HRV Stress. How iTHRVE Heart Rate Variability app measures stress?
Source: http://hrv-app.com/stress.html by Dan Winter – 2 January 2016
How iTHRVE Heart Rate Variability app measures stress?
HRV and stress
Firstly – there is a primary measure of stress – related to change in long-term resting heart rate. Using the Polar chest strap- overnight HRV analysis with iTHRVE – is an ideal way to reveal – resting heart rate change – which is a primary useful indicator of stress:
Next: remember – that (lack of) internal HEART COHERENCE – is another primary indicator of stress. If coherence is high – then it is more likely stress is low. Please see our article on COHERENCE measure with the iTHRVE app
Internal heart coherence
Note particularly how iTHRVE offers a far more sophisticated measure of internal heart coherence (3rd order power spectra) – that we can far more meaningfully measure and reward overall internal heart coherence (called HARMONIC INCLUSIVENESS ) – rather than the simplistic single harmonic peak (see “Heart Math Mistake”).
Further – then below – we illustrate another more sophisticated way iTHRVE measures stress: internal resonance/phase lock between internal (blood) pressure – vs. the body’s EKG heart electrical peaks.
Note: the iTHRVE can use multiple blue-tooth input sensors: of these- the finger clip /oximeter sensor – and the iPhone camera light sensor can measure the below longer blood pressure wave – the third input device for iTHRVE – the bluetooth chest strap – does not see this longer pressure wave – and is more for long term/ overnight hospital grade analysis of HRV.
Watch Dan Winter and Patrick Botte talking about how the iTHRVE app measures stress
The story of Dan Winter’s original discovery: How Heart Coherence is Measured: The Mathematics
Note: Dan’s original discovery credited in the literature for inventing the term Heart Coherence-
was the use of the SECOND Order FFT called CEPSTRUM – to measure internal cardiac phase coherence
with the itHRVe app- that has been expanded to use a THIRD Order FFT
– providing an even smoother measure of HRV/Heart Internal Coherence-ideal for Breath Training.
Dan Winter’s original new book: Fractal Space Time-Origin of Biologic Negentropy
Related Article: Fractal Phase Conjugate Origin of Perception
Important credit here: the technique to measure the per cent time when the blood pressure peaks are in vs. out of phase with the HRV peaks-to quantify stress is thanks to Patrick Botte.
Measuring stress as feedback
Measuring stress is one of the primary goals of biofeedback – because teaching people relaxation / how to relax – is one of the primary needs and goals of health training related biofeedback systems. In modern society- stress is so all pervasive- that people are most often unaware of how stressed they are, as they are often unaware of the damage this stress is doing to their health (EVERY doctor wants to tell you about this). Stress measurement can be essential to almost every industry (not to mention for designing education)- as employers for example often critically need to measure how much stress their people are exposed to- not just for health but also to optimize performance. Stress often needs to be measured- so that it can be minimized.
What are the principles behind HRV, stress and health?
There are 2 principles in fundamental physics which not only reveal the electrical relationship of stress to health – but also hide a secret to how stress can be measured electrically with biofeedback (especially iTHRVE): increased ability to relax and that stress is directly related to blood pressure.
1) increased the ability to relax – in general INCREASES electrical conductivity in the body. Intuitively this makes sense because- electrical resistance is more than metaphorically connected to the psychological resistance.
2) stress is directly related to blood pressure – AND ability to vasodilate (send blood to the surface – which is how iTHRVE measures HRV!). Again this is intuitively easy to understand because we call psychological ‘pressure’- by the same name PRESSURE. Psychological pressure and blood pressure – are much connected of course.
The relationship of blood pressure – to the speed of the waves – which we use to measure heart rate and HRV – also hold the clue to how we measure stress.
When I was in graduate school designing polygraphs to measure hypertension – with my mentor Dr Albert Ax (one of the inventors of biofeedback)- one of our tasks was to use our polygraph to simplify and speed up the measurement of blood pressure. To do this – we did many studies and tests to prove that: THE SPEED OF THE WAVE OF YOUR HEARTS PULSE TO THE PERIPHERY OF YOUR BODY – COULD BE USED TO MEASURE BLOOD PRESSURE. You see- the wave velocity of your pulse on the surface of the hose/tubes called your blood vessels is obviously proportional to the liquid pressure on the hose/tube/blood vessel. This is easy to understand because when you stiffen a drum or tension a string- it affects the wave speed moving along it. The kool thing- is that the time it takes for your heart to send a message out to your fingertips IS easy (and cheap) to measure! You simply note the time of the peak of the EKG electrical wave (QRST high point )- and then merely count the milliseconds until it arrives at your finger tip ( like in the finger clip or iPhone camera light catching your pulse for itHRVe). We are about to explain how this phase relationship (coherence/embedding) between the electrical peak of your heart, and the resonance to the mechanical/sonic peak of your hearts blood pressure pulse CAN also be used in a somewhat different method of analysis – to measure overall stress as well.
