(01-16-2015 10:17 PM)leiko49 Wrote: Is the method of air control that much different in an asv machine, so that it would likely be less effective for me, or even cause some harm? Or is the method of sensitivity on when to lower or increase pressure still likely to be helpful to me?
Wondering if I should return for an auto bipap, such as the respironics system one.
Hi leiko49, welcome to Apnea Board.
I use the initial version of the S9 ASV machine. I suggest you go ahead and try the machine. A likely problem, however, is that the medical equipment provider may have left the machine on its default settings (wide open), which would likely be unnecessarily uncomfortable or worse.
I suggest you should get a copy of the prescribed equipment and therapy settings from the doctor.
The new ASV machines like the AirCurve 10 ASV and the BiPAP autoSV Advanced are Auto machines, by which I mean these do slowly auto-titrate EPAP to minimize obstructive events, much like the ResMed AutoSet or the AirCurve 10 VAuto or the PRS1 BiPAP Auto. EPAP slowly auto-adjusts itself within a range, to prevent Snore and Flow Limitation and reduce the likelihood of obstructive events.
Where the ASV machines differ from the AirCurve 10 Auto and the PRS1 BiPAP Auto is neither of those standard bi-level Auto machines will do anything to end an apnea or hypopnea which is in progress.
In contrast, when an apnea or hypopnea begins (of any type, obstructive or central) an ASV machine will immediately counteract both obstructive or central events, by starting to automatically cycle between IPAP and EPAP, to keep us breathing at our recent natural respiration rate.
Also unlike the AirCurve 10 Auto and the PRS1 BiPAP Auto, an ASV machine will immediately increase Pressure Support (PS, the pressure difference between IPAP versus EPAP), if necessary, to keep us breathing at least 90% as much air as we were breathing recently, before the obstructive apnea or obstructive hypopnea or central apnea or central hypopnea began. The AirCurve 10 Auto uses manually adjusted PS. The PRS1 BiPAP Auto does slowly adjust PS within a range, but its PS adjustments are not made faster than about 1 cm H2O per minute.
The AirCurve 10 Auto and the PRS1 BiPAP Auto machines (and also the standard auto-titrating CPAP machines like the
AutoSet or REMSTAR Auto) will do nothing to end an apnea or hypopnea which is currently in progress. After the apnea or hypopnea has ended, these machines may adjust the pressure higher in order to help avoid future apneas.
(01-16-2015 11:21 PM)leiko49 Wrote: You stated,
It can work as a Bilevel CPAP
my last machine was an auto bipap, so a bilevel cpap would not be as complex an algorhthm (if it is not also "auto". As I said in my initial post, I may be better off getting a different machine.
"CPAP" is sometimes used as a general term for all types of Continuous Positive Airway Pressure therapies and can refer to fixed-pressure CPAP or auto-adjusting APAP or bi-level or auto-adjusting bi-level or ASV therapy modes.
Quote:I have had sleep apnea since i was a minor, and the machines have helped me sleep through the night, but my AHI has always run high, i get headaches, sleepy at noon (take a nap). Not really sure, as I have gotton better machines over the years, that the more advanced machines as I used them (cpap, bipap, auto bipap), have helped any more than my first cpap. Not sure, in the end, that it makes a difference, whether I use a asv for OSA, or not.
Maybe you would benefit from ASV therapy, but it does usually take a few weeks to get used to ASV therapy mode. It feels different, but we can get used to it and it may help to end your headaches and tiredness, after you get used to ASV therapy and can sleep with it. I would suggest watching TV or reading while using ASV therapy, so you can get used to the different feeling, before you try to sleep using the machine.
Also, at least for a few days, you may want to adjust your pressure settings to be close to the settings which are used on your old machine, to help you get used to the new therapy mode.
but it is an Assisted Servo Ventilator for people with central apnea that do not breath on their on (patient initiated breaths). That machine is capable of delivering timed breaths when the patient stops breathing, and inflate the lungs with servo pressure.
not sure what I timed breath is, and what the difference is between the lungs being inflated with servo pressure and the lungs being inflated with cpap pressure. Perhaps a. when the air pressure is increased after an event of breath cessation, the servo times differently when the increase occurs, and b. servo pressure reacts differently than non servo pressure to apneas and hypopneas, than an auto bipap would. c. servo pressure is designed to target csa events, not osa events.
If I have a, b, and c correct, will the servo mess me up even more, since as far as I know, i have osa, not csa, though I am not sure I have faith in the medical professionals I have seen these past three decades?
An ASV machine reacts the same way to both obstructive and central apneas. It immediately starts cycling between EPAP and IPAP, and it increases Pressure Support as much as necessary in an attempt to immediately end the apnea or hypopnea.
I think the word "servo" may simply refer to controlling or varying the pressure level, which all bi-level and ASV machines do.
(01-17-2015 12:23 AM)leiko49 Wrote: sometimes I wonder how much of the description is bs marketing jargon vs scientific description. For example, from your quote it states that the servo "targets the patient's own recent minute ventilation. By treating central breathing disorders with auto-adjusting pressure support, and upper airway obstruction with auto-adjusting expiratory positive airway pressure, the device works to rapidly stabilize breathing.'
From what I understand, an auto bipap also "targets recent ventilation" that would trigger pressure increases on the inhalation, and same on exhalation. I think that auto bipap also treats breathing disorders with auto adjusting inhalation and expiratory pressure to rapidly stabilize breathing.
No, AirCurve 10 Auto and the PRS1 BiPAP Auto machines do not target recent ventilation. Instead, the Auto bi-level machines analyze the Flow (which is the rate of airflow entering and exiting our lungs) for signs of apnea and hypopnea and Flow Limitation (partial obstruction) and snore, and these machines try to adjust EPAP by the minimum amount necessary to make future obstructive events less likely.
The A10 ASV adjusts Pressure Support as much as needed in an attempt to maintain 90% of our recent natural Minute Ventilation (which is the total amount of air breathed during one minute, which is the Tidal Volume in Liters per breath, times the Respiration rate in breaths per minute).
Quote:I suppose I can just submit myself to be a guinea pig on this, but then it is an expensive machine (not as expensive as a similar Respironics for ASV System One DS960HS) which I read you can set up as an auto bilevel.
Well, the BiPAP autoSV Advanced DS960 is definitely more adjustable (and mis-adjustable) compared to the ResMed ASV machines. There are fewer settings which can be adjusted on the ResMed ASV machines because more things are automatic. But neither one can be configured into a therapy mode which is exactly like the ResMed AirCurve 10 Auto or the PRS1 BiPAP Auto.