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Therapy numbers, lack of them, weight loss, etc
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vsheline Offline

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Machine: S9 VPAP Adapt (USA Model# 36007, not better 36037 or 36067)
Mask Type: Full face mask
Mask Make & Model: F10 or SimPlus w/ 2Liners. MirageQuatro & Gecko gel pad
Humidifier: H5i
CPAP Pressure: 15 EPAP, PS 5-10
CPAP Software: ResScan

Other Comments: Marfan Syndrome, chronic bradycardia, occasional Cheyne-Stokes Respiration

Sex: Male
Location: California, USA

Post: #81
RE: Therapy numbers, lack of them, weight loss, etc
(09-11-2014 08:35 AM)Galactus Wrote:  These are the available machine settings;
[Image: i2k3l3.jpg]

[Image: 11w3ipi.jpg]

The suggested settings change (and they make sense to me now that I understand more) are as follows;

Min EPAP: 13 (about 5 less than now)
Max EPAP: 18 (about the same as now)
Min Pressure Support: 1
Max Pressure Support: 4
Max IPAP (or perhaps called Max Pressure): 22 (set to the sum of Max EPAP plus Max Pressure Support, unless you start to experience problems from high pressure.)
Ramp: same as now
Bi-Flex: same as C-Flex now


This part is easy;
In settings I have Min EPAP which I can find and set to 13.
Pressure Support Min and Max are there so can set those to 1 and 4.
Max IPAP I have and can set as well to 22.
Ramp I don't use so I'll leave it off.
Bi-Flex set to 3 same as CFlex.


Here are the questions though;
I don't see a Max EPAP though, so how is that set?

Now that I see the available settings which you have listed, I see there is no explicit Max EPAP setting, which I think means the machine can raise EPAP as high as Max IPAP minus whatever happens to be the present value of PS. (The machine adjusts EPAP independently from its adjustments of PS.)

(09-11-2014 08:35 AM)Galactus Wrote:  There are also stand alone lines for IPAP, EPAP, CPAP Pres, do I need to set anything there?

No, the IPAP and EPAP settings only apply when in BiPAP mode, not AutoB mode. The CPAP Pres only applies when in CPAP mode.

(09-11-2014 08:35 AM)Galactus Wrote:  There is a Rise time setting of 0-3, do I set anything there? What is that? Is that how fast or slow it will change? I think someone mentioned that as well.

For Rise Time, a setting of zero is shortest (the most abrupt, 150 milliseconds).

So, if you find that the abruptness of the EPAP/IPAP transition is annoying to you, then change the Rise Time to a larger (longer, more gradual) value.


(09-11-2014 08:35 AM)Galactus Wrote:  I just read the settings again now and I am confused, I thought Min and Max PS I understood to be 1 and 4. However when I read it I don't think so as it says Max PS 0.0 - min of [8 or (Max IPAP - Min EPAP)] and then Min PS shows 0.0 - (Max PS) so now I'm not sure what should be set.

"Min PS 0.0 - (Max PS)" means the PS Min setting can be set as small as zero or can be set as large as the PS Max setting.

"Max PS 0.0 - min of [8 or (Max IPAP - Min EPAP)]" means that the Max PS setting can be set as small as the PS Min setting (which can be as small as zero) or can be set as large as the difference between Min EPAP and Max IPAP, except PS Max can never be larger than 8.

(09-11-2014 08:35 AM)Galactus Wrote:  Edit -- I'm reading and reading and I have come to the following; Seems to me the settings should be;

Max IPAP 20 (I am now fixed at 18 so +2 should be more than enough)
Min EPAP 13 (Seems like a good starting point)
Max PS- 7 (This is the max difference allowed between IPAP & EPAP and is 20-13=7)
Min PS- 1 (This is the min difference allowed between IPAP & EPA)
Rise Time- 1 (0 is off 1 is 200 msec, 2 is 300 msec and 3 is 400 msec, just seemed like a place to start though maybe 0 is better)
Flex- BiFlex at 3 (Same as my current CFlex setting)

I think your revised settings are fine as a starting point, but please note the points below.

If Min EPAP is 13 and if Max IPAP is 20, the Max PS setting CAN be set as high as 7, but the Max PS setting does not necessarily need to be set that high. The reason I suggested 4 as a Max PS limit was to be cautious, so that PS could not get higher than 4, in case you may find that a high value of PS increases the number of CA apneas or increases the severity of the Periodic Breathing episodes. With a minority of patients, the larger the value of PS, the larger the number of central events they get.

