of pneumonia, atelectasis, and emphysema. He discovered that intermittent negative pressure ventilation in phase with the patient’s inspiration could be used for respiratory failure. He then made an iron cuirass covering the chest with an air-filled rubber edge to “seal.” Agitated patients made this device unworkable, which led to the design for the first tank-type respirator, covering the whole body, “Pneumatische Apparate [28].” The whole subject was enclosed supine in this tank, including the scalp covered with an elastic cap which was sealed to the tank edge with elastic plaster, leaving the face free. It was hand operated for 2–3 h per “treatment.” He used it for many conditions including neonatal asphyxia, atelectasis, pneumonia, tracheitis, croup, and diphtheria. L. Waldenburg, his colleague, reported that it kept a small girl alive for 3 months suffering from “great debilitation and double pneumonia” when she improved, and gained weight. It also “straightened” her rachitic chest wall [29].

In the same year, 1876, Eugene Joseph Woillez from France, designed a workable manually operated negative pressure tank respirator he called a “Spiroscope”. Repeating the work of John Mayow, he stated that “the primary reason for the entry of air into the lungs is not the pressure of the air but the expansion of the thoracic cavity by the respiratory muscles.^”He then made an improved model encasing the whole body called the “Spirophore” with an adjustable rubber collar to seal around the neck with the head protruding, resting on a shelf, and a sliding bed, which became the prototype for all the negative pressure tank units that followed. A manually operated bellows generated the pressure changes from the opposite end. It had a unique feature, a rod resting perpendicular to the supine patient’s chest which signaled the motion of the chest cage with each breath cycle, thus allowing for its detection [30] (Fig. 2.2). A unit lent to a Dr. Voisin for three drowned victims failed to revive the already dead victims. Woillez refused to patent his unit. His goal was to place these units all along the river Seine for drowning victims but lack of financial support doomed the project, possibly due to the failed attempts.

In 1887 Charles Breuillard, MD of Paris designed an impractical “bath cabinet” for a seated patient which required the patient to operate a valve to shift between vacuum for inhalation and release to atmospheric pressure for exhalation, requiring a conscious subject who could not fall asleep [31]. But it was the first unit to be continuously powered by steam from a boiler heated by a “spirit lamp” rather than manually (Fig. 2.3).

Alexander Graham Bell, the inventor of the telephone, and not a physician, after the death of his 1-day-old son in 1881 designed a metal vacuum jacket in 1882 which developed negative pressures with a separate hand pump to artificially “expand’ the lungs to save lives. It was a unit made of two rigid halves with soft linings held to the chest by a strap, with negative pressure provided by large bellows. He successfully experimented with healthy volunteers. Even after he presented the results to a meeting of the Advancement of Science and loaned it to someone at the University College in London, however, it generated little interest and went unused, perhaps because Bell was not a physician [32].

In 1889, Dr. Egon Braun of Vienna devised an infant “resuscitator” consisting of a box in which was placed a small supporting plaster mold conforming to an infant’s body, with a rubber diaphragm seal around the head, leaving the nose and mouth exposed to air. Through a tube at the base of the box the operator would blow into the pipe to force chest compression, causing the air to exhaust out of the infant, allowing for chest recoil to generate a suction, or negative pressure, to inflate the chest (Fig. 2.4). This was repeated 20–30 times a minute by volunteers and reported to be “completely successful in 50 cases” reported by OW Doe [33].

In 1901, a Hungarian physician, Rudolph Eisenmenger, patented the first portable negative/positive pressure “cuirass” ventilator used for cardiopulmonary arrest from drowning or intoxication, consisting of a two part box enclosing the chest and abdomen, allowing the throat and limbs free. A foot operated bellows was later replaced by motors in 1904 (the “Biomotor”) and was reported as “extraordinarily successful” when he reported the resuscitation of a man who had hung himself [34] (Fig. 2.5).

