1931: The Emerson Respirator

His father worked as Commissioner of Health in New York during the polio epidemic of 1916, and perhaps as a result of this inventor John Haven Emerson (1906-1997) had a recollection of suffering from the illness as a child.  So he had a vested interest in inventing a mechanical respirator that was more efficient and more comfortable than the Drinker and Shaw Respirator.  He ultimately refined the Drinker and Shaw Respirator and came up with his own product that became the Emerson Respirator.

Like the Dinker and Shaw Respirator, the patient would lie on a table that could be slid in and out of the tank.  The table was often referred to as a cookie tray.  The side of the tank, which was blue, had portal windows so nurses could have access to the patient whenever they needed.  Over the patient's head was a mirror they could see behind then. The bellows were stored under the tank, which was lightweight, and wheels were added to make the devices mobile. (1)

The machine could also produce a large range of tidal volumes by adjusting the pump settings, and it was relatively quiet (a noted improvement over the Drinker Respirator).  In the event of power failure there was a hand crank at the foot end of the device so the doctor or nurse (or later the inhalation therapist) could provide breaths manually. It was also simple to produce, which made it affordable.   It was said to be about half the cost of the Drinker Respirator.   Emerson's design still cost as much as a house, yet it was still somewhat reasonable, or about half the cost of other such respirators at the time. (see chart below) (2)

Emerson introduced his iron lung during a polio epidemic in 1931, and it soon became the most popular respirator in hospitals in Europe and the U.S.  Emerson's respirators continued to be the most used ventilator until  the 1950s and 60s when the Jonas Salk and Albert Sabin polio vaccine became available for kids around the world.  The vaccine was first introduced in 1954, and injected into millions of kids between 1956 and 1960 "with dramatic results." An oral vaccine was later introduced and administered to millions of kids between 1962 and 1964. (3)

There were various versions of the Emerson Lung, and the Drinker and Shaw Respirator, that were available in hospitals around the United States and Europe.  Richard Daggett, in his 2010 book "Not just polio: my life," explains that the machines made a whooshing sound as air entered and exited the patient's lungs. He explained that he was placed in a Drinker Collins Iron Lung in the early 1950s, and he described waking up in the machine: (4, page 30, 31)

There was a mirror over my head and, in the mirror, I could see a row of large black bellows across the room.  They were going up and down.  I didn't know much about respirators, but I figured one of them must be making me breathe.  I tried to figure which one it was by timing my breathing with the motion of each bellows.  None of them seemed to match my breathing pattern. It wasn't until later in the day, when my mirror was adjusted upward, that I realized that those bellows were all attached to the underside of other respirators.  I couldn't see mine because it was beneath me.... I was in a Drinker Collins Iron Lung."  (4, page 29)

Daggett explains that as a child it was difficult to grasp the seriousness of having bulbospinal polio and, ultimately, pneumonia.  He wrote: "I was very naive. I had no understanding of how serious my condition was.  Oh, I knew I was completely paralyzed, but the long-term impact did not sink in.  My greatest concern was that I might miss the first day of school." (4, page 33)

It must have been common for these patients to develop pneumonia, as their would have been constant secretions forming in the upper air passages that needed to be cleared, or they would be inhaled, thus causing respiratory infections such as pneumonia.  Daggett mentions the constant urge to blow his nose, which he often did "without even using a tissue." (4, page 31, 33)

Because their muscles of respiration would have been paralyzed, these patients would have lacked the ability to clear their own secretions. So, despite having the means of breathing for them, some of these patients still drowned in their own secretions. Others developed pneumonia, and this this further complicated treatment. So keeping airways clear of secretions was a constant concern for caregivers. This made it important to have easy access to these patients.

Yet bulky iron lungs made it hard to access patients. Their bed had to be slid out from inside the tank, and artificial breaths performed manually. One person had to turn the patient, while another cleared secretions.

This problem was remedied somewhat with the invention of a suction device in 1937.  Daggett said he had a tracheotomy that gave caregivers an easy means of clearing his airway. This may have been aided by an early suction device. (4, page 30)

Iron lungs were viewed as neat life saving devices. Yet they were also viewed as horrible way to spend the rest of your life. Thankfully, for most of those kids inflicted with polio, the paralyzation was only temporary, with most recovering after spending a week or  two inside a tank. Many, like Dagget, lived to tell their stories.

