Analysis Methods

The Science Behind Every Session

Respiriva combines established HRV science with advanced analysis methods. From time domain metrics to fractal analysis and AI-powered interpretation, every session is analyzed in depth.

HRV Analysis Overview
HRV Analysis

Comprehensive Heart Rate Variability

Every uploaded session is automatically analyzed for heart rate variability. Respiriva calculates all standard HRV metrics from the raw RR interval data, giving you a complete picture of autonomic nervous system activity during the IHHT session.

RMSSD

Root mean square of successive RR differences. Primary parasympathetic marker.

SDNN

Standard deviation of RR intervals. Reflects overall autonomic variability.

Stress Index

Baevsky's Stress Index. Quantifies sympathetic activation and regulatory tension.

Mean HR/RR

Average heart rate and RR interval. Baseline cardiovascular indicators.

Time Domain Analysis
Time Domain

Time Domain Analysis

Time domain analysis examines how RR intervals change over the course of the session. These metrics are the foundation of HRV analysis and provide direct insight into cardiac autonomic regulation.

Respiriva calculates these metrics both for the full session and for individual hypoxia/hyperoxia phases, allowing you to see how the autonomic nervous system responds to each training stimulus.

Frequency Domain

PSD Spectral Analysis (Welch Method)

Power Spectral Density analysis decomposes heart rate variability into frequency components. Using the Welch method, Respiriva separates sympathetic and parasympathetic contributions to HRV, providing insights that time domain metrics alone cannot reveal.

VLF (0.003-0.04 Hz)

Very Low Frequency. Linked to thermoregulation, hormonal, and renin-angiotensin systems.

LF (0.04-0.15 Hz)

Low Frequency. Mixed sympathetic and parasympathetic activity, baroreflex function.

HF (0.15-0.4 Hz)

High Frequency. Predominantly parasympathetic (vagal) activity, respiratory sinus arrhythmia.

LF/HF Ratio

Sympathovagal balance indicator. Higher values suggest greater sympathetic dominance.

PSD Spectral Analysis Graphs
DFA Analysis
Fractal Analysis

Detrended Fluctuation Analysis (DFA)

DFA reveals the fractal-like scaling properties of heart rate time series. Unlike simple statistical metrics, DFA captures the complexity and long-range correlations in cardiac rhythm that reflect the health of autonomic regulation.

DFA Alpha1 (a1)

Short-term fractal scaling. Values near 1.0 indicate healthy complexity. Lower values suggest uncorrelated dynamics.

DFA Alpha2 (a2)

Long-term fractal scaling. Reflects slower regulatory mechanisms and overall autonomic system health.

Poincare Scatter Plots
Nonlinear Analysis

Poincare Scatter Plots

Poincare plots visualize the relationship between consecutive RR intervals by plotting each interval against the next. The resulting scatter pattern reveals beat-to-beat dynamics that are invisible in aggregate statistics.

SD1

Short-term variability (perpendicular to identity line). Reflects instantaneous beat-to-beat changes, primarily parasympathetic.

SD2

Long-term variability (along identity line). Captures overall HRV including both sympathetic and parasympathetic contributions.

SpO2 Phase Detection
SpO2 Analysis

SpO2 Phase Detection & Episode Analysis

Respiriva automatically identifies hypoxia and hyperoxia episodes within each session. The algorithm detects phase transitions, calculates individual episode durations, and provides comprehensive distribution statistics.

This analysis is critical for evaluating training effectiveness. How deep did the desaturation go? How quickly did the client recover? How consistent were the cycles? Respiriva answers all of these questions automatically.

AI-Powered Interpretation
AI Layer

AI-Powered Interpretation

All analysis results are fed into AI models (Claude, GPT, or Gemini) that generate comprehensive, human-readable session assessments. The AI considers the full client history, previous sessions, and current metrics to provide personalized, context-aware interpretations.

The result is not just numbers, but actionable insights: What went well? What could be improved? How does this session compare to previous ones? What should the next session look like?

See the Analysis in Action

Request a demo and explore how Respiriva's analysis engine can elevate your IHHT practice with scientific depth and AI intelligence.

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