CPAPtalk.com

-SWS wrote:We'd need 180 oscillations every 3 seconds for 60 Hz. We can rule out electrical noise across the flow sensor leads...

Right.

Since Flow Trigger is running you're using Active Exhalation which is a pretty busy routine:

Active Exhalation Valve Control - The active exhalation valve consists of a two valve system. One valve dumps the pilot pressure while the other provides proportional control of the pilot pressure. Both the valves are controlled by the CPU via connector on the system board (J10). To control the proportional valve the CPU generates an analog control voltage uses a 16-bit DAC (U27). This signal drives a precision current sink (U28 and Q5) controlling the current flow through the proportional active exhalation valve.

but with it being so transient seems almost academic.

Can you query the Error Log? If it's something significant it may show up in there.

Since Flow Trigger is running you're using Active Exhalation which is a pretty busy routine:

Active Exhalation Valve Control - The active exhalation valve consists of a two valve system. One valve dumps the pilot pressure while the other provides proportional control of the pilot pressure. Both the valves are controlled by the CPU via connector on the system board (J10). To control the proportional valve the CPU generates an analog control voltage uses a 16-bit DAC (U27). This signal drives a precision current sink (U28 and Q5) controlling the current flow through the proportional active exhalation valve

I don't think madalot is using the active exhalation circuit. Just the regular passive circuit.

Okay. I'm up from last night. I will upload last night's data later when my son brings my cart out (will be a couple hours). I was very aware of my movements and how they equated to the pulsing I'm experiencing on exhale. At first, I thought that was it, but later, it was at least 2 minutes AFTER moving that they started. Another time, I hadn't moved at all and they started.

I stopped "screen watching" a long time ago and have the screen saver turned on. I turned the screen on this morning to look at the clock to see, how it compared with the clock I looked at around 5:25 this morning when I noticed pulsing compared to movement and wanted to check in the data (they are about 2 minutes apart so I know where to look in the data).

Something I DID notice, though, is that during one of these pulses, the EPAP on the screen was bouncing back and forth between two numbers, usually 9.9 and 10. When NOT pulsing, it was a straight number, usually 10. A little surprising because I was on my side (9 should be adequate on my side, but maybe not).

Obviously I need to look at last night's data and try to access the error log, which I will do later this morning. But it seems to me that I really should consider giving Auto Trak a run and see what they might change.

boots wrote:

Since Flow Trigger is running you're using Active Exhalation which is a pretty busy routine:

Active Exhalation Valve Control - The active exhalation valve consists of a two valve system. One valve dumps the pilot pressure while the other provides proportional control of the pilot pressure. Both the valves are controlled by the CPU via connector on the system board (J10). To control the proportional valve the CPU generates an analog control voltage uses a 16-bit DAC (U27). This signal drives a precision current sink (U28 and Q5) controlling the current flow through the proportional active exhalation valve

I don't think madalot is using the active exhalation circuit. Just the regular passive circuit.

I'm almost positive this is correct, but would like to verify the settings. Once my cart is brought out, I can do that.

Madalot wrote:

boots wrote:

Since Flow Trigger is running you're using Active Exhalation which is a pretty busy routine:

Active Exhalation Valve Control - The active exhalation valve consists of a two valve system. One valve dumps the pilot pressure while the other provides proportional control of the pilot pressure. Both the valves are controlled by the CPU via connector on the system board (J10). To control the proportional valve the CPU generates an analog control voltage uses a 16-bit DAC (U27). This signal drives a precision current sink (U28 and Q5) controlling the current flow through the proportional active exhalation valve

I don't think madalot is using the active exhalation circuit. Just the regular passive circuit.

I'm almost positive this is correct, but would like to verify the settings. Once my cart is brought out, I can do that.

No, that's right. AVAPS only runs in Passive. It appears that

Flow Trigger with leak compensation is only available if the Active Flow circuit is selected.

Boots & Pulmonette -- you both seem very knowledgeable about the Trilogy. Have either of you seen and/or worked with the AVAPS-AE? I just happened upon it on this loaner machine, asked some questions and then wanted to try it.