Aside from these issues of negative pressure ventilators to allow for resuscitation, there had been no system that allowed a surgeon to operate on the lung without its collapse until 1904, when Ernst Ferdinand Sauerbruch of Germany designed and built an airtight continuous negative pressure operating room, a giant “pleural space,” where the subject’s head protruded through a hole, exposed to atmospheric pressure, allowing for inflow of air to the lungs, and where the surgeon, also in the room, could work on a patient with an open chest. It was completely abandoned due to the heat in the room for the operators, the lack of space to work, and the inability to talk with the anesthetist. But it encouraged the brothers Willy and Julius Meyer to construct a formidable double operating room in 1909 in New York. It consisted of an outer negative pressure chamber where the patient and the surgeon worked and a positive inner pressure chamber where the anesthetist sat. While considered brilliant at the time, it too failed to be practical and never gained widespread use [35].

In 1905 Dr. William Davenport of London designed several iron lungs: one for a seated subject, one for supine use, and a portable unit modifying the one of Woillez’s design. The patients frequently experienced an extended dying process with their use despite the addition of oxygen. Operating the bellows or piston pump to generate negative pressure by hand limited its application [36] (Fig. 2.6).

In 1908, Dr. Peter Lord of Worchester, Massachusetts, patented the design of a respirator room with cyclic pressure changes allowing nurses to work inside it with the patient. Huge pistons in the ceiling provided the negative pressures and the fresh air (Fig. 2.7).

In 1911, Charles Morgan Hammond of Memphis, Tennessee, patented his cabinet respirator or artificial lungs, similar in design to Woillez, having worked on it since 1905. It passed its first clinical trial in 1912, saving more human lives by 1914. He improved on his models for the next 20 years, but for lack of commercial support, its production was limited to Tennessee. When he failed to renew his patent, it expired and his sentinel “first” was abandoned [36] (Fig. 2.8).

In 1916 a cumbersome, useless unit patented by Melvin L. Severy of Boston was made. Here the patient had to stand in a box, pressing his nose and mouth through triangular openings between two eye slits. It was powered by a bicycle like apparatus of pulleys and electromagnets to create the negative pressures to assist breathing [36] (Fig. 2.9). Severy also designed a negative pressure cuirass.

In 1918 two physiologists, Felix P. Chillingworth and Ralph Hopkins from Tulane University, reported a new idea, the successful use of an electrically powered body plethysmograph to ventilate tracheotomized dogs by alternating pressures around the body, when studying the effects of lung distension on circulation. With a tracheotomy tube the lack of a neck seal did not matter. They did not realize the potential for using such a negative pressure system for humans but it showed the potential for supporting breathing by alternating pressures around the body and served to inspire Philip Drinker et al. [37].

Poliomyelitis epidemics, while prevalent from the 1870s, resurged in 1916, and were spreading worldwide. Children were the most frequently affected, leading to its designation as the dreaded “Infantile Paralysis.” The high mortality rate when breathing was affected was soon recognized and spurred the development of efforts to reverse the near 100 % mortality from respiratory failure. Many negative pressure ventilator innovations followed, spurred by this need, but poor communication and/or an absence of training and resources limited their application.

W. Steuart in South Africa, in 1918, made an airtight, rubber-lined rigid wooden box, with a mattress, that was applied over the chest and abdomen. It was the first workable cuirass, through which a variable speed motor drove a bellows rhythmically to produce negative pressures. Tidal breath and minute volume were adjustable along with valves that could adjust the amount of negative pressure. A glass panel allowed observation and the top of the box could be removed quickly in case of need for patient access. Steuart presented this work to the South African Medical Society. He was unable to conduct a clinical trial because the last patient died before he completed the work. However, the principal of longer term artificial respiratory support where breathing could be individually adjusted had now been introduced for the first time [38] (Fig. 2.10).

