How Ventilator works

How Ventilator works

Short summy of the article so that you can find your answer faster
1) How ventilator works
2)Ventilator setup, step by step
3)Ventilator cost

How ventilator works

How ventilator works, Ventilator

To appreciate the value of ventilation OR How Ventilator works, we need to understand how the respiratory system works. We breathe by contracting our diaphragms, which expands our chest cavities. This allows air to be drawn in which inflating the alveoli— millions of small sacs inside our lungs. 

Each of these tiny balloons is surrounded by a mesh of blood-filled capillaries. This blood absorbs oxygen from the inflated alveoli and leaves behind carbon dioxide. When the diaphragm is relaxed, the CO2 is exhaled alongside a mix of oxygen and other gases. And when our respiratory systems are working correctly, then this process happens automatically on its own. 

But the respiratory system can be interrupted by a variety of conditions like,
  • Sleep apnea can stop diaphragm muscles from contracting. 
  • Asthma can lead to inflamed airways which obstruct oxygen and pneumonia, often triggered by bacterial or viral infections, attacks the alveoli themselves. 
  • Invading pathogens kill lung cells, triggering an immune response that can cause lethal inflammation and fluid buildup.

 All these situations render the lungs unable to function normally. But mechanical ventilators take over the process, getting oxygen into the body when the respiratory system cannot do.

 These machines can bypass constricted airways, and deliver highly oxygenated air to help damaged lungs diffuse more oxygen.

 There are two main ways that ventilators can work— pumping air into the patient’s lungs through 
  1. positive pressure ventilation,
  2. allowing air to be passively drawn in through negative pressure ventilation. 

Research has shown that
In the late 19th century, ventilation techniques largely focused on negative pressure, which closely approximates natural breathing and provides an even distribution of air in the lungs. To achieve this, doctors created a tight seal around the patient’s body, either by enclosing them in a wooden box or a specially sealed room. 

Air was then pumped out of the chamber, decreasing air pressure, and allowing the patient’s chest cavity to expand more easily. 

In 1928, doctors developed a portable, metal device with pumps powered by an electric motor. This machine, known as the iron lung, became a fixture in hospitals through the mid-20th century. 

However, even the most compact negative pressure designs heavily restricted a patient’s movement and obstructed access for caregivers. 
This led hospitals in the 1960s to shift towards positive pressure ventilation. 

For milder cases, this can be done non-invasively. Often, a facemask is fitted over the mouth and nose, and filled with pressurized air that moves into the patient’s airway. 

But more severe circumstances require a device that takes over the entire breathing process. 

A tube is inserted into the patient’s trachea to pump air directly into the lungs, with a series of valves and branching pipes forming a circuit for inhalation and exhalation. 

In most modern ventilators, an embedded computer system allows for monitoring the patient’s breathing and adjusting the airflow. These machines aren’t used as a standard treatment, but rather use, as a last resort. 

Enduring this influx of pressurized air requires heavy sedation, and repeated ventilation can cause long-term lung damage. But in extreme situations, ventilators can be the difference between life and death. 

And events like the COVID-19 pandemic have shown that they’re even more essential than we thought. Because current models are bulky, expensive, and require extensive training to operate, most hospitals only have a few in supply. This may be enough under normal circumstances, but during emergencies, this limited cache is stretched thin. 

The world urgently needs more low-cost and portable ventilators, as well as a faster means of producing and distributing this life-saving technology.

A short history of Ventilator
 In the 16th century, Flemish physician Andreas Vesalius described how a suffocating animal could be kept alive by inserting a tube into its trachea and blowing air to inflate its lungs. In 1555, this procedure didn’t warrant much acclaim. But today, Vesalius’s treatise is recognized as the first description of mechanical ventilation— a crucial practice in modern medicine.

Ventilator setup

There are a few steps you need to follow before starting ventilation. The whole procedure takes approximately three minutes.

1) Connect to a power source

Make sure the power cable is firmly connected in the socket to prevent accidental disconnection and then connect it to the primary power outlet. The battery status indicator shows the charge status of the battery even when the ventilator is turned off.
Power source of the ventilator

 When the indicator is solid green the battery is fully charged and connected to primary power.

