Choosing an oximeter

[McSleepy]

The consensus here seems to be that the Contec CMS-50D plus, -E and -F are the ones to get, but I didn't find many discussions on long-term reliability and durability. There was already one posted concern about battery life and this is also my main concern. Like many other micro-portable electronics designed in China, some of those oximeters seem to be using a Lithium Polymer battery, which are not known for long life and there seems to be little to be done in extending their lifetime. Has anyone established the exact kind of battery their oximeter uses and whether a replacement can be easily obtained (not one that costs half the price of the entire device)? It would also be good to get a statistic of current usage (one member has already reported the battery failing after 2 years and little use). It seems like the 50D plus uses AA batteries, which could be a great "plus" for its longevity.
On the other hand, the IR sensor has a relatively short life (in the sleep labs they throw them away after a single use), I'd be curious to know how many uses one can expect from those oximeters before their reading accuracy becomes unusable. The -F model has an external sensor (much like the one used in labs), has anyone been able to find a replacement sold separately?
Judging from how often there are posts about oximeters, it might be a good idea to create a FAQ and make it a "sticky".
McSleepy

[xenablue]

I think a sticky for comparing oximeters is a great idea!

Cheers,
xena

[Snuff-L-Reddy]

Hello McSleepy;
I have been doing some extensive searching on this. Finger sensors are available for the wrist & handheld units but they cost nearly half the price or more of the entire unit. If a batt. is not charged periodically it may completely die . I have decided on a Handheld unit, they are not as bulky on the finger like an all in one, and appear to be sturdier than the wrist units. Also if the batt dies a handheld can use AC power. I am not too concerned about an extra wire attaching me to my nightstand

[davelikesbeer]

...
On the other hand, the IR sensor has a relatively short life (in the sleep labs they throw them away after a single use), I'd be curious to know how many uses one can expect from those oximeters before their reading accuracy becomes unusable. The -F model has an external sensor (much like the one used in labs), has anyone been able to find a replacement sold separately?
...
McSleepy

Not sure why you think the sensor has a short life. The IR sensor in my TV has been working for many years of daily use. I think the sleep labs use disposable because they can. I suspect the reason they do so is so they can tape it to your finger. The click on models have a tendency to fall off during the night. It would suck to lose a night's sleep lab simply because a failure of a cheap $10 part.

Once during a regular doctor's visit, she hooked me up to an O2 sensor that was connected to a computer very similar to the Contec sensors, but they were much more expensive. Those were not disposable and I'm sure cost alot more than the one I have.

[McSleepy]

Hello McSleepy;
I have been doing some extensive searching on this. Finger sensors are available for the wrist & handheld units but they cost nearly half the price or more of the entire unit. If a batt. is not charged periodically it may completely die . I have decided on a Handheld unit, they are not as bulky on the finger like an all in one, and appear to be sturdier than the wrist units. Also if the batt dies a handheld can use AC power. I am not too concerned about an extra wire attaching me to my nightstand

Hello, Snuff-L-Reddy,
I would appreciate seeing the results of your research, for example, what models, their advantages and disadvantages, prices, sources to buy from, etc.
McSleepy

[McSleepy]

Not sure why you think the sensor has a short life. The IR sensor in my TV has been working for many years of daily use. I think the sleep labs use disposable because they can. I suspect the reason they do so is so they can tape it to your finger. The click on models have a tendency to fall off during the night. It would suck to lose a night's sleep lab simply because a failure of a cheap $10 part.

Once during a regular doctor's visit, she hooked me up to an O2 sensor that was connected to a computer very similar to the Contec sensors, but they were much more expensive. Those were not disposable and I'm sure cost alot more than the one I have.

The reason oximeter sensors are not very durable is because they are completely different than the one in your TV. First, they have special narrow-wavelength light-emitting diodes (there are, in fact, two of them, with a different wavelength) and a highly sensitive photodiode receiver, which like most low-volume products are not as robust as the mass-produced LED/PD used in consumer devices. Second, they need to precisely measure very minute changes in light intensity - unlike the unobstructed view of the TV remote, the light in the oximeter sensors has to traverse half an inch of flesh and distinguish the variations caused by blood flow only by specific absorbents (hemoglobin and oxyhemoglobin) and, thus, have much lesser threshold of failure: if the remote gets 50% reduction in intensity and 20dB of S/N, I bet it still keeps working; not so for the oximeter. Third, because of these strict requirements, the sensor in most oximeters (definitely in the cheap ones we can buy) is exposed in order to minimize the obstructions in the light path (diffusion, interference). This causes skin oils and other contaminants to deposit on the sensor surface and ultimately damage it. Lastly, in the case of external wired sensors (like the CMS-50F), the wires are subjected to a lot of pressure and flexing, and I highly doubt they can withstand a long duty. After all, there are some good reasons why those other oximeters cost so much.

It would be nice to get some statistics from people here who use them, something like: bought it X years ago, use it Y nights a month, still working/so-and-so stopped working, etc.

McSleepy

[HoseCrusher]

I replace my oximeter after 2 years. I keep the old one as a spare and loan it out, but feel that anything over 2 years is on borrowed time.