a woman asleep in her bedroom bed duvet comforter sheets pillows using a ventilator machine

Let’s Discuss Respiratory Aids for COPD

In our community, the need for ventilator support is a shared reality. Among our conversations, terms like "ventilator," "Trilogy," "AVAPS," "BiPAP," and "CPAP" frequently surface.

These terms hold diverse meanings and applications, often sparking curiosity and questions. As a result, let's go on an adventure to learn more about these respiratory aids.

What is a ventilator?

A ventilator is a medical device that sits alongside your bed. It delivers a flow of air into and out of your lungs to ensure you are taking effective breaths.

These work great for people who are having difficulty breathing on their own. This basic definition encompasses a range of breathing machines. Some of the modes they offer are CPAP, BiPAP, AVAPS, all designed to provide respiratory support.

There are two types of ventilators: invasive and non-invasive.

Non-invasive ventilators (NIV)

These are machines that supply pressure via a mask over your nose and/or mouth. Another term you may hear is Non-Invasive Ventilation (NIV). Below I will list the the types of NIV.


This is an acronym for Continuous Positive Airway Pressure. These are devices that supply a continuous positive pressure to your airway. This pressure makes it so your next breath comes easier.

It also splints your lower airways to prevent them from collapsing when you exhale. This helps keep your oxygen levels normal when you are sleeping. The pressure also splints your uppper airway preventing it  from collapsing when you are sleeping, preventing sleep apnea. So these machines are often prescribed for people diagnosed with sleep apnea.


This is an acronym for Bilevel Positive Airway Pressure. “Biilevel” essentially means that these devices deliver two different pressures.

The two types of pressures are as follows:


This is an acronym for Inspiratory Positive Airway Pressure. It is a higher pressure during inhalation. It ensures each breath is deep and effective, helping your lungs remove carbon dioxide, which is a waste product of breathing.

This elevated pressure supports your breathing and is important for overall respiratory health.


This is an acronym for Expiratory Positive Airway Pressure. It is a lower pressure during exhalation. It helps to splint your airways to prevent them from collapsing. Like CPAP, it makes it so your next breath comes easier and also helps maintain normal oxygen levels.

There are several companies that manufacture BiPAP machines, so you'll come across various brands. Some companies produce machines that offer BiPAP along with other modes, such as AVAPS. One of the most commonly mentioned brands is Trilogy, specifically made by Philips Respironics.


This is an acronym for Average Volume-Assured Pressure Support.  It operates similarly to BiPAP by providing pressures during both inhalation and exhalation.

The key distinction lies in AVAPS guaranteeing a specified tidal volume, which is a measure of how deep your inhalations are. Like BiPAP, this guarantees you will blow off carbon dioxide while you are sleeping.

Your doctor will determine the appropriate tidal volume based on your respiratory needs. AVAPS sets a pressure range, and the pressure support ensures each breath delivers a consistent tidal volume

Because of this unique feature, people sometimes call AVAPS machines 'ventilators.' So, if you hear someone refer to your AVAPS machine as a ventilator, they're talking about the helpful device that makes sure you're getting a breath that is deep enough  to be effective for YOU.

Because AVAPS machines guarantee a tidal volume, they are often referred to as ventilators. So, when you hear people talking about using ventilators at home, chances are it’s a device that offers AVAPS. Trilogy is a common brand name. But, technically, they are NIV devices because they use masks.

Invasive ventilators

Invasive ventilators are machines that go beyond using just a mask for respiratory support. Instead, they deliver flows and pressures through a tube inserted into the airway or through a hole in the neck called a tracheostomy.

In addition to providing all the flows and pressures of non-invasive ventilators, they offer a myriad of advanced modes. While invasive ventilators are primarily employed in hospital settings, including emergency rooms and critical care units (ICUs), they can also be used in the home setting.

Embracing non-invasive respiratory support

As a respiratory therapist immersed in the hospital setting, the term "ventilator" has traditionally evoked thoughts of invasive respiratory support. In our realm, CPAP, BiPAP, and AVAPS hold distinct places in the non-invasive landscape.

Yet, the evolving landscape of respiratory care has witnessed a shift, with the term "ventilator" expanding to encompass these non-invasive devices. This post seeks to bring clarity to this terminology, acknowledging the evolving usage of the term "ventilator" and the vital roles played by CPAP, BiPAP, and AVAPS.

Your insights are invaluable, so I’d like to know what you think. Have you encountered any of these devices? What are your thoughts about them? Please share your thoughts in the comments below.

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This article represents the opinions, thoughts, and experiences of the author; none of this content has been paid for by any advertiser. The COPD.net team does not recommend or endorse any products or treatments discussed herein. Learn more about how we maintain editorial integrity here.

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