 When flashing, it means that the battery is still charging. If the battery is not charging, for whatever reason, the indicator will remain dark. Make sure the ventilator is connected to a power source prior to starting ventilation. 

2) Connect the oxygen supply

If you have done the first step already then connect the oxygen hose to the ventilator and then to the gas supply or a gas cylinder. 

3) Set up the patient breathing circuit

To connect the breathing circuit do the following: 
First, install the expiratory valve then select the appropriate breathing circuit and components. 
Second, assemble the breathing circuit then connect the external devices and sensors.
Finally, perform the preoperational checks. 

4) Connect external devices and sensors

Follow the steps to connect external devices and sensors,
1 ) Installation of single-use expiratory valve set 


If you are using a single-use expiratory valve set first remove the safety cover. Ensure that the membrane is properly aligned with the expiratory valve housing and the metal plate is visible and facing upwards. Position the valve in the expiratory port ensuring it is straight and twists it clockwise until it locks into place.
2 ) intallation of autoclavable expiratory valve set

If you are using an autoclavable expiratory valve set, first assemble the expiratory valve set by placing the silicon membrane onto the expiratory valve housing to ensure that the metal plate is facing upwards and is visible. Position the valve in the expiratory port ensuring it is straight and twists it clockwise until it locks into place.

3) Connecting of inspiratory bacterial and viral filter
To prevent patient or ventilator contamination, connect a bacterial and viral filter between the patient and the inspiratory port 

An expiratory filter is not required but you may use one for infection control according to your institution protocol.
If you use one, place it on the patient side of the expiratory valve.

Humidity and nebulized and the drug might affect the resistance of the expiratory filter: Monitor expiratory flows and replace the filter on a regular basis.

4 ) Connect the breathing set

Install a water bag or bottle above the humidifier. Choose the correct breathing circuit according to the patient group or selected treatment. ( Install water source at least 0.5m above the humidifier )

 The following information applies if you are using the HAMILTON-BC8022 breathing circuit or any other double limb breathing circuit for an active humidifier. 

First, insert the humidifier chamber. Connect the shorter blue tube to the inspiratory port on the ventilator and then connect the expiratory tube to the expiratory valve. 

Connecting of inspiratory bacterial and viral filter

Insert the water feed line into the water bag or bottle. Make sure that all electrical contacts on the breathing circuit match the connecting element on the humidifier. 

5 ) Connect the flow sensor

Insert a flow sensor into the breathing circuit in front of the patient connection. That is the Y piece. Attach the blue and clear tubes to the flow sensor connection ports on the ventilator. To prevent water accumulating in the flow sensor and tubing position the flow sensor tubing on top of the flow sensor. The gas temperature is measured at the Y piece by means of the temperature probe, integrated into the inspiratory limb. Keep the inspiratory limb positioned correctly. 

If you are using coaxial breathing set with the proximal flow sensor first connect the main tube to the inspiratory port on the ventilator. Then, connect the expandable expiratory tube to the expiratory valve. 

Finally, attach the blue and clear tubes to the flow sensor connection ports on the ventilator. To prevent water accumulating in the flow sensor and tubing position the flow sensor tubing on top of the flow sensor. 

If you are using a mainstream CO2 sensor connected at this point to the corresponding connection port. Slide the CO2 sensor on to the airway adapter. Align the arrows on both components and press them together until you hear a click. 

Then connect the sensor with the airway adapter to the breathing circuit before the flow sensor. Position the breathing circuit in such a way that the tubes will not be pushed pulled or kinked if the patient moves. 

5) Turn on the ventilator and perform the pre-operational checks. 

This is how you can know about How ventilator works and Ventilator setup

Ventilator cost

There are many types of ventilators like,

  • Low, medium, and high-acuity ventilators
  • High-frequency ventilators
  • Home care ventilators
  • Transport ventilators

ventilators can cost you in range of $5,000 to $25,000 (In India 3lakhs to 20laks) according to there different gas delivery designs, or including turbine-based air supply and proportional solenoid (PSOL) valve control, or a combination of the two systems.

I guess now you know how ventilator works, ventilator setup and How much ventilator cost

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  1. Nice refresher. Good info. As a Respiratory Therapist this was a great review to me!

    1. Thanks if there any mistake please let me know so i can learn and correct it

  2. Very informative article
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