Smart Phone Biofeedback Software without External Hardware

Biofeedback Graph

A Quick Refresher on Biofeedback

Biofeedback uses the availability of data to track and be aware of physiological functions using technology, though manual input is possible. Hardware and software offer the advantages of detailed analysis and input. The goal of biofeedback is by hacking the data and the inherent need for multiple biological systems to balance each other out, we can thus manipulate them at will.

It is also possible to manipulate this homeostasis without manual user input, for example photic stimulation with the David Delight devices, or beta blockers like propranolol which slow down the heart and reduce stage fright.

By being able to alter physiological activity, we can improve performance and health of individuals. Instruments allows us to rapidly and accurately feed information back to the user, by the user analysing this information and reacting to it, changes can be brought about physiologically in the short term, and in the long term without equipment as the user develops habits of their wanted physiological states, for example by breathing to reach closer to mental and physical coherence.

Biofeedback on Smartphones – Is it possible?

The smart phone is capable of doing some rudimentary biofeedback, this is done by monitoring heart rate using the camera function, the flash shines light through your finger and via the changes of volume in your blood, certain software can measure heart rate and heart rate variability (HRV).

HRV is useful in the application of biofeedback to reach coherence with breathing. It is important that the software tracks changes in heart rate over continuous time, rather than just heart rate. HRV measures the variability in which your heart rates changes from beat to beat, as the way you breath alters your heart rate, it is thus able to determine if you are breathing in synchrony with your heart, being able to achieve that is known as coherence.

Using the phone’s camera to measure HRV, is not as accurate as specialised devices, but in the scheme of proper simple breathing to achieve better states, it can be a cheap and effective tool. It also saves you the cost of investing in equipment.

In this article I review some of the software I’ve tried for the purposes of heart rate coherence.

Phone Application Review

Azumio Stress Doctor

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Azumio measures your heart rate variability, and teaches you to control your breathing via a beautiful constantly changing landscape graph, where you learn to control your breathing by making the graph go up and down fluidly, as you do so and balance our the curve, you get these ying yang awards to tell you you are breathing right.

The software is great because its easy to use, the interface is sleek and the instructions are straightforward. It also shows your minimum and maximum heart rate which is a useful indicator of how stressed you are, especially when you can see the graph being completely ierratic

Unfortunately Azumio is highly limited in that it doesn’t teach you “exactly” how to breath, nor does it show you how much coherence and control you are really having over your lungs and heart, trying to just use the chart is frustrating as the only advice giving is to breath in when the chart reach’s bottom, and breath out when the chart reaches the top, doing so does not guarantee correct breathing. As the heart sensor technology isn’t that accurate using a camera this often leads to frustrating experiences, with seemingly no guide to how to achieve those ying yang awards.

From a pure biofeedback perspective, it just doesn’t give you enough data for you to feedback, in other words it’s too dumb and assumes you are dumb.
In addition the way its done means that there is no distinct levels of coherence, nor are there different states to reach as there is only the act of balancing the graph, since we don’t know how those ying yang symbols are reached we have no idea how the coherency is happening, if at all.

Still it remains a fun experience and a fun app, if one wants to watch their heart rate variability and try to seize control of it over a cascading graph. It’s a pretty helpful indicator of how your heart rate is going, and the graph is landscape and full screen, which is pretty.

Appstore Link:

Heart Rate + Coherence

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Now here is a biofeedback app I like.

It works in the same principle as the Azumio stress doctor but instead it shows you exactly the level of coherence you are at. On the bottom of an app there is a nifty guided animation that shows you exactly when to inhale and exhale, and the cool thing with this is that you can choose balanced, relaxed, or energy which you can customize. It also teaches you how to inhale and exhale properly.

The interface is unattractive vs Azumio, and there is no landscape option. So your view of the graph is very limited. You have to also swipe on the screen to move from heart rate variability view to coherence view, which is annoying when one of your fingers is stuck on the camera. It also offers addition in view of spectrum of HRV (which you have to pay more). This helps to tell whether you are achieving coherence or not.

Most importantly, It also gives you a percentage of coherence you are currently on. So you know how on target you are. This is better in comparison to Azumio where you are after ying yang signs that you do not know why or how they appear.

The ability to choose breathing regimen is also very cool, in general I go with the state you want to “be in”, so if you want to sleep I would choose “relax”, if I want to be more focused I would choose “energy”. if I want to practice breathing and biofeedback I can just choose balance.

The only disadvantage to this app is the lack of a breath analyzer, also the duration of the guided breathing animation is adjustable, but there is no instructions on whether you should adjust it to say 7 , 10, 15 seconds, so I have no way of knowing which duration is suitable for me. The lack of a landscape full screen view of heart rate variability is not a deal breaker, but it would be nice to have.

Overall I find this is my go to app for quick biofeedback, especially for relaxing at night when my breaths are still erratic from a day of work and I need to wind down.

Appstore Link

Breathing App

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Self explanatory, the major function of this app is that it can analyse your breaths. It guides your breath slowly to a slower breath. A limited application for the price, also I would have thought they would have integrated the breath analyser with the software, however in the app, it’s a separate small tool not integrated with the main app. You have to use separately in the settings page, which sort of eliminates the whole description of biofeedback.

The rest of the software is rudimentary, the animation of breathing in and breathing out isn’t impressive nor attractive, but it does serve the purpose of being able to first work out your breathing rate, then giving you 2 minute sections in which it guides you to slowly slow your breathing, it would be great if this simple breath analyser was implemented with the other biofeedback software above but its not.

The breath analyzer is also not very complicated, from what I gather it really just records your breath on the microphone and roughly works out your breaths per minute using 4 breaths which to me is an extraordinarily inaccurate measurement.

The app is simple, but it serves its purpose. It always starts with a high breath rate, then slowly moves your breath rate down by telling you when to breath in and when to breath out. It works. All in all, an okay purchase if you have want to find something simple that guides you to a slower breath, but overall a not very satisfying app to own.

Also you don’t have to hold the finger permanently on the camera of your phone, which to some people may be a plus?

Appstore Link:

Additional Tips

Something that works really well for me in a noisy coffee shop or public space is this:

  1. Plug headphones into laptop, go to, start playing uptempo or whatever track you like, these beats help with focus. Put some white noise on to help drown out the noise. I recommend running both at the same time.
  2. Unlock your phone and turn on heart rate and coherence app, select energy under settings and breath following the diagram until heart rate coherency reaches about 90% or so
  3. Now work!

1 Comment

  1. Hi! First of all frikkin great article!
    I was looking for a way to better understand and grasp the situation on the HRV coherence messurements on popular iphone HRV apps.
    What I found missing though may be of key importance here:
    Is the best app I have found as it gives you a coherence messurement to relate to and works with the breathing cycle.
    I should also say that I am in no way financial or otherwise related to the production or making of this app. I am simply a biohacking looking for alternatives in HRV training.

    All the best!

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