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HeartRateVariability

This node calculates heart rate variability (HRV) from the detected R peaks in QRS complexes.

The input to this node should be the output of the RDetection node, or a packet having a marker stream named -peaks with events corresponding to the R peaks and having an instance axis where the times array holds the timestamps of those peaks. The calculated HRV statistics are based on the event markers contained within a sliding window of the defined length. The following 8 time-domain heart variability measures or statistics are calculated: - RRI (ms): R peak-to-peak interval. - SDNN (ms): the standard deviation of peak intervals - RMSSD (ms): root mean square of successive peak interval differences - SDSD (ms): standard deviation of successive peak interval differences - NN50 (#): the number of pairs of adjacent peak intervals that differ more than 50 ms - pNN50 (%): the percentage of adjacent peal interval differences that differ from each other more than 50 ms - NN20 (#): the number of pairs of adjacent peak intervals that differ more than 20 ms - pNN20 (%), the percentage of adjacent peak interval differences that differ from each other more than 20 ms. The output of this node is a new stream having the same name as the input stream except that peaks is replaced by hrv (i.e., eeg-hrv), containing a feature axis with 8 elements named as shown above. More Info... Version 1.2.0

Ports/Properties

data

Data to process.

  • verbose name: Data
  • default value: None
  • port type: DataPort
  • value type: Packet (can be None)
  • data direction: INOUT

window_length

Sliding window length (beats or seconds). A history of events spanning this duration (or this many events) will be used to calculate heart rate variability statistics.

  • verbose name: Processing Sliding Window Length
  • default value: 300
  • port type: FloatPort
  • value type: float (can be None)

window_length_unit

Unit in which the window length is given.

  • verbose name: Window Length Unit
  • default value: seconds
  • port type: EnumPort
  • value type: str (can be None)

wait_full_buffer

Wait for the full sliding window buffer to be filled before calculating and outputting HRV statistics.

  • verbose name: Wait For Full Buffer
  • default value: False
  • port type: BoolPort
  • value type: bool (can be None)

override_axes

Replace the incoming instance axis with a time axis, add a feature axis with a single element named HRV. If False, a feature axis will not be added, and instead a field will be added to the incoming instance axis.

  • verbose name: Override Axes
  • default value: True
  • port type: BoolPort
  • value type: bool (can be None)

window_shift

  • verbose name: Window Shift
  • default value: 0
  • port type: FloatPort
  • value type: float (can be None)

set_breakpoint

Set a breakpoint on this node. If this is enabled, your debugger (if one is attached) will trigger a breakpoint.

  • verbose name: Set Breakpoint (Debug Only)
  • default value: False
  • port type: BoolPort
  • value type: bool (can be None)

metadata

User-definable meta-data associated with the node. Usually reserved for technical purposes.

  • verbose name: Metadata
  • default value: {}
  • port type: DictPort
  • value type: dict (can be None)