Looking for oximeter with live logging

I am looking for an oximeter that logs to a csv,txt or other similar file while I am using it while sleeping. I want to monitor the file with an application that I am building. I do not care if the data is being transferred via bluetooth, USB cable or by some other means. I only prefer that the file is saved to a Windows machine.

There are several oxygen saturation devices for sale on amazon but I cannot tell if any of them log while you use them.

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Hello Bill, mind checking my.aidlab.com? We work with Nonin and several other oximeters (SpO2):

https://www.reddit.com/r/SleepApnea/comments/5ewf82/sleep_and_day_study_oximeter/ cheap but Chinese. ALSO HARD TO WEAR unless sleeping.

I started sleeping with a Contec CMS50F several years ago, it broke and i did not replace it since my SPO2 barely changes during sleep and was ok. Recently i got curious about Perfusion Index with sleep (PI) and purchased this upgraded model from china on ebay (~$120): CMS50I Fingertip Pulse Oximeter,Wrist,Sound,PI,Pulse oxygen saturation,PulseRate …

it generates csv files but so far i have been unable to translate the PI column into percent based data. It allows logging ~4-5 nights of sleep before the memory fills, but i typically offload and charge via USB every morning. You can learn more at: http://www.cpaptalk.com/CPAP-Sleep-Apnea-Forum.html

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■With SpO2 value and pulse rate value of storage, the storage data can be uploaded to computers
Nice form. I have been looking for something like this. Is it FDA certified? How detailed is the pulse waveform record in csv?

I only have one pulse oximeter, a Contec CMS50DA+. (I ordered a CMS50D+, but I think that may no longer be in production.)

My notes:

Contec CMS50DA+ Instructions (needed because manufacturer’s instructions are hard to understand, and because OSCAR doesn’t seem able to directly import CMS50DA+ data)

  1. The SPO2 Assistant (Windows PC) software that comes with it was on a micro-CD with title “”. In addition to installing SpO2, it installs the “CP210X USB to UART Bridge Driver Installer”, which it requires.

  2. It was expensive as oximeters go (about $31), but Sleepyhead/Oscar’s oximeter module (running on my Windows 7 machine) said they could import data from it, which I wanted, so I could line plots of O2 and Pulse underneath the plots of data from my CPAP machine. (Oscar documentation: “OSCAR is currently compatible with Contec CMS50D+, CMS50E, CMS50F and CMS50I serial oximeters. (Note: Direct importing from bluetooth models is probably not possible yet) You may wish to note, other companies, such as Pulox, simply rebadge Contec CMS50’s under new names, such as the Pulox PO-200, PO-300, PO-400. These should also work.It also can read from ChoiceMMed MD300W1 oximeter .dat files.”)

  3. In reality, Oscar could not import the data directly - I had to use SpO2 Assistant to import the file into the PC, after the sleep session was over. I could alternately run SpO2 Assistant while the session is in progress, but then I would have had to connect the USB cable (it looks like a standard micro-USB to Type A USB cable, but I found a remark somewhere that it might be wired different) while I was asleep. but I wonder if any of the cheaper models could connect through the USB cable and transfer data.

  4. It says it can record on-board for 24 hours, though I haven’t tested it for more than about 8 - 10.

  5. It is powered by two AAA batteries - I use rechargeables. Be careful about using devices that require more expensive special size or disposable batteries - the batteries could increase your cost a lot. In addition, for travel (especially weight-limited backpacking), it is obviously beneficial to use as few interchangeable battery types for everything electronic as possible.

  6. Even without that cable, clipping onto your finger is a bit awkward while asleep, and would be very awkward or impossible while doing sports activity. In some respects, a wrist-worn unit would be better - but I haven’t tested them. Also, they might use expensive and/or non-rechargeable batteries.

  7. This was the cheapest listed Contec unit that could import into SleepyHead or OSCAR - but it has no built in time. So you have to record the start time, or make it the same as the CPAP unit. In addition, every time it starts a session, it forgets the previous session - so import before you start a new session. And if you take it off your finger for a few seconds, it turns itself off - so if you put it back on, it starts a new session. And OSCAR can’t import two sessions from the same night.