OK new idea.

Since everyone seems to get this chatter, it is limited in duration, and seems totally benign, perhaps it's the solenoid valve:

Solenoid Valve - The sensor board uses a solenoid valve to auto null/vent the control pressure sensor to atmosphere periodically via port 1 of the plastic manifold.

Guest wrote:OK new idea.

Since everyone seems to get this chatter, it is limited in duration, and seems totally benign, perhaps it's the solenoid valve:

Solenoid Valve - The sensor board uses a solenoid valve to auto null/vent the control pressure sensor to atmosphere periodically via port 1 of the plastic manifold.

Egads. I have no idea what you just said!! But I have a question, if I may...

I know I'm using the AE mode and varying the EPAP from 9-10. But I didn't have any issues with the machine on straight AVAPS with EPAP of 9. If the machine was malfunctioning, wouldn't it be having issues before?

I want to point something out that many may not be aware of.

NOBODY has been looking at or monitoring my data in a very, very long time. My current DME doesn't have DirectView installed anywhere at their location, which I find really strange considering they have a hand full of Trilogy's in the field.

I had one RT, early on, look at it carefully and he felt "something" was off back then. But nobody else cared enough to look at it the way he did.

I was able to get my hands on DirectView (don't ask me how) and *I've* been the only one looking at it at all for at least two years.

I thought it might be important to make that clear.

Boots & Pulmonette -- you both seem very knowledgeable about the Trilogy. Have either of you seen and/or worked with the AVAPS-AE? I just happened upon it on this loaner machine, asked some questions and then wanted to try it.

I use a trilogy 100. It hasn't been updated in a while, so there is not an Avaps AE feature on it.

I don't think madalot is using the active exhalation circuit. Just the regular passive circuit.


I'm almost positive this is correct, but would like to verify the settings. Once my cart is brought out, I can do that.

You would know if you had the active exhalation circuit. It has a bulky valve on the circuit along with 2 small tubes running the length of the circuit and it's loud when you exhale

boots wrote:

I don't think madalot is using the active exhalation circuit. Just the regular passive circuit.


I'm almost positive this is correct, but would like to verify the settings. Once my cart is brought out, I can do that.

You would know if you had the active exhalation circuit. It has a bulky valve on the circuit along with 2 small tubes running the length of the circuit and it's loud when you exhale

And wouldn't work at all if you are using a vented mask, which, according to your sig, you are.

Pulmonette wrote:

boots wrote:

I don't think madalot is using the active exhalation circuit. Just the regular passive circuit.


I'm almost positive this is correct, but would like to verify the settings. Once my cart is brought out, I can do that.

You would know if you had the active exhalation circuit. It has a bulky valve on the circuit along with 2 small tubes running the length of the circuit and it's loud when you exhale

And wouldn't work at all if you are using a vented mask, which, according to your sig, you are.

"Assuming" you're not using the NIV elbow.

Madalot wrote:

Guest wrote:OK new idea.

Since everyone seems to get this chatter, it is limited in duration, and seems totally benign, perhaps it's the solenoid valve:

Solenoid Valve - The sensor board uses a solenoid valve to auto null/vent the control pressure sensor to atmosphere periodically via port 1 of the plastic manifold.

I know I'm using the AE mode and varying the EPAP from 9-10. But I didn't have any issues with the machine on straight AVAPS with EPAP of 9. If the machine was malfunctioning, wouldn't it be having issues before?

Following that solenoid-valve theory a bit... Perhaps the Trilogy firmware doesn't bother with solenoid-valve purges in AVAPS mode---but occasionally purges in AVAPS-AE mode. Additionally the bed-shifts might present the machine with pressure characteristics matching algorithmic criteria for a purge.

Madalot wrote:But it seems to me that I really should consider giving Auto Trak a run and see what they might change.

If the new firmware on your loaner contains Auto-Trak improvements, then you might have better luck now compared to past Auto-Trak trial(s).