HRV Metrics

This message contains current values of HRV metrics. Backend starts sending this message to the frontend after session length reaches 30 seconds. After that backend sends this message to the frontend after receiving each image frame from the frontend.

Example:

{
    "messageType": "HRV_METRICS",
    "data": {
        "ibi": 123.0,
        "rmssd": 45.0,
        "sdnn": 78.0,
        "stress_index": 121.23,
        "stress_label": "NORMAL",
        "rr": [
            666.6666666666667,
            600.0,
            666.6666666666667,
            ....
            ],
            
    }
}

Field	Type	Name	Unit	Description
ibi	double	Interbeat interval	Milliseconds (ms)	Current value of IBI metric
rmssd	double	Root Mean Square of Successive Differences between normal heartbeats	Milliseconds (ms)	Current value of RMSSD metric
sdnn	double	Standard deviation of all normal to normal R‐R (NN) intervals	Milliseconds (ms)	Current value of SDNN metric
rr	List	R-R Intervals - The difference in ms between PPG peaks	Milliseconds (ms)	List with double values of RR Intervals
stress_index	double	Calculated Stress Index	Normalized unit	Current value of Stress Index from HRV Microservice
stress_label	String	Stress Label based on Stress Index	Categorical	Current label of Stress Label from HRV Microservice

Possible values of stress_label field:

stress_label	Description
LOW	Low stress level
NORMAL	Normal stress level
ELEVATED	Elevated stress level
VERY_HIGH	Very high stress level

Map of Stress Index <> Stress Label:

stressStatus	Stress Index (SI)
LOW	SI <= 50
NORMAL	50 < SI <= 150
ELEVATED	150 < SI <= 700
VERY_HIGH	SI > 700