xiugai.m

读入mit库的心电信号

clc; clear all;
%------ SPECIFY DATA ------------------------------------------------------
PATH= 'e:\bp'; % path, where data are saved
HEADERFILE= '100.hea';      % header-file in text format
ATRFILE= '100.atr';         % attributes-file in binary format
DATAFILE='100.dat';         % data-file
SAMPLES2READ=3000;         % number of samples to be read
% in case of more than one signal:
% 2*SAMPLES2READ samples are read
%------ LOAD HEADER DATA --------------------------------------------------
fprintf(1,'\\n$> WORKING ON %s ...\n', HEADERFILE);
signalh= fullfile(PATH, HEADERFILE);
fid1=fopen(signalh,'r');
z= fgetl(fid1);
A= sscanf(z, '%*s %d %d %d',[1,3]);
nosig= A(1);  % number of signals
sfreq=A(2);   % sample rate of data
clear A;
for k=1:nosig
z= fgetl(fid1);
A= sscanf(z, '%*s %d %d %d %d %d',[1,5]);
dformat(k)= A(1);           % format; here only 212 is allowed
gain(k)= A(2);              % number of integers per mV
bitres(k)= A(3);            % bitresolution
zerovalue(k)= A(4);         % integer value of ECG zero point
firstvalue(k)= A(5);        % first integer value of signal (to test for errors)
end;
fclose(fid1);
clear A;
%------ LOAD BINARY DATA --------------------------------------------------
if dformat~= [212,212], error('this script does not apply binary formats different to 212.'); end;
signald= fullfile(PATH, DATAFILE);            % data in format 212
fid2=fopen(signald,'r');
A= fread(fid2, [3, SAMPLES2READ], 'uint8')';  % matrix with 3 rows, each 8 bits long, = 2*12bit
fclose(fid2);
M2H= bitshift(A(:,2), -4);        %字节向右移四位，即取字节的高四位
M1H= bitand(A(:,2), 15);          %取字节的低四位
PRL=bitshift(bitand(A(:,2),8),9);     % sign-bit   取出字节低四位中最高位，向右移九位
PRR=bitshift(bitand(A(:,2),128),5);   % sign-bit   取出字节高四位中最高位，向右移五位
M( : , 1)= bitshift(M1H,8)+ A(:,1)-PRL;
M( : , 2)= bitshift(M2H,8)+ A(:,3)-PRR;
if M(1,:) ~= firstvalue, error('inconsistency in the first bit values'); end;
switch nosig
case 2
M( : , 1)= (M( : , 1)- zerovalue(1))/gain(1);
M( : , 2)= (M( : , 2)- zerovalue(2))/gain(2);
TIME=(0:(SAMPLES2READ-1))/sfreq;
case 1
M( : , 1)= (M( : , 1)- zerovalue(1));
M( : , 2)= (M( : , 2)- zerovalue(1));
M=M';
M(1)=[];
sM=size(M);
sM=sM(2)+1;
M(sM)=0;
M=M';
M=M/gain(1);
TIME=(0:2*(SAMPLES2READ)-1)/sfreq;
otherwise  % this case did not appear up to now!
% here M has to be sorted!!!
disp('Sorting algorithm for more than 2 signals not programmed yet!');
end;
clear A M1H M2H PRR PRL;
fprintf(1,'\\n$> LOADING DATA FINISHED \n');
%------ LOAD ATTRIBUTES DATA ----------------------------------------------
atrd= fullfile(PATH, ATRFILE);      % attribute file with annotation data
fid3=fopen(atrd,'r');
A= fread(fid3, [2, inf], 'uint8')';
fclose(fid3);
ATRTIME=[];
ANNOT=[];
sa=size(A);
saa=sa(1);
i=1;
while i<=saa
annoth=bitshift(A(i,2),-2);
if annoth==59
ANNOT=[ANNOT;bitshift(A(i+3,2),-2)];
ATRTIME=[ATRTIME;A(i+2,1)+bitshift(A(i+2,2),8)+...
bitshift(A(i+1,1),16)+bitshift(A(i+1,2),24)];
i=i+3;
elseif annoth==60
% nothing to do!
elseif annoth==61
% nothing to do!
elseif annoth==62
% nothing to do!
elseif annoth==63
hilfe=bitshift(bitand(A(i,2),3),8)+A(i,1);
hilfe=hilfe+mod(hilfe,2);
i=i+hilfe/2;
else
ATRTIME=[ATRTIME;bitshift(bitand(A(i,2),3),8)+A(i,1)];
ANNOT=[ANNOT;bitshift(A(i,2),-2)];
end;
i=i+1;
end;
ANNOT(length(ANNOT))=[];       % last line = EOF (=0)
ATRTIME(length(ATRTIME))=[];   % last line = EOF
clear A;
ATRTIME= (cumsum(ATRTIME))/sfreq;
ind= find(ATRTIME <= TIME(end));
ATRTIMED= ATRTIME(ind);
ANNOT=round(ANNOT);
ANNOTD= ANNOT(ind);
%------ DISPLAY DATA ------------------------------------------------------
figure(1); clf, box on, hold on
plot(TIME, M(:,1),'r');
if nosig==2
plot(TIME, M(:,2),'b');
end;
for k=1:length(ATRTIMED)
text(ATRTIMED(k),0,num2str(ANNOTD(k)));
end;
xlim([TIME(1), TIME(end)]);
xlabel('Time / s'); ylabel('Voltage / mV');
string=['ECG signal ',DATAFILE];
title(string);
fprintf(1,'\\n$> DISPLAYING DATA FINISHED \n');
% -------------------------------------------------------------------------
