SelfSenseSelfSense HRV

How SelfSense Works

SelfSense uses cutting-edge science to help you improve both your HRV and your adaptive movement variability — two sides of the same adaptive system.

The Science Behind SelfSense

Unlike traditional breathing apps that use fixed patterns like square or resonant breathing, SelfSense employs fractal variability to create more natural, adaptive breathing and movement rhythms. You can use our our HRV entrainer to synchronize your body with those natural rhythms. The app includes the Adaptive HRV Tracker which helps you track your HRV using Apple Watch or Polar H10 and tag the recordings where your heart rate variability is in its most adaptive state. For some people it will be during sleep, some people can achieve it through breathing, some others are naturally fractal during periods of rest.

Learn more about the science behind it at our website EightOS Selfsense Blog.

Fractal Variability Explained

Fractal patterns are found throughout nature - from coastlines to heartbeats. A healthy heart doesn't beat like a metronome; it has natural variability that follows fractal patterns.

DFA Alpha Analysis

SelfSense uses Detrended Fluctuation Analysis (DFA) to measure the fractal characteristics of your heart rate variability. The same algorithm is applied to accelerometer and stride-interval data, so you also get a DFA alpha score for your movement — useful for running, walking, postural work, and detecting the onset of fatigue or bracing. This gives you a more accurate picture of your nervous system's adaptability across both cardiac and motor domains.

Real-Time Biofeedback

The app provides real-time haptic feedback through your Apple Watch, guiding your breathing in sync with your body's natural rhythms.

Benefits of Fractal Training

  • Improved stress resilience
  • Better recovery
  • Enhanced cognitive performance
  • More adaptive nervous system

The Technology

SelfSense processes heart rate data from Apple Watch or Polar H10 sensors, and accelerometer / gait data from Apple Watch, iPhone, or external Movesense sensors streaming over OSC. Advanced algorithms apply DFA alpha analysis to both streams to create personalized breathing and movement guidance.

References

The fractal-variability framework behind SelfSense draws on research across cardiology, neuroscience, gait science, and complex-systems physiology. The most relevant sources:

  • Hardstone, R., Poil, S.-S., Schiavone, G., Jansen, R., Nikulin, V. V., Mansvelder, H. D., & Linkenkaer-Hansen, K. (2012). Detrended Fluctuation Analysis: A Scale-Free View on Neuronal Oscillations. Frontiers in Physiology. — pedagogical reference for the DFA algorithm SelfSense uses on both HRV and movement signals.
  • Goldberger, A. L. and colleagues — foundational cardiology work on loss of fractal complexity as a marker of pathology (the "complexity loss hypothesis").
  • Hausdorff, J. M., et al. (1996). Fractal dynamics of human gait. Journal of Applied Physiology. — long-range correlations in stride intervals; the basis for gait-mode DFA.
  • Stergiou, N., & Decker, L. M. (2011). Human movement variability, nonlinear dynamics, and pathology. Human Movement Science. — the "optimal movement variability" framework.
  • Dierick, F., Nivard, A.-L., White, O., & Buisseret, F. (2017). Fractal Analyses Reveal Independent Complexity and Predictability of Gait. Scientific Reports.
  • Werner, G. (2010). Fractals in the Nervous System. Frontiers in Physiology. — fractals at every level of the nervous system; criticality as the reference dynamical state.
  • Van Orden, G. C., Kloos, H., & Wallot, S. (2009). Living in the Pink: Intentionality, Wellbeing, and Complexity. — 1/f noise as the signature of healthy multi-scale coordination.
  • Whitfield, J. (2006). In the Beat of a Heart: Life, Energy, and the Unity of Nature. — accessible synthesis of fractal physiology and allometric scaling.
  • Löfblom, J. (2019). Prototyping with Movesense Platform — Breathing Application. Metropolia University of Applied Sciences. — reference on simultaneous HRV and breathing measurement from chest-worn sensors.
  • Paranyushkin, D. (2012). Metastability of Cognition in the Body-Mind-Environment Network; EightOS: Variability in Physical Practice (2025); SelfSense: Body-Network Isomorphism and Movement Signatures (2026). — the SelfSense framework itself, integrating these sources into a single research-and-practice program.

A fuller reading list is maintained as part of the SelfSense fractal-variability research wiki.