Is a wearable, non-invasive blood glucose and blood pressure tracker possible?Aitis, a manufacturer in the wearables space, claims that its$250 mymonX wearable fitness trackeris exactly that. WhileApple and Fitbit have teased blood glucose monitoring, their plans have yet to materialize. On the other hand, mymonX has ventured into new territory, offering blood glucose and blood pressure tracking. Combining Electrocardiogram (ECG) and Photoplethysmograph (PPG) sensor technology, the watch promises groundbreaking metrics. But how well does it deliver on this promise?
While it shows promise, the mymonX fitness tracker falls short in everything except glucose and blood pressure monitoring, which is functional but not scientifically validated. Even those features are limited, with frequent sensor dropouts and a lack of notifications.
Unfortunately, I only have access to a ketone breathalyzer (technically a CO2 breathalyzer), ketone acid strips, and a blood pressure cuff. But I can say with some certainty that the mymonX’s fitness tracking isn’t all smoke and mirrors. There is at least some degree of accuracy present, although exactly how accurate it is, I can’t say. It’s definitely not good enough to advise someone with a medical condition. However, it might be helpful as a secondary, non-medical measurement tool.
Design and Build
At first, the mymonX resembles a Samsung Galaxy smartwatch, featuring an all-metal body, a black silicone rubber strap, and a lone mechanical screen-on button. There is also a motion sensor. Swing your arm or press the button, and the 1.3-inch LCD TFT touchscreen display switches on, showing an analog clock, your heart rate, and the battery charge level. The device also houses an ECG sensor on the lower-right edge, with additional ECG and PPG sensors on the back.
The watch is robust and waterproof. Not only did it survive two half-hour dunkings in salt water, it has also been into a shower ten times. Both trials verify its IP68 waterproof rating. And while it’s waterproof and comfortable, it’s slightly overweight, weighing in at 200g. It’s a bit bulky and heavy compared to rivals like the Fitbit Versa 4.
Key Features
Blood Oxygen and Heart Rate Monitoring
Before jumping into the mymonX’s novel features, let’s talk about the bread and butter of a fitness tracker: SpO2 and heart rate. The device monitors blood oxygen and heart rate effectively using its PPG sensor, matching the accuracy (within 10%) of a Fitbit Versa Lite and a blood pressure cuff within a margin of several beats per minute. However, SpO2 is notoriously difficult to track. More importantly, it’s not a metric that consumers should place any faith in. Like most SpO2 trackers, there are frequent sensor erorrs and drop-offs in measurement. But overall the sensor works the same as on other wearable devices.
ECG Sensor
The ECG sensor is a unique addition, offering two modes: one when touched with a finger and another when the back sensors are in contact with your skin. The ECG provides more accurate readings than the PPG, thanks to its better conductivity. Although it’s worth noting that ECG on the wrist is less accurate than aPolar strap, which is designed to make continuous contact with the skin. However, I don’t have a Polar Strap anymore and can’t comment on the degree of accuracy of the mymonX.
Blood Pressure and Blood Glucose Monitoring
While I couldn’t verify the accuracy of the blood glucose monitor due to the lack of a medical grade comparator, I could reasonably estimate whether the tracker was at least detecting fluctuations in blood glucose and blood pressure. Indeed, the mymonX registered an increase in blood glucose levels two hours after meals and a decrease post-exercise. The same was the case for the blood pressure readings, which increased during activity and decreased when I was stationary.
These readings were in line with my ketone breath meter and blood pressure cuff, suggesting that the device could potentially be a game-changer for those concerned with either blood glucose or high blood pressure. But I cannot confirm whether it’s equal to a medical grade tracker. My gut instinct is that it isn’t given that there were frequent sensor drop-offs, when the watch apparently lost contact with my wrist.
Exercise Tracking and GPS
The device supports a variety of manually tracked exercises, but the tracking features are lackluster when compared to competitors. For example, unlike many high-end trackers, the mymonX relies on smartphone GPS, which is likely a contributing factor to its extended battery life. And that means you’ll have to take your phone with you when you go running.
