Heart Rate Monitor Recommendations for 24/7 Continuous Monitoring and Logging

Hi FuChieh Hsu,
Thank you for the link. When I get my system running overnight I will investigate this further.

I was also interested in the link http://www.bioshare.info/en/eegecg.
How do you convert the data into a format that can be displayed in Audacity?
For example I have Heart rate data as RR measurements in .hrm format that I can get into CSV format but neither can be read by Audacity (and it is not a fixed sample rate). Also I have accelerometer data in CSV format that I would like to overlay with heart rate. How do I get that into Audacity for viewing?
I am on a Mac so that appears to limit the options. I have both EDF Browser and Audacity.
Thank you

Hi Guys,

I am looking for an Android app that can display live HRV taken from cheststraps.
Currently i am using ithlete which can not do that.
Do you know any?


Does your phone have Android 4.3? Does your cheststrap use Bluetooth LE (a.k.a. Bluetooth Smart)?

for my data taken using TrueSense kit, the OPI Console program can do conversion to .edf or .wav (for Audacity viewing) formats.
if you have .edf file, you can use EDF2WAV.exe freeware (use HPF=0.01Hz, EMG default) to convert to .wav file. (http://www.softpedia.com/get/Multimedia/Audio/Audio-Convertors/EDF-EDF-plus-to-WAV-Converter.shtml or other download sites)

Unfortunately both answer is no.
But what if i have, and what if not?
What do you suggest?

What kind of phone do you have? It matters, because most newer heart rate monitors use Bluetooth LE (a.k.a. Bluetooth SMART), but most (pre 4.3) Android devices don’t support Bluetooth LE. There may be some devices that use Bluetooth (non-LE), but their batteries probably won’t last long enough to make 24/7 monitoring practical.

Hi FuChieh Hsu,

I am on a Mac so I will look at alternative approaches. I am still working on the software side for getting my 24 hour HRV data captured. I did get the CSV accelerometer data into EDF format. I may process it and put it in AIFF so that I can overlay with my HRV.

What sample rate are you using for you input data and what output data rate are you using for your WAV files.

Thank you.

Hi Adam,

I looked up the iThlete web site for specs on their ECG receiver. It looks like it uses the audio jack on your phone to connect to their app. It looks like your external receiver uses the Polar standard and is not Bluetooth compatible(http://myithlete.com/FAQ.html). I don’t know of any other apps that use the microphone input for their signal source. There may be some open source Android apps that could be modified to get their data from the microphone port.

Most of the newer heart rate straps use seem to use Bluetooth 4 Low Power signaling to get hundreds of hours of operation from a single battery. There may also be a possibility to plug in a usb cable into your phone and attach a USB Bluetooth 4 dongle. Here is an article discussing using an external ANT+ dongle with an android phone http://www.thisisant.com/forum/viewthread/2034. Some of the discussion was technical enough to indicate that this was not a plug and play approach. Some of it depended on phone OS version. I also don’t know how much power the USB Bluetooth Dongles require. Your phone may not provide enough (or any) power to run the dongle.
Not sure what apps will do HRV using Bluetooth 4 (assuming the above actually works).

Good luck and keep us posted.

Thanks for the help guys, i will post what i find.

So the results are:
I have not found any good app for Android, so i switched to these two iPhone apps:
to the very excentric HeartsRing
and to SweetWater’s SweetBeat.

Hi Adam,
How did you track down these apps among the iTunes haystack?

I looked at the Heartstring website and it seemed more mystical than technical. However one of the links did provide some interesting material on fractal heart rate variation (which further justifies 24 hr HR monitoring). <http://physionet.org/tutorials/ndc/> 
Does the HeartString app share information (documents) through iTunes?

SweetBeat by SweetWaterHRV looks interesting. I assume you use the 60beat Rx HR monitor setting for your iThlete adapter. I looked at the free app (Food Sense) that is related to the one you purchased. They store the data in an SQLite file under documents, but do not share it with iTunes. I suspect your app is the same.

