Ventilators are machines that are used to artificially breath for an individual who is unable to do so on their own. They are typically in use in certain portions and wings of hospitals. These ventilators can use various methods to do this. Ventilators also have to be highly reliable and very sensitive about when to generate each breath.
Ventilators are medical devices that assist in breathing when an individual is unable to do so on their own. In an emergency setting, mechanical ventilation is typically started after intubation. During this process, a tube is inserted down the patient's throat. This tube serves as the place where the air is delivered.
The first ventilator came into use during the first polio epidemic and was called the "iron lung." In 1949, a ventilator for use during anesthesia was developed at Harvard by John Haven Emerson. The modern version of the ventilator, which is is entirely gas-propelled, was developed in 1952 by Roger Manley in London. This version is similar to ventilators in use today.
There are two main types of ventilators. The most primitive is a negative pressure ventilator. Negative pressure ventilators use a vacuum to generate negative pressure within the chest, causing the chest to expand. This allows air to flow in. When the lungs have filled with air, the vacuum is sealed off, allowing passive exhalation. The other type of ventilator is a positive pressure one. More modern, it pushes air into the lungs and allows the natural buildup of pressure then to cause exhalation.
Most modern ventilators have setting that allow for different volumes of air to be pumped in accordance with the size of the patient's lungs. In addition, since most people "sigh" naturally about 6 to 8 times an hour, many ventilators will have a setting which will periodically deliver more air to artificially reproduce a sigh. There are also settings that can vary the concentration of oxygen in the air delivered, as well as altering the end volume of air in the lungs after each breath.
Artificial ventilation is required when natural respiration is not sufficient for the patient. This can occur due to acute lung injury, as well chronic obstructive pulmonary disease (COPD). Ventilators can also be used when it is clear that there is extra effort needed to breath, thus assisting the patient without overexerting them. They are also often used during surgery to ensure that the patient's breathing does not slow too much.