A Smart Case For Your Heart – The Prizma G2 Review

The smartphone is the Swiss army knife of our times.

Did you know you can even check the batteries in the remote or diagnose your car’s problems with it? Apart from checking e-mails or tracking anyone’s GPS location, dozens of other options are at your fingertips. G Medical Innovations, a medical gadget startup based in Israel, offers yet another one: measuring the electrical activity of your heart through their smartphone case. Beyond giving you an echocardiogram (ECG), the tool promises to read body temperature, oxygen saturation, heart rate, and stress level, too. While I found this ambitious smart case quite promising, instead of a must-have device it felt more like a proof of concept with lots of room for improvement. Here’s my detailed review of the Prizma G2 medical smartphone case.

A power-bank-styled universal cover

The Prizma G2 is somewhat of a misnomer, given that it is the only medical smartphone case that G Medical Innovations created but they still opted to add the G2 tag to it somehow. As an ultimate nerd searching for logic everywhere, I was a bit confused with the naming as I tried to find the non-existent “G1” but only came across the G2.

Naming convention aside, the Prizma G2 functions as a smart bumper of sorts to your phone. Smartphones with dedicated cases include the iPhone 7, iPhone 8, Samsung S7 with models for the Huawei P10 and Samsung S8 coming soon. If you do not own a device in this exclusive list (like me), you can get hold of the Universal Cover which is actually not a smartphone case fitting any phone but an extra carry-on, very much akin a power bank you would carry around. This is the version that I have tested and I have to say that despite the annoying bit that it doesn’t fit in my phone, it is not that uncomfortable. Although it is as thick as my actual phone, it is quite light and okay to handle.Biometric parameters at your fingertips

Setting up the Prizma G2 is a child’s play. You just download the companion app, create an account, pair the charged device, and you are good to go. Once ready, five parameters can be measured – the user’s ECG, temperature, oxygen saturation, heart rate, and stress level – via three built-in sensors: a single-lead ECG, a pulse oximeter and its temperature sensor. You can also add data about your blood pressure, body weight and glucose levels taken with external devices (not the Prizma device, although it would be pretty cool to have a single device to do all of these).

Prior to firing a test, the app provides a tutorial on how to get the measurements taken and what information it will give you. All measurements take seconds to record and to output data. Thereafter, you have the option to generate a report which you can share with your doctor via email or a messenger app. This is a very handy feature especially if you think something is wrong (the app will tell you if a result is abnormal) and want the definitive advice of a physician.

High temperature without fever

While setting up the Prizma G2 case was very easy, using it was not without its caveats. A pesky inconvenience that I came across is the inability to take measurements while the user’s phone is charging, which feels odd in this day and age. But that’s just the beginning.

Using the Universal Cover, as it actually doesn’t fit your phone, you have to hold it fixed separately, with both fingers on the ECG leads for example, while the phone is on the table.Given how light the case is, it is easy to move it around and get wrong results. As such, when I first used it for an ECG test, I got an “Abnormal Result” and the app told me to consult a physician but it did not actually indicate what suggested the abnormal result. But holding my arms still with the help of my office chair’s armrests did the trick and I did get accurate ECGs, which would vary according to my expectations, whether at rest or during exercise. The same goes for heart rate monitoring.

Temperature monitoring was one of the worst parameters to have measured. From the picture and information shown in the app, I should put the sensor behind my earlobe but when I did it gave me a result above the normal range. Even after several tries, I could not get an accurate result. It stated that my temperature was out of range, even if I didn’t have any fever. It seems like the measurement depends on the pressure applied and the angle that the device is oriented but even when I applied various tricks, the results were a hit-or-miss affair. A regular home thermometer that costs a fraction of the Prizma G2 would have given me a more accurate result without having to double check.

Prizma G2

Should taking a stress test be stressful?

In addition to temperature, the Prizma G2 also promises to measure oxygen saturation (SpO2), which refers to the percentage of oxygen in your blood. In theory. In practice, it was a pain in the neck to actually get it to measure anything – in spite of the fact that I haven’t turned into a vampire or joined the Army of the Nightking as a White Walker. But when I somehow tricked the device to measure my SpO2, the measurements were accurately displayed.

Stress was one of the features that I was most skeptical about. But the Prizma G2 explains that it calculates current stress levels by taking into consideration the user’s heart rate variability, age, and gender. And I’m sorry to say this but “of course” I had issues with it. After having my heart rate measured, the stress test wasn’t able to process the data, stating that the test contains errors. I came across the same issue whenever I tried the test. Quite stressful for a stress test, but I managed to squeeze out one measurement from the device and surprise-surprise, it found that I was slightly stressed and gave me some tips as to how to take it easy.

Prizma G2

Prizma G2

Prizma G2

The future comes at a cost

I was looking forward to the Prizma G2 with its concept of bringing pocket-sized diagnostic tools to life. However, it did not fully impress me and unfortunately, it all comes at some cost, on both the financial and feature fronts.

First and foremost, it is a costly device. At $249, the Prizma G2 is not accessible to everyone and while it is a convenient tool, investing in one will largely depend on your needs and background. If you have cardiac conditions, it might come in handy but there are much more convenient smartwatches on the market that can monitor your heart rate and ECG – and offer various other features, too. Also given the many errors that I have come across while taking measurements, I would not bet that it is the most reliable device out there.

Moreover, I would have appreciated if the company had provided more details regarding its sensors but information on those were scant and detailed instructions on how to troubleshoot problematic readings were absent. As such, I could not figure out what was the cause of the numerous inaccurate data that were measured during my tests.

The future of diagnosis in your pocket

G Medical Innovations’ idea for a medically-oriented smartphone case is truly innovative, aiming to remove the need to go to hospitals and tediously wait in line to get measurements taken. However, the Prizma G2 still feels like a prototype of sorts rather than a final product, especially the Universal Cover. It does have a finished look but on the feature front and usability aspect, it begs for improvements regarding accuracy and reliability of the measurement process. On a softer tone, we didn’t test the Prizma G2 on phones that have their dedicated case, and perhaps my experiences would have been quite different. Moreover, with some tweaks to the mentioned conditions, the Prizma can be used in the future by healthcare providers in remote areas and by patients at the comfort of their homes.