fprintf(1,'\\n$> ALL FINISHED \n');
%------ SPECIFY DATA ------------------------------------------------------
PATH= 'e:\bp'; % path, where data are saved
HEADERFILE= '100.hea';      % header-file in text format
ATRFILE= '100.atr';         % attributes-file in binary format
DATAFILE='100.dat';         % data-file
SAMPLES2READ=3000;         % number of samples to be read
% in case of more than one signal:
% 2*SAMPLES2READ samples are read
%------ LOAD HEADER DATA --------------------------------------------------
fprintf(1,'\\n$> WORKING ON %s ...\n', HEADERFILE);
signalh= fullfile(PATH, HEADERFILE);
fid1=fopen(signalh,'r');
z= fgetl(fid1);
A= sscanf(z, '%*s %d %d %d',[1,3]);
nosig= A(1);  % number of signals
sfreq=A(2);   % sample rate of data
clear A;
for k=1:nosig
z= fgetl(fid1);
A= sscanf(z, '%*s %d %d %d %d %d',[1,5]);
dformat(k)= A(1);           % format; here only 212 is allowed
gain(k)= A(2);              % number of integers per mV
bitres(k)= A(3);            % bitresolution
zerovalue(k)= A(4);         % integer value of ECG zero point
firstvalue(k)= A(5);        % first integer value of signal (to test for errors)
end;
fclose(fid1);
clear A;
%------ LOAD BINARY DATA --------------------------------------------------
if dformat~= [212,212], error('this script does not apply binary formats different to 212.'); end;
signald= fullfile(PATH, DATAFILE);            % data in format 212
fid2=fopen(signald,'r');
A= fread(fid2, [3, SAMPLES2READ], 'uint8')';  % matrix with 3 rows, each 8 bits long, = 2*12bit
fclose(fid2);
M2H= bitshift(A(:,2), -4);        %字节向右移四位，即取字节的高四位
M1H= bitand(A(:,2), 15);          %取字节的低四位
PRL=bitshift(bitand(A(:,2),8),9);     % sign-bit   取出字节低四位中最高位，向右移九位
PRR=bitshift(bitand(A(:,2),128),5);   % sign-bit   取出字节高四位中最高位，向右移五位
M( : , 1)= bitshift(M1H,8)+ A(:,1)-PRL;
M( : , 2)= bitshift(M2H,8)+ A(:,3)-PRR;
if M(1,:) ~= firstvalue, error('inconsistency in the first bit values'); end;
switch nosig
case 2
M( : , 1)= (M( : , 1)- zerovalue(1))/gain(1);
M( : , 2)= (M( : , 2)- zerovalue(2))/gain(2);
TIME=(0:(SAMPLES2READ-1))/sfreq;
case 1
M( : , 1)= (M( : , 1)- zerovalue(1));
M( : , 2)= (M( : , 2)- zerovalue(1));
M=M';
M(1)=[];
sM=size(M);
sM=sM(2)+1;
M(sM)=0;
M=M';
M=M/gain(1);
TIME=(0:2*(SAMPLES2READ)-1)/sfreq;
otherwise  % this case did not appear up to now!
% here M has to be sorted!!!
disp('Sorting algorithm for more than 2 signals not programmed yet!');
end;
clear A M1H M2H PRR PRL;
fprintf(1,'\\n$> LOADING DATA FINISHED \n');
%------ LOAD ATTRIBUTES DATA ----------------------------------------------
atrd= fullfile(PATH, ATRFILE);      % attribute file with annotation data
fid3=fopen(atrd,'r');
A= fread(fid3, [2, inf], 'uint8')';
fclose(fid3);
ATRTIME=[];
ANNOT=[];
sa=size(A);
saa=sa(1);
i=1;
while i<=saa
annoth=bitshift(A(i,2),-2);
if annoth==59
ANNOT=[ANNOT;bitshift(A(i+3,2),-2)];
ATRTIME=[ATRTIME;A(i+2,1)+bitshift(A(i+2,2),8)+...
bitshift(A(i+1,1),16)+bitshift(A(i+1,2),24)];
i=i+3;
elseif annoth==60
% nothing to do!
elseif annoth==61
% nothing to do!
elseif annoth==62
% nothing to do!
elseif annoth==63
hilfe=bitshift(bitand(A(i,2),3),8)+A(i,1);
hilfe=hilfe+mod(hilfe,2);
i=i+hilfe/2;
else
ATRTIME=[ATRTIME;bitshift(bitand(A(i,2),3),8)+A(i,1)];
ANNOT=[ANNOT;bitshift(A(i,2),-2)];
end;
i=i+1;
end;
ANNOT(length(ANNOT))=[];       % last line = EOF (=0)
ATRTIME(length(ATRTIME))=[];   % last line = EOF
clear A;
ATRTIME= (cumsum(ATRTIME))/sfreq;
ind= find(ATRTIME <= TIME(end));
ATRTIMED= ATRTIME(ind);
ANNOT=round(ANNOT);
ANNOTD= ANNOT(ind);
%------ DISPLAY DATA ------------------------------------------------------
figure(1); clf, box on, hold on
subplot(211);plot(TIME, M(:,1),'r');
f_N=360;
%f_p=[49,300];R_p=3;f_s=[49.9,100];R_s=30;     %按要求设定参数
%Ws=f_s/(f_N/2);Wp=f_p/(f_N/2);                %计算归一化角频率
%[n,Wn]=cheb1ord(Wp,Ws,R_p,R_s); %计算阶数和截止频率
%[b,a]=cheby1(n,R_p,Wn,'stop');   %计算带阻H(z)系数
FS=360;
[n,Wn]=buttord(20/(FS/2),25/(FS/2),1,25); 
[b,a]=butter(n,Wn); 
t=0:1/360:8.3306;
y=filter(b,a,M(:,1));                %滤波后的输出信号
subplot(212);plot(t,y);

