How to Calculate Heart Rate from Ecg Matlab

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ECG to Heart Rate Calculator (MATLAB Helper) .ecg-calc-wrapper { font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif; max-width: 800px; margin: 20px auto; padding: 20px; background-color: #f9fbfd; border: 1px solid #e1e4e8; border-radius: 8px; color: #333; } .ecg-calc-header { text-align: center; margin-bottom: 30px; border-bottom: 2px solid #0073aa; padding-bottom: 10px; } .ecg-calc-row { display: flex; flex-wrap: wrap; gap: 20px; margin-bottom: 20px; } .ecg-input-group { flex: 1 1 300px; display: flex; flex-direction: column; } .ecg-input-group label { font-weight: 600; margin-bottom: 8px; color: #2c3e50; } .ecg-input-group input { padding: 12px; border: 1px solid #ccc; border-radius: 4px; font-size: 16px; } .ecg-input-group .help-text { font-size: 12px; color: #666; margin-top: 5px; } .ecg-btn { background-color: #0073aa; color: white; border: none; padding: 15px 30px; font-size: 18px; font-weight: bold; border-radius: 4px; cursor: pointer; width: 100%; transition: background-color 0.3s; } .ecg-btn:hover { background-color: #005177; } .ecg-results { margin-top: 30px; background-color: #fff; padding: 20px; border-radius: 6px; box-shadow: 0 2px 8px rgba(0,0,0,0.05); display: none; } .result-item { display: flex; justify-content: space-between; align-items: center; padding: 10px 0; border-bottom: 1px solid #eee; } .result-item:last-child { border-bottom: none; } .result-value { font-size: 24px; font-weight: 700; color: #0073aa; } .matlab-code-block { background-color: #2d2d2d; color: #f8f8f2; padding: 15px; border-radius: 5px; overflow-x: auto; font-family: 'Courier New', Courier, monospace; margin: 20px 0; font-size: 14px; line-height: 1.5; } .article-section h3 { color: #0073aa; margin-top: 25px; } .article-section p { line-height: 1.6; margin-bottom: 15px; }

ECG Signal to Heart Rate Calculator

Verify your MATLAB calculations by converting Sampling Frequency and R-R intervals into BPM.

The number of samples per second (Hz) defined in your MATLAB variable.
The number of data points between two consecutive R-peaks.
Calculated Heart Rate: 0 BPM
R-R Interval (Time): 0.00 s
Nyquist Frequency: 0 Hz

How to Calculate Heart Rate from ECG in MATLAB

Calculating heart rate from an Electrocardiogram (ECG) signal in MATLAB involves detecting the prominent R-peaks in the QRS complex and measuring the time difference between them. The calculator above helps you verify your manual calculations or debug your code logic.

The Logic Behind the Calculation

Heart rate is essentially the reciprocal of the R-R interval. In a digital signal processing context within MATLAB, you are dealing with discrete samples rather than continuous time. To convert the sample distance to beats per minute (BPM), you apply the following formula:

1. Convert Samples to Seconds:
Time (s) = Number of Samples / Sampling Frequency (Fs)

2. Convert Time to BPM:
BPM = 60 / Time (s)

Combining these, the direct formula used in the calculator above is:
BPM = (60 * Fs) / RR_samples

MATLAB Implementation Guide

To implement this programmatically, you typically use the findpeaks function to locate the R-waves. Here is a standard snippet of MATLAB code to calculate heart rate from a raw ECG vector:

% Load your data % ecg_signal = load('ecg_data.mat'); % Fs = 360; % Sampling frequency in Hz % 1. Detect R-peaks % MinPeakHeight helps filter out smaller P and T waves [pks, locs] = findpeaks(ecg_signal, 'MinPeakHeight', 1.0); % 2. Calculate distances between peaks (in samples) rr_intervals_samples = diff(locs); % 3. Calculate average heart rate avg_rr_samples = mean(rr_intervals_samples); heart_rate_bpm = (60 * Fs) / avg_rr_samples; fprintf('Heart Rate: %.2f BPM\n', heart_rate_bpm);

Troubleshooting Common Errors

  • Noisy Signal: If your calculated BPM is extremely high (e.g., >200), your findpeaks threshold might be too low, detecting T-waves as R-peaks. Use a high-pass filter or increase 'MinPeakHeight'.
  • Drifting Baseline: Ensure you remove the baseline wander (low-frequency noise) before peak detection to ensure accurate R-peak amplitude measurement.
  • Variable Heart Rate: In cases of arrhythmia, calculating the mean R-R interval might obscure variability. It is often better to calculate the "Instantaneous Heart Rate" for every interval.
function calculateBPM() { var fs = document.getElementById("samplingFreq").value; var rr = document.getElementById("rrSamples").value; var resultBox = document.getElementById("resultContainer"); // Input validation if (fs === "" || rr === "" || fs <= 0 || rr <= 0) { alert("Please enter valid positive numbers for Sampling Frequency and R-R Interval."); return; } // Parse values var fsVal = parseFloat(fs); var rrVal = parseFloat(rr); // Core Calculations // Formula: BPM = 60 / (Samples / Fs) var timeInSeconds = rrVal / fsVal; var bpm = 60 / timeInSeconds; var nyquist = fsVal / 2; // Update DOM document.getElementById("resultBPM").innerHTML = bpm.toFixed(2) + " BPM"; document.getElementById("resultTime").innerHTML = timeInSeconds.toFixed(4) + " s"; document.getElementById("resultNyquist").innerHTML = nyquist.toFixed(0) + " Hz"; // Show results resultBox.style.display = "block"; }

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