FAQ

Do I need a smartwatch to use Breathe Flow and other VAGUS® apps?

Yes, you can only use Breathe Flow with Apple- and Withings ECG enabled smartwatches.  For Apple these are series 4 and higher but not the SE version.   Withings ECG enabled watches are the Scanwatch and Move models.   We will also soon enable it for Samsung Galaxy 4 and 5 smartwatches.

How should I wear an ECG watch?

We generally recommend wearing your smartwatch on the left arm because it is usually easier to do the ECG tests in that position.  For Apple Watches we recommend having the button on the left side when wearing on the left hand.  This enable the most stable ECG recording.

How do I connect the watch with the phone and app?

First connect the watch to the phone according to the smartwatch manufacturer’s instructions.  Then follow our apps instructions.   

How many users can use one watch?

We only support one user account per watch.   We do not recommend having many users doing tests on the same user account because the data sets will then not be compatible and longer-term graphics are irrelevant.  We cannot analyse and personalize your diagnostics in the future. 

How do I track my heart rate with a smartwatch?

An ECG-enabled smartwatch usually has dual heart rate measurement methods.  They have an optical pulse sensor which is measuring the pulse with a light sensor on the bottom of the watch.   The other way to measure pulse is to use the ECG measurement. 

I only see the notifications on the watch a short time – can I retrieve them?

Some watches have enabled for us to send notifications.   Follow the watch instructions to view them.

What is Vagus Nerve Explorer?

Nerve Explorer is a premium subscription for the Vagus Watch Tests where the user can access and download her/his data through the cloud interface at www.vagus.app.

Why won’t my watch connect to my phone and/or synchronize the data?

Follow the watch manufacturer’s instructions to connect the watch to the phone.   Test that it is synchronizing with the manufacturers apps.

What is the BREATH FLOW chart?  How can it help me?

The Breathe Flow chart is showing how well you were inhaling and exhaling during the ECG recording.  You should try to make deep and smooth diaphragmatic breathing with 5 seconds inhalation and 5 seconds exhalation.  The x-axis shows the time and y-axis the depth changes.  Follow the timer on the watch. The blue line is moving upwards when inhaling and down when exhaling.  When the graph becomes ‘blurred’ or it changes colour, then your breathing – at that specific time – was not smooth enough.

When doing the BREATHE FLOW test recording, you should always try to do deep and calm diaphragmatic breathing.  The Vagus nerve and the body’s autonomic cardiac/respiratory system is working best when the breathing waves are deep and smooth like a sine-wave.  Your diaphragm (stomach) should visibly move in and out during breathing.   The breathing smoothness is described by the RSS index and the breathing depth is described with the BRE-index.  Both are shown in the ‘diamond’.  When you are mindful of your breathing, the diaphragm movement and pulse changes become synchronized, the Vagus nerve is activated and your oxygenation becomes optimal.  The Vagus nerve’s ‘relax and healing’ capacity improves.  We recommend practicing deep controlled breathing several times per day so that your Breathe Flow graph is consistently smooth.

What is the BREATHE PULSE chart?  How can it help me?

The Breathe Pulse chart is showing how ‘well’ your pulse was varying during the test.   This chart is a ‘quick’ 30 seconds Heart Rate Variability (HRV) display. HRV measurements are common on activity trackers that measure optical pulse.  The BREATHE PULSE is more accurate since it is based on an ECG signal.  If you have made deep and smooth diaphragmatic breathing during the test, the graph should show that your heart rate is changing in synchrony with your breathing. This occurs when your Vagus nerve is healthy and you are not stressed.   The x-axis shows the time and the y-axis is your pulse (beats per minute, BPM).  The red line is moving upwards when the pulse increases and down when it is decreasing.  When the graph becomes ‘blurred’, then your pulse change – at that specific time – is not smooth (good).

Remember to always do deep and calm diaphragmatic breathing during the VAGUS® test.  The Vagus nerve and the body’s autonomic cardiac/respiratory system is working best when the breathing waves are deep and smooth like a sine-wave.  If you are breathing well, the pulse change should be smooth.   This smoothness is described by the CSS index and shown in the ‘diamond’.  Your diaphragm (stomach) should visibly move in and out during breathing.  The pulse variation is described with the HRV-index.    When you are mindful of your breathing, both the diaphragm movement and pulse changes become synchronized, the Vagus nerve is activated and your oxygenation becomes optimal.  The HRV is then high (good).   This shows that the Vagus nerve ‘relax and healing’ capacity improves.  We recommend practicing deep controlled breathing several times per day so that your Breathe Pulse graph is smooth.

What is the DIAMOND graph?