 [c,l]=wavedec(M(:,1),3,'db4');   %用db4在尺度3下分解分解

%提取近似部分与细节部分系数

 Ca3=appcoef(c,l,'db4',3);  %从c中提取第三级近似部分系数  
 
%从c中提取尺度为3、2、1时的细节系数
 Cd3=detcoef(c,l,3);       
Cd2=detcoef(c,l,2);
Cd1=detcoef(c,l,1);  
A3=wrcoef('a',c,l,'db4',3);  %重建尺度3水平下的近似部分系数
%重建尺度为1、2及3时的细节系数 
D1=wrcoef('d',c,l,'db4',1);
D2=wrcoef('d',c,l,'db4',2);
D3=wrcoef('d',c,l,'db4',3);
% 显示多尺度分解结果曲线
subplot(2,2,1);  plot(A3);  title('approximation A3');
subplot(2,2,2);  plot(D1);  title('detail D1');
subplot(2,2,3);  plot(D2);  title('detail D2');
subplot(2,2,4);  plot(D3);  title('detail D3');


for k=1:length(ATRTIMED)
text(ATRTIMED(k),0,num2str(ANNOTD(k)));
end;
xlim([TIME(1), TIME(end)]);
xlabel('Time / s'); ylabel('Voltage / mV');
string=['ECG signal ',DATAFILE];
title(string);
fprintf(1,'\\n$> DISPLAYING DATA FINISHED \n');
% -------------------------------------------------------------------------
fprintf(1,'\\n$> ALL FINISHED \n');