Unfortunately, the mymonX doesn’t include any feature for tracking less strenuous exercises, such as walking or hiking. And again, this comes up short against its competitors. Probably the worst feature is its lack of automatic exercise detection. That means you’ll be reliant on manually setting the exercise and then remembering to disengage the exercise tracking at the conclusion of the activity. In my case, I remember to turn the watch off maybe one in five exercises. Although, as I’ve learned, the exercise tracking is fairly buggy and prone to crashes anyway. In other words, you’ll occasionally lose an exercise or two.
Sleep Tracking
The mymonX’s sleep tracking isn’t something to write home about. The biggest issue is that the accuracy isn’t very good compared to a Fitbit and a polysomnograph (Muse S). The sleep and non-sleep states that other trackers are superb with, such as wake-from-sleep, aren’t detected by the mymonX. And it doesn’t detect REM sleep at all. You would imagine that a fitness tracking smartwatch that can do ECG would manage to squeeze enough data out of its sensor suite to match all those single-sensor Fitbits. Unfortunately, it seems that mymonX focused on other aspects of health tracking and skimped on its sleep tracking. As it stands, if you need a phasic sleep tracker, look elsewhere. The mymonX is useless for generating useful sleep-stage data.
Display and User Interface
Navigating the device is relatively straightforward, without a learning curve if you’re familiar with Fitbit’s user interface. A swipe down brings up notifications, and swiping from the right gives you a comprehensive biometric readout, from blood glucose to blood pressure.
Each swipe from the right will bring up a different biometric statistic. However, I found that the blood glucose reading was rarely available, likely because it depended on the ECG sensors making continuous contact with the wrist or sufficient moisture to provide an electrical connection.
Notably, there’s a lack of any integration with services like IFTTT, Zapier, or Strava, which could be a potential drawback for some. However if you don’t use any of those services, then it’s a trivial concern. Even so, I can’t help but feel a sense of disappointment that there’s no way to set up a blood pressure or blood glucose alert. There is, however, a heart rate warning option. But as this watch was advertised as tracking blood glucose and blood pressure, it’s a sad omission not to allow for other kinds of warning systems.
Battery Life
Advertised to last around ten days, the mymonX managed a respectable six days in my testing. Unfortunately, using any of the sensors incurred massive amounts of battery drain.
Usability and Comfort
Comfort is subjective, but in ten days of constant wear, the watch didn’t cause any skin irritations. However, its bulk and size are not suitable for those involved in heavy manual labor.
Comparisons
Priced at $250 USD, the mymonX faces stiff competition from well-established brands like Fitbit and Apple. While none of these can do blood pressure or blood glucose, the absence of scientific validation is a big warning sign. This shortcoming is magnified when compared to the Fitbit series, which has demonstrated excellent accuracy in sleep and activity tracking.
However, it’s worth noting that both Google and Apple have both announced that they were working on a PPG-based blood glucose tracker and my guess is that when they release their PPG-based blood-glucose trackers, it will compare on a similar footing to a medical-grade tracker.
As of 2023, no company has yet released a scientifically-validated, wrist-mounted fitness-tracking watch that uses PPG sensors to detect blood glucose. In other words, there are no competitors, although the accuracy of both health metrics is probably not medical grade. There are, however, a lot of fitness trackers without scientific validation that do track blood glucose. To my knowledge, no device offers blood pressure readings as well.
As a side note, blood pressure measurement using PPG is possible and comparable to a cuff. In a 2023 study, a University of San Diego teamdesigned a finger-mounted optical sensorthat could accurately measure blood pressure. Unfortunately, the mymonX doesn’t use this technology.
Should You Buy a mymonX Wearable Fitness Tracker?
The mymonX is an interesting device with an ambitious set of features. While it needs to work on its software bugs and, above all else, seek scientific validation, its pioneering blood glucose and blood pressure tracking functionalities cannot be ignored. However, the lack of validation means the watch cannot be used for any health condition, and its fitness and sleep-tracking capabilities are otherwise unremarkable compared to the competition.