In 1900 Dr. Tursten Thunberg of Lund, Sweden, developed a truly novel concept: ventilating without chest movement. He designed a “Barospirator,” producing the final sarcophagus-like version in 1920. It was a tank large enough to encase the whole patient. His idea was to limit chest motion to a minimum. His was the first mechanical ventilator applied successfully for “long-term” use of several months [39] (Fig. 2.11). Its first success was to save a patient from paralyzing poliomyelitis [40]. A. L. Barach, in order to make the chest cage completely immobile to “rest” the lungs to allow advanced tuberculosis cavities to “close,” modified the Barospirator by making an upper section, encasing the head, and a lower body section, separated by a fine mesh nickel plated screen, producing cyclic, equal pressures both inside and outside the chest so that air would flow with no chest motion. He separated the head in his Barospirator because of a delay in pressure transfer due to airflow resistance from the upper airways, which allowed continued, albeit reduced, chest movements, and thus not total rest. He reported applying this therapy for 12 h per day and felt that it could take the place of induced pneumothorax, without or with the instilling of space occupying materials in the pleural cavity to collapse the cavitated lungs, all before the availability of chemo therapy for tuberculosis [41]. The effectiveness of Streptomycin and Para-aminosalicylic acid in 1945-46 ended the need for this.

In 1926, Wilhelm Schwake of Germany patented a totally impractical pneumatic chamber in which the patient had to stand and use his own hands to move a large bellows, comprising the whole side of the box, to generate negative pressure to “draw out the gaseous by-products” [36] (Fig. 2.12).

In New York that same year, the Consolidated Gas Company faced the need for resuscitation and respiratory support for an “alarming number” of electric shock, carbon monoxide gas, and smoke inhalation asphyxiated workers. They engaged Dr. Cecil K. Drinker, Professor of Physiology at the Harvard School of Public Health, to help these victims. Dr. Drinker called on his brother engineer Philip A. Drinker, who worked with pediatrician Dr. Charles F. McKhann, III, and physiologist Dr. Louis Agassiz Shaw. Like Chillingworth and Hopkins, they had been experimenting with placing intact curare-paralyzed cats in iron boxes, with only the head protruding through a rubber, now airtight, collar. To move their thoraces, negative pressures were generated by a hand-operated syringe and later by a hand-operated cylinder piston pump causing inspiration when the air was sucked out. Pressure measurements in the plethysmograph, correlated with volumes of air moved in the cats. By 1927 they showed that, by alternating suction and release, the cats could be kept alive for several hours [42]. Such success, and the demands from the polio epidemic, led to their constructing a unit large enough to accommodate a human. They salvaged materials to make the first unit for about $ 500.00 ($ 6579 in 2013 US dollars). It was a metal cylinder with one end for the head to protrude with the neck encircled by an airtight collar. The other end had a piston pump through which pressure changes were generated [43]. Reliable electricity became available first on the two coasts in the USA about 1926; [44, 45] this allowed the unit to continuously produce alternating positive and negative pressures by a series of valves, thus moving the thorax. They used the units on themselves and on a diener recruited from the laboratory. Harvey Cushing was the “audience” for these experiments. Drinker himself was hyperventilated by this device and even though he did not resume breathing for 4 min he felt no anxiety as he “simply waited until he felt the need to take a breath.” Their first patient was a patient of Dr. McKhann, an 8-year-old girl with polio who was first acclimated to the noise of the unit by placing it in her room over night. By morning she was cyanotic and comatose. She was placed in the chamber and regained consciousness in several minutes and was said to have asked for ice cream a short time later [46]. Even though she died of pneumonia several days later, this dramatic success for the first reported human use of the iron lung, a device that supported breathing by externally applied alternating pressures, and the terrible polio epidemics, led to their widespread use. The funding for 14 more units was provided by the New York Consolidated Gas Co; one of these units was donated to Bellevue Hospital in New York City in 1929 when its use saved an unconscious apneic student nurse from an accidental drug overdose, a now expanded clinical indication for such ventilatory support. It was then applied to a Harvard student who had contracted poliomyelitis in Cambridge. This allowed him to gradually regain his breathing ability, to finish school, and go on to a full career. This was the first documented instance of private corporate financial support for research that led to direct and wide spread clinical application, i.e., “translational” medicine, becoming the model for such enterprises since. The incredible success of the Drinker-Shaw iron lung tank ventilator, in conjunction with the availability of reliable electric power across the whole country, and the escalating number of polio victims (from 20,000 to 60,000 cases per annum [47], affecting mostly children), set in motion the demand for mass production of the now-named Drinker Respirator. Warren E. Collins Company of Braintree, Massachusetts, was commissioned to make the units but their cost of $2000.00 each ($ 21,444 in 2013 US dollars) equaling the cost of two automobiles in 1929, limited their distribution (Fig. 2.13).

