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DreamDiver wrote:Here's why:

How does an oximeter work?
A source of light originates from the probe at two wavelengths (650nm and 805nm). The light is partly absorbed by haemoglobin, by amounts which differ depending on whether it is saturated or desaturated with oxygen. By calculating the absorption at the two wavelengths the processor can compute the proportion of haemoglobin which is oxygenated. The oximeter is dependant on a pulsatile flow and produces a graph of the quality of flow. Where flow is sluggish (eg hypovolaemia or vasoconstriction) the pulse oximeter may be unable to function. The computer within the oximeter is capable of distinguishing pulsatile flow from other more static signals (such as tissue or venous signals) to display only the arterial flow.

Undoubtedly there is more going on than this firmware-wise, since the light winks if there is no finger in the clip and emits continuously if there is a finger present. I'm guessing an infrared powerful enough to blister tissue at 650nm uses more mA than a red led at 805nm. What do you think?

Mine doesn't show through the side. It's very dim light. Dimmer than my alarm clock - and that's really dim. It's just a slightly glowing red finger from the side.

DreamDiver, excellent! Thank you for sharing that info. I was going to look up how an oximeter works after I come back from my walk.

I also know now that even when it appears to be constant, as I had also thought before, it is really pusling. You can check that by moving your finger around. I have not looked up the efficiencies of those leds, they could be using about same amounts of current, but they get the power by pulsing for a very short duration at high current, the duty cycle might be as low as 1/10 or even 1/100. It winks when there is no finger to save even more energy; makes sense. BTW, I had used IR led at another project and have learned that it is better not to look straight into it, because our eye does not respond by reducing the iris opening. Also you can see the light if you take your digital camera and look at it, it might appear brighter than the red one.

The light coming through the side might depend on the geometry of our finger. What I see at night is not diffused, I can see the led directly through the side and at night it is very bright. But it is easy to apply masking tape, I put a little hanging blinds type flap of tape on one side partly folded over on itself, so I do not have to remove it every morning.

I had a chance to compare the accuracy of this meter with the Nonen 3100 wrist recording type. There two meters on different fingers, they follow each other very closely +-1 count, mostly because finger contact variations, etc. There may be minor changes from finger to finger too, such I did check by exchanging the fingers on which each was. For all practical purposes they are identical in readings. To get lower readings, I held my breath

I had done a couple of nights' study with the two instruments. The results will not be available for a couple of weeks, since my doc is on vacation (and the dme will only give the results to the doc). I will report that comparison here when available.

Two more review items: I do like the Nonen's extremely simple auto mode. Put it on it records, remove it stops! But cms-60D is probably 1/6 the price...

I wish they had provided an internal clock.

After downloading the data to the PC, I wish they had simply turned the machine off, just like it turning itself off after a few minutes if there is no finger present. So often I catch myself forgetting to turn off, while the machine is in high battery consumption mode.

Q: Does their wrist model have recording capability? Really one does not need all this color and other features. Just showing the o2 level in non recording mode, and just recording in the other mode is all one needs. The rest are gimmicks of no value to me. I wish they could add recording their wrist model.

In spite of all those above comments, this may still be the best price/value machine out there!!

feeling_better wrote:I had a chance to compare the accuracy of this meter with the Nonen 3100 wrist recording type. ...
In spite of all those above comments, this may still be the best price/value machine out there!!

Thanks for doing this! You ROCK.
The CMS-50F has recording capability, but since it uses the same software, I'm guessing it doesn't have an internal clock either.

I talked to the manufacturer in China about charging through the USB. Some of their other meters charge the rechargeable batteries through the USB port.

Regarding the CMS-60D, they replied:

yes, you can charge the device through USB when connecting to computer, but when you turn it down, it cannot be charged, however, we offer the power charger with the device, so please use the charger to charge the battery.

I have a feeling they were not referring to the model in discussion in this thread. I asked for clarification, but have not got a reply for over a week. With rechargeable batteries, I tried an experiment by keeping it connected to the USB port for a very long time. I do not think it is charging at all through the usb port.

feeling_better wrote:I talked to the manufacturer in China about charging through the USB. Some of their other meters charge the rechargeable batteries through the USB port.

Regarding the CMS-60D, they replied:

yes, you can charge the device through USB when connecting to computer, but when you turn it down, it cannot be charged, however, we offer the power charger with the device, so please use the charger to charge the battery.

I have a feeling they were not referring to the model in discussion in this thread. I asked for clarification, but have not got a reply for over a week. With rechargeable batteries, I tried an experiment by keeping it connected to the USB port for a very long time. I do not think it is charging at all through the usb port.

Absolutely no charging on my end either. They must be talking about another model.

DreamDiver wrote:

feeling_better wrote:I had a chance to compare the accuracy of this meter with the Nonen 3100 wrist recording type. ...
In spite of all those above comments, this may still be the best price/value machine out there!!

Thanks for doing this! You ROCK.
The CMS-50F has recording capability, but since it uses the same software, I'm guessing it doesn't have an internal clock either.

