Philips Sleep Waveform data accuracy

Do you know on what basis the Philips Sleep Waveform Chart can confirm the data accuracy?
How reliable are you when you see a patient's waveform on encorepro?
If anyone have reliable data, can you share it?

Welcome to the forum pompom1,

Encore Pro software prints a fairly fuzzy and small waveform as I remember (I have not used it since 2011). OSCAR is much better at presenting the Philips Respironics data in my opinion.

How accurate? That’s an engineering question best asked of Philips Respironics directly. Personally, I trust that the wave forms shown are accurate. They have a lower sample rate than ResMed waveforms, but have always been good enough for me to scroll through and confirm whether the machine has caught the OA, CA, H, and RERA events properly (or skipped anything when it was scoring).

As you look around the forum you will find many attached images from OSCAR. I don’t know that you’ll find any images from Encore software on this forum, unless you go way back to 2009-2010 when OSCAR or its predecessors didn’t exist yet.

Is this part of a school project?

- SleepyCPAP

Thank you for your reply.
I am an assistant delivering Philips waveforms to physicians. I wonder how accurately the Philips cpap product detects the patient.
This is because there is no data to prove how reliable the apnea flags appearing on the chart on the waveform are.
We can know better if we have research data on how many sleep disorders the sleep analyzer the device records has been tested.

I have scrolled through the breath patterns many nights to see if the Apnea or Hypopnea flags are correct. The machine seems to be pretty good in its count of times my breathing is restricted. Sometimes it marks a hypopnea after a recovery breath, which is technically incorrect but the physical result on the body may be the same. I also wear a pulse/oximeter and can see sometimes the machine scores an hypopnea that didn't have >3 desaturation. The machines don't check SpO2 when they score.

My individual opinion isn't scientific. You won't get scientific personal answers here - you need to go to PubMed or journals to read those.

There is an old study out there comparing machine scores to sleep tech scores, but it was using a ResMed 8, which is out of date compared to the machines of this past decade. The authors state that they were aware that newer machines had better detection of CA vs OA, for example, and suggested further study.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3767059/

In their charts, the apneas were scored about the same on the machine as the human scoring, but the hypopneas were overstated by the machine.

- SleepyCPAP

The documentation is available comparing sleep lab in person PSG scoring to machine scoring because all these machines have done it to prove their machine scored data is fairly accurate. You would need to do more detective work to find that documentation though. Is it 100% perfect....no but then again even in person sleep techs can have a difference of opinions as to scoring.

The main potential discrepancy is the chance that since these machines really can't measure sleep status is that sometimes awake breathing irregularities get some sort of apnea flag and the person wasn't asleep when it happened.
These machines measure air flow but can't reliably measure sleep status. Until a reliable way to measure actual sleep status is found that doesn't involve EEG leads is found we are going to have the potential for some awake flagging of events maybe happening.

On a whole though the data is actually fairly accurate as long as people aren't having massive prolonged periods of being awake when using the machine. Many years ago I did read documentation as to comparing machine generated scoring results to in lab PSG human scoring and it was at least 90% matching....human scoring to machine scoring. I don't have those documents handy but they are out there.

There is a study older than the one SleepyCPAP referenced. It found,

... good agreement between auto-CPAP AHI and PSG AHI.

... Conclusion: Auto-CPAP estimate of AHI may be used to estimate residual AHI in patients with OSA of varying severity treated with auto-CPAP.

https://pubmed.ncbi.nlm.nih.gov/19408029/