Accuracy of the o2ring compared to checkme

[kappa]

Interesting study. I wonder if there's a similar study that looks at measurements at the finger tip vs closer to the hand as would be measured by O2Ring, SleepU sensor, Oura ring, etc.

I expect all these devices use some sort of moving average to smooth out the values. If the average is for a shorter period then the values will be more variable and errant readings are going to disturb the value more, and (true) short desaturations are going to be reported rather than skipped over.

[coolwater]

Since there is a sensing difference between the various digits, did you swap the oximeters from the previous night's recording location?  This will tell you if the variance is caused by the digit or the device.

Given I only used the O2rings each night, I presume you are referring to the variance between them. Yes I used different digits the second night. I didn't swap them though as I used checkme on my thumb so didn't have enough thumbs spare. The first night was both on thumbs so they should be relatively similar. I will try more nights and see if the results are replicated.

[Crimson Nape]

I am going to use the digit references as used in the article I linked to clear up what I was asking. Here is the scenario; Night one, you have device #1 attached to R1 and device #2 attached to R4. For the next night, you attach device #1 to R4 and device #2 to R1. It doesn't matter which two digits you pick, you just reverse the devices for a better comparison.

- Red

[coolwater]

Yep, I know what you were asking. I didn't do it so scientifically as I didn't realise how much difference it could make. They were mostly on the thumbs only. Based on more nights data, the Old one actually picked up more drops a few nights, so digit usage has probably played a bigger role than I thought and age less of a role. I have to return one of the rings to a friend now so can't compare more.
I'll do more comparisons between o2 and checkme and be more scientific about the digits used this time. This is the more insightful comparison anyway.

[Crimson Nape]

Good job! I knew not to pick certain fingers, but until your post, I didn't think it would be that significant. I always thought that the L4 or R4 would have been the preferred digits for the reason they are called the ring finger.

[coolwater]

I was able to keep the rings more nights. I did as you suggested, using the thumbs and then swapping the next night. The Old ring picked up a few more drops each night (something like 5 vs 3). So I've dropped the idea that the new one is more sensitive! I guess there is just a certain amount of variance with this product.

I will continue to update the review on the cpap forum, title "Wellue CheckMe O2 Max vs O2Ring: Anyone use both?" because I can edit the post there (I think because it's the last post on the thread).

[dataq1]

There’s a newer model (“Pro” I think?) that has a faster sample rate.

The older ones only advertised 4s, just some of the files recorded at 2s doubled.

Perhaps people have different understandings of "sampling rates".

According to Wellue tech support the O2 ring sampling rate is 150 HZ.
Also "The interface is refreshed in real time, also 4s point records the last data (that is the 600th single data, not the average data)."

I interpret "interface" to mean "display" and the "record" as the datum written to a file.

If that tech support statement is correct, that the record/file data point is the last of 600 samples (a period of 4 sec at 150 hz) then, what was observed in the prior 599 samples is NOT reported (or weighted).

[Crimson Nape]

I just copied this off of Wellue's website:
OXYGEN LEVEL RANGE
70%-99%

PULSE RATE RANGE
30 to 250 bpm

MEASURE INTERVAL
1S

DISPLAY INTERVAL IN APP DATA CHART
4S

[dataq1]

I just copied this off of Wellue's website:
OXYGEN LEVEL RANGE
70%-99%

PULSE RATE RANGE
30 to 250 bpm

MEASURE INTERVAL
1S

DISPLAY INTERVAL IN APP DATA CHART
4S

@Crimson,
Are these two (your copy) and my email (above) reconcilable?
If not, who you gonna believe, a nameless market guy or a nameless Tech support guy?

[Crimson Nape]

Good point! The bottom line is, the only data that we have to analyze are data points on a 4-second interval.