Pulse vs. Continuous Flow Portable Oxygen Concentrators

Pulse vs. Continuous Flow

Rate This Story

21 Votes So Far

No votes so far! Be the first to rate this post.

When you’re first prescribed oxygen by your doctor, you will likely discuss the various options available to fit your needs. One of the first determining factors in starting oxygen therapy is figuring out if you’ll need a pulse or continuous-flow oxygen unit. Perhaps you’ve heard your doctor use the phrase “pulse” and “continuous flow” but do you really understand what it means? How does it correlate with machine pulse-dose settings? What’s the difference between the two? Which one is right for you? Let’s explore the differences below:

Liters Per Minute & Flow Rate?

Many patients, once they see “liters per minute” on their prescription, assume their only option is a continuous-flow oxygen concentrator or tank. In reality, both pulse and continuous units use LPM or liters per minute. LPM actually refers to the flow rate of oxygen you’re prescribed. Flow rates are measured in liters of oxygen flowing through the cannula and past the nasal passages. The vast majority of people are prescribed 2 liters of oxygen per minute (2LPM).

It is important to note that your prescription may not tell you whether you need a pulse or continuous flow unit. It’s also imperative to understand that liters per minute does not directly relate to the pulse-dose settings on oxygen concentrators. Generally, most home or continuous flow units have exact LPM settings. However, most portable or pulse-dose units will have a setting ranging from 1 to 9. How much oxygen is released on each setting will differ between each concentrator and each brand. For example, if you are prescribed 2 liters per minute of oxygen and the concentrator you’d like to buy has 1-3 settings there is a chance it may not fit your needs. A setting of 2 on one portable concentrator may give you an insufficient amount of the oxygen your prescription requires while a different brand concentrator’s setting of 2 could give you too much.

Pulse vs. Continuous Flow Video

Pulse-Flow Oxygen Concentrators

Pulse does delivery goes by many names including pulse flow, on-demand, intermittent-flow, conserving device, and puffer. Pulse flow puffs or pulses oxygen into your nasal passageway, through a cannula, with each breath. This means that oxygen is delivered only during inhalation and the device stores the oxygen when you exhale. Should the breathing rate increase, the oxygen concentrator will automatically adjust the pulse size and delivery frequency to maintain the required flow rate.

The sophistication of pulse dose delivery is best described as drinking water with a straw; the delivery is more controlled and individualized per need. In juxtaposition, a continuous flow machine is akin to that of drinking out of a water fountain; the delivery is less controlled. Units with pulse flow delivery systems tend to be more energy-efficient due to the rest periods between each breath. Rest periods significantly increase the battery life of your unit allowing you to enjoy portable solutions for longer. Another benefit of a pulse dose machine is size. Due to the increased efficiency, units can be made much smaller providing patients with more freedom and mobility.

It’s important to note that each brand has a different pulse dose delivery mechanism. This means the “puff” or “pulse” of oxygen may feel slightly different brand to brand and even unit to unit. Most people cannot tell a noticeable difference but if your current solution is uncomfortable, you may want to experiment with another model.

Another notable difference between pulse and continuous flow oxygen delivery is that pulse dose machines do not deliver oxygen in exact LPM (liters per minute) like that of a continuous flow machine. As we mentioned above, there is little standardization in the industry when it comes to pulse-dose settings and oxygen output. The setting of 2 on one machine does not mean the same thing as the setting of 2 on another machine. We cannot stress this enough and you should work with your doctor to understand the best settings for your needs.

Is Pulse-Flow Oxygen Right For Me?

To answer this question always start with your doctor. While pulse dose works for many people, there are some medical conditions where it is not an option. If you require oxygen at night, many doctors will recommend a continuous flow machine for nocturnal or nighttime use. That being said, many patients can still use a pulse dose machine during daytime hours. The reason doctors lean toward continuous flowing for sleep is that shallow and mouth breathers may not trigger the pulse sensor. If no pulse is triggered, some machines will alarm causing patients to wake up frequently throughout the night.

