The History of Negative Pressure Ventilation

Hayek is the Innovator of Biphasic Cuirass Ventilation Learn More


Take a look at the evolution of the ideal ventilator solution.


Artificial Respiration Machine

  • In Denver, Colorado a physician developed an “artificial respiration” device, which predates Drinker and Shaw’s design, however he did not file a patent.


Polio Epidemic

  • First wave of poliomyeltis hits North America.
  • Saturday, June 17, 1916 in Brooklyn an official announcement was made of the polio epidemic.
  • In that year, the United States saw more than 6000 deaths and 27000 infections.


Franklin Roosevelt

  • In 1921, Franklin Roosevelt contracts polio, which leaves his legs paralyzed.


Phillip Drinker and Louis A. Shaw develop first negative pressure ventilator

  • Members of Harvard University faculty, Dr. Phillip Drinker and Dr. Louis Agassiz develop the first negative pressure “respiration apparatus”.
  • Their device could create pressures of -60 cmH2O and rates between 10 and 40 breaths per minutes. “The pressure was initiated at -18 cmH2O and the patient was asked to count out loud as pressure was adjusted until the patient could no longer speak.”


John Emerson’s "Iron Lung"

  • Biomedical inventor John Haven “Jack” Emerson improves negative pressure ventilator, making a version that is lighter in weight, less expensive and quieter than Drinker and Shaw’s design.
  • His first unit was finished in 1931.
  • Emerson would later be sued by Drinker and Shaw, but won the case.


Rocking Bed

  • At the estimated rate of normal respiration, patients would be tilted head to foot.
  • When head was tilted down, the diaphragm would be pushed by the contents of the abdomen assisting in expiration.
  • When head was tilted up, gravity caused the abdomen to descend in conjunction with the diaphragm assisting in inspiration.


Polio Epidemic Continues

  • Polio epidemic continues to be a concern in North America throughout the 1940’s, innovation ensued. New version of negative pressure ventilation were invented utilizing a cuirass shell or tight fitted garments.
  • Polio took 2720 lives in the US and there were 42173 cases reported


Dual Cuirass Respirator

  • Charles Wilm developed a duel negative pressure cuirass ventilator


F.T. Wallin Patent Filed

  • A patent for the portable respirator using negative pressure ventilation with a garment and shell was filed in 1948 by Francis Wallin.
  • Trend continued, air-tight garment, like ponchos and raincoats was used to ensure a better seal


Worst Polio Outbreak in US History

  • In 1952, there were 57628 cases, 21269 ended up with some form of paralysis, and 3145 people died.
  • As a response and with limited availability of iron lungs and other negative pressure ventilators around the country, a magazine published blue prints for “do-it-yourselfers” on constructing a wooden negative pressure ventilator.


Ventilator Innovation

  • A negative pressure ventilator was developed for multiple people by Dr. James Wilson at Boston Children’s Hospital.
  • Throughout 1950’s, other forms of negative cuirass ventilation were created such as the Emerson Chest Respirator and the Thompson Ventilator.
  • 1958 welcomed the Pneumobelt, which used an inflatable belt that was applied around the patient waist and would inflate and deflate to assist in ventilation.


Emerson Raincoat

  • Like F.T. Wallins designs a case that would enclose the thorax with an airtight raincoat producing negative pressure for inhalation.


The Age of Positive Pressure Ventilation

  • Other forms of negative pressure ventilation would be used and designed, but would later fall out of favor for the less bulky and, at the time, easier to apply, forms of positive pressure ventilation, except for select circumstances.


Hayek Oscillator

  • The precursor to the Hayek RTX Biphasic Cuirass Ventilator, the Hayek Oscillator was designed by Dr. Zamir Hayek in response to the negative side effects associated with PPV, particularly with children in mind.
  • The Hayek Oscillator was a non-invasive high frequency chest ventilator, which controlled both phases of respiratory cycle.


First home use of the Hayek Oscillator

  • The Hayek Oscillator was easy to apply and operate, and used at Home in Secretion Management.