Sweetwater also has a link to HR monitors. They link to a shirt that connects to many HR monitors (electronics not included), is under $65, and may be good for 24 Hr monitoring <http://www.numetrex.com/about/cardio-shirt>. 
I have evaluated a similar approach and it is certainly more comfortable than a strap.

Good luck and keep us posted on your experiences/results using these apps.

1.How did you track down these apps among the iTunes haystack?
I was motivated :slight_smile: but i do not remember the exact search phrases…

2.Does the HeartString app share information (documents) through iTunes?

  1. Sweetbeats whitepapers and all their stuff seems quite thoughtful.

Thanks for the shirt, do you have one? i am looking for Omsignals solution.

Sorry for the delay…here are my answers:

1.How did you track down these apps among the iTunes haystack?
I was motivated :slight_smile: but i do not remember the exact search phrases…

2.Does the HeartString app share information (documents) through iTunes?
Nope, but you can talk with their programmer Filippo, and they will do it.
I asked a couple of questios from them, and they were quite friendly.
So i can connect you with him.

  1. Sweetbeats
    Their whitepapers and other stuff seems quite thoughtful.

Thanks for the numetrex link, do you have one?
I am looking for Omsignals solution, which seems the best so far!

Hi everyone,
I’ve been reading this topic with great interest. I myself want to do 24/7 HRV logging for a number of reasons. Mostly because I want access to a biomarker of trauma states activation (it’s related to stress but described with more detail). Look at this article:
Also magnesium is known to influence HRV and I’d like to experiment with different doses.

I’ve considered to buy a Bluetooth HR device and pair it with my iPhone, but I’m wondering about accuracy of both hard- and software. I’d also like a dedicated device just for monitoring.

Has someone tried to use TrueSense for HRV tracking and monitoring? How did it went?

I’m also interested in monitoring of other stress markers, I’d really apreciate your suggestions.

Hi Adam,

I do not have the numetrex shirt yet. I am still working on getting the software to capture a full night of HRV data.
Thank you for the link to OMSignals. I agree their shirt looks very interesting. I applied for a free evaluation unit and will report back if I get one. I wonder how far away from production they are, given that they appear to be beta testing.

Take care.

Dear all,
in case you are looking for an iphone app able to record, store and export HR and HRV features, I developed this one some time ago. It works with Bluetooth low energy heart rate monitors which send R-R intervals (e.g. polar H7). Give it a try: https://itunes.apple.com/us/app/heart-rate-variability-logger/id683984776?mt=8
(You can contact me if you need promo codes)

I am also looking for something to measure heart rate, and ideally HRV, while being mobile, so unfortunately @op engr setup would not work.

So far I have come across the Polar H7 Heart Rate Sensor, which seems to do the job when paired with an iPhone (in my case I have an Android phone but I have read that someone managed to get it working with Android also by upgrading to 4.3), it also comes in at a reasonable price.

Has anyone experience with this, or has a better strap option?

I was investigating the watch options also but it seems that the Polar watches don’t allow you access to the HRV data, unless you buy the very high end watches, while the Garmin watches have a maximum of 8 hours before they need recharging. But there may be one I have missed, as there are so many options out there.

I have been using the Polar H7 with a Nexus 4 (Android 4.3) to record resting heart rate (5min), or workouts (<1h). But the Bluetooth LE support on this device does not yet appear to be reliable enough for 24/7 recording.

TrueSense allows 24/7 continuous monitoring of Heart Rate by alternating two sensors (using memory module) applied to the same electrodes, all for <$100 for two sets of sensors now. you have full access to the raw data (in .edf format) and can use other programs to analyze the data.

for attaching electrodes to skin for extended time period. there’s now ComfoPore breathable, waterproof film available in accessory pack.

another neat chart showing effect of deep breathing and meditation on heart rate.

That is disappointing, how much data was actually lost? Could it have been another app on the device interfering with the transfer? When you do get HRV data off the device is it at least accurate?

Is this specifically a problem with Android then? So if you switched to iOS it worked well?