One result of setting the Max IPAP to 20 and setting the Max PS higher than 2 is that sometimes EPAP may not be able to go as high as 18 (which was your fixed CPAP prescription). The AutoB settings which were originally suggested would have guaranteed that the machine would always be able to raise EPAP at least as high as 18, if needed. With the original suggested settings, even if PS is at its maximum limit, the Max IPAP setting is high enough to allow EPAP to raise itself to 18 if needed.

Membership in the Advisory Member group should not be understood as in any way implying medical expertise or qualification for advising Sleep Apnea patients concerning their treatment. The Advisory Member group provides advice and suggestions to Apnea Board administrators and staff on matters concerning Apnea Board operation and administrative policies - not on matters concerning treatment for Sleep Apnea. I think it is now too late to change the name of the group but I think Voting Member group would perhaps have been a more descriptive name for the group.
(This post was last modified: 09-12-2014 06:53 AM by vsheline.)
09-12-2014 05:51 AM
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Galactus Offline

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Machine: Phillips Respironics System One PRS1 DS760P Auto BiPAP
Mask Type: Nasal pillows
Mask Make & Model: ResMed Airfit P10 Nasal Pillow
Humidifier: System One Heated Humidifier + Climate Line
CPAP Pressure: E/I 13/20 PS 4/7 BiFlex 3
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Other Comments: Sleep can be a good thing.

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Post: #82
RE: Therapy numbers, lack of them, weight loss, etc
(09-12-2014 05:51 AM)vsheline Wrote:  
(09-11-2014 08:35 AM)Galactus Wrote:  Here are the questions though;
I don't see a Max EPAP though, so how is that set?

Now that I see the available settings which you have listed, I see there is no explicit Max EPAP setting, which I think means the machine can raise EPAP as high as Max IPAP minus whatever happens to be the present value of PS. (The machine adjusts EPAP independently from its adjustments of PS.)

I believe that is correct as it extrapolates the Max EPAP from the other settings (I did read that yesterday in my travels too)

(09-12-2014 05:51 AM)vsheline Wrote:  
(09-11-2014 08:35 AM)Galactus Wrote:  There are also stand alone lines for IPAP, EPAP, CPAP Pres, do I need to set anything there?

No, the IPAP and EPAP settings only apply when in BiPAP mode, not AutoB mode. The CPAP Pres only applies when in CPAP mode.

Yes, I figured this one out when setting the machine as nothing came up, and when I looked again at the settings it says right there "will only come up if machine is set to CPAP" and all that. But thank you.

(09-12-2014 05:51 AM)vsheline Wrote:  
(09-11-2014 08:35 AM)Galactus Wrote:  There is a Rise time setting of 0-3, do I set anything there? What is that? Is that how fast or slow it will change? I think someone mentioned that as well.

For Rise Time, a setting of zero is shortest (the most abrupt, 150 milliseconds).

So, if you find that the abruptness of the EPAP/IPAP transition is annoying to you, then change the Rise Time to a larger (longer, more gradual) value.

Just so you are aware for the future in assisting anyone else, and for anyone else reading, the rise time setting is only available if BiFlex is OFF. I spent 10 minutes scrolling back and forth through the settings looking for it till I read the setup manual for the 10th time and saw the statement that says "Only available if Flex has been disabled". As I am using BiFlex at 3 it is not available.

(09-12-2014 05:51 AM)vsheline Wrote:  
(09-11-2014 08:35 AM)Galactus Wrote:  I just read the settings again now and I am confused, I thought Min and Max PS I understood to be 1 and 4. However when I read it I don't think so as it says Max PS 0.0 - min of [8 or (Max IPAP - Min EPAP)] and then Min PS shows 0.0 - (Max PS) so now I'm not sure what should be set.

"Min PS 0.0 - (Max PS)" means the PS Min setting can be set as small as zero or can be set as large as the PS Max setting.

"Max PS 0.0 - min of [8 or (Max IPAP - Min EPAP)]" means that the Max PS setting can be set as small as the PS Min setting (which can be as small as zero) or can be set as large as the difference between Min EPAP and Max IPAP, except PS Max can never be larger than 8.

I guess what I don't understand here and the reason for my confusion is what exactly is PS? Is it how much added pressure the unit will add in the event of an apnea? Like if set at 13 for Min EPAP and PS=1 when it senses an event will it raise to 14 and then by 1's? Or am I misunderstanding what PS is?