It only looks like a wristwatch. I am guessing (by analogy with the other devices) that it probably does not have an onboard clock also.

liv2kite wrote: It only looks like a wristwatch. I am guessing (by analogy with the other devices) that it probably does not have an onboard clock also.

liv2kite, I assume your reference to the wristwatch shape was for the model CMS-50F? This thread was mostly about CMS-60D (as in the subject line), just to clarify for others. BTW, Contec appears to have a whole series of these oximeters in various forms, one even a finger only model which was discussed in another thread in this forum.

Hello,
I have been using a CMS 60C TFT colour Pulse oximeter for some months now.
You mention, in the review, about an adult ear sensor.
Does anyone know of a supplier please?
Guy.

guyrws wrote:You mention, in the review, about an adult ear sensor.
Does anyone know of a supplier please?

Guy,

In the review there's a link to the supplier:
http://www.semedicalsupply.com/cms-60d.htm
Scroll down the page, and you'll see the ear sensor you can buy from this supplier.

feeling_better wrote:I had a chance to compare the accuracy of this meter with the Nonen 3100 wrist recording type. There two meters on different fingers, they follow each other very closely +-1 count, mostly because finger contact variations, etc. There may be minor changes from finger to finger too, such I did check by exchanging the fingers on which each was. For all practical purposes they are identical in readings. To get lower readings, I held my breath

I had done a couple of nights' study with the two instruments. The results will not be available for a couple of weeks, since my doc is on vacation (and the dme will only give the results to the doc). I will report that comparison here when available.

Two more review items: I do like the Nonen's extremely simple auto mode. Put it on it records, remove it stops! But cms-60D is probably 1/6 the price...

Accuracy comparison update: I finally got the results of my clinical model (Nonen) 4 nights study, during which nights I had also used the CMS-60D at the same time. I had alternated putting the meters on two fingers every other night to make the study as balanced as possible.

The results are virtually identical, so both meters have similar accuracy! The clinical Nonen was sampling every 4 seconds, but the CMS does sampling every second. I had no control over the sampling rate setting of either meter. Because the CMS was sampling more often (which gives more detailed information), the CMS graphs were showing more changes.

So this reinforces my recommendation for this meter.

Thank you for pointing that out.
I have emailed them to find out how much postage to the UK would be.
Very expensive for just a sensor though!? The CMS 60C TFT colour Pulse oximeter I have only cost $99 of an international ebay seller.
Having said that, the only UK supplier I have fond that sells sensors, is charging £250??!! I have emailed Contec regarding an ear sensor twice and they do not seem keen on replying.
GuyRWS.

What a great review.

You know, what we REALLY need is a oximeter that we could plug into our CPAPs and record the data to the smart card along with everything else so it would be easier to compare....

Kiralynx wrote:What a great review.

You know, what we REALLY need is a oximeter that we could plug into our CPAPs and record the data to the smart card along with everything else so it would be easier to compare....

I am not into your CPAP's software but the Contec SPO2 software creates two files one of which is an Excel file. I am sure some bright spark could make a way of combining the two data flows.
GuyRWS.
PS.
I would like to point out that the SPO2 Review software is not fully compatible with Windows Vista.
I have heard form the suppliers who say they do not use Vista much in China. Some good sense there eh??!!

guyrws wrote:

Kiralynx wrote:What a great review.

You know, what we REALLY need is a oximeter that we could plug into our CPAPs and record the data to the smart card along with everything else so it would be easier to compare....

I am not into your CPAP's software but the Contec SPO2 software creates two files one of which is an Excel file. I am sure some bright spark could make a way of combining the two data flows.
GuyRWS.
PS.
I would like to point out that the SPO2 Review software is not fully compatible with Windows Vista.
I have heard form the suppliers who say they do not use Vista much in China. Some good sense there eh??!!

Have just been playing with my own CMS-50E (just arrived from China today I thought I was ordering it from Australia )

But it looks neat & seems easy to work. It records details at the rate of 1 per second (that is what is in the xls file). In the past I used to feed my prior Ohmeda 3740 into a program that created a csv file that I fed into excel & turned into a picture. e.g. http://www.internetage.ws/cpapdata/menu_0815.html
This was a bit of a painful process & trying to get the SpO2 data to line up with the output from the Vpap software (back then I used AutoScan), was painful.

I think the Resmed Reslink SpO2 records 3 events per second so trying to get the CMS-50E data into a format that ResScan software can see may prove tricky.

The unit can record 24 hrs of data & transfers it to the computer through a USB cable & a program (claimed to be Vista compatible) can display the data & produce the nice report shown on the CMS-50E web site.

I'll use it for the 1st time tonight & will post a page of the data it produces.

Cheers

DSM

guyrws wrote:I would like to point out that the SPO2 Review software is not fully compatible with Windows Vista.

I have SPO2 working fine on both Vista x86 and Vista x64, so I don't know yoiu think its not fully compatible

Cheers,

Bill