In 1930, James L. Wilson, desperate to treat children with paralysis from polio, worked with Drinker to have the tank redesigned so many children could be treated in a “Respiratory Center,” allowing concentrated nursing care, although not knowing if recovery would ensue. Most children recovered and no longer required such ventilatory support, but the ones who did not recover lived in their tank ventilators, sometimes for more than 50 years. This was the beginning of designated respiratory care units for larger numbers of patients, the pre-intensive care units of today. As the key organizer, Wilson recruited The March of Dimes to establish 13 such centers across the USA [48] (Fig. 2.14).

The polio epidemic reached its “worst in the 20th century” in 1931. The Drinker unit was bulky and complex, and its cumbersome design making it difficult to use, coupled with the unaffordable cost, inspired John Haven Emerson, an engineer in Cambridge, Massachusetts and the grandson of poet Ralph Waldo Emerson, to simplify, modify, and improve the unit at half the cost in 1931. In addition to a sleeker design, his additional innovation was adding an airtight, transparent dome for the head for the application of IPPB so the body of the unit could be opened for unhurried nursing care while the patient was continuously supported noninvasively [50]. This unit had several glass side ports and larger rectangular metal doors on both sides through which care could be administered, blood gases and bloods drawn, and clinical observations made. He made a thick leather diaphragm to move the air and powered it with a standard vacuum cleaner pump to which a cyclic feature was added. Two vacuum pumps could be connected in series to amplify the pressures if needed. It could also be manually operated should there be a power failure, not uncommon at that time. The adult unit was 33”wide × 92”long × 56” high, and despite the weights for varying sizes from 640 to 800 lbs (290–337 kg), it was a great success (Fig. 2.15a, 2.15b an opened unit; 2–15 C a unit with a transparent dome for the head; 2-15D Custom made model for a judge). Emerson deliberately decided not to patent his design because he wanted to make the units affordable and available as soon as needed throughout the country [51]. Their use was rapidly expanded where the new “respiratory centers” could accommodate many patients into single large rooms for multiple patients (aka “Tank Farms”) and became the first dedicated respiratory care units (Fig. 2.14). A lawsuit by Drinker for infringement of patent rights failed after John Emerson published a pamphlet with a series of pictures depicting The Evolution of “Iron Lungs” with previously designed negative pressure tank ventilators long before the Drinker model [49]. This pamphlet is the source for some of the figures in this chapter. Some of the patients, who either were unable to regain independent breathing function or only regained partial function while awake, were continuously or nocturnally supported for more than 60 years in their iron lungs [52, 53]. One such woman, who contracted polio in 1955 at age 5 just before the polio vaccine, is still using negative pressure ventilation 58 years later. She wrote a Haiku poem: “The story of Jonah—narrow my bed in the belly of this iron lung yet wide enough for the dreams any child would chase [54].” The Emerson Tank Respirator needed only “greasing of the motor and a new fan belt once a year” to maintain reliable function for many years [55].

Another cheaper innovation was designed in Denmark in 1931 by August Krogh, a physiologist, who, as with Cecil Drinker, was concerned that the tight neck collar would limit blood flow to the head. After seeing the Drinker model work in New York, and with bulk and costs prohibitive for transporting the iron lung to Denmark, he “simplified” and improved on it by using water to power it from city pipes. A piston cylinder, acting on a large spirometer bell, created reciprocating movements from alternating the water between the upper and lower compartments of the piston to effect breathing cycles. The temperature inside the tank could be regulated by a water jacket. Another innovation was that the head could be placed in a 15° head down position and could be encased in a hood through which oxygen or a mixture of 95 % oxygen and 5 % carbon dioxide would be administered to “stimulate” respiration (Fig. 2.15c). Mortality fell to 30 % using this ventilator. He also made an infant-sized version and a rocking stretcher, a forerunner of the Rocking Bed [56]. John Emerson advanced the Rocking Bed design and manufactured and distributed an electrically operated one used for long-term (for as long as 45 years) intermittent noninvasive ventilatory support for polio and other patients with persistent diaphragmatic paralysis [57] (Fig. 2.24). He also designed a Motion Bed to prevent skin decubitus ulcers and lung atelectasis, and to enhance circulation, in bed-ridden patients. We reported the use of the Emerson Rocking Bed for patients who developed diaphragmatic paralysis after open heart surgery, allowing for extubation or tracheostomy decannulation and recovery at home [58].