Using an oxygen concentrator with pulse flow technology is a great solution for those with an active or ever-changing lifestyle. If you’re frequently out and about running errands, exercising, traveling, or even if you just enjoy a daily morning walk pulse flow can adjust to your changing breath rates to ensure you’re always getting the oxygen therapy you need.

We always recommend that you try out the unit and delivery systems before purchasing or renting, especially if you’re going to be traveling!

Pulse Dose Only Machines:

Continuous-Flow Oxygen Concentrators

Continuous flow delivery is the most common type of oxygen delivery. Continuous flow constantly flows oxygen at a steady and specified rate. Continuous flow is easiest to understand when you liken it to a water fountain. When you turn on a water fountain, water streams out at a somewhat steady pace. If the water fountain were flowing at 1 liter per minute and you were to drink from the said stream the likelihood of you consuming 1 complete liter of water in your singular drink is highly unlikely.  The same applies to a continuous flow machine, there will naturally be excess oxygen supplied due to the state of constant oxygen delivery.

If you’re concerned about excess oxygen waste or your current machine’s settings no longer fit your needs you may want to consider an Oxymizer Pendant. The Oxymizer Pendant is capable of reducing oxygen costs by 75% on a continuous flow machine and is our simplest conserving device, operating without batteries or controls! This oxygen saver also has the capability of increasing your oxygen output up to 2 LPM. Having this extra reserve of oxygen allows you to run your concentrator on a lower setting, saving energy, money, and battery life!

It is also important to note that all home or stationary oxygen concentrators operate in continuous flow delivery. Additionally, oxygen tanks deliver continuous-flow oxygen.

Is Continuous Flow Right For Me?

Just like pulse delivery, this question starts with your doctor. While continuous flow machines work for many people, it’s always best to consult your doctor. An oxygen concentrator with the continuous flow is a sufficient solution if you lead a more relaxed lifestyle. All at-home or stationary machines operate in continuous flow delivery. If your activity level is low to moderate and your breathing rate stays relatively consistent throughout the day, a continuous flow machine may be right for you. Continuous flow units are often great solutions for those with sleep apnea or other conditions in which you require oxygen at night.  Like we mentioned above, a continuous flow machine won’t alarm while you’re sleeping if you happen to breathe through your mouth or have shallow breathing.

All continuous flow oxygen concentrators are compatible with bottle humidifiers. This is especially helpful in those dry conditions when the nose and mouth get dry.  Humidifiers are recommended for high oxygen flows. So, whether you have a portable or a stationary unit set on continuous flow, you can use a compatible humidifier bottle.

Moreover, you can use an Oxygen Mask instead of a nasal cannula on continuous flow. Also, CPAP and BiPAP machines can be added to a continuous-flow oxygen delivery system.

Continuous Dose Only Machines:

Pulse and Continuous:

Why not both? There are several wonderful machines on the market that offer both pulse and continuous flow in a single machine. These machines are usually portable and offer the most flexibility as they are great for nocturnal use, use with sleep apnea equipment, and can be used during the day on pulse dose to extend the life of the batteries. Our popular and lightweight SimplyGo concentrator by Philips Respironics features pulse and continuous flow and weighs just 10 pounds with a battery!

Pulse and Continuous Flow Machines:

Pulse vs Continuous Oxygen - Caire Eclipse5

Additional Factors to Consider:

One of the most important factors we urge our customers to consider is their lifestyle! Unfortunately, some doctors may not take into account just how you’d like to use your oxygen solution. Below is a list of questions you’ll want to ask yourself and your doctor before selecting your oxygen delivery system and machine!

  • Do I require continuous flow delivery for either nocturnal or daytime use?
  • Do I need to use sleep apnea equipment? (CPAP or BiPAP Machine)
  • What is my required liter flow rate?
  • Do I want or need to use oxygen on the go? Example: in the car, at the store, etc.
  • How heavy of a concentrator do I want? What can I comfortably carry?
  • How long of a battery life do I need on a daily basis?