Iron lungs were replaced during the 1950s by positive pressure breathing machines. This was a necessary change because it made it easier to access patients. This also made it easier to breathe for patients during operations and in emergency situations. Still, during an era when many children were inflicted with a paralyzing disease, the iron lung was a godsend.

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Here are some interesting facts about iron lungs from http://americanhistory.si.edu/ :

1. The National Foundation of Infantile Paralysis began mass distribution of tank respirators in 1939
2. In the 1930s, an iron lung cost about $1,500  -- the average price of a home
3. 1n 1959 there were 1,200 people using tank respirators in the U.S., in 2004 there were 39

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References

1. "The Iron Lung and Other Equipment,"  http://americanhistory.si.edu/,  http://americanhistory.si.edu/polio/howpolio/ironlung.htm, accessed February 27, 2012
2. Previtera, Joseph, "Negative Pressure Ventilation: Operating Procedure (Iron Lung)," Tufts Medical Center, Respirator Care Programs, http://160.109.101.132/respcare/npv.htm, and http://160.109.101.132/respcare/ironlung.htm, accessed February 27, 2012
3. "Emerson Infant Respirator," Case Western Reserve University, Ditrick Medical History Center,  http://www.neonatology.org/pdf/EmersonInfantRespirator.pdf, accessed February, 27, 2012
4. Daggett, Richard Lloyd, "Not just polio: my life story," 2010, Bloomington, IN, iUniverse
5. Drinker, Charles, Charles F. McKhann, "The Use of a New Apparatus for the Prolonged Administration of Artificial Respiration: A Fatal Case of Poliomyelitis," Journal of the American Medical Association,  May 18, 1929, reprinted in same publication on March 21, 1986, volume 255, no. 11, pages 1473-1475 
6. Drinker, Phillip A., Charles F. McKhann, "The iron lung: first practical means of respiratory support,"  Journal of the American Medical Association, 1986, March 21, vol. 255, no. 11,, pages 1476-1480

1929: The Drinker Respirator

A clipping from a newspaper article, probably sometime around 1928.
Photo form the University of Virginia Historical Collections. Photo
originally published in "The use of a new aparatus for the prolonged
administration of artificial respiration" by Phillip Drinker and Charles
F. McKhann. (1, Iron Lung)

The first effective ventilator that gave breaths without an operator was the Drinker Respirator by engineer Phillip Drinker (1894-1972).  The product was  introduced to the world in a 1929 article by Dr. Phillip Drinker and Dr. Charles F. McKhann. (1, Iron Lung)(4)

The report highlighted the fact that manual resuscitators (such as the lungmotor or pulmotor) forced too much air into the lungs too fast, and could only be used for so long due to worker fatigue. Plus, they wrote that "respiratory excursion obtainable by manual efforts is most disappointing. In our experience, it is almost impossible to produce and maintain adequate oxygen interchange by manual methods of artificial respiration alone, in cases requiring long term administration." (4, page 1658)

Their solution was the Drinker Respirator.  It was the first mass producible negative pressure ventilator, otherwise known as the iron lung, mechanical respirator, or tank respirator.

Image of the Drinker Iron Lung.  You can see the marine like port
holes on the sides of the tank that could be used to see the patient.
Small holes could be accessed for basic toughing. (5, page 232)

This respirator is often referred to as the Drinker and Shaw respirator because Phillip Drinker worked with his brother Cecil and Dr. Louis Shaw to create and test the device. The Consolidated Gas Company of New York came up with the idea and recruited Harvard Professor Cecil Drinker. He in turn recommended his brother, who was a chemical engineer. Dr. Shaw was a colleague of Phillip. (1, Iron Lung)

The final product was first introduced to physicians at Harvard in 1928. Actually, the original name for this respirator was the Drinker Tankrespirator, but the name iron lung is the name that ultimately stuck. No one knows for sure who came up with the term "iron lung." One article cited an "anonymous journalist."

While it was useful for many types of patients (morphine overdose, carbon monoxide poisoning, electric shock, near drowning, etc) it was originally made for those affected by coal gas poisoning.  (7, page 93) Yet it is is most remembered as being associated with the polio epidemics, used to breathe for the many children most severely stricken with the disease infantile poliomyelitis.