Chance favors the prepared mind, and with the extensive worldwide polio epidemics there was an increasing demand for negative pressure ventilators. In England in 1938, resources were contributed by William Morris (aka Lord Nuffield), an engineer-philanthropist, and owner of the Morris auto factory. After reading a newspaper headline that “Iron Lung Arrives Too Late” to save the life of a young woman, he conferred with Sir Robert Macintosh, head of the Department of Anesthesia at Oxford, who had earlier impressed him with a film of the Both Respirator’s capacity to perform artificial respiration. This unit was invented in 1937 by the brothers Edward and Donald Both in Adelaide, Australia. It was made from plywood, making it lighter, easier to transport, and cheaper than earlier versions. Edward had gone to England to sell an electrocardiograph he designed. Learning about the polio epidemic while there, he offered his design of the Both Portable Cabinet Respirator, which was quickly accepted, manufactured locally, and put into use (Fig. 2.16). After Edward built a unit for Robert Macintosh, a short film was made. This was the film that inspired the philanthropic act of Lord Nuffield when he offered to manufacture 5000 Both Respirator units at a personal cost of £ 500,000 (equal to $ 2.5 million in 1938 and $ 32.7 million in 2013 US dollars) so that one unit could be given to every hospital in the UK, giving him “the pleasure” of saving lives. Nuffield entrusted Macintosh to accomplish their distribution, and for teaching their use through daily demonstrations at the Radcliffe Clinic. By 1939, only 1 year later, more than 1700 Both Respirators had been allocated and its use taught throughout the UK. This heralded the extensive application for successful prolonged intervention for breathing inadequacies saving countless lives with NPNIV . Since Macintosh was an anesthesiologist, he conceived of using the Both Respirator to manage postoperative patients as well. He was the first, in 1940, and then with Mushin and Faux, in 1944, to demonstrate the successful prevention of postoperative atelectasis by use of the Both Respirator. This gave birth to the advent of “critical care” medicine to provide respiratory support, and eventually to critical care units [59, 60]. Space needs and nursing care demands, however, remained impediments to the widespread use of such still bulky equipment.

In 1952, an English doctor-engineer, George Thomas Smith-Clarke, made the Cape Warwick iron lung with a head down option, redesigning it from the Both model, which was then widely used in England for polio patients [61] (Fig. 2.17).

In 1961, W. Howlett Keheller, MD, modified the design of the iron lung so it could be rotated 180°, allowing for automatic turning, to treat or prevent atelectasis, successfully treating three patients with neuromuscular respiratory weakness (2 post-polio, 1 Guillain-Barre) who developed life threatening airway secretion retention associated with atelectasis [62].

In 1975, Sunny Weingarten, a polio survivor from age 7 ½, designed a lighter (100 lbs; 45.5 kg), more portable tank, a “Porta-Lung.” It was made from fiberglass, in four sizes, the extra small for children at 30” length and up to 71” for adults. The unit had flexibility for clinical use in that it had several brands of vacuum pumps accommodating adjustment of pressures ranging from + 20 to − 60 cm H₂O, respiratory rates from 4 to 60/min, and variable inspiratory/expiratory ratios (Fig. 2.18). He traveled over 50,000 miles in his van using it in all the then 48 states. He died at age 70 in 2012 having been on ventilator support for life, initially full time, then nocturnal only, and finally back to full time, switching to positive pressure as he aged before his death [63]. The Porta-Lung was patented and FDA approved, and is still being used by patients due to their comfort and reliability [64]. The problem with this unit currently is replacing worn out negative pressure pumps, since the five that were available are no longer manufactured [65].

