Reliable, accurate pulse oximeter?

[plnelson]

I have paroxysmal atrial fibrillation, and ultrasound studies show an enlarged left atrium. People who have slept in the same room with me have complained of loud snoring with abrupt cessations. I occasionally wake up with headaches or sore throats. Two cardiologists have suggested I be evaluated for sleep apnea.

So my PCP gave me a questionnaire which the insurance company requires before paying for it, and the questionnaire was heavily weighted toward daytime sleepiness which I DO NOT have. I NEVER feel sleepy during the day or nod off or anything like that. (I do, however sometimes have trouble concentrating during the day) So my score on the questionnaire was very low, so it looks like the insurance company won't do it.

No biggie - I'm a serious hardcore science geek. I'll actually have my own personal Holter Monitor (a 7-lead Northeast Monitoring DR200) in a few weeks and I thought with the addition of a recording oximeter I could do a good simulation of a home sleep apnea test and present that to the doctor or insurance company if it finds anything. (Yes, I know how to read and interpret an ECG)

So what is a good, reliable, recording oximeter that will stay on and keep recording as I roll over in bed? I typically sleep on my side but I alternate sides a lot. Money is a not a huge object - obviously I don't want to spend more than I have to, but the difference between, say $80 and, say, $250 is not an issue.

Thanks in advance.

[DocWils]

Doesn't the NEM DR200 have an input for pulse-ox? I vaguely recall it did, so you would only need the finger tip and cable and the Holter does the rest. If not, have a dig around here in the product review section, lots of various brands and models are discussed. Hint - most recording pulse-oxs that are in consumer price ranges are pretty much alike in accuracy terms - to avoid noise and fall-offs, a bit of Hypafix or surgical tape lengthwise from the side of the fingerling to the finger to hold it in place does the job. Do not wind the tape around or in any way make the device tight on the finger - it simply needs to be set in a way it won't shift.

[trish6hundred]

Hi plnelson,
WELCOME! to the forum.!
Hang in there for more responses to your post and much success to you.

[plnelson]

Doesn't the NEM DR200 have an input for pulse-ox? I vaguely recall it did, so you would only need the finger tip and cable and the Holter does the rest.

Their model 180 has an oxi input. I'm not aware that the 200 does but I suppose I should double check.

[lmoretti]

Also, the stuff they use in sleep studies are EEG, not ECG. ECG monitors heartbeat, EEG monitors brain activity (and sleep state).

[DocWils]

No, they use both, but only in lab studies - home studies are done with a device similar to a Holter that take EKG, sO2sat, movement, chest expansion and measures air in and outflow. If there is a clear evidence of something, but it is unclear as to the cause, they will suggest an in-lab test to determine if it is CA or OSA driven, or complex. EEG only determines if it is CA driven, and examines levels of sleep, but the "white coat" effect can negate a lot of that, so to save money and time, home tests are a good start. Using a holter alone, even with a pulse-ox, may give an indication of the possibility of OSA, but not much more - you need all the other things I listed above to get a clear ruling. Splashing out for your own devices, though, is a waste of money - a Holter, even a cheap second hand one, will set you back 1K at least, and the software usually comes separately and is node-locked, meaning for one computer only. If you first suspect only OSA, a recording pulse-ox will tell you the same as the Holter/pulse-ox combo. if you suspect a cardiac problem driven syndrome, then the Holter makes sense.

[plnelson]

Also, the stuff they use in sleep studies are EEG, not ECG. ECG monitors heartbeat, EEG monitors brain activity (and sleep state).

Actually, in the last 10 or 15 years ECG's have become quite a common component of sleep apnea studies.

[plnelson]

Splashing out for your own devices, though, is a waste of money - a Holter, even a cheap second hand one, will set you back 1K at least, and the software usually comes separately and is node-locked, meaning for one computer only. If you first suspect only OSA, a recording pulse-ox will tell you the same as the Holter/pulse-ox combo. if you suspect a cardiac problem driven syndrome, then the Holter makes sense.