(09-12-2014 05:51 AM)vsheline Wrote:  
(09-11-2014 08:35 AM)Galactus Wrote:  Edit -- I'm reading and reading and I have come to the following; Seems to me the settings should be;

Max IPAP 20 (I am now fixed at 18 so +2 should be more than enough)
Min EPAP 13 (Seems like a good starting point)
Max PS- 7 (This is the max difference allowed between IPAP & EPAP and is 20-13=7)
Min PS- 1 (This is the min difference allowed between IPAP & EPA)
Rise Time- 1 (0 is off 1 is 200 msec, 2 is 300 msec and 3 is 400 msec, just seemed like a place to start though maybe 0 is better)
Flex- BiFlex at 3 (Same as my current CFlex setting)

I think your revised settings are fine as a starting point, but please note the points below.

If Min EPAP is 13 and if Max IPAP is 20, the Max PS setting CAN be set as high as 7, but the Max PS setting does not necessarily need to be set that high. The reason I suggested 4 as a Max PS limit was to be cautious, so that PS could not get higher than 4, in case you may find that a high value of PS increases the number of CA apneas or increases the severity of the Periodic Breathing episodes. With a minority of patients, the larger the value of PS, the larger the number of central events they get.

One result of setting the Max IPAP to 20 and setting the Max PS higher than 2 is that sometimes EPAP may not be able to go as high as 18 (which was your fixed CPAP prescription). The AutoB settings which were originally suggested would have guaranteed that the machine would always be able to raise EPAP at least as high as 18, if needed. With the original suggested settings, even if PS is at its maximum limit, the Max IPAP setting is high enough to allow EPAP to raise itself to 18 if needed.

I think this really confirms that I don't get the PS situation. PS must be different from the unit raising and lowering pressure. Maybe you can explain what I am missing, will try and look it up myself as well.

Your first paragraph here warning on CA's I understand a little. The second paragraph I'm lost on. I don't understand how Max EPAP is unable to reach 18 with a Max PS setting of 7. I thought that if Min EPAP =13 and Max EPAP = 20 with a Max PS of 7 that 13+7=20 and that with a Min PS of 1 that Max IPAP could =20 and Max EPAP could =19 which left both numbers above my original script. Did I misinterpret something?

Below are my results from last night as well. Seems had I just listened to the Dr and lowered my brick to 15 I would have been under what I needed. Also seems the EPAP never broke 13 and that the leak rate reduced to almost nothing with the lowered pressures, and it was a whole lot less effort for me through the night with the lowered pressure which was nice. And with a 1.63 I think I might be on the right track. Anyway, tell me what you think and if you want to see anything else let me know and I'll post it.

[Image: 205p9go.jpg]

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09-12-2014 09:32 AM
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retired_guy Offline

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Machine: ResMed S9 Autoset
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Post: #83
RE: Therapy numbers, lack of them, weight loss, etc
Wow Galactus, for the first night out those numbers look good dude!

I would not change a thing for awhile. 1/2 of your ahi comes from CA that very well might go away all by itself. The bulk of the rest of it is Hypop. The OA's are nearly extinct.

So, first night? Good job.

Let's see what Vaughn thinks, but I like what I see.
09-12-2014 11:03 AM
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Galactus Offline

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Machine: Phillips Respironics System One PRS1 DS760P Auto BiPAP
Mask Type: Nasal pillows
Mask Make & Model: ResMed Airfit P10 Nasal Pillow
Humidifier: System One Heated Humidifier + Climate Line
CPAP Pressure: E/I 13/20 PS 4/7 BiFlex 3
CPAP Software: SleepyHead EncoreBasic

Other Comments: Sleep can be a good thing.

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Location: USA

Post: #84
RE: Therapy numbers, lack of them, weight loss, etc
(09-12-2014 11:03 AM)retired_guy Wrote:  Wow Galactus, for the first night out those numbers look good dude!

I would not change a thing for awhile. 1/2 of your ahi comes from CA that very well might go away all by itself. The bulk of the rest of it is Hypop. The OA's are nearly extinct.

So, first night? Good job.

Let's see what Vaughn thinks, but I like what I see.

Thanks Bud, I was pretty happy myself, I was more impressed with the fact that we all figured it out with no Dr's lol.

I'm also happy for the lowered pressure, my nose feels so much better this morning.

