qrs波群定位matlab代码

以下是使用Pan-Tompkins算法进行QRS波群定位的MATLAB代码示例：

% 读取心电图数据
ecg_data = load('ecg_data.mat');
signal = ecg_data.val;

% 滤波处理
fs = 1000; % 采样频率
fc = [5 15]; % 截止频率
[b, a] = butter(2, fc/(fs/2));
signal_filt = filtfilt(b, a, signal);

% 计算差分和平方
diff_signal = diff(signal_filt);
diff_signal_sq = diff_signal.^2;

% 滑动窗口处理
win_size = round(0.12*fs); % 窗口大小
win = ones(win_size, 1)/win_size;
delay = win_size/2; % 延迟
signal_conv = conv(diff_signal_sq, win, 'same');
signal_delay = [zeros(delay, 1); signal_conv(delay+1:end)];
signal_delay_sq = signal_delay.^2;

% 计算峰值
[~, locs_R] = findpeaks(signal_delay_sq, 'MinPeakHeight', max(signal_delay_sq)/3);

% 计算QRS波群位置
locs_QRS = zeros(size(locs_R));
for i = 1:length(locs_R)
    [~, locs_QRS(i)] = max(signal(locs_R(i)-floor(0.1*fs):locs_R(i)+floor(0.15*fs)).^2);
    locs_QRS(i) = locs_QRS(i) + locs_R(i) - floor(0.1*fs) - 1;
end

% 绘制QRS波群位置
figure;
plot(signal);
hold on;
plot(locs_QRS, signal(locs_QRS), 'r*');
xlabel('Sample');
ylabel('Amplitude');
legend('ECG signal', 'QRS complexes');

需要注意的是，该算法仅适用于单导联的心电图数据，并且需要根据实际数据进行参数调整，例如截止频率、窗口大小等。建议结合相关文献和实验数据进行调试和优化。