1.               Breathing Health Index

The ‘diamond’ graph is a summary of the most important Breathe Flow ECG test analytics values. A larger covered area is better.  The Breathing Health Index (BHI) is a summary value for the four ‘diamond’ display breathing health indexes.  A higher BHI value indicate better breathing and Vagus nerve health.  We recommend that you exercise your breathing and reduce stress levels so that the BHI index is consistently above 50.

2.             HRV: Heart Rate Variability

Heart rate variability or HRV is the physiological phenomenon of the variation in the time interval between consecutive heartbeats. A normal, healthy heart does not have even heartbeats like a metronome. When the body is healthy and not stressed, the vagus nerve is optimising oxygenation by changing the length between heart beats to synchronize them with breathing. If breathing-pulse synchronization is good, then the HRV value is high if the user is performing deep, calm controlled breathing.  For instance, if the minimum heart rate during the test is 60 bpm and maximum is 75 bpm, then the HRV average is usually considered to be ‘good’, for instance 70 (ms). The HRV values in the ‘diamond’ view are expressed as an HRV-index in the range 0-100.

3.             BRE: Breathing Depth Index (0-100)

The breathing depth index is a calculation of how well the electrocardiogram amplitude is reacting to your breathing. When the index is higher, the person normally is doing deeper and ‘better’ breathing with larger changes in air volumes.  If the BRE-value is low, then the user is usually doing shallow ‘high’ breathing which is increasing a person’s stress levels.  We recommend to breathe so that the index is higher than 50. The scientific cause of this amplitude change, is the rotation of the heart when the diaphragm muscle moves up and down during breathing. The deeper one is breathing, the more the diaphragm moves. This amplitude variation can also be influenced by other factors such as muscle inflammations, stress- or other disease related issues. It is very important to monitor and exercise the diaphragm muscle for it to perform optimally during breathing.  Breathing Depth measurement for smartwatches is a novel test & analytics analysis system invented by Gustaf Kranck (pat. pend. for Vagus Health Ltd) and it is only available for Vagus ECG test clients.

4.             RSS: Respiratory Sinus Smoothness (0-100)

 Respiratory Sinus Smoothness is an index for how smooth the breathing curve is during the VAGUS® ECG test recording. The index is a presentation for how smooth ‘sinus-like’ the breathing (QRS amplitude change) varies during the test. The index values are between 0-100 where 100 is very smooth (good) and 0 is not smooth at all. RSS is a novel test & analytics analysis system invented by Gustaf Kranck (pat. pend. for Vagus Health Ltd) and it is only available for Vagus ECG test clients.

5.             CSS: Cardiac Sinus Smoothness (0-100)

Cardiac Sinus Smoothness is an index for how smoothly the heart rate is varying up and down during the VAGUS® ECG test. This index is quantifying how well ‘sine wave form like’ and smooth the heart rate variability (HRV) pattern is during the ECG breathing test. The index values are between 0-100 where 100 is very smooth (good) and O is not smooth at all. CSS is a novel test & analytics analysis system invented by Gustaf Kranck (pat. pend. for Vagus Health Ltd) and only available for Vagus ECG test clients.

What is an NFT?  

NFT is short for non-fungible token.  Non-fungible is this context means that that different tokens are not similar.   A one-dollar bill is similar to another one-dollar bill but the information in one NFT is different from another NFT.  This uniqueness is a defining and fundamentally very important feature of the NFT market.  Until recently, the main emphasis of NFTs has been on digital artworks but during 1st half of 2022 there are a multitude of new use cases for the NFT technology concept. 

What is a V-NFT?

The V-NFT is a method whereby we package 10 days of BREATHE Flow test data into an anonymized data package.  The V-NFT needs to be Blockchained if the user wants to sell or buy it.   For more information visit www.vagusnft.com

What is a smartwatch detecting automatically?

The watch is automatically detecting movement which it is reporting as steps, calories burned and for how long time the user is standing upright.   The watch usually also continuously track optical pulse by measuring the pulse during 1 minute each 10 minutes.   These pulse measurements are displayed in the ‘heart rate’ display window.  When worn during the night, the watch may automatically detect sleep patterns which is displayed in the ‘sleep’ window on the app.

What is an electrocardiogram, ECG?

An ECG is the recording of the electrical activity of the heart through electrodes.  In smartwatch ECGS the electrodes are under the watch and on the metal surface beside or on the top of the watch.   

How do I do an ECG test with the Vagus ECG smartwatch?

To record an ECG, you have to rest your hand on the leg or a table. Then initiate the ECG recording with the manufacturer’s watch app.  Place your right hand’s thumb on the watch’s electrode metal surface.  Then follow the instructions shown on the watch / app.  Sit still while doing the full test.

Are the VAGUS apps FDA-cleared – do they give medical advice?