You know I don't have all the jargon down yet so when you say CA vs Hypop's and OA's does that mean that OA's are the worst, followed by Hypop's and CA's? Just wondering, trying to educate myself on all this stuff.

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09-12-2014 11:17 AM
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retired_guy Offline

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Posts: 2,744
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Machine: ResMed S9 Autoset
Mask Type: Nasal pillows
Mask Make & Model: Resmed Airfit P10
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CPAP Software: ResScan SleepyHead

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Post: #85
RE: Therapy numbers, lack of them, weight loss, etc
I don't know if there really is a worse. We don't like any of them. But CA's can be harder to get rid of than the others, and Hypop's look to me like OA's that never had the chance to grow up. So what I like to do is focus on the OA's, and watch to make sure my CA's don't decide to come to life. Once I got rid of the OA's and CA's, I worked on the Hypops by fine tuning the pressure.
09-12-2014 12:02 PM
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PaytonA Offline
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CPAP Pressure: VAuto MinE14.0 MaxI 20.6 PS4.0
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Post: #86
RE: Therapy numbers, lack of them, weight loss, etc
Just a couple of comments, Galactus. When I got my new S9 VPAP Auto, it felt a lot gentler than my S8 VPAP Auto. I operate it in BiPAP (VPAP) mode and I have a feature that Resmed has called EasyBreathe turned on. The pressure transitions between EPAP and IPAP are also a lot gentler.
Just for your information, if you ever get around to "futzing" with the rise time, the Resmed machine comes with the rise time set at the factory default which is 350 ~milliseconds. Looks like you are doing great. Keep it up!
Sleep-well

Best Regards,

PaytonA
09-12-2014 12:42 PM
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Galactus Offline

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Machine: Phillips Respironics System One PRS1 DS760P Auto BiPAP
Mask Type: Nasal pillows
Mask Make & Model: ResMed Airfit P10 Nasal Pillow
Humidifier: System One Heated Humidifier + Climate Line
CPAP Pressure: E/I 13/20 PS 4/7 BiFlex 3
CPAP Software: SleepyHead EncoreBasic

Other Comments: Sleep can be a good thing.

Sex: Male
Location: USA

Post: #87
RE: Therapy numbers, lack of them, weight loss, etc
(09-12-2014 12:02 PM)retired_guy Wrote:  I don't know if there really is a worse. We don't like any of them. But CA's can be harder to get rid of than the others, and Hypop's look to me like OA's that never had the chance to grow up. So what I like to do is focus on the OA's, and watch to make sure my CA's don't decide to come to life. Once I got rid of the OA's and CA's, I worked on the Hypops by fine tuning the pressure.

Gotcha, and thanks.

(09-12-2014 12:42 PM)PaytonA Wrote:  Just a couple of comments, Galactus. When I got my new S9 VPAP Auto, it felt a lot gentler than my S8 VPAP Auto. I operate it in BiPAP (VPAP) mode and I have a feature that Resmed has called EasyBreathe turned on. The pressure transitions between EPAP and IPAP are also a lot gentler.
Just for your information, if you ever get around to "futzing" with the rise time, the Resmed machine comes with the rise time set at the factory default which is 350 ~milliseconds. Looks like you are doing great. Keep it up!
Sleep-well

Best Regards,

PaytonA

Thanks for the info. I have this one running in AutoB Mode, and I have the BiFlex/Cflex on. It appears that in order to use the adjustable Rise Time you have to shut off the BiFlex/Cflex off. I'm not actually sure that would be better. Do you know?

Thanks for the help.

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09-12-2014 10:34 PM
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vsheline Offline

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Machine: S9 VPAP Adapt (USA Model# 36007, not better 36037 or 36067)
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Mask Make & Model: F10 or SimPlus w/ 2Liners. MirageQuatro & Gecko gel pad
Humidifier: H5i
CPAP Pressure: 15 EPAP, PS 5-10
CPAP Software: ResScan

Other Comments: Marfan Syndrome, chronic bradycardia, occasional Cheyne-Stokes Respiration

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Location: California, USA

Post: #88
RE: Therapy numbers, lack of them, weight loss, etc
(09-12-2014 09:32 AM)Galactus Wrote:  
(09-12-2014 05:51 AM)vsheline Wrote:  
(09-11-2014 08:35 AM)Galactus Wrote:  I guess what I don't understand here and the reason for my confusion is what exactly is PS? Is it how much added pressure the unit will add in the event of an apnea? Like if set at 13 for Min EPAP and PS=1 when it senses an event will it raise to 14 and then by 1's? Or am I misunderstanding what PS is?
...

