Pulse Oximeter Approved UK, 72 hr Battery Life Sleep Apnea

I will preface this review with the fact that I am a big fan of Viatom/Wellue pulse oximeters as I have used them daily for several years now, and I’ve tried several different models, as well as several by other manufacturers. My go-to was the Visual Oxy (which seems to be functionally identical, to the CheckMe O2 base model). That lasted me three years of being used for around 14-16 hours a day because of my medical issues before a component popped. Despite whatever had failed inside, I was still able to turn it on and download the data. I suspect it would have still worked even if it didn’t charge properly or for as long, but I went ahead and got this version instead. Don’t get me wrong, though – my local hospital uses the base CheckMe O2 model in some of their wards, so it’s more than effective, but this has some functions that – for me – make it superior.

The CheckMe O2 Max is somewhat chunkier and heavier than the base model, presumably because of the slightly bigger screen and to contain the better battery compared with the base model. It’s still less chunky, however than any other company’s comparable product. It also has so much more battery life – around seventy-two hours, versus 16 hours for the base model. Even though I never had the device run out of battery at an inappropriate time, and even when it did, the data up to that point was saved, this means I really don’t have to charge it that often – every five days or so instead of every day, and for most people at least a week.

The strap seems to be the same as the base model (and a definite improvement over the strap used with the Visual Oxy) which fastens with two plastic pegs. I did find that I suffered some irritation from the tiny metal peg that clips the device to the strap with the Visual Oxy, but a simple piece of medical tape over the peg resolved that easily enough.

It’s faster to start collecting and recording data it seems than the base model, and it stores twice as many data points for the reports – rather than saving data every four seconds, this model saves the data every 2 seconds, giving you much more accuracy with the resulting reports.

While the base model has two modes – night (which records with the screen off and records movements during the night) and monitor (which records with the screen on and measures steps) – this model has a single mode, and you can switch between always-on, and standard mode (where the screen turns off after a minute or so) in the settings.

While the base model provides a vibration alert if your oxygen drops below a specific threshold, this model improves on that by providing not only a device-based vibration and audio alert for both low SpO2 and high and low pulse rates, it also allows you to monitor the device in real-time on your phone, and ring an alert there, too (as well as if the finger is removed from the sensor). This means that (as long as you are within Bluetooth range, you can mix and match the alerts in whichever way suits you best, including changing the thresholds, the volume of the alerts and the strength of the vibrations. The only thing I find perhaps lacking is the presence of a “finger out” alert build into the device itself. But I love that, unlike some other brands, each alert can be configured separately rather than all being on or off at once.

With the bigger screen, the icons are easier to see and recognise, especially if, like me, you’re squinting and half-blind in the darkness without glasses on!

The one thing that I have loved with all of the Viatom/Wellue wrist-worn products is the ring sensor. I know that they look like they might snap really easily at the thinnest part of the sensor ring, but my first one is still working and actually cracked the plastic sheathing around the wires at the opposite end rather than snapping at the sensor. That said, even if it does snap, replacements are pretty easy to get hold of. These are the biggest reason I love these pulse oximeters. The standard Duck Bill clip-on sensors are clunky, they slip and fall off so easily, they get hot and sweaty and they and I just don’t mix well. In the past, even using medical tape to hold other sensors in place has failed, so finding something that is both as comfortable and as lightweight as this sensor is amazing. I’d recommend you try one of their products if only to test the sensor out.

Like the base model, this also has four memory slots, with each one storing up to 10 hours of data at once. However, the biggest improvement I have found with the CheckMe O2 Max is that at the end of the session, it saves and then immediately starts recording in the next slot. This means there is no break in your data if you happen to be asleep at the time, apart from less than the three seconds it took to start the next recording. In addition, if the sensor is taken off your finger, it will give you ten seconds to replace it (to change fingers etc) and continue recording. Otherwise, after ten seconds, it will end the session and save it. If, during the next couple of minutes before the device switches itself off, you place your finger back into the sensor, it will automatically start recording in the next session.

It’s hard to describe what a big difference this makes for me. Because of my health issues, I routinely need to record for longer than 10 hours, and this would require me to either lose data (often at a time when it was most needed) or I would have to disturb my sleep, even more, to manually stop the recording, turn off the base model, then turn it back on again to start a new session, and this would take two minutes at a time when I didn’t want to be awake. The fact that it now continues to automatically start a new session, or recognises when the sensor is placed on your finger just takes away all of the awkwardness associated with the ten-hour limit.

In terms of software, there are several options, at least one of which should work for most people. The ViHealth app works for Android 5.0 and above, and iOS 9 and above. This allows you to tweak all of the settings, check for updates to the device’s firmware and automatically downloads the data when connecting via Bluetooth. Once connected, you can switch between looking at the recorded data previously saved, or viewing the current data in real-time. The real-time screen shows pulse and SpO2, and (unlike the base model) also indicates PI (which is a measure of how strong the signal is). It’s important to know that you can view the data at the same time as it’s recording, too, and that afterwards when your finger is removed, you will be able to download the new data file.

In the historical data, the app allows you an overview of average, high and low values over the session, as well as how much time was spent below 90% oxygenation and a graph of how much time was at certain percentages. You can zoom in to the chart in order to see the fine detail, as well as export the data as a PDF or CSV file.

There is also software that is available for Windows and Mac (sadly not linux at this stage) – it lacks the ability to manipulate the data graphically, but it presents it to you as a static graph and provides access to the same PDF and CSV download options, as well as (a paid-for) cloud storage. I haven’t used the cloud option, myself, as I can just use other cloud devices to back up the relevant folders of data. To use the PC or Mac software, you need to download the data via the USB charging cable rather than via Bluetooth (it’s not a standard USB to micro USB cable, though, so don’t lose it). Replacement cables are available to purchase but they can be a little pricy. This specific CheckMe O2 Max seems to have a slightly different cable (previously, the others were black, while this is white and appears to be sturdier). in the past, I’ve had issues with the plastic case around the electronics in the USB end popping off and exposing some delicate wiring after a lot of use, but this one appears to be moulded around them, instead. At this stage, I’m not sure what the charging time from empty would be. The base model is a couple of hours, but this came fully charged and has only been topped up since then.

If you also happen to use OSCAR, this product isn’t officially supported yet, but it will correctly handle the data (with warnings) using the current version (1.3.0).

All-in-all, I have zero regrets about purchasing this product – it has resolved all of the niggles I had with the base version (and I loved that too) and I am hoping that I will get similarly long use out of it in the future. Knowing that my hospital values Viatom devices in their ventilation unit is very reassuring, and the improved handling of long recording times with a longer battery life makes this a great product if you have to spend significant amounts of time on a very regular basis monitoring your sats. The only minor niggle is the lack of a “finger out” warning on the device itself, but I can work around that using my phone for now. Not an inexpensive product, but pays for itself in quality, the amazing ring sensor and the screen not fading out after a few months of use (unlike certain competitors products).