No, they are not since and we do not provide any medical- or disease diagnostics.  It is not a medical device and should not be used as such.

Can the VAGUS apps detect Atrial Fibrillation (AFib)?

No, we do not provide AFib detection.  Atrial Fibrillation (AFib) is a medical condition and some smartwatches are diagnosing it with their own apps.  

What is the vagus nerve?

The vagus nerve is the most important nerve for long-term health.   It is called the ‘Rest and Digest’ nerve as opposite to the sympathetic nervous system which is called the ‘fight and flight’ system.    The vagus nerve is the longest and most complex of the 12 pairs of cranial nerves.   It transmits information to and from the brain to internal organs in the body such as the gut and heart.   The Vagus nerve is the main component of the parasympathetic nervous system which is also known as the ‘rest and digest’ system.   The ‘opposite’ of this system is the sympathetic nervous system which is known as the ‘fight and flight’ system which is activated when the body is in stress such as during disease progress. 

How do I measure my vagus nerve?

The vagus nerve is usually measured with optical pulse sensors on activity armbands, watches or chest-bands and expressed as heart rate variability (HRV).  HRV only gives a very limited indicator of the vagus nerve activity.  The Vagus apps measures several types of vagal tones from both optical pulse and ECG (HRV, RSA and RSAsync) and it provides a unique in-depth analytics in the form of the Vagal Homeostasis value.

Why is the vagus nerve important for the heart?

The vagus nerve is synchronizing the heart beats to breathing in order to optimise oxygen delivery to body tissues.   This function is more active when the body is relaxed.   When the body is stressed from mental issues or disease, this heart/breathing synchronization is altered.   This alternation is described by Vagus Health as a RSAsync index and used in the Vagal Homeostasis evaluations.

What is the vagus nerve doing when you breath?

When the vagus nerve is active, it optimises the blood oxygenation by periodically changing the level of oxygen absorption and transfer to the blood in the lungs.   This it does by ‘pulsing’ the lungs oxygen absorption parts in synchrony with its influence on increasing and decreasing the heart rate.   This is a very important functionality of the vagus nerve because it helps to optimize cardiac/respiratory energy consumption and homeostasis.

What is vagal tone?

Vagal tone refers to the level of activity and health of the vagus nerve.   To date, the most common methods to measure vagal tone has been heart rate variability (HRV as SDNN or rMSSD) and respiratory sinus arrhythmia (RSA).  Vagus Health with the Vagus ECG Watch is introducing a new type of vagal tone index which we call Respiratory Sinus Arrhythmia Synchronization (RSAsync).  Traditional vagal tone measurements do not normally address this synchronization periodicity between the timings of the increase or decrease of heart rate in relation to the corresponding inhale or exhale.   The Vagus Health analytics therefore take into account three Vagal Tone values – HRV, RSA and RSAsync.   We do not consider it appropriate and in order to not cause confusion in reference to traditional methods – we do not express this combination as ‘vagal tone.  Instead, we describe the health of the vagus nerve by estimating and expressing a value for ‘Vagal Homeostasis’.  The vagal homeostasis level statements in the app are incorporating several bio signals with the traditional values of ‘vagal tone’ and our introduced value ‘RSAsync’.   The word ‘vagal’ is here always used according to the definition ‘relating to the vagus nerve’.

 

What is homeostasis? How does the vagus nerve influence homeostasis?

Human life requires that many of the body’s interior parameters maintain a ‘magic’ interval known as the homeostatic range.  The process of achieving this balanced state is called homeostasis.  In its broadest sense, homeostasis is considered a description of when the body is self-sustaining and enable to uphold optimum balance for continued natural life spans.    There are also many narrow definitions of homeostasis limiting themselves to certain control centres that for instance enable healthy balance in fluids, temperature, gut-, gene-, immune-, mental-, molecular- and internal cell activities.  Traditionally it is considered that the vagus nerve is an essential part of cardiac-, respiratory-, gut digestion-, internal organ- and autonomic nervous system homeostasis.  Lately it has been found that it is also a very important part of the mental- and immune homeostasis. 

What is Vagal Homeostasis?  

In estimating Vagal Homeostasis, the Vagus Health analytics system take into account three Vagal Tone values – HRV, RSA and RSAsync plus a number of other bio signal parameters measured by the Vagus ECG smartwatch and machine learning individualization based on the user’s data.   The Vagal Homeostasis Index (VHI) is expressed between 0-100 where 100 is a very high level of homeostasis which also can be expressed as a good and healthy ‘balance’ in the autonomic system.   The VHI is a novel test & analytics analysis system invented by Gustaf Kranck and it is pat. pend. for Vagus Health Ltd.  It is only available for Vagus ECG Smartwatch clients.