Here is my procedure for recording data and loading it into OSCAR:


  1. Insert Batteries, as marked. With battery compartment up, left AAA battery has - side against spring, right AAA battery has + side against spring.
  2. Set up CPAP machine, but don’t start it yet, so can record CPAP data approximately at the same time.
  3. Disconnect cable
  4. Push button and hold to Turn on
  5. Insert finger
  6. Push and hold to get menu
  7. Push button to go to Record.
  8. Push and hold to turn on. At this point, the data starts to record.
  9. Start CPAP machine.
  10. push button twice to go to Exit
  11. Push and hold to Exit.
  12. Let run during sleep.
  13. Stop CPAP machine.
  14. Push on hold button to get to menu
  15. Push button to get to Record
  16. Push and hold to turn Record off
  17. Push button twice to go to Exit.
  18. Push and hold to Exit.
  19. Take off finger - unit will turn itself off after a few seconds.

Transfering file to PC disk

  1. If you make a mistake, the current OSCAR version cannot delete oximetry data without messing up the whole database, so before importing data, make a backup copy of the OSCAR_Data folder inside your Documents (or My DOcuments) folder, that you can restore.
  2. For ResMed CPAP machines, wait for CPAP machine to stop transmitting data. (Blinking blue dot)
  3. Remove SD card from CPAP machine, switch it to be write-protected.
  4. Insert it into PC.
  5. Run Oscar, import CPAP data from SD card.
  6. Click on drive icon, “eject” it; wait for it to say it is done.
  7. Pull out SD card from PC, switch it to undo write protection, insert into CPAP machine
  8. Write down start time of CPA data, based on the Daily tab, Details subtab info. Exit OSCAR.
  9. Connect CMS50DA+ cable between unit and PC. It looks like a micro USB cable, but may not be - so label the cable.
  10. Push and hold CMS50DA+ button to turn on, again to move to the menu.
  11. Start SpO2 Assistant
  12. File -> Connect Device
  13. Select Com3 (or other USB port #)
  14. Click on View device stored data only.
  15. Click on connect
  16. Select file 1
  17. click on Receive Data
  18. Exit SpO2 Assistent
  19. Disconnect cable
  20. Push button to go to Exit
  21. Hold button to exit
  22. Device will turn itself off.
  23. Start Oscar
  24. Log in to Profile
  25. Select oximeter type CMS0D+ (is really CMS50DA+, but compatible??)
  26. Select: “Import from a data file saved by another program, like SPO2Review”
  27. Select Data2 folder (folder C:\Users\USER\AppData\Local\VirtualStore\Program Files (x86)\SpO2 Assistant V3.0.5\Data, where USER is the username. On my PC, data2 in My Documents is a shortcut to this folder.)
    29 Select file. It will have a name of form _user_1_1_YYYYMMDDHHMMSS.SpO2 - however the day is the day the data was input to the PC from the CMS50DA+, not when the data was actually taken.
    30 Do not click on “I started this oximeter recording at (or near) the same time as a session on my CPAP machine.” It mostly doesn’t work, and completely messes OSCAR up.
  28. Set the start date to be the date the session began, and the time to be the same as step 7. If there was a few seconds delay between steps 8 and 9 in the Recording data section, set this time a few seconds before the time in step 7.
  29. The SpO2 (blood oxygen saturation) and Heart Pulse rate plots will now be available.
  30. Write Enable the SD card, and re-insert into CPAP machine.

Additional info: It rounds the O2 saturation levels to integral percentages. I would prefer a finer quantization, because my levels apparently only change a few % points during apnea events. Also, some people say Contec units may be off by a few %.

The ads say it is FCC approved - as I think are other Contec Pulse/Oximeters. I don’t know if that matters to people like me, who are just trying to figuring out how to deal with sleep apnea.

I don’t know the file format. Perhaps you can reverse engineer from the Oscar or SleepyHead Pulse Oximeter module? (EDITED MOD: It also imports a .csv file, whose format is fairly clear.) Anyway, I would suggest you instead pick a unit with a built in clock, and maybe a wrist-worn unit.

Hope that helps.

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yeah the built in chargeable battery died pretty fast

By the way, the Contec CMS50F wrist-worn device actually uses a wired connection to a fingertip clamp. So it isn’t what I meant by a wrist unit.

Hi, I’m also in the market for a sleep oximeter for home sleep apnea tests. Anything that can get data to sleepyhead/Oscar, or any other sensible accessible format. It sounds like wrist is more reliable. BT so I don’t have to USB sync would be preferred. Any recommendations?

Thanks for posting, I posted a link to Twitter to see if anybody knows. (I don’t.)