Heart Rate Variability (`lamp.heartratevariability_sdnn`)

Reports SDNN (standard deviation of NN intervals), a common HRV metric reflecting autonomic nervous system activity. Lower SDNN values may indicate higher stress or reduced autonomic flexibility.

Configuration

SensorSpec: lamp.heartratevariability_sdnn
Sampling: Continuous (events synced from health platform)
Platform: iOS (HealthKit), Android (Health Connect)
Typical source: Apple Watch
Requirements: Connected wearable with HRV measurement capability; health platform permissions granted

Usage

HRV measurements are recorded periodically by the wearable (typically during rest or sleep) and synced via the health platform.

Data

Fields

Field	Type	Description
`value`	number	SDNN value in milliseconds
`unit`	string	`"ms"`
`source`	string or null	Data source identifier

Example

{
  "timestamp": 1649859212042,
  "sensor": "lamp.heartratevariability_sdnn",
  "data": {
    "value": 42.5,
    "unit": "ms",
    "source": "com.apple.health"
  }
}

Cortex Features

No Cortex features currently process HRV data. Access raw values via cortex.raw.heartratevariability_sdnn.

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Configuration​

Usage​

Data​

Fields​

Example​

Cortex Features​