Adaptive Servo Ventilation (ASV) – is a medical technology that utilizes positive airway pressure ventilatory support that is adjusted based on the detection of apneas, or pauses in breathing, during sleep. It is primarily used in the treatment of Central Sleep Apnea. It is also used for complex sleep apnea, mixed sleep apnea, periodic breathing – Cheyne – Stokes respirations. The device resembles CPAP machines (Continuous Positive Airway Pressure) and uses the same masks, hoses, and attachments.

How is Adaptive Servo Ventilation (ASV) different from CPAP and BiPAP?

While CPAP provides one continuous pressure, and BiPAP provides two pressures (on inhale and exhale), ASV adjusts the pressure based on an algorithm.

ResMed’s devices is called Adapt SV.

How Adaptive Servo Ventilation (ASV) Works

Philips has a similar technology called AutoSV that is features in their DreamStation BiPAP unit.

Per ResMed’s website, the algorithm is programmed as follows:

“The patient’s own recent average respiratory rate—including the ratio of inspiration to expiration and the length of any expiratory pause.The instantaneous direction, magnitude, and rate of change of the patient’s airflow, which are measured at a series of set points during each breath. A backup respiratory rate of 15 breaths per minute.”

 “By ventilating the patient appropriately during periods of hypopnea and apnea and reducing support during periods of hyperventilation and normal breathing,the ASV algorithm rapidly stabilizes breathing patterns and arterial blood gases and minimizes discomfort and arousals often associated with bilevel treatment.”adaptive servo ventilation and autoSV

Comparison of CPAP, BiPAP, APAP (auto-PAP) and Adaptive Servo Ventilation (ASV) are described in the above sections.

8 thoughts on “Adaptive Servo Ventilation: Treatment for Central Sleep Apnea

  1. Rick Reply

    I have complex/mixed/cpap-bipap emergent central sleep apnea without signs of heart failure, I have had two ASV machines, one ResMed and now a Phillips Respironics. I have used the Phillips with excellent results for nine months, average use 7.5 hours AHI 1.5 with excursions to 3.5 and 0.5 respectively. I find the Phillips machine much ‘softer’ in the pressure changes making it easier to fall and stay asleep.

  2. Jim Larson Reply

    I have been diagnosed with CSA. I did not tolerate CPAP and now I use a BiPAP. I actually can wear the mask all night. The problem I am having is a inconsistent # or apnea’s throughout the night. When I have less than 5 apnea’s per hour I feel like a million bucks. The next night I could have over 20 apneas per hour and I wake up groggy. I wonder if I will ever experience a consistent # of apneas?

    Secondly, what I noticed is that I stay in the exhale way too long even during the day. So I would prefer we call this condition central apnea as it affects me during the waking hours as well. I am active as I’m a cyclist and I play tennis. I have to consciously inhale and breath in order to not get lightheaded throughout the day. Does anyone else in this forum experience the same.? Thank you.

  3. Brad Crouch Reply

    Could somebody make a recommendation for an ASV machine that would be good for both Obstructive and Central Sleep Apnea? I was looking at the ResMed AirCurve 10 ASV until I came to page 15 of the owner’s manual, which said that that machine was unable to detect Central Apnea’s. Are there any machines that actually treat both?


  4. Dawn Capewell Reply

    My friend has been diagnosed with severe sleep apnea. She was not able to use the CPAP until she had developed a buildup of CO2, and was rushed to the hospital. They wanted to put her on BiPap, but the machine was so big and invasive that she would not tolerate it. Now I read that the BiPap uses the same masks and supplies as CPAP. Can you tell me why the hospital BiPap was so much different than the CPAP? Does ASV use the same masks and supplies as CPAP? How does she know if she needs ASV?

    • rick gerken Reply

      Don’t know if anyone answered you yet but I can tell you the hospital BIPAP (at last the model that would be used in a “critical” situation) is usually the “Cadillac” of BIPAPS. Home PAP units only need to be set and then forgot, with a re-evaluation every couple of years, the hospital units need to be able to cover a wide variety of modes (CPAP, BIPAP, AVS, AVAPS, etc.) and accommodate a variety of masks and tubings. The feel of the therapy should be the same, 10 cm/h20 is 10 cm/h20 whether it is being delivered by a large machine or small. I would guess that when your friend was brought in, the ER staff probably set the machine up higher settings because she was in an acute attack, and that probably made it hard to tolerate, also they probably didn’t use a mask that she was familiar with, and lastly your friend was probably quite anxious to start with and the emergent setting would have made her more anxious (like a viscous circle). As for your friend’s need of ASV, they would be able to ascertain her need from a formal, in house sleep study. ASV seems to be geared towards the sleep apnea patient with a “central” apnea, which is more rare than the more common obstructive apnea. I hope this helped.

      Rick, therapist x 30 years at a mid-sized, regional hospital.

      • Paul M Reply

        Rick, just as an FYI, I have both obstructive and central sleep apnea. I’ve been using a BiPAP machine quite successfully for several years now.

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