序识别MIT-BIH下载的.mat文件中的R波、Q波、S波、P波、T波的MATLAB程序

以下是一个基于Pan-Tompkins算法的MATLAB程序，用于识别MIT-BIH数据库中.mat文件中的R波、Q波、S波、P波、T波：

clear all;
close all;

% 读取MIT-BIH数据库中的.mat文件
load('100m.mat');

% 读取信号数据和采样率
signal = val;
fs = 360;

% 滤波和去除基线漂移
[b,a] = butter(2, [0.5, 45]/(fs/2), 'bandpass');
signal_filt = filtfilt(b, a, signal);
signal_d = detrend(signal_filt);

% 计算QRS波形和R波位置
[qrs_amp_raw,qrs_i_raw,delay]=pan_tompkin(signal_d,fs,0);

% 计算QRS波宽度
[qrs_widths,locs]=findpeaks(qrs_amp_raw,'MinPeakHeight',0.5*max(qrs_amp_raw));
qrs_widths = qrs_widths/fs;

% 确定R波位置和QRS波宽度
R_locs = qrs_i_raw;
QRS_width = mean(qrs_widths);

% 根据R波位置确定Q波、S波、P波和T波位置
Q_locs = zeros(length(R_locs), 1);
S_locs = zeros(length(R_locs), 1);
P_locs = zeros(length(R_locs), 1);
T_locs = zeros(length(R_locs), 1);

for i = 1:length(R_locs)
    % 计算R-R间期
    if i == 1
        RR = R_locs(i+1) - R_locs(i);
    elseif i == length(R_locs)
        RR = R_locs(i) - R_locs(i-1);
    else
        RR = (R_locs(i+1) - R_locs(i-1))/2;
    end
    
    % 确定Q波位置
    Q_width = round(QRS_width/3*fs);
    if R_locs(i)-Q_width >= 1
        [Q_peak, Q_loc] = min(signal_d(R_locs(i)-Q_width:R_locs(i)));
        Q_locs(i) = R_locs(i)-Q_width+Q_loc-1;
    else
        [Q_peak, Q_loc] = min(signal_d(1:R_locs(i)));
        Q_locs(i) = Q_loc;
    end
    
    % 确定S波位置
    S_width = round(QRS_width/3*fs);
    if R_locs(i)+S_width <= length(signal_d)
        [S_peak, S_loc] = min(signal_d(R_locs(i):R_locs(i)+S_width));
        S_locs(i) = R_locs(i)+S_loc-1;
    else
        [S_peak, S_loc] = min(signal_d(R_locs(i):end));
        S_locs(i) = R_locs(i)+S_loc-1;
    end
    
    % 确定P波位置
    P_width = round(RR/2*fs);
    if R_locs(i)-P_width >= 1
        [P_peak, P_loc] = max(signal_d(R_locs(i)-P_width:R_locs(i)));
        P_locs(i) = R_locs(i)-P_width+P_loc-1;
    else
        [P_peak, P_loc] = max(signal_d(1:R_locs(i)));
        P_locs(i) = P_loc;
    end
    
    % 确定T波位置
    T_width = round(RR/2*fs);
    if R_locs(i)+T_width <= length(signal_d)
        [T_peak, T_loc] = max(signal_d(R_locs(i):R_locs(i)+T_width));
        T_locs(i) = R_locs(i)+T_loc-1;
    else
        [T_peak, T_loc] = max(signal_d(R_locs(i):end));
        T_locs(i) = R_locs(i)+T_loc-1;
    end
end

% 绘制心电图并标记各波形位置
t = (1:length(signal))/fs;
figure();
plot(t, signal);
hold on;
plot(t(R_locs), signal(R_locs), 'ro');
plot(t(Q_locs), signal(Q_locs), 'g*');
plot(t(S_locs), signal(S_locs), 'm*');
plot(t(P_locs), signal(P_locs), 'b*');
plot(t(T_locs), signal(T_locs), 'k*');
xlabel('Time (s)');
ylabel('Amplitude (mV)');
legend('ECG', 'R wave', 'Q wave', 'S wave', 'P wave', 'T wave');
title('ECG with wave annotations');

这个程序使用了Pan-Tompkins算法来检测R波位置，然后根据R波位置和QRS波形特征来确定其他波形的位置。最后，绘制心电图并在图上标记各波形的位置。需要注意的是，这个程序的结果只是一个基本的波形识别，可能需要进一步优化和改进以提高准确性。