When making this important decision it’s best to think of your daily routines and how adding a device with pulse or continuous flow might alter or improve them.

At the end of the day, it truly comes down to your medical needs and personal preference in selecting a pulse or continuous unit. As we discussed above, there are solutions that offer both pulse and continuous flow oxygen delivery systems. If you’re not sure which solution is right for you we suggest consulting your doctor and discussing your lifestyle, prescriptions, and how you’d ideally like to use oxygen.

Date Updated: March 21, 2024
Date Published: October 10, 2016

Rate This Story

21 Votes So Far

No votes so far! Be the first to rate this post.

Danielle is extensively trained oxygen specialist and used her oxygen therapy knowledge to write on products from leading manufactures such as Inogen, Respironics, Chart, Invacare and ResMed.

About Danielle Jason:

Danielle is extensively trained oxygen specialist and used her oxygen therapy knowledge to write on products from leading manufactures such as Inogen, Respironics, Chart, Invacare and ResMed.

42 thoughts on “Pulse vs. Continuous Flow

    • Please feel free to communicate with us via email at sales@amsrco.com or you can use the chat function on our website. Please just let mention in your email or chat that you need to communicate via email or chat only. We will do everything we can to assist you.

      • Hello
        I am on 6 liters of continuous flow with activity. At rest some times I need no oxygen. Way back when I had an innogen but as I need Ed more 02 it didn’t work. My question is would a machine that delivers 9 pulse be enough if my needs are 6 liters continuous?
        Thank you
        Corinne

        • We’d suggest that you check this with your doctor. Whether pulse dose will be suitable for your requirement. Our Oxygen Specialist would be happy to help you out with your requirements. Please give us a call at (877) 644-4581.

    • Nice report. I use both; Pulse – sitting, walking, day’s driving @ 4+. I use Continues – night & longer walks @ 2 to 4. When I use Pulse @ nite with a regular mask, air supply reading is slightly higher. It keeps oxygen reading higher by 2+(91 vs 88) etc. John

  1. My father has copd and has a continuousl flow oxygen generator upstairs running at 2Lpm for bed time. He also has a small portable pulse flow generator for when he is out and about. My question is, is the pulse flow portable unit good enough for him to use ALL day or would he benefit from having another continuous flow machine downstairs also?

  2. I have a respironics simplygo machine that I bought on craigslist and would like to have it checked for proper function and repaired if necessary. Would you give me an estimate of your cost to work on my machine? How to ship, etc?

    • Unfortunately, we are not an authorized repair center for Respironics and therefore can not help in servicing of your machine. You can, however, call Precision Medical Parts at 678-903-3102 and they should be able to assist you.

    • These machines are pretty fool proof. If it runs for a long length of time without an alarm, it’s likely working just fine. All they do is pump room air through a filter that diverts larger molecules and directs the oxygen to your tube. When they have an issue, you should get an alarm. When you do get an alarm it likely means the air intake filter should be cleaned or replaced – a simple procedure.

      • The highest a portable unit can go on a continuous flow is 3 liters per minute and that would be CAIRE Eclipse 5. It can also reach a setting of 9 on pulse dose.
        If you need continuous flow higher than 3 LPM, then stationary units are an option. Talk to our Oxygen Specialist for a free consultation, please give us a call at (877) 644-4581.

  3. We live off the grid with our own power system. The energy used by a unit is very important to us. My wife has been on oxygen for a few years now, using bottles at a 3 LPM pulse rate, which worked fine until recently. Now she needs continuous flow. The EverFlo provided our supplier is a real energy hog. Any ideas that may help.

  4. we want to travel but my wife needs more than 3l sometimes to walk around…just sitting 3l is ok…this is on cont. does any portable machine do this?

    • We would love to help you out. Please give us a call at 888-360-9628, and one of our oxygen specialists would like to talk with you about your specific situation and let you know what your options are. If you prefer email, you can reach us at sales@amsrco.com.
      We look forward to helping you.