The machine consisted of a metal tank that completely enclosed the patient's body except for the head.  The patient would lie on his back on a bed.  The bed would then be slid into the tube or tank.  The neck would be sealed around rubber collars to provide a seal to prevent air from entering or escaping the tank.

Inside the tank was completely air tight.  Pumps, which were originally two vacuum cleaners with bellows, and a manometer used to operate the device, sat on a table next to the tank, and they were operated by electricity and a large bedside oxygen tank.  The rate could be set by adjusting dials on the gearbox.  While there was no means of measuring tidal volume, breaths could be provided at a constant depth and rate. There are reports that the machine was quite noisy, so one must imagine this only compounded the stress of patient.

A patient could live inside one of these tanks for days or weeks without harm.  The patient, since his head was outside the tank, could "adapt themselves quickly to their new method of breathing and learn to eat, drink and sleep without having the attendant stop the machine." (6, page 95)

To examine, treat, and bathe the patient the bed would have to be slid out of the tube.  If necessary, manual methods of ventilation could be used while these procedures were being performed.  (5, page 232)

Image of the Drinker Respirator.  You can see that the pumps
and manometer were on a separate table to the left.  To access the
patient, the bed was slid out as shown. While outside the tank
the patient could be kept alive with manual methods of respiraiton
if necessary. As you can see, maintaining the tanks and
caring for the patient was a cumbersome task.   (5, page 231)

For less invasive procedures, such as taking temperatures, blood pressures, auscultation, checking IV lines, and basic touching of the patient, there were "small holes (pipe taps) on the sides of the tank.  For the basic observation of the patient there were "marine like port holes' also on the sides of the tank.  (5, page 234)

Here you can see the rubber collar that secures
tightly around the patients neck so that the
head could rest outside the tank on the
adjustable support.  (5, page 233)

Over time the iron lung was improved in order to make the machines more accessible to patient care, and to make the machines easier to operate and move from one room to another.  For example, by the 1950s the pumps and bellows would set under the tank to make the unit more compact, and wheels were added to the legs.  Of course another reason this was probably done was to keep up with the competition.  

The Drinker Respirator was ideal because it allowed physicians an opportunity to keep their patients alive long enough to treat them, thus allowing their bodies a chance to recover.  While the machines were ideal for victims of all ages, they were most remembered as being used for the many children stricken with the most severe forms of infantile poliomyelitis, which causes respiratory paralysis. Without the ventilator these kids would often succumb to fatigue, respiratory failure, and ultimately death.

While the devices may have been cumbersome, uncomfortable and noisy:

"The response of these patients to the respirator was very gratifying," according to a 1931 article in the Western Journal of Medicine.  "Usually before their condition became alarming they were told that if they became too fatigued they could have the help of the respirator, and in several instances patients asked to be placed in the machines for a trial.  A few of the children were very apprehensive and had to be given opiates over a short period when first placed on the respirator.  None of these patients had any difficulty in adapting themselves to the rhythm of the machine."  (2, page 5)

Many children with poliomyelitis recovered after a week or two in the iron lung, and went on to live normal lives. .  

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The Technical Exposition:  Opportunity to try the Dinker Respirator:  Warren E. Collins Inc. will exhibit the Dinker Respirator, for prolonged administration of artificial respiration in cases of infantile and diptheretic paralysis, gas and drug poisoning, electric shock, alcoholic, coma, etc.  Doctors are invited to make a personal trial of the Respirator to see how it feels. New improvements on the Roth-Barach oxygen tent and the Benedict-Roth Metabolism Apparatus will also be of interest, and demonstrations will be gladly given without obligation.  See these in Booth 110, near the main entrance.  (3, page 1617)

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References:

