Devilbiss DV54 - Smartlink and Sleepyhead

I am a relative newbie to xPAP. I have been using my unit for about two weeks now, but my wife has been on one for almost a decade. Her diagnosis was pretty much classical OSA. Mine is a bit more complex since I have what another thread called "classic" UARS. My sleep test showed an AHI of 10 (I think this may have been inflated for the benefit of the insurance company because my coverage will not cover xPAP therapy for UARS - experimental clause) and an RDI of 28. During my titration tests, I had a Pes monitor and this clearly showed that my UARS issues were resolved at 9, but not at 8.

To clarify my diagnosis as UARS, I have a BMI less than 20, a narrow jaw and high palate and also suffer from chronic nasal congestion due to severe allergies. I also have chronic low blood pressure and frequently experience cold hands and feet.

I bought a Devilbiss IntelliPAP because I travel a fair amount and needed a small, compact unit because I hate to check baggage. At the time, I did not realize that I would need to separately purchase a Smartlink module to be able to get anything more than rudimentary reports out of my machine.

My question is therefore, how much added benefit would I get from a Smartlink and Sleepyhead? I have a clear pressure target based upon my titration test. Since I am attempting to resolve RERAs rather than outright true apneas, would the extra data from the machine justify the expense.

Steve

There is no Flow waveform provided by Smartlink module, outside of "Live" serial-port recording, which sleepyhead does not do... yet, and even when it does, it won't work like the other machines that record this to SD. (it would require a computer running all night to record it's data, and the computers clock and CPAP machine would have to be in harmony to sync)

Looking at the code, the Intellipap machine provides (on it's SD card) pressure, leak, respiratory rate, tidal volume, minute ventilation and snore graphs, and various event flags.. Hyponea, Obstructive, Expiratory Puff, NRI's (Non-Responding something.. I'm not even sure what they are.. simillar to RERA, but not the same) and a Leak flag. All very useful information even without the flow waveform.

Smartlink is a useful module, and definitely worth owning if the Intellipap is your primary machine. I just wish they'd of added the ability to write that flow waveform to the SD card... it would have been so easy for them to do it, but the manufacturer says it's something planned for a future machine.

Thanks for the response Jedimark. That was pretty much what I suspected, but I needed to hear it from someone who is more familiar with Sleepyhead and the dataset that is available from the machine.

As for the definition of Non-Responding Events Index, according to this Devilbiss document, it combines Leaks with Centrals to report the frequency of detected breathing events that the machine did not respond to with a pressure change.

http://www.devilbisshealthcare.com/file ... erview.pdf

Steve

Rustsmith wrote:Thanks for the response Jedimark. That was pretty much what I suspected, but I needed to hear it from someone who is more familiar with Sleepyhead and the dataset that is available from the machine.

As for the definition of Non-Responding Events Index, according to this Devilbiss document, it combines Leaks with Centrals to report the frequency of detected breathing events that the machine did not respond to with a pressure change.

http://www.devilbisshealthcare.com/file ... erview.pdf

Steve

Thanks for the link and reminding me about that document.. there's quite a bit of good information in there. When I wrote SleepyHead's Intellipap importer, I skimmed over a lot of it, as I was just focused at the time on matching the data to SmartLink's printed reports.

I found the section on Operational Commonalities very useful.. I absolutely love Intellipaps doc writers!

As you probably noticed for dealing with RERAs, the DV54 does not detect them at all, unless you tweak the Hypopnea definition settings. Basically a RERA, or Respiratory Effort Related Arousal is a restriction in airflow less severe than a Hypopnea for a duration of at least 10 seconds, that still causes the patient to awaken/have their sleep disrupted. Effectively, RERA's are just the a little brother of the hypopnea.

The Philips Respironics System One attempts to flag them separately, but if has no real way of detecting if they patient was truly awoken by them.

None of the machines can really detect true awakenings (F&P ICON SenseAwake included), as caused by any significant breathing reduction/restriction/obstruction (yet! I recently read through a very promising study on performing sleep staging using a minimal set of data.)

This is where the presence of a flow waveform really becomes a useful diagnostic tool, even without a machines ability to detect those kind of events, you can have a better idea of what is going on. Because this is lacking, I don't personally see Intellipap CPAP/APAP machines (in their current form) being an optimal choice for monitoring anything but plain old textbook obstructive sleep apnea. It will of course still provide the treatment you need though.

The whole point of CPAP and related ventilators is to help keep the O2 saturation levels reasonably close to normal range, and to keep the sleep disturbances and wake ups to a minimum. If those two conditions are dealt with, you can't really ask for much more.

Thanks for the earlier responses JediMark.

As a bit of followup, I delayed getting the SmartLink module for a while because I did not see that it would provide me that much more useful data than the machine's Smartcode. That was until I had a couple of anomalous nights when the pressure seemed to go wild and keep waking me up. That has not happened since I got the Link unit, so I am still waiting.

However, I tweaked the machine's definition for Hyponeas by dropping the detection limit to 30, as described in the Clinician manual. By comparing the H flagged events with the Respiration Rate, Tidal Volume and Minute Ventilation data I am able to see that virtually 100% of my reported AHI are really RERAs. This is consistent with my lab test results and makes me feel better that even though my redefined AHI is still running between 5 and 10, it is still a lot lower than my reported RDI.

So, I guess my only issue with the data beyond what you have listed as missing is the coarseness of the readings compared to what I see in the reports from other machines. It would be nice to see more than one data point every 5 minutes.

Steve