I'm not getting a Holter to diagnose sleep apnea; I'm getting Holter anyway and, as I explained in the OP, I figure that data from that and a decent oximeter might persuade the insurance company to pay for a proper test.

I'm getting the Holter to study and document an interesting heart rhythm phenomenon: I get a low, steady background level of PAC's ( AKA APB's, AKA atrial ectopic beats) - a few dozen a day. But every so often I get what I call a "PAC storm" where I get hundreds of PACs a day. I've had 8 afib attacks in my life and each one occurred during a "PAC storm" (although not all PAC storms result in afib) I've always cardioverted on my own (although 3 times I was in the hospital at the time) and following cardioversion I always have a minimum of 3 (and sometimes as much as 7) days of no PAC's at all - zero, nada, zilch, before my normal background level resumes. Furthermore, the non-PAC period is independent of how long I was in afib. I had an attack last week for 11 hours, and in May I had an 8-minute afib attack and they each resulted in a similar period of no PACs. I have a regular ECG monitor butr I wnt to supplement this with a Holter to collect longer periods of data, so I can present this to a research electrophysiologist since my regular EP is stumped. Also next year I hope to audit an electrophysiology course at a local medical school in the Boston area.

BTW the Holter I'm getting is $1600 for the monitor and about $5K for the software.

Now can we get back to the oximetry question, please?? What's a good, accurate reliable, recording oximeter - I want one that stays on and gives accurate readings as I roll over in my sleep.

[DocWils]

I know that - wasn't referring to you, I read your original op and understood that, I wanted to discourage other from doing it for home OSA diagnostic purposes. For what you need it for, I heartily encourage you to gather as much data at home as possible - one of the greater problems with things like this is you get a run at home, get your appointment and see your doc, but by then the run is over and he turns up nothing, so having a good recording while it is happening is a great, if expensive idea.

Pulse-ox: I have a simple CMS50E from Contec at home, and with a bit of Hypafix along the side it doesn't shift, gives a sufficiently clean reading for diagnostic purposes, what noise there is is easy to distinguish from real data, and above all is cheap, at around $100, AFAIR. There are newer wrist types from Contec that are nearly as cheap, and have the advantage in that the fingerling doesn't need taping, as it is a rubber finger tip. Caveat - don't expect support or software updates from Contec. They never answer any e-mail support requests and never have any useful downloads. What you get in the box, that's it, software disk and all. Still, it works, they work and all are around as accurate as each other - accuracy is more dependant on sensor placement and finger thickness than anything else, really - the algorithms all pulse-ox devices use is open source, so they all work around the same. Also, Contec sensors don't run hot - I have had a few German made devices that ran extremely hot after a few hours.

Yeah, Holter software is not cheap, but then again, it is intended for the professional market, so the licensing system is designed with that in mind. The idea is that the devices break and need regular replacement, but the software doesn't (until you upgrade your computer system, and the licenses are not transferable).

As for your case, I've heard of a few like it, and of course, seen a lot on such things in our textbooks, but I never encountered one in my cardio rotation (back when dinosaurs ruled the earth). Is ablation a possible solution for you, or is there some other cause besides faulty electricals in your heart? And has your doc tried to put you on Bilol to see if that smooths it out?

[plnelson]

.
As for your case, I've heard of a few like it, and of course, seen a lot on such things in our textbooks, but I never encountered one in my cardio rotation (back when dinosaurs ruled the earth). Is ablation a possible solution for you, or is there some other cause besides faulty electricals in your heart? And has your doc tried to put you on Bilol to see if that smooths it out?

Not sure what Bilol is - there are various formulations of Bisoprolol which might be the same thing - that's a beta adrenergic blocker, and I take atenolol, which is another a beta adrenegic blocker. It helps with the PACs but over a certain dose it slows my heart down too much.