1. "Iron Lung: 1929 Dinker Respirator," University of Virginia Historical Collections at the Claude Moore Health Sciences Library,"  http://historical.hsl.virginia.edu/ironlung/pg4.cfm, accessed February 26, 2012
2. Shaw, E.B.,  H. E. Thelander, and M. A. Limper, "Respiratory Failure in PolioMyelitus -- it's treatment and the Dinker Respirator," Western Journal of Medicine, 1931 July; 35(1), pages 5–7
3. "The technical exposition," Journal of the American Medical Association,  1931, vol. 96, no. 19, page 1617, http://jama.ama-assn.org/content/96/19/1615.full.pdf
4. Drinker, Charles, Charles F. McKhann, "The Use of a New Apparatus for the Prolonged Administration of Artificial Respiration: A Fatal Case of Poliomyelitis," Journal of the American Medical Association,  May 18, 1929, reprinted in same publication on March 21, 1986, volume 255, no. 11, pages 1473-1475; 
5. Drinker, Phillip, Louis Shaw, "An apparatus for the prolonged administration of artificial respiration,"  Journal of Clinical Investigation, June 29, 1929, 7 (2), pages 229-247
6. "Philip Drinker '15 given medal of invention," The Princeton Alumni Weekly, October 23, 1931, volume 32, page 95
7. "Obituaries: Phillip Drinker 1894-1972," Anal of Occupational Hygiene, 1973, 16 (1), pages 93-94
8. truy this one or this one or htis one. or htis one 'list of landmark articles,            check out this presentation

1830-1900: Early ventilators and intubation devices

Figure 1 -- Bouchut's Endotracheal Tube
(23, page 6)

If you are a physician, nurse, or respiratory therapist you can skip the next couple paragraphs. For the rest of my readers, I would like to take a moment to explain about breathing and artificial breathing. I want to explain about ventilators and intubation.

Obviously, in order to stay alive people must continue breathing. By 1830 physicians were well aware of this fact. This was important for victims of near drownings, and for patients who required anaesthetics during complicated surgeries. During these times, some method of artificial resuscitation was required, or some means of breathing for the these patients, at least until they regained their ability to spontaneously breathe.

How do people inhale? Natural inhalation occurs when the muscles of inspiration constrict, thus pulling the chest wall outward. This creates a negative pressure inside the chest resulting in air being drawn (sucked) into the lungs.

How do people exhale? Natural exhalation occurs when the muscles of inspiration relax, thus causing the chest wall to naturally recoil. This creates a positive pressure inside the chest resulting in air being forced out of the lungs.

Figure 5

Negative Pressure Ventilators mimic the natural means of inhaling. The patient is placed inside a tank that creates a negative pressure that draws the chest outward, thus causing inhalation. The problem with these machines is that they made it so that it was difficult to gain access to the patient. This problem was resolved with positive pressure ventilation.

Positive pressure ventilation essentially involves forcing inhalation by creating a positive pressure. The most primitive, and most basic, form of positive pressure ventilation is mouth to mouth breathing. Another mean is to provide positive pressure by using a mask. A modern name for this is noninvasive positive pressure ventilation, although this term would not be introduced to the medical profession for another 150 years.

By the 1830s, the medical profession was well aware of the importance of breathing. They had some methods of manual resuscitation, although most of these required more than one person to perform, were time consuming, and were exhausting. None could be performed for any length of time.

An added concern of these methods is that they involved moving the patient's arms and legs, risking injury to the body. They also did not guarantee that a patient was receiving an adequate tidal volume. So the need arose for some mechanical apparatus to provide artificial resuscitation.

That said, the need had arisen for a mechanical apparatus to provide, or at least assist, with artificial resuscitation. Ideally it would be something that would eliminate the risk of breaking arms and legs, would provide an adequate tidal volume with a low pressure, and would reduce or eliminate the need for manual power.

1832:  Dalzeil respirator:  In 1832, Scottish physician John Dalzeil described what many refer to as the precursor to negative pressure ventilators that would follow, including the Woillez Iron lung which is described below. (16)  It was essentially the first known example of noninvasive negative pressure ventilation.

It was a box, and he once used it to ventilate a man who was a near drowning victim.  The patient sat up while in the box with his head and arms outside the box.  The box was airtight, and bellows inside caused a negative pressure that caused inspiration.(16)

A window on the outside of the box allowed an observer to see if it was actually causing respirations.  This is often referred to as the first tank respirator, or the first iron lung.  The box had to have been hand powered, and there is no documentation it actually worked.  (16)

1845:  Oxygen breaths  Of course another thing that physicians learned early on was the importance of making sure a patient is getting enough oxygen while artificial breaths were being performed. A man named Erichson invented the first device that provided positive pressure breaths with oxygen through a cannula inserted through a pipe inserted into one of the nostrils.  He recommended ten breaths a minute.

