iPhone heart rate monitoring

Recently there have been posts on a portable ECG using an iPhone <[www.afibbers.org]; and afib detection using an iPhone <[www.afibbers.org];

I've been playing around with iPhone apps from Azumio. Two have free versions, one is $4.99 US. I believe the afib detection app is based on the same or similar technology.

The apps include Stress Doctor [www.azumio.com] $4.99
Stress Check [www.azumio.com]
Instant Heart Rate [www.azumio.com]

They all use the camera on the phone, and the flash if the device has it to act as a plethysmograph. This is how a pulse oximeter measures pulse rate. It is also how the eMwave (formerly Freeze Framer) device measures pulse rate. Hans, PC and myself all have Freeze Framer devices and some heart rate vs. time charts are shown for these devices in CR 52 [www.afibbers.org] There are also many HR vs time charts for Polar HR monitors in this file. The Polar charts give the same signal as the Freeze Framer, even though what is measured is different.

In my ginger thread [www.afibbers.org], I mentioned getting a 3AM afib episode after pigging out on carbs at a Christmas dinner. I had the Instant Heart Rate app loaded, so tried it. It was diagnostic in that it had a very difficult time getting a rate. You can see the pulse wave displayed and can see the great HR variability in the pulse wave.

Today I was looking around and found the Stress Check app. It appears to be marketed for the same purposes as eMwave, i.e. stress reduction. In any case it will store the heart rate vs. time graph and I think should give a very similar signal for PACs, PVCs and afib. It may smooth the data when stored, which will mute the signal. Fortunately, I've not had afib to test this, but thought it promising and worth reporting on.

You can play with the free apps, which both show the pulse wave, though only the most recent 10 beats or so. If you get an idea what your pulse wave looks like in NSR, the chaos of afib should be obvious. I'm pretty sure this is what the afib detection app is doing, only algorithmically, not visually.

George

Is the Polar RS800CX still worth it or are there better options now?

[www.polarusa.com]

Eric,

I love my Polar S810 (a prior model to the RS800CX). It has been a great tool. I recently upgraded to an Apple laptop. Haven't yet gotten the 810 to talk to the Mac, but also haven't really tried either. I still have my PC, so can use the Polar on it, if I need it. The issue was the IR interface, which has changed for the RS. My issue is using old technology on new hardware/software.

The only real disadvantages to this technology are (and for our purposes, the RS and the S are the same) that you need to put the strap on and start recording, then download the data to the PC to interpret. These are not huge issues at all.

With an iPhone, I was looking to see if there was something that was instantaneous. I know there are heart rate monitor straps that work with the iPhone, but I'm not sure if the software records beat to beat (r to r). I've not looked very hard either. If I had a bluetooth strap with an app that did the same thing as the Polar, but with the iPhone, I'd get it.

Since I already had the iPhone, the $5.00 for the app was trivial.

An ECG device can give more info, however it takes a lot longer to interpret. If you know you have afib, then a Polar (or other R to R recording device) can tell you: PAC'S, PVC'S and afib. It can do this very quickly.

George