  5. My portable inogen one-g3 sometimes, shows a red warning light saying battery is hot. Do I need to replace the battery

    • Sometimes that this is not the battery being hot but the unit itself, trying cleaning off the particle filters and see if that helps. If you still have issues, I would recommend that you contact customer care at 877-303-9289.

  6. my hubby is on oxygen and he is a mouth breather should we keep his oxygen on continuous when we have it on conserve sometimes his o2 drops and we have to put it back on continuous

    • Hi Rosie,

      I think you should continue with it on continuous but the next visit, discuss this with his doctor. He may want to adjust his oxygen or recommend other options that can work for your husband and his medical needs. Good Luck.

  7. My husband is on 3 LPM he was on pulse but right now hes on continuous after getting sick we need to find a POC pulse and a continuous 3 at least he loves being outside can you recommend a POC that meets his need with a long battery run time.

  8. Danielle — thank you for this incredibly illuminating articl. That said, still can’t decide on a portable. — MY problem, and although I have a great doctor, he doesn’t seem to have a clue about concentrators!

    Beyond-appreciatvely,
    Lynne

  9. I use a continuous flow model provided through Medicare. I have central sleep apnea so the continuous flow is necessary. It is very heavy and when I travel it is almost unmanageable. Is there a portable, lighter machine I could use? The machine is an older report I s

    • You may try the SeQual Eclipse 5 portable oxygen concentrator for up to 3 liters per minute (LPM) of continuous flow. Or the Inogen At Home for up to 5 LPM. Though Inogen at Home is a home oxygen concentrator, it is lighter and smaller to carry when you are traveling. Moreover, there is a travel case available for Inogen at Home.

  10. oxygen supplier says have dr. submit an order for a portable concentrater. with 5 or more level but dr. office says talk to supplier. so what do we do to rent a unit that fits my husbands needs!? he is o.k. at rest with level 3, but when using his arms or walking even a little bit, he cranks the tank up to 5 and still gasps for breath. he wants to be able to move around, do simple tasks, but just can’t. you would think the dr. would be more helpful than that.

    • We can quickly answer all your questions over a phone call. Please reach us out at 888-387-5914. We are open seven days a week.

  11. I have found the best solution for me is to have a G3 pulse (one of the few that can be used on an airline) portable unit with a 6 hr battery and a continuous home unit. Nick has been great with all the units and accessories I have purchased from them.

  12. Hello I am a copd female using at home an oxygen converter with continuous oxygen at 2 liters per minute. In order to change to a pulse (inogen 5 settings 1 – 6 with 1260 ml at the highest setting) what should my setting be at? I have tried 2 and my oxymeter hovers at 97-99 but when walking plummets to 85. I am at a loss my doctor just says 2L on the script as he expects the company to translate that to the appropriate equivalent setting on their machines, and the company has no idea what 2L should relate to on their pulse machines. I understand 2L equals to 32ml/breath on continuous but what is that in their measurements of 210 per setting? Can you please help?

    • I am using continuous from a large tank of liquid O2. 2L is fine for sitting, but I need more to do anything physical. I use an on-demand backpack unit filled from the tank to work in the garden, walk (at 7600′). The Helios backpack unit set even at 4 is still not giving me enough O2. You need your to use your oximeter to determine how much you need for a specific activity. Tell your doc to use the oximeter at his office while you are walking, walking up stairs, doing something more than sitting to get an accurate idea of how much O2 to prescribe. Then use your oximeter at home to decide what setting to use for the pulse unit. We don’t spend our lives sitting!

  13. If you can train yourself to breathe with pulse, great for daytime & in car. Nigh-time use works less, but I use a mask which keeps pulsating oX in area of nose & mouth to get may be enough for night use. I do this at nite to keep oX in high 80s. Vs low 90s w my continuous flow too bulky machine to take.

Leave a Reply

Your email address will not be published. Required fields are marked *