What is RSA – Respiratory Sinus Arrhythmia?

The RSA value describes the relation between breathing intervals to pulse variation intervals.   In a healthy person, the vagus nerve is optimizing oxygenation of the blood by increasing heart rate when a person inhales and decreasing heart rate at exhaling.  The RSA value is derived from the ‘Vagus ECG Test’ controlled breathing periodicity.  The Vagus Health RSA index is between 0-100 where 100 is a perfect timing-synchronicity between breathing and heart rate peak-to-peaks.

What is RSAsync – Respiratory Sinus Arrhythmia Synchronization?

RSAsync is used in the VAGUS ECG app for Apple Watch.   RSAsync describes the timing and nature of the rising and falling heart rate compared to the corresponding breathing pattern.   When a person inhales, the pulse should rise in order to optimize oxygenation.   When the person exhales, the pulse should go down.  The RSAsync measures how ‘well’ this timing works and it is an indicator of changes to the autonomic and/or immune system.  A higher RSAsync values implies a better oxygenation and healthier vagus nerve.  There can be considerable individual base-line differences for this RSAsync value due to genetical dispositions or longer-term changes in the vagal influence of the cardiac/respiratory cycle when a person  for instance has blood pressure issues.  The vagus nerve baroreceptor has a primary over-riding influence on this respiratory-cardiac synchronization periodicity.    We recommend tracking the individual changes to this base-line as indicator of the persons stress-, immune- or for instance anxiety induced changes.  RSAsync is a novel test & analytics analysis system invented by Gustaf Kranck and it is pat. pend. for Vagus Health Ltd.  It is only available for Vagus ECG Smartwatch clients.

Are vagal homeostasis and immunity correlated?

The vagus nerve is a very important part of the immune system.  There is ample evidence that the activity level of the vagus nerve is correlated with a person’s immune system activity.   For instance, HRV measurements in diverse disease syndromes indicate that decreased vagus nerve activity is associated with increased morbidity and mortality.   Immune system changes affect multiple vagus nerve activities and hence we hypothesize that immune changes can be analysed by doing the Vagus ECG Test.    We hope that crowdsourcing of data with the Vagus ECG smartwatch together with clinical studies will provide further insights to the nature of this correlation between vagal homeostasis and immunity.

What does the pulse values mean?

The pulse in the Vagus ECG Test app display is shown as the three ECG recoded heart rate values: 1) Average heart rate.  2) Maximum heart rate as an average of maximum heart rates from each breathing cycle.   3) The minimum heart rate as average of the minimum heart rates from each breathing cycle.  The minimum heart rate is highly correlated with resting heart beat and we recommend placing more attention on this value in the Vagus ECG Test than on the average or maximum heart rates.   

What does the HRV values mean?

Heart rate variability or HRV is the physiological phenomenon of the variation in the time interval between consecutive heartbeats. A normal, healthy heart does not tick evenly like a metronome, but instead to keep the body healthy the vagus nerve is optimising oxygenation by modulating the length between heart beats  to synchronize with breathing.  When doing the Vagus ECG Test, we show the traditional variability as calculated with SDNN during the test and additionally we calculate the (HRmax – Hrmin)/ HR during the controlled breathing phase and establish a variation percentage as an index with a scale of 0-100 where 100 is a very strong variation and 0 is the lack of heart rate variability.

What does the VHI values mean?

In the VAGUS ECG app, we use VHI as a term for the summary of health analytics.  The VHI is short for Vagal Homeostasis index.  The main components in VHI are HRV, RSA and RSAsync.  Additionally, the VHI takes into account also a number of other bio signal parameters measured by the Vagus ECG smartwatch and machine learning individualization based on the user’s data.   The Vagal Homeostasis Index (VHI) is expressed between 0-100 where 100 is a very high level of homeostasis which also can be expressed as a good and healthy ‘balance’ in the autonomic system.   The VHI is a novel test & analytics analysis system invented by Gustaf Kranck and it is pat.pend. for Vagus Health Ltd.  It is only available for Vagus ECG Smartwatch clients.

Why are the watch ECG pulse and heart pulse measurements not the same?

A smartwatch is usually measuring optical pulse during a 1-minute period each 10 minutes. Therefore, it does not measure pulse during the next 9 minutes. This periodicity is used in order to save battery.   The optical pulse is additionally set so that it does not measure at the same time as ECG because the electrical signals arising from the optical pulse measurements can disturb the ECG electrical signal measurements on the watch. There therefore may be differences between ECG heart rate and Optical Pulse Heart Rate values due to timing reasons.  Another reason for a different heart can also be that he ECG measurement is more accurate than the optically derived heart rate estimations.  Studies have shown that optical hear rate measurements are statistically true only as averages for longer term measurements.

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