sloperange¶
Compute ECG-derived respiration (EDR) using slope range method.
Syntax¶
function varargout = sloperange(decg, rWaveTimes, fs)
Description¶
EDR = SLOPERANGE(DECG, RWAVETIMES, FS) computes an ECG-derived respiration (EDR) signal using the slope range method. This method analyzes the derivative ECG signal (DECG) around ECG R-wave occurrence times (RWAVETIMES). EDR is a column vector in the same arbitrary amplitude unit as DECG, aligned with RWAVETIMES, with NaN for beats whose analysis windows are incomplete.
[EDR, UPSLOPES, DOWNSLOPES, UPMAXPOS, DOWNMINPOS] = SLOPERANGE(...) returns four diagnostic outputs for visual inspection: - UPSLOPES - Column vector aligned with DECG. It copies DECG inside the union of complete upslope windows and is NaN elsewhere. - DOWNSLOPES - Column vector aligned with DECG. It copies DECG inside the union of complete downslope windows and is NaN elsewhere. - UPMAXPOS - Column vector aligned with RWAVETIMES containing the one-based DECG index of each selected upslope maximum, or NaN for an incomplete beat. The earliest sample is selected on ties. - DOWNMINPOS - Column vector aligned with RWAVETIMES containing the one-based DECG index of each selected downslope minimum, or NaN for an incomplete beat. The earliest sample is selected on ties. UPSLOPES and DOWNSLOPES have the same arbitrary amplitude unit as DECG; UPMAXPOS and DOWNMINPOS are positions in samples using MATLAB indexing. A beat contributes to both slope vectors only when both windows are complete.
Source¶
Example¶
% Derive respiratory signal from ECG using slope range method
load('ecg_data.mat'); % Load ECG signal and R-wave positions
decg = diff(ecg); % Calculate ECG derivative
edr = sloperange(decg, rWaveTimes, fs);
% Plot results
figure;
plot(rWaveTimes, edr);
title('ECG-derived Respiration');
xlabel('Time (s)');
ylabel('EDR Amplitude');
See also¶
- PANTOMPKINS
- BASELINEREMOVE