Edit -- I'm reading and reading and I have come to the following; Seems to me the settings should be;

Max IPAP 20 (I am now fixed at 18 so +2 should be more than enough)
Min EPAP 13 (Seems like a good starting point)
Max PS- 7 (This is the max difference allowed between IPAP & EPAP and is 20-13=7)
Min PS- 1 (This is the min difference allowed between IPAP & EPA)
Rise Time- 1 (0 is off 1 is 200 msec, 2 is 300 msec and 3 is 400 msec, just seemed like a place to start though maybe 0 is better)
Flex- BiFlex at 3 (Same as my current CFlex setting)

I think your revised settings are fine as a starting point, but please note the points below.

If Min EPAP is 13 and if Max IPAP is 20, the Max PS setting CAN be set as high as 7, but the Max PS setting does not necessarily need to be set that high. The reason I suggested 4 as a Max PS limit was to be cautious, so that PS could not get higher than 4, in case you may find that a high value of PS increases the number of CA apneas or increases the severity of the Periodic Breathing episodes. With a minority of patients, the larger the value of PS, the larger the number of central events they get.

One result of setting the Max IPAP to 20 and setting the Max PS higher than 2 is that sometimes EPAP may not be able to go as high as 18 (which was your fixed CPAP prescription). The AutoB settings which were originally suggested would have guaranteed that the machine would always be able to raise EPAP at least as high as 18, if needed. With the original suggested settings, even if PS is at its maximum limit, the Max IPAP setting is high enough to allow EPAP to raise itself to 18 if needed.

I think this really confirms that I don't get the PS situation. PS must be different from the unit raising and lowering pressure. Maybe you can explain what I am missing, will try and look it up myself as well.

Your first paragraph here warning on CA's I understand a little. The second paragraph I'm lost on. I don't understand how Max EPAP is unable to reach 18 with a Max PS setting of 7. I thought that if Min EPAP =13 and Max EPAP = 20 with a Max PS of 7 that 13+7=20 and that with a Min PS of 1 that Max IPAP could =20 and Max EPAP could =19 which left both numbers above my original script. Did I misinterpret something?

Hi Galactus,

Regarding your question, "what exactly is PS? Is it how much added pressure the unit will add in the event of an apnea? Like if set at 13 for Min EPAP and PS=1 when it senses an event will it raise to 14 and then by 1's?"

On your machine, during an apnea PS would not be increased or decreased at all.

Unlike your machine, ASV (adaptive servo ventilator) machines do react immediately to an apnea or hypopnea, to interrupt and counteract apneas and hypopneas. On ASV machines, within a few seconds the PS might skyrocket from very low to very high if the machine is suddenly faced with an apnea, or the PS might be changed by less than 1 if faced with a small increase or decrease in how much air we are breathing.

Even if we are not making any effort to breathe, an ASV machine will (on its own) cycle between EPAP and IPAP at a "backup respiration rate", unlike CPAP and BiPAP and BiPAP Auto machines which will not try to counteract the present apnea or hypopnea.

In general, an ASV unit reacts immediately to boost or lower PS however much is needed to end the apnea and to keep the volume of air being breathed steady.

The PRS1 BiPAP Auto does auto-adjust PS, but only very slowly: Every few minutes the machine decides whether to leave PS unchanged or whether to increase or decrease PS by 1 cm H2O.

Below is an excerpt from my earlier post #52. It discusses the how slowly PS is adjusted on your machine.

- - - BEGIN EXCERPT FROM POST #52 - - -
Min EPAP: 13 (about 5 less than now)
Max EPAP: 18 (about the same as now)
Min Pressure Support: 1
Max Pressure Support: 4
Max IPAP (or perhaps called Max Pressure): 22 (set to the sum of Max EPAP plus Max Pressure Support, unless you start to experience problems from high pressure.)
Ramp: same as now
Bi-Flex: same as C-Flex now

The above settings would make the EPAP pressure start at 13, so the pressure whenever exhaling would be 13 until the machine [slowly] automatically raises the EPAP pressure when it senses obstructions or partial obstructions.

The above settings would make the Pressure Support start at 1. The IPAP would start at IPAP = EPAP + PS = 14, so the pressure whenever inhaling would be 14 until the machine automatically raises the EPAP pressure when it senses obstructions. If PS remains unchanged and EPAP is raised in response to obstructive events, then EPAP and IPAP would be raised and lowered together the same amount.