Others, especially Italian doctors, remain active in using negative pressure noninvasive ventilation (NPNIV) , and some have made their own version of a tank. Drs. Sauret and his associates [66], and Corrado and Gorini summarized in 2002 the literature on the use of both NPNIV and noninvasive positive pressure ventilation (NPPV) for both acute and chronic respiratory failure , which consisted in mostly uncontrolled reports. The need for endotracheal intubation or tracheotomy was the primary end point assessed, and was not different between patients who used NPNIV or NPPV. Mortality was also no different [67–70].

Complications from iron lung use slowly became apparent with their wider use. It stemmed from their bulk and weight, taking up so much space in a hospital room that floors had to be reinforced to support many tanks (Fig. 2.14). The patients felt isolated, resulting in claustrophobia, disorientation, and loneliness for many as well as inhibiting good nursing care. One such patient of mine, a post-polio wheelchair-dependent judge in New York City, started having recurring nightmares of being “trapped” in the iron lung when he developed right heart failure from chronic hypoventilation 40 years later [71]. Using the Pneumosuit (Nu-Mo suit), instead, reversed the hypoventilation, and restored his capacity to work. Vital signs in the iron lung were cumbersome to measure, providing personal hygiene was difficult, and frequent turning to prevent decubitus ulcers was necessary. Even though the Emerson transparent dome reduced these problems for some of the time, air leak prevention from the tightness of the collar created neck skin abrasions and headaches. Patients experienced distress on hearing their own pulses from the tight collars. When less tight, the air leak made them feel cold, especially if they had total body paralysis as well. Some had difficulty initially learning how to synchronize their swallowing while in the iron lung. Aspiration due to the imposed supine posture would occur, at times resulting in death from pneumonia despite the support. Inadequate airways clearance, absent cough capacity, and lack of effective antibiotics contributed to such lethal pneumonias [72]. While some patients successfully used these units in their homes for many years, such units could not be housed there for many patients, particularly at the time that home care was not yet a developed discipline. The polio epidemics and his own polio inspired Franklin Delano Roosevelt (FDR) with friends to found The March of Dimes to provide the financial support for many patients in hospitals, in rehabilitation units, in the homes, and for scientific research for the polio vaccines. In fact it was FDR, focused on regaining the use of his legs after polio, who helped to establish the first rehabilitation unit in Warm Springs, Georgia, dedicated to the care and recovery of polio patients in 1924 [73].

These problems furthered the design of negative pressure devices that only covered the chest or the chest and abdomen called cuirasses, or chest shells, due to their resemblance to medieval protective chest armor made of leather or metal which covered the neck to the waist. While Steuart’s model was designed in 1918 it was not widely known or used. The design of the earlier cuirass models also allowed for only the anterior expansion of the chest wall due to its ending at the waist which limited diaphragmatic descent by compressing the anterior abdominal wall during inspiration. Lateral expansion was severely limited when the unit was flush with the lateral chest walls. The apices were usually excluded by the shell’s upper configuration and necessary seal. Other shell designs that ended at the umbilicus or just above the pubis allowed for more diaphragmatic descent. If the metabolic requirements were low, the neck to waist model could be adequate. The advantages were their portability, lower cost, and the freeing of the extremities and pelvis with greater mobility and less claustrophobia. Some patients were able to be adequately ventilated in a near sitting position with such units, allowing for more daytime use. Some combined it with positive pressure using a mouth piece or lip-seal [74]. In fact, one of my chronic obstructive pulmonary disease (COPD) patients who had intractable dyspnea and chronic hypercapnic respiratory failure used NPNIV via a Nu-Mo suit nightly, achieving eucapnia, and went home to Brazil (Fig. 2.23). She worsened 2 years later. On her reevaluation, she had gained 35 lbs. This resulted in upper airways obstruction while using nocturnal NPNIV as Goldstein and Levy had reported [75, 76]. Increasing negative pressure from − 35 to − 40 cm H₂O worsened this. She refused any other form of support. Adding  + 5 cm H₂O nasal continuous positive airway pressure (CPAP) circumvented the upper airway obstruction, and she went home successfully using her Nu-Mo suit NPNIV and nasal CPAP.