Whether you are interested in measures of resting physiology and chronic stress, biofeedback exercises, would like to design your own research study or to embed our camera-based technology in your product, we can help

​Assessment of resting physiology
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For individuals and teams. Check out HRV4Training to learn more

Biofeedback and deep breathing
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For individuals and coaching. Check out HRV4Biofeedback to learn more

​Research projects and protocols
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Camera Heart Rate Variability apps for iOS and Android

​Custom solutions and SDK licensing
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Contact us to learn more about our native SDK for iOS and Android

Validated technology

The camera-based PPG and HRV analysis employed in our solutions has been validated [1] with respect to the clinical standard (electrocardiography, or ECG) as well as consumer chest straps (Polar H7). You can find the full paper at this link.

Here you can find an example where we show a comparison of peaks detected from a full ECG (Cosmed, reference system) and PPG data acquired using our technology, showing how the peaks are perfectly aligned
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[1] 2017. D.J. Plews, B. Scott, M. Altini, M. Wood, A.E. Kilding and P.B. Laursen, "Comparison of heart rate variability recording with smart phone photoplethysmographic, Polar H7 chest strap and electrocardiogram methods", accepted for publication in the International Journal of Sports Physiology and Performance.

Frequently Asked Questions

Resting physiology or biofeedback?

HRV analysis can be used for various applications. What we do with HRV4Training is to quantify baseline physiological stress (what we could call "chronic" stress), and how this changes in response to training and lifestyle over periods of weeks or longer. To quantify baseline physiological stress, measurements need to be taken in a very precise moment, which is first thing in the morning, so that we can avoid the effect of confounding factors. You can find a few examples here

By capturing changes in resting physiology, we can provide useful feedback that helps individuals to make meaningful adjustments to better balance training and lifestyle. This is particularly relevant as we all respond differently even to the same stressors depending on various aspects (how novel is the stressor, how much of that stressor we are used to take, what other stressors are present), hence only by measuring our individual response we can figure out if it's all proceeding according to our plans or not

What about HRV biofeedback then? 

HRV Biofeedback is a technique that we use to improve self-regulation, and also strengthen the parasympathetic system. While our morning measurements should be done while resting and breathing naturally, during biofeedback we use deep breathing to elicit higher parasympathetic activity

You can see your biofeedback session the same way you see your other training sessions, this is something you do so that in the longer term, there can be beneficial changes in health and performance. Biofeedback is just a positive stressor

Where do regular baseline HRV measurements and Biofeedback meet?

Normally we would recommend doing biofeedback exercises as an add on the regular morning measurement done with HRV4Training. Combining biofeedback with morning measurements taken with HRV4Training, you could see also potential changes in baseline chronic physiological stress as measured in a known context (first thing in the morning), as a result of your biofeedback sessions

What phones are supported?

Our camera-based technology works reliably on all iPhones from the 5 onwards. You can find instructions for the camera-based measurement here

HRV4Training and Camera Heart Rate Variability are also available on Android. While not all Android phones can be supported, the apps use special algorithms to determine if the phone is supported and report back to the user, so that only accurate data is collected

Have the apps been used in other research studies?

Yes, the apps have been used in many research studies over the years, leading to novel insights due to the practical ease of use which enabled longitudinal data collection where it was not possible beforehand. Two good examples are the ones below [2] on the relation between the menstrual cycle and HRV, and [3] on HRV-guided training and the associated improved performance

[2] Kokts-Porietis, R. L., Minichiello, N. R., & Doyle-Baker, P. K. (2019). The effect of the menstrual cycle on daily measures of heart rate variability in athletic women. Journal of Psychophysiology
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[3] Javaloyes, A., Sarabia, J. M., Lamberts, R. P., Plews, D., & Moya-Ramon, M. (2020). Training prescription guided by heart rate variability vs. block periodization in well-trained cyclists. The Journal of Strength & Conditioning Research, 34(6), 1511-1518

Can I get the raw data?

Camera Heart Rate Variability, our research tool, provides RR intervals in csv files (as well as heart rate and HRV features). If you are interested in the raw PPG to be further processed for algorithm development, please reach out and we can discuss a custom solution