Plethy graphs - need explanation

[jillplum]

I have started adding Pleth Graphs in SleepyHead, but need an explanation of how to interpret the graphs.

This is a tracing from this morning.

Any ideas what is causing the abrupt changes in amplitude?

[OkyDoky]

This wave form from your pulse ox is the pulse that is detected where your monitor is connected to you. Probably your finger. The amplitude can change with things that decrease your pulse pressure such as lowering blood pressure or cold hands. I found a web site that explains medical equipment to medical professionals but you might find lots of helpful information. http://www.howequipmentworks.com/physic ... meter.html

If you have an irregular waveform it's probably artifact from movement and the SpO2 would not be accurate.

[pbriggs]

Hello - my first question is what device are you using that records the pleth graph?
S9 ResMed VPAP ST Oximeter : Contec CMS50E

Does the ResMed record it? Or did you attach the cable from the Contec to the computer all night?

[SGearhart]

Hello - my first question is what device are you using that records the pleth graph?
S9 ResMed VPAP ST Oximeter : Contec CMS50E

Does the ResMed record it? Or did you attach the cable from the Contec to the computer all night?

It has to be the S9. I have a CMS50F and it doesn't provide that information. Actually, he's the first I've ever seen that has the oximeter option on a Resmed.

[pbriggs]

Let's see - We can with the current CMS50F version and run live data into the newest version of sleepyhead to record the pleth graph - but then you would need to have the wire from the CMS50F to the computer with sleepyhead running all night.... I am not aware, as of yet, that there is a device that actually records the pleth graph for later retrieval - I would sure be interested in an SpO2 device that does record the pleth data too...

http://www.edwards.com/files/venousoxim ... /main.html

here is another website that dives into some details on the pleth graphs - but it is important to understand what they actually are - and the previous link http://www.howequipmentworks.com/physic ... meter.html does a good job explaining the difficulty of getting a good graph