【心电信号ECG】基于matlab小波变换心电信号检测R波【含Matlab源码 3589期】.zip

%-------------------------------------------------------------------------- % 利用小波变换检测R波,并给出模极大曲线 %-------------------------------------------------------------------------- clear all; load M.mat ecgdata=M(:,2)'; plot(ecgdata) points=4000;%截取的点数 range=2:1:32;%尺度范围 sr=360;%抽样率 signal=ecgdata(1:points)'; figure(1),subplot(311) plot(signal),title('心电信号波形'),axis tight,grid on; % 对心电信号作小波变换，选'db1'为分析用小波 wf='db1'; subplot(312) ccfs = cwt(signal,range,wf); imagesc(ccfs); %title('Continuous Transform, coefficients.') colormap(gray(128)); %ylabel('Scale') swd=ccfs; ddw=zeros(size(swd)); % 对ECG信号进行分段 pddw=ddw; nddw=ddw; posw=swd.*(swd>0); pdw=((posw(:,1:points-1)-posw(:,2:points))<0); pddw(:,2:points-1)=((pdw(:,1:points-2)-pdw(:,2:points-1))>0); negw=swd.*(swd<0); ndw=((negw(:,1:points-1)-negw(:,2:points))>0); nddw(:,2:points-1)=((ndw(:,1:points-2)-ndw(:,2:points-1))>0); ddw=pddw|nddw; ddw(:,1)=1; ddw(:,points)=1; wpeak=ddw.*swd; wpeak(:,1)=wpeak(:,1)+1e-10; wpeak(:,points)=wpeak(:,points)+1e-10; %figure,imagesc(wpeak); sam=sum(ccfs,1); posi=sam.*(sam>0); posi=(posi>max(posi)/2); nega=sam.*(sam<0); nega=-1*(nega<min(nega)/2); interva=posi+nega; loca=find(interva); diff=interva(loca(1:length(loca)-1))-interva(loca(2:length(loca))); seg=[1,round((loca(find((diff==2)))+loca(find((diff==2))+1))/2),points];%分段的结果保存在seg中 subplot(313) figure(2), plot(interva,'r--'); hold on; plot(signal/100); hold on stem(seg,ones(length(seg))),grid on; % 分别对每一段进行R波检测 for pha=1:length(seg)-1 block=wpeak(:,[seg(pha):seg(pha+1)]); [maxvalue,maxpos]=max(block,[],2); coefposi=polyfit(range,maxpos',1); [minvalue,minpos]=min(block,[],2);% 找出模极大的位置和值 coefnega=polyfit(range,minpos',1);% 对模极大点进行直线拟合找到最大线 Rpeak(pha)=round((coefposi(2)+coefnega(2))/2+seg(pha)-1)/sr;% 每一段R波时刻存在Rpeak中 end % 绘制模极大随尺度变化的曲 figure(3) subplot(223) plot(log2(range),log2(abs(minvalue./sqrt(range'))),'b--');hold on; plot(log2(range),log2(abs(maxvalue./sqrt(range'))),'r');grid on; %xlabel('log2(s)'),ylabel('log2(maxima)'), %title('estimation of the singularity at the R peak'),, hold off; R_R=Rpeak(2:length(Rpeak))-Rpeak(1:length(Rpeak)-1); subplot(221) imagesc(ccfs(:,[seg(pha):seg(pha+1)]));colormap(gray); block=zeros(size(block)); for i=1:length(range) block(i,maxpos(i))=1; block(i,minpos(i))=-1; end subplot(222) imagesc(block);colormap(gray); subplot(224) plot(maxpos,range,'r+'),hold on,plot(minpos,range,'k*'),grid on; xr=[0, 1, range]; hold on,plot(xr*(coefnega(1))+coefnega(2),xr,'-'); hold on,plot(xr*(coefposi(1))+coefposi(2),xr,'--');