Wildly Inaccurate Index BPM and Bad Fit Issues

I have recently discovered I have high blood pressure and the Index BPM seems like it would be the perfect solution for helping me keep an eye on my condition. I already have a Garmin scale, watch and bike computer as well as enjoying the Garmin Connect app for keeping all my health metrics in one place. However, the Index BPM is highly inaccurate (+25-35/+15) and has issues fitting (which may or may not be the cause of the bad readings).

Accuracy: I have a cheap $25 monitor that has been reading a bit low compared to readings at the doctor’s and so decided to buy the Garmin version. The Garmin one continually shows MUCH higher readings and bumps me from you-need-to-keep-an-eye-on-your-BP to the you-need-to-go-to-the-ER category. The results were so shocking I went straight to Walgreens and bought a $100 BP unit to compare results. The Garmin unit is very high. I also took all 3 units to my doctors and we ran several side by side tests. The cheapo $25 one showed -10 lower results. The $100 Walgreens one matched with the doc's equipment and the Garmin was +25-35/ +15… It is way off.

Fit: The Garmin’s cuff is, for some reason that I can not understand, delineated by hard plastic strips. So rather than having a strap that you can adjust to any size you seat the metal bar between one or another of the plastic strips. In my case seating it in one position (the 2/3 bit in Garmin’s drawing) means in its tightest position the cuff is too lose and the unit will slip from my arm and fall off. On the other side of this position (position 1 on Garmin’s diagram) the cuff is far too tight. I can not slide it on to my arm and if I force the unit to strap to that position it cuts circulation off to my arm immediately. I really can not understand what they are thinking here as the gap between the two positions is quite large. By the way, maybe I’m doing something wrong, my upper arm measures 39cm (Garmin says the Index BPM should fit between 22-42cm) but actually trying to fit the cuff puts me in between the small and medium positions of Garmin’s sizing for the cuff.   

If I force the hard plastic area of the cuff into the metal band and then fold the cuff at that point the fit is good but as soon as I remove the unit the cuff’s velcro sticks together on both sides of the plastic strip and the only way to refit the unit it to completely start over (so no quick slide-the-unit-on and do a test).

In any case, whether the unit is way too tight, way too lose, or in the position where the plastic strip is folded I get the exact same far too high readings (in the “too lose” position I also often get an “E3” error).

One last note which might also be part of the problem, the velcro seems comparatively weak. The other unit’s I have on hand have very strong velcro on their cuffs. The Garmin velcro does not feel very grippy. The entire time the unit it testing the velcro is crackling and popping as if it never quite locks in place. No amount of smoothing the connection or trying to force the pieces together changes this. The other two BP units I have crackle for a minute as the velcro sets but then lock into place as the pressure of the cuff ramps up.

Calling customer care was not a solution for the issues. I was told that “this probably wasn’t the unit for me” and so have started a return for it.