Hayek RTX Biphasic Cuirass Ventilator (BCV) Introduced

  • BCV is one of few ventilators in present times that offers negative pressure ventilation, biphasic cuirass ventilation and the only to provide true high-frequency chest wall oscillation


Hayek RTX First use in USA

  • In 2008, the Hayek RTX was used on the its first US patient in Buffalo, New York
  • Dr. Joe Cronin with others from the Lung & Cystic Fibrosis Center announce the FDA has cleared for use the Hayek RTX Ventilator within weeks after Cystic Fibrosis patient Tyler Blake, 26, of Celoron, NY, became the first and only patient in the United States to receive treatment from this device at WCHOB


First home use of RTX

  • Patient discharged from Temple University Hospital and sent home with BCV.

Success Stories

Our Clients
Mike Polidoro

On BCV, I can have a conversation, eat and drink, so I’m not losing any major comforts in my life.

Our Clients
Mr. Gayton

The cuirass is very comfortable. I am able to talk to my family and I do not get sores as I did by wearing a mask on my face.

Our Clients

Archer's care team could successfully extubate this determined 2-year-old.

More on Biphasic Cuirass Ventilation

Dr. Zamir Hayek set out to design the ideal ventilator that would be a clinical tool to assist nearly anyone. He achieved his goal with the Hayek RTX ventilator. In doing so, he birthed a new and powerful pulmonary treatment concept, Biphasic Cuirass Ventilation (BCV).

Mechanical assistance of ventilation is frequently provided with an invasive airway and positive pressure breath delivery. Both fraught with significant risk and side effects, these methods of ventilation should be the last resort in meeting the needs of patients. Many patients needing ventilator support can also have their needs met without the artificial airway for connection to the ventilator and can be supported non-invasively with facial or mask type interfaces. These, although useful, have important limitations. Breath delivery is still positive pressure and patients are frequently intolerant.

Dr. Hayek’s invention and creation of his vision of the ideal ventilator resulted in the RTX. The therapies provided with BCV offer significant advantages over positive pressure. This unique device is an important therapeutic tool that can benefit multiple organ systems, particularly in this time when positive pressure appears to be a catalyst for worsening lung disease.

BCV Fun Facts

Breathing is a core function of the human-machine. Biphasic Cuirass Ventilation facilitates this function. Positive pressure ventilation opposes it.

Since they were first marketed in the 1940’s positive pressure ventilator monitoring capability and modes of ventilation, have become more varied and complex but have been consistent in their opposition to the normal respiratory cycle of all mammals.

Mammals breathe through generating a pressure differential between their thoracic cavity and the surrounding environment. The relative negative pressure within the thorax, created on inspiration, allows the air outside the body to flow to the welcoming alveoli within the lungs residing in the thorax.

The Hayek RTX series ventilator works by facilitating the normal function of the lungs. It delivers this therapy by creating negative and relative positive pressure, via a flexible plastic cushioned cuirass, around the thorax and upper abdomen of the individual in need of respiratory support.

It provides this via an efficient pump providing the pressures in a square wave pattern via the cuirass in synchrony with the patient’s respiratory demands.

The Hayek RTX series Ventilator assists in this process for people who have either chronic or acute need for respiratory assistance. It does so non-invasively and can assist in easing both inspiratory and expiratory efforts.

This device can provide passive support with a continuous negative mode that eases the work of breathing in multiple clinical settings.

Additionally, active support can be provided to the patient in synchrony with their efforts while providing a backup rate should apnea occur. Without changing devices, an airway clearance mode can be initiated to provide true chest wall oscillation as well as a cough-assist to clear material from the airways.

How would you like to be ventilated? Certainly, anyone would prefer the method which allows us to continue to eat and remain a verbal and active part in our healthcare decision making.

We would all prefer that our airways remain clear and heal without risk of further damage by the intervention being used to help us. We would certainly enjoy the greater mobility and ease of positioning to avoid too much pressure on one area of our body for prolonged periods.

The Hayek RTX can ventilate us while attending to all of these issues and, if invasive ventilation is needed, the Hayek RTX can reduce the pressures required to ventilate us and thereby reduce the risk of injury.


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