Figure 4

1858:  Bouchut's Intubation Tube:  The noninvasive methods of providing positive pressure ventilation were not effective long term.  The negative pressure ventilators were fine, although they usually consisted of large, bulky tanks that made gaining access to the patient difficult. So another means was needed to provide artificial resuscitation long term. 

So this inspired early experiments with inserting hollow tubes into the airway.  This is considered to be invasive. So, from here on out, anytime a person needs to have a tube inserted into their airway to provide resuscitation, it is referred to as invasive ventilation. 

Earlier physicians tried using a catheter, but this wasn't very effective. In 1858, French physician Eugene Bouchut (1841-1898) became the first to describe insertion of a tube into the airway as opposed to a catheter in a case of dyspnea. The tube he used during seven cases between 1856-1858 (24, page 661-662) was a rounded silver tube narrower at the end to be inserted as you can see in Figure 1, and it was 1.5 to 2 cm long and 7 cm in diameter.

Interestingly, a silk thread was attached to the distal end of the tube that was "brought out to the mouth, and was intended to prevent the tube from going down the trachea or esophagus; and to allow it to be taken out when necessary." 

He later "insisted on the distinction between his method and catheterism." However, of the seven cases he cited to the French Academy of Medicine, only two lived and both required tracheotomy.  Yet he proved the procedure could be done. 

Various other physicians described success with this or similar procedures between 1858 and 1880 when Joseph O'Dwyer (see below) introduced a more effective tube. (see figure 1)(23, page 5)

1867:  Richardson's Double Acting Rubber Bellows:  Benjamin Ward Richardson created a bellow system similar to Hunter's Bellows (although he may not have known of Hunter's Bellows). The original system took up a lot of room, so he invented the double acting bellows, which "consists of two rubber bulbs terminating in common tube that was called the nostril-tube."  One bellow supplied inspiration, the other expiration.  (See figure 4)

1875:  Blake cures poison victim:  Using a device similar to Richardson's Bellows, Blake connected a reservoir of condensed oxygen to it and treated a case of acute poisoning with success.  Before this time artificial respiration (often referred to as insufflation) was used mainly to treat neonatal asphyxia, but now the focus was also on treating adults.  The nozzle of the device was inserted into the nostril.  

1876:  Woillez Iron Lung (Spirophone): While the iron lung wasn't mass produced until the late 1920s, there were some earlier models that acted as prototypes of later designs.  In fact, the design described by Woilliz was quite similar to the Drinker and Shaw and Emerson iron lungs.  The only drawback to Woillez's design was he didn't have access to electricity, so his machine was powered by hand.

At the French Academy of Medicine in Paris in 1876 Woillez described his respirator this way:

"(The apparatus is) a zinc or sheet iron cylinder large enough to receive the body of an adult up to the neck. It is equipped with wheels which permit moving it rapidly to the place where it is necessary. The cylinder set almost horizontal slightly inclined is hermetically closed at the boot end and open at the head end. Through this opening at the head end you slide the body of the patient by means of a sort of stretcher equipped with rollers, on which he is previously placed; then you close the head opening around his neck by means of a diaphragm that you attach to the edges of the opening. The head thus remaining free rests on an appropriate support. A flexible impermeable fabric attached to the cover diaphragm is secured around the neck to avoid as far as possible the passage of exterior air to the inside of the apparatus, at the moment when the vacuum is produced there.

The air thus confined in the apparatus around the body of the patient can be partially rapidly withdrawn by means of a powerful aspirator bellows of about 20 litres capacity actuated by means of a lever. The interior of this pump communicates with the interior of the apparatus through a large tube tightly screwed on." (17)

There were other similar designs, yet none became mass producible mainly due to lack of knowledge of electricity at the time.

O'Dwyer's Intubation Tube for a child 2-3 years old (23)

1880:  The first useful endotracheal tube:  Dr. Joseph O'Dwyer (1841-1898) of New York, and his fellow physicians at the New York Foundling Asylum, observed problems with trachetomy.  He decided another means of breathing for patients was necessary, and he at first trialed flexible catheters into the nasal passages.