But also, occasionally, the machine will do a slow dance to see whether to raise or lower PS, based on how this affects Flow Limitation. In brief, PS is occasionally raised a little (causing IPAP to be raised because IPAP = EPAP + PS) and if this causes Flow Limitation to be reduced then PS will stay at its new higher value for the next several minutes, until the next test to see if PS should be raised or lowered. Also, PS is occasionally lowered a little (causing IPAP to be lowered because IPAP = EPAP + PS) and if this does not cause Flow Limitation to start then PS will stay at its lower value for the next several minutes, until the next test to see if PS should be raised or lowered. But PS will always stay within the limits set by the Min PS and Max PS settings.

In this way the machine will [slowly] raise the pressure only as much as needed to avoid obstructive events and any signs of Flow Limitation.
- - - END EXCERPT FROM POST #52 - - -

Regarding, "I don't understand how Max EPAP is unable to reach 18 with a Max PS setting of 7. I thought that if Min EPAP =13 and Max EPAP = 20 with a Max PS of 7 that 13+7=20 and that with a Min PS of 1 that Max IPAP could =20 and Max EPAP could =19 which left both numbers above my original script."

Yes, in your example, EPAP could be as high as 19, but only if PS happens to be 1. EPAP and PS are separately getting raised or lowered in accordance with their separate algorithms, and I think the EPAP algorithm is not allowed to change PS and the PS algorithm is not allowed to change EPAP.

Keep in mind that whenever EPAP is adjusted IPAP is adjusted by the same amount, so that PS will be unchanged.

Let's take the case that Max IPAP is 20, and EPAP has been adjusted to 15, and PS has been adjusted to 4. (EPAP is 15 and IPAP is 19, which is 1 less than Max IPAP.) In that scenario, if your machine senses that a higher EPAP is needed, it can adjust EPAP to 16. (EPAP raises to 16 and IPAP raises to 20, which happens to be Max IPAP.)

If it so happens that your machine later senses that a still higher EPAP would be beneficial, I think the EPAP could not go to 17, because if EPAP were to be raised any higher, IPAP would also need to be raised by an equal amount, which is not allowed because IPAP is already at its limit.

Later, if the algorithm for adjusting PS happens to lower PS (to 3, say) then EPAP could be raised to 17 at that time (if the algorithm for adjusting EPAP still indicates that higher EPAP would be beneficial).

Membership in the Advisory Member group should not be understood as in any way implying medical expertise or qualification for advising Sleep Apnea patients concerning their treatment. The Advisory Member group provides advice and suggestions to Apnea Board administrators and staff on matters concerning Apnea Board operation and administrative policies - not on matters concerning treatment for Sleep Apnea. I think it is now too late to change the name of the group but I think Voting Member group would perhaps have been a more descriptive name for the group.
(This post was last modified: 09-13-2014 12:37 AM by vsheline.)
09-12-2014 11:58 PM
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Galactus Offline

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Machine: Phillips Respironics System One PRS1 DS760P Auto BiPAP
Mask Type: Nasal pillows
Mask Make & Model: ResMed Airfit P10 Nasal Pillow
Humidifier: System One Heated Humidifier + Climate Line
CPAP Pressure: E/I 13/20 PS 4/7 BiFlex 3
CPAP Software: SleepyHead EncoreBasic

Other Comments: Sleep can be a good thing.

Sex: Male
Location: USA

Post: #89
RE: Therapy numbers, lack of them, weight loss, etc
(09-12-2014 11:58 PM)vsheline Wrote:  
(09-12-2014 09:32 AM)Galactus Wrote:  
(09-12-2014 05:51 AM)vsheline Wrote:  I think your revised settings are fine as a starting point, but please note the points below.

If Min EPAP is 13 and if Max IPAP is 20, the Max PS setting CAN be set as high as 7, but the Max PS setting does not necessarily need to be set that high. The reason I suggested 4 as a Max PS limit was to be cautious, so that PS could not get higher than 4, in case you may find that a high value of PS increases the number of CA apneas or increases the severity of the Periodic Breathing episodes. With a minority of patients, the larger the value of PS, the larger the number of central events they get.

One result of setting the Max IPAP to 20 and setting the Max PS higher than 2 is that sometimes EPAP may not be able to go as high as 18 (which was your fixed CPAP prescription). The AutoB settings which were originally suggested would have guaranteed that the machine would always be able to raise EPAP at least as high as 18, if needed. With the original suggested settings, even if PS is at its maximum limit, the Max IPAP setting is high enough to allow EPAP to raise itself to 18 if needed.

