Segmentation of electrical signal by wave specifications

Usage

segmentation(
  object,
  by = "sinus",
  pad = "before",
  pad_length = 0L,
  center = NULL
)

segment_by_sinus(object)

pad_sequence(object, pad, pad_length)

center_sequence(object, center, pad_length)

Arguments

object

Object of the egm class, which includes header, signal information, and annotation information.

by

A character string naming waveform type to segment by. Options include the following:

sinus = Will call segment_by_sinus() on egm object

pad

character String to specify which side of sequence to pad (or both). Options include c("before", "after", "both").

Default is before. If center is being used, then the this argument is ignored.

pad_length

Offers padding of the segmented beats to a maximum length, as an integer. The default is 0L, which means no padding will be applied. If pad > 0 then will add the baseline value (specified within the header of the signal) to either before or after the signal. You can also choose to center the sequence, which will also only occur if pad > 0. I.e., if pad = 500 then each segmented object will be increased TO a max length of 500. If the maximum size is larger than the padding size, then a warning will be issued and the sequence will be truncated.

center

A single Roman alphabetic letter character that utilizes the annotations given in the egm object to center the sequence. This is found under the type variable in the annotation table.

For example, if sinus waveforms were annotated as c("P", "R", "T") at their peak, then could center around R. This will only occur if pad > 0L. This is case-insensitive. The amount of padding will be determined by the pad_length argument

Value

Returns a list of egm objects. Each item is a segmentation of an egm, using the selected channels (if available). It will attempt to optimize and pick the best annotations to help create consistencies between the signal channels as possible.

Details

Requires a 12-lead ECG that has been digitized, and input as an egm object. This object must have an annotation file associated with it that contains demarcation annotations. Please see below for approaches based on the annotation type. Current, the following are supported:

sinus = supports using ecgpuwave as the annotator

Sinus beat segmentation

Identify individual sinus beats on surface ECG and extract as individual beats, returning a list of sinus beats in the form of the egm class. a consistent P, R, and T wave amongst all channels. If a channel does not have, for example, a visible T wave, it will still label it as information gained from other channels. This is based off of the algorithm from the annotation tool named ecgpuwave. Please see read_annotation() for further details.