Yet this didn't meet his satisfaction so he devised a tube to be placed into the larynx where it would remain.  By trial and error he tinkered with the device until it met his satisfaction.  The device was made with a bivalve tube with a narrow transverse diameter, and about an inch long."

A shoulder on the upper end prevented the tube from slipping down.  By trial and error the tube transformed so the tube was a "plain tube of elliptical form about an inch in length."  He then played with longer tubes until he found the desired length.  The final tube used was made of brass and lined with gold, and was accepted by the medical community.  (See figures 2 and 3.)

A complete set was included in a box, that included sizes for different aged children, an obturator, an introducer, an extractor, and a gag.  The length of the tubes in inches were 1.5, 1 3/4, 2, 2.25 and 2.5.   The obturator of the physicians choice is connected to the end of the introducer, and this is used to insert the tube.  If necessary a small thread could be inserted and tied to a hole on the outer edge of the tube to prevent it from going down the trachea, and to facilitate removal.

The kit also came with a scale (see figure  5) which helped the physician determine appropriate depth of the tube according to age.  The scale is used like this: "The smallest tube reaches line 1, and is intended for children about one year and under. The next reaches line 2, and is for children between one and two years. The third size, marked 34 on the scale, should be used between two and four years. The fourth, marked 5-7, is for the next three years, and the largest tube is for children from eight to twelve."

O'Dwyer also designed larger tubes and equipment for adult intubation. (23, page 9-18)

O'Dwyer's introducer connected to obturator (23, page 16)

1888:  Foot operated Bellows

Dr. George Fell invented a system of bellows whereby the operator would use his hands to provide positive pressure breaths.  He would either use a tracheotomy or face mask.  In 1891 this system was revised by Joseph O'Dwyer of New York so that breaths were provided by pressing down on a lever with your foot.  O'Dwyer preferred to connect his bellow system to an endotracheal tube.  O'Dwyer was concerned about over-distention of the lungs due not allowing enough time for expiration, and therefore recommended giving slow breaths, or 10-12 per minute. (21, page 283)

1891:  Concerns of Intubation:  By the late 19th century many of the same concerns physicians have today about intubation were considered.  One such concern being the ulceration of tissue due to pressure of the tube set upon it for a long period of time.  Tubes were generally taken out after six days with success, although in some cases were left in 12 days or longer. Dr. Rank, a German physician, ultimately recommended removal of the tube after 10 days, and if necessary, the physician should consider tracheotomy.

Some physicians recommended extubation after the 5th day, which would be in line with modern protocols. Feeding the patient was also a concern, and was either done with soft foods or liquids, or by nasalgastric tube.  It was recommended that if the tube was accidentally spit up that the nurse take advantage of the moment to try feeding the patient prior to re-introducing the tube (if the tube was still needed). (23, page 29-20)

1898 Matas's Apparatus for Artificial Respiration:  Around this time the need arose for a means to prevent asphyxia when chloroform was used. There was also the concern of preventing pneumothorax during artificial respiration.  Matas deviced the "experimental automatic respiratory apparatus" as you can see in figure 4.  

This was never put in use on a real patient, and was mainly used to study the effects of pressure during inspiration and expiration.  You can see some of the major components in the picture: MF = O'Dwyer intubating cannula and stopcock for introducing chloroform; M = Mercurial manometer to measure pressure or vacuum; H is the handle to work the pump and forces air into the lungs. The operator placed a finger over a hole in the O'Dwyer intubation cannula, and when he removed his finger expiration occured.  (R = Rubber tubing.)

It was quite a contraption for its time. Experiments were performed on dogs and human cadavers, although it was decided it was not fit for use on humans. (See figure 4) (21, page 284)

Figure 4 (21)

1900:  Cuffed Endotracheal Tubes and laryngoscopes

Right around the turn of the century was when the furst cuffed endotracheal tubes (ETT) started showing up.  This was necessary to prevent air from leaking around the tube so that bigger breaths could be given, and it also worked nice to prevent aspiration around the tube. 