I think this really confirms that I don't get the PS situation. PS must be different from the unit raising and lowering pressure. Maybe you can explain what I am missing, will try and look it up myself as well.

Your first paragraph here warning on CA's I understand a little. The second paragraph I'm lost on. I don't understand how Max EPAP is unable to reach 18 with a Max PS setting of 7. I thought that if Min EPAP =13 and Max EPAP = 20 with a Max PS of 7 that 13+7=20 and that with a Min PS of 1 that Max IPAP could =20 and Max EPAP could =19 which left both numbers above my original script. Did I misinterpret something?

Hi Galactus,

Regarding your question, "what exactly is PS? Is it how much added pressure the unit will add in the event of an apnea? Like if set at 13 for Min EPAP and PS=1 when it senses an event will it raise to 14 and then by 1's?"

On your machine, during an apnea PS would not be increased or decreased at all.

Unlike your machine, ASV (adaptive servo ventilator) machines do react immediately to an apnea or hypopnea, to interrupt and counteract apneas and hypopneas. On ASV machines, within a few seconds the PS might skyrocket from very low to very high if the machine is suddenly faced with an apnea, or the PS might be changed by less than 1 if faced with a small increase or decrease in how much air we are breathing.

Even if we are not making any effort to breathe, an ASV machine will (on its own) cycle between EPAP and IPAP at a "backup respiration rate", unlike CPAP and BiPAP and BiPAP Auto machines which will not try to counteract the present apnea or hypopnea.

In general, an ASV unit reacts immediately to boost or lower PS however much is needed to end the apnea and to keep the volume of air being breathed steady.

The PRS1 BiPAP Auto does auto-adjust PS, but only very slowly: Every few minutes the machine decides whether to leave PS unchanged or whether to increase or decrease PS by 1 cm H2O.

Below is an excerpt from my earlier post #52. It discusses the how slowly PS is adjusted on your machine.

- - - BEGIN EXCERPT FROM POST #52 - - -
Min EPAP: 13 (about 5 less than now)
Max EPAP: 18 (about the same as now)
Min Pressure Support: 1
Max Pressure Support: 4
Max IPAP (or perhaps called Max Pressure): 22 (set to the sum of Max EPAP plus Max Pressure Support, unless you start to experience problems from high pressure.)
Ramp: same as now
Bi-Flex: same as C-Flex now

The above settings would make the EPAP pressure start at 13, so the pressure whenever exhaling would be 13 until the machine [slowly] automatically raises the EPAP pressure when it senses obstructions or partial obstructions.

The above settings would make the Pressure Support start at 1. The IPAP would start at IPAP = EPAP + PS = 14, so the pressure whenever inhaling would be 14 until the machine automatically raises the EPAP pressure when it senses obstructions. If PS remains unchanged and EPAP is raised in response to obstructive events, then EPAP and IPAP would be raised and lowered together the same amount.

But also, occasionally, the machine will do a slow dance to see whether to raise or lower PS, based on how this affects Flow Limitation. In brief, PS is occasionally raised a little (causing IPAP to be raised because IPAP = EPAP + PS) and if this causes Flow Limitation to be reduced then PS will stay at its new higher value for the next several minutes, until the next test to see if PS should be raised or lowered. Also, PS is occasionally lowered a little (causing IPAP to be lowered because IPAP = EPAP + PS) and if this does not cause Flow Limitation to start then PS will stay at its lower value for the next several minutes, until the next test to see if PS should be raised or lowered. But PS will always stay within the limits set by the Min PS and Max PS settings.

In this way the machine will [slowly] raise the pressure only as much as needed to avoid obstructive events and any signs of Flow Limitation.
- - - END EXCERPT FROM POST #52 - - -

Just so you know, I have read all your posts thoroughly, most many times over. Just want you to be aware I am paying attention. I think the real issue is I just don't get it. I don't understand how the machine is working, and the math that you are providing doesn't add up for me. My presumption is that is because I just don't get it. I think the one thing that I specifically don't get is the PS. I had thought till this post that PS raised and lowered EPAP and IPAP, but after reading this post I think I am revising that thought to understand that even though when we start at IPAP=EPAP+PS that is not to say these numbers depend on each other, or that PS raises them as I previously thought. It seems that in actuality IPAP EPAP and PS all raise and lower independently of each other based on their specific algorithms. Is that correct or am I still missing this?


