eSense Pulse Analysis

RMSSD ms
RMSSD (Root Mean Square of Successive Differences) is a measure of heart rate variability (HRV) that shows how much your heartbeat changes from one beat to the next. Higher RMSSD values generally indicate better heart health and relaxation, while lower values may suggest stress or fatigue.

SDNN ms
SDNN (Standard Deviation of NN Intervals) measures the overall variability of your heartbeat over time. A higher SDNN value typically indicates better heart health and adaptability, while a lower value may suggest stress or poor heart function.

LF ms2
LF (Low Frequency) is a measure of heart rate variability (HRV) that reflects both the body’s stress response and part of the nervous system that controls heart rate. Higher LF values may indicate better adaptability, while very high or very low values may suggest stress or imbalance.

HF ms2
HF (High Frequency) is a measure of heart rate variability (HRV) associated with relaxation and the activity of the parasympathetic nervous system (which helps the body rest and recover). Higher HF values typically indicate better relaxation and stress resilience, while lower HF values may suggest stress or fatigue.

LF/HF Ratio
The LF/HF (Low Frequency to High Frequency) ratio is a measure of the balance between stress (LF) and relaxation (HF) in heart rate variability (HRV). A higher LF/HF ratio may indicate more stress or activity, while a lower ratio suggests relaxation and recovery.

Score (developed specifically by Mindfield)

For the Mindfield app, we have developed our own score system. This score, developed by us, should simply tell you how good your heart rate variability is with just one number.

Simply put, the better your heart rate variability, the higher this value.

In detail: The score is the sum of the regularity of the curve (in percent) and the amplitude (absolute value) divided by the rate of data from eSense Pulse (which transmits the last measured values via Bluetooth® every 200 ms) plus the previous score.
Therefore

Whereby the time interval between Score and Score₀ is just 200ms. If Regularity Percent << 90 then:

Thus, especially measurements of the same duration can be compared well (for example, if you always set 15 minutes as the measurement duration in the settings), since a higher regularity of the curve and / or a higher amplitude but constant time results in a higher value.

Regularity (developed specifically by Mindfield)

We also included the regularity as another value. This is also recorded by a formula developed by us and displayed in color (from a measurement duration of 5 minutes or more) in the overview after the measurement:

Attention: The colored coloring of the regularity does not correspond 100% with the color distribution in the pie chart as these are detected in different ways.

For the background coloring of the oscilloscope, a period of 20 seconds is taken and it is determined which regularity value is the most common color.

The pie chart, on the other hand, uses all the numeric regularity values of the entire session, with the percentages in red, yellow, orange, and green taken from them.

The frequency-based HRV analysis can be unlocked as an in-app purchase. However, due to technical reasons, it is not possible to apply this analysis retrospectively to measurements created before purchasing the feature.