Another problem was how to insert the tube into the ETT into the airway. Blind insertion meant there was a risk of intubating the esophagus, which, if not recognized, resulted in asphyxia and death. 

A laryngoscope is a device that allowed the doctor to open the airway in order to see the vocal cords and glottis. This increased the likelihood of tracheal intubation. 

A larygoscope was first described in 1855 using sunlight to see the vocal cords, and by 1913 a battery powered laryngoscope with an external light was invented.  This was refined so it had a handle with a battery and a light bulb at the end of the scope for easy visualization of the vocal cords.   (18)

Related posts:

• 4000 B.C. - 1800:  Evolution of Artificial Respiration
• 1800-1900:  The Beginning of Pressure Therapy
• 1800-1900:  The Beginning of Pressure Therapy (part II)

References:

1. Szmuk, Peter, eet al, "A brief history of tracheostomy and tracheal intubation, from the Bronze Age to the Space Age," Intensive Care Medicine, 2008, 34, pages 222-228
2. Price, J.L., "The Evolution of Breathing Machines," (this must have been written in the 1950s or early 1960s because the last reference was to IPPB being used as a respirator) (reference to The Bible, Kings, 4: 34)
3. Tan, S.Y, et al, "Medicine in Stamps:  Paracelsus (1493-1541): The man who dared," Singapore Medical Journal,  2003, vol. 44 (1), pages 5-7
4. "Resuscitation and Artificial Respiration," freewebs.com, Scientific Anti-Vivisectionism,  http://www.freewebs.com/scientific_anti_vivisectionism4/resuscitation.htm, accessed March 1, 2012
5. Price, op cit
6. Lee, W.L., A.S. Stutsky, "Ventilator-induced lung injury and recommendations for mechanical ventilation of patients with ARDS," Semin. Respit. Critical Care Medicine, 2001, June, 22, 3, pages 269-280
7. Price, J.L., "The Evolution of Breathing Machines,"  (see also reference #1 and #3 above)
8. Szmuk, op cit, page 225
9. Price, op cit
10. "Resuscitation and Artificial Respiration," freewebs.com, Scientific Anti-Vivisectionism,  http://www.freewebs.com/scientific_anti_vivisectionism4/resuscitation.htm, accessed March 1, 2012 (see also reference 1 above)
11. Lee, op cit
12. Price, op cit
13. Price, op cit
14. Szmuk, op cit, page 225
15. Price, op cit
16. Woollam, C.H.M., "The development of apparatus for intermittent positive pressure respiration," Anaesthesia, 1976, volume 31, pages 537-147
17. Previtera, Joseph, "Negative Pressure Ventilation: Operating Procedure (Iron Lung)," Tufts Medical Center, Respirator Care Programs, http://160.109.101.132/respcare/npv.htm, and http://160.109.101.132/respcare/ironlung.htm, accessed February 27, 2012
18. Szmuk, op cit, page 226-7
19. Fourgeaud, V.J, "Medicine Among the Arabs," (Historical Sketches), Pacific medical and surgical journal, Vol. VII, ed. V.J. Fourgeaud and J.F. Morse, 1864, San Fransisco, Thompson & Company,  pages 193-203  (referenced to page 198-9)
20. "Biographical Dictionary of the society for the diffusion of useful knowledge," Longman, Brown, Green and Longmans, volume III, 1843, A. Spottingwood, London, page 124-5
21. Tissler, Paul Louis Alexandre, "Pneumotherapy: Including Aerotherapy and inhalation...," 1903, Philadelphia, Blakiston's sons and Company, page 284,5
22. Hasan, Ashfaq, "Understanding Mechanical Ventilation: A practical Handbook," 2010, New York, Springer
23. Ball, James B, "Intubation of the Larynx," 1891, London, H.K. Lewis
24. Garrison, Fielding Hudson, "An introduction to the history of medicine," 1922, 3rd edition, Philadelphia and London, W.B. Saunders Company
25. Banser, Robert C., Sairam Parthasarathy, editors, Nocturnal Noninvasive Ventilation, Theory, Evidence, and Clinical Practice," 2015, Springer, New York, chapter 2, "Negative Pressure Noninvasive Ventilation (NPNIV): History, Rational, and Application," by Norma M.T. Braun