(09-12-2014 05:51 AM)vsheline Wrote:  Regarding, "I don't understand how Max EPAP is unable to reach 18 with a Max PS setting of 7. I thought that if Min EPAP =13 and Max EPAP = 20 with a Max PS of 7 that 13+7=20 and that with a Min PS of 1 that Max IPAP could =20 and Max EPAP could =19 which left both numbers above my original script."

Yes, in your example, EPAP could be as high as 19, but only if PS happens to be 1. EPAP and PS are separately getting raised or lowered in accordance with their separate algorithms, and I think the EPAP algorithm is not allowed to change PS and the PS algorithm is not allowed to change EPAP.

Keep in mind that whenever EPAP is adjusted IPAP is adjusted by the same amount, so that PS will be unchanged.

Let's take the case that Max IPAP is 20, and EPAP has been adjusted to 15, and PS has been adjusted to 4. (EPAP is 15 and IPAP is 19, which is 1 less than Max IPAP.) In that scenario, if your machine senses that a higher EPAP is needed, it can adjust EPAP to 16. (EPAP raises to 16 and IPAP raises to 20, which happens to be Max IPAP.)

One thing I think you have missed, the max on the unit is 25 and not 20. That was part of my consideration in using 20 as being 2 over my 18 as 18 + 7 (PS) = 25 (in my mind) which meant I couldn't get over the script by more than 5 and couldn't be over the machines 25. Because even if EPAP being set to 13 was raised to my script value of 18 and PS =7 then IPAP would still be at 25 which was the machines max. Did I interpret that correctly or miss the boat?

I'm sorry I am really confused by this despite having read it like 50x now.

The one thing I got was IPAP = EPAP + PS. With that in my mind, starting EPAP at 13 and PS at 1 the IPAP = 14. Then I read the line for PS Max and it said "This is the max difference permitted between IPAP & EPAP. So if start EPAP = 14 and 7 = Max difference than 14 + 7 = 21 leaving me 4 under machine max. And in the event the machine raised IPAP to 18 (using what I believed was PS's number) then 18 + 7 (Max allowed difference) = 25 which was the machine max.

(09-12-2014 05:51 AM)vsheline Wrote:  If it so happens that your machine later senses that a still higher EPAP would be beneficial, I think the EPAP could not go to 17, because if EPAP were to be raised any higher, IPAP would also need to be raised by an equal amount, which is not allowed because IPAP is already at its limit.

I believe this changes once you adjust the max to 25 vs 20, but I am not sure.....

(09-12-2014 05:51 AM)vsheline Wrote:  Later, if the algorithm for adjusting PS happens to lower PS (to 3, say) then EPAP could be raised to 17 at that time (if the algorithm for adjusting EPAP still indicates that higher EPAP would be beneficial).

Based on the above, I understood what you tried explaining here I think.

I've also posted todays numbers as well, so you can see where we are. And when I look at the graph on the right for pressure I don't see IPAP and EPAP moving in tandem, it appears they are moving independently of each other and it make me think somehow I am missing this yet again.

The one other thing I'd like to sya to everyone here that contributed and to you and RG is that I thank you for making me go out and buy this machine because regardless of whether or not I ever understand this I do know I am getting better therapy and I can see what is happening and I am sleeping better and the machine is bothering me way less, so I thank you all for that, and a shout out to SS who has the board up so others may learn the same. And to all of us that help everyone we can.

[Image: rk0nr8.jpg]

If everyone thinks alike, then someone isn't thinking.
Everyone knows something, together we could know everything.
09-13-2014 04:47 PM
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retired_guy Offline

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Posts: 2,744
Joined: Jan 2014

Machine: ResMed S9 Autoset
Mask Type: Nasal pillows
Mask Make & Model: Resmed Airfit P10
Humidifier: ResMed
CPAP Pressure: 10.6/14, EPR 3
CPAP Software: ResScan SleepyHead

Other Comments: Is it bedtime yet?

Sex: Male
Location: Beautiful, albeit very wet Oregon Coast

Post: #90
RE: Therapy numbers, lack of them, weight loss, etc
Hummphhh. What's that? One lousy OA? Geezzzzz, you'd think you were a old pro at this. .......and by gum you'd be right! Congrats on the great results. Galactus. The machine could not have done it without you.
09-13-2014 04:55 PM
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