reference

`labkit.biosignal.measureSegments`

Measure generic template-residual segment quality.

Syntax

result = labkit.biosignal.measureSegments(segments, template)
result = labkit.biosignal.measureSegments(segments, template, opts)

Description

Measures each segment against a representative template. SignalP2P is the peak-to-peak amplitude inside the signal window. NoiseRMS is the root mean square of segment minus template inside the selected noise windows. SNRdB is 20*log10(SignalP2P/NoiseRMS), and TemplateCorrelation is the mean-centered correlation between the complete segment and template.

The function also summarizes the per-segment measurements with means and sample standard deviations. If either the segment matrix or template is empty, both returned tables and metadata are empty.

Inputs

segments: Segment structure returned by labkit.biosignal.segmentByEvents. Its values matrix must have the same number of rows as template.values.
template: Template structure returned by labkit.biosignal.buildTemplate.
opts: Optional scalar struct containing the fields listed below.

Options

signalWindowSec: Two-element interval used for SignalP2P. The default is [-0.06 0.06] seconds relative to the event. The interval must include at least one timeOffset sample.
noiseWindowsSec: N-by-2 matrix of intervals used for NoiseRMS. The default is [-0.30 -0.20; 0.40 0.50] seconds. Their union must include at least one timeOffset sample.

Outputs

result: Structure containing per-segment measurements, aggregate statistics, and the windows used in the calculation.

Output Fields

type: String scalar "biosignalSegmentMeasurements".
perSegment: Table with Segment, EventIndex, EventTime, SignalP2P, NoiseRMS, SNRdB, and TemplateCorrelation columns.
summary: One-row table with SegmentCount and the mean and standard deviation of SignalP2P, NoiseRMS, and SNRdB, plus the mean TemplateCorrelation.
metadata.signalWindowSec: Signal interval used for the calculation.
metadata.noiseWindowsSec: Noise intervals used for the calculation.

Errors

labkit:biosignal:InvalidSegments: segments lacks values or timeOffset.
labkit:biosignal:InvalidTemplate: template lacks values.

Example

segments = struct('values', [0 0; 2 1.8; 0 0], ...
'timeOffset', [-0.1; 0; 0.1], 'eventIndex', [10; 20], ...
'eventTime', [1; 2]);
template = struct('values', [0; 1.9; 0]);
opts = struct('signalWindowSec', [-0.05 0.05], ...
'noiseWindowsSec', [-0.1 -0.05; 0.05 0.1]);
result = labkit.biosignal.measureSegments(segments, template, opts);

labkit.biosignal.buildTemplate — Build a representative segment template.
labkit.biosignal.segmentByEvents — Extract fixed windows around event anchors.
labkit.biosignal.compareGroups — Summarize groups and compute pairwise Welch comparisons.
labkit.biosignal.cropSignal — Return a signal clipped to a time range in seconds.
labkit.biosignal.defaultEcgPeakOptions — Return documented defaults for ECG/QRS peak detection.
labkit.biosignal.detectEcgPeaks — Detect ECG/QRS peaks as event anchors.
labkit.biosignal.filterSignal — Apply a zero-phase FFT-domain filter to a biosignal.
labkit.biosignal.getChannel — Return one signal from a recording by display name or index.

Source

This page is generated from the MATLAB help text in +labkit/+biosignal/measureSegments.m.

labkit.biosignal.measureSegments