The way your iPhone camera or finger clip pulse sensor are used for iTHRVE HRV measure – in biofeedback science is called ‘finger plethysmography’.
There are many studies like “Comparison of finger plethysmograph to ECG in the measurement of heart rate variability”. Remember that Heart Rate Variability (HRV) is probably the most studied and published subject in ALL of medicine. This is because HRV is such a beautiful indicator of so many health conditions – especially including probably the best way to measure overall immune health! (Harmonic inclusiveness- or FRACTALITY- in the HRV- as the immune health measure– my article on this: www.goldenmean.info/holarchy )
SO – what is a ‘finger plethysmogram’ practically? (your finger motionless on your iPhone camera- or finger clip light). When your heart’s electrical pulse point (the time when the electric voltage wave perfectly squeezed your heart blood)- finally reaches the end of the stretched ‘pipe’ (your blood vessels)- THEN that wave causes a bit more blood to reach the surface (your finger ‘vasodilates’). This principle of VASODILATION- refers to the difference between the cold hands (and heart?)- of the stressed person- versus the warm hand of the relaxed (and vasodilated) person. Vasodilation is the SKILL to relax and vaso-dilate allowing the blood to unpack from the body core- to the periphery.
Vasodilation – (and hence inner relaxation) is such an important (and relatively lost) – spiritual skill – that there is a name for it in mythology: “The Order of the Red Hand’! This can refer to a spiritual master- one who can vasodilate his chi/plasma – and thus direct his energy outward rather than inward- by intentional relaxation. (Not to be confused with William Butler Yeats ‘bloody red hand’. In British parlance- it is always important to discriminate between ‘a bloody good show’ vs a bloody bad show.)
All this esoteric conversation about the spiritual importance of relaxing in order to vasodilate- and send a pink message to your skin surface- COULD even be important to you as a teenager. Because your best indicator for when it might be time to hug your new girlfriend- if she relaxes enough near you- is probably WHEN she gets a little bit.. ‘PINK.. (your ‘blushing’ bride?)’!
The way modern common devices like iPhones camera and iTHRVE fingerclip measure HRV / pulse – uses VASODILATION. We use a light (finger plethysmogram/ blood volume measure)- to tell us when the blood reaches the skin surface. By using a light sensor (your iPhone camera- or fingerclip photoreceptor)- we can measure how much of that light PENETRATED your skin- and thus how much relative blood was near the surface.
From this device in itHRVe we get a curve that looks like this:
HRV low frequency and stress
By calculating the HRV – LF (low frequency) harmonics separately using just the pure HRV peaks – more locked to the EKG, separately versus using the wave shape harmonics of the LONGER BLOOD PRESSURE WAVE – we determine whether your body is RELAXED – IN PHASE – with itself… That is to say – phase synchrony – literally INNER HARMONIC between your bodies – electrical ringing – versus it’s sonic/liquid longer wave natural resonance!
Note that in addition to the simple up and down (shortwave in YELLOW)- of the HRV pulse- we ALSO get a LONGER wave (here in RED) ’embedded on the wave’- which is related to BLOOD PRESSURE. This is because the longer wave cycles of blood pressure change – ALSO influence how much light bounces in and out from the little light sensor.
This is very neat because that longer wave of blood pressure ALSO indicates Heart Rate Variability in another way. You see there are very important longer wave-blood pressure cycles inside your body- which profoundly indicate whether you are healthy. One of these important ‘long wave’ lower frequencies in your body is called the MAYER WAVE. This is a natural universal resonance frequency around .1 hertz- which develops because of the natural peristaltic pumping inside your blood vessels – in resonance to your spine liquid (sacral cranial). So- sacral cranial healers talk about measuring the MAYER wave- frequently.
We can measure this all-important MAYER WAVE- in relation to blood pressure cycles – AND HRV- AND Sacral Cranial spine liquid pumping- all using this relationship of the shortwave (pure HRV- in Yellow here) versus this longer wave – of blood pressure embedded – as you see in the picture.
AND one of the original reasons I was excited to be part of the team building iTHRVE biofeedback here – WAS – because I had just discovered (with great excitement) that the EXACT known frequency of this essential blood pressure MAYER WAVE- in the body – .1 hertz – AND virtually the exact centre point frequencies of all Heart Rate Variability- known as LF (low frequency) – versus HF – high frequency – were .1 hertz (LF), and .251 hertz (HF). This means that the perfectly relaxed normal MAYER blood pressure cycle in the body IS – the perfectly relaxed normal HRV – much studied – LF frequency peak (picture below)
Source: http://hrv-app.com/stress.html by Dan Winter – Jan 2, 2016