基于小波变换的方法识别ECG信号的中的PT波程序

function [QQ,SS,RR,T,P,pup,pdown,tdown,xd]=locationP_QRS_T(signal) % -------------- 信号降噪去毛刺 wname='sym6';lev=5; [c,l]=wavedec(signal,lev,wname); sigma=wnoisest(c,l,1); alpha=2; thr=wbmpen(c,l,sigma,alpha); keepapp=1; xd=wdencmp('gbl',c,l,wname,lev,thr,'s',keepapp); % figure(1) % subplot(211);plot(signal);xlabel('原始信号 '); % hold on % subplot(212);plot(xd);xlabel('去除毛刺信号 '); %-------------------- x1=xd; L=length(x1); [c,l]=wavedec(x1,8,'db6'); d8=wrcoef('d',c,l,'db6',8); d7=wrcoef('d',c,l,'db6',7); d6=wrcoef('d',c,l,'db6',6); d5=wrcoef('d',c,l,'db6',5); d4=wrcoef('d',c,l,'db6',4); d3=wrcoef('d',c,l,'db6',3); d2=wrcoef('d',c,l,'db6',2); d1=wrcoef('d',c,l,'db6',1); y=d1+d2+d3+d4; % figure() % subplot(211);plot(xd);xlabel('去除毛刺信号 '); % hold on % subplot(212);plot(y);xlabel('重构信号 '); y1=zeros(1,L); for i=1:L if y(i)>=0 y1(i)=y(i); end end may=max(y1);%不考虑不正常的幅值太大的R峰，以免干扰阈值的选取 for i=1:200 n=find(y1>may); if size(n,2)>20 break else may=may*0.9; end end for i=1:L if y1(i)>=may y1(i)=may; end end % Th=may*0.4; y_std=std(y1); y_mean=mean(y1); if y_std>0.1 Th=y_std*3+y_mean; dianshu=50; else Th=y_std*3.3+y_mean; dianshu=70; end t=Th*ones(1,L); % figure % subplot(2,1,1); % plot(y1); % subplot(2,1,2) % plot(y1); % hold on % plot(t,'m','linewidth',3); % xlabel('(b)The location signal') % legend('the location signal','threshold') k=1; i=10; while(i<L-26) if y1(i)>Th m=0; r=1; for n=0:25 if m<y1(i+n) m=y1(i+n); r=i+n; end end if r~=1 R(k)=r; k=k+1; i=i+dianshu; else i=i+1; end else i=i+1; end end b=length(R); %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% inter=diff(R);%当r间隔小于90时，认为是噪声引起的，把此时的R波描点去掉 for i=1:b-1 if inter(i)<90 for j=i+1:b-3 if inter(j)>90&&inter(j+1)>90&&inter(j+2)>90 break end end if i-2>0 for g=i:j R(g)=0; end else R(1)=0;R(2)=0; end end end k=1; for i=1:b if R(i)~=0; R1(k)=R(i); k=k+1; end end rb=length(R1); % subplot(3,1,3); % plot(x1); % for i=1:rb % xx=R1(i); % hold on % plot(xx,x1(xx),'m.','Markersize',20); % end %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %检测Q，S波 %用拐点来检测 k1=1; for i=1:rb if i==1 scal=2; else scal=R1(i)-40; end flag=1; for j=R1(i)-5:-1:scal if x1(j)<=x1(j-1)&&x1(j)<=x1(j+1) flag=0; end if flag==0 break; end end Q(k1)=j; k1=k1+1; end b1=length(Q); for i=1:b1 xx=Q(i); hold on plot(xx,x1(xx),'r.','Markersize',20); end k2=1; for i=1:rb scal=R1(i)+40; flag=1; for j=R1(i)+1:scal if x1(j)<=x1(j-1)&&x1(j)<=x1(j+1) flag=0; end if flag==0 break; end end S(k2)=j; k2=k2+1; end b2=length(S); for i=1:b2 xx=S(i); hold on plot(xx,x1(xx),'g.','Markersize',20); end title('(c)The location of QRS') %检测P波 k3=1; for i=1:b1 n=Q(i);cc=-100; for kk=1:40 if n-kk==0 n1=kk-1; break else n1=40; end end p=1; for j=n-5:-1:n-n1 if cc<x1(j); cc=x1(j); p=j; end end if p~=1 P(k3)=p; k3=k3+1; end end b3=length(P); k4=1; for i=1:b2 n=S(i);cc=-100; for kk=1:55 if n+kk==L n1=kk; break else n1=55; end end t=1; for j=n+10:n+n1 if cc<x1(j); cc=x1(j); t=j; end end if t~=1 T(k4)=t; k4=k4+1; end end b4=length(T); for i=1:b4 xx=T(i); hold on plot(xx,x1(xx),'m.','Markersize',20); end %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %截取数据前后端 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% for kk=1:15 if P(1)-kk==0 nn=kk-1; break else nn=15; end end n1=P(1)-nn; n2=P(b3)-10; j=1; for i=n1:n2 x2(j)=x1(i); j=j+1; end LL=length(x2); k=1; for i=1:rb if R1(i)-n1+1>0 RR(k)=R1(i)-n1+1; k=k+1; end end r=length(RR); if RR(r)>LL R2=RR(1:r-2); end clear RR RR=R2; aa=length(RR); subplot(2,1,2) plot(x2); for i=1:aa xx=RR(i); hold on plot(xx,x2(xx),'m.','Markersize',20); end %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %重新定位Q，S，P波 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% k=1; for i=1:b1 if Q(i)-n1+1>0 QQ(k)=Q(i)-n1+1; k=k+1; end end q=length(QQ); if QQ(q)>LL Q2=QQ(1:q-2); end clear QQ QQ=Q2; aa1=length(QQ); for i=1:aa1 xx=QQ(i); hold on plot(xx,x2(xx),'y.','Markersize',20); end k=1; for i=1:b2 if S(i)-n1+1>0 SS(k)=S(i)-n1+1; k=k+1; end end s=length(SS); if SS(s)>LL S2=SS(1:s-2); end clear SS; SS=S2; aa2=length(SS); for i=1:aa2 xx=SS(i); hold on plot(xx,x2(xx),'r.','Markersize',20); end k=1; for i=1:b3 if P(i)-n1+1>0 PP(k)=P(i)-n1+1; k=k+1; end end p=length(PP); if PP(p)>LL P2=PP(1:p-2); end clear PP PP=P2; aa3=length(PP); for i=1:aa3 xx=PP(i); hold on plot(xx,x2(xx),'g.','Markersize',20); end k=1; for i=1:b4 if T(i)-n1+1>0 TT(k)=T(i)-n1+1; k=k+1; end end t=length(TT); if TT(t)>LL TT=TT(1:t-1); end aa4=length(TT); for i=1:aa4 xx=TT(i); hold on plot(xx,x2(xx),'b.','Markersize',20); end %平滑去噪 note=zeros(1,LL); for i=1:aa for j=QQ(i):SS(i)+10 note(j)=1; end end for kk=1:3 for i=2:LL-1 if note(i)~=1 x2(i)=(x2(i+1)+x2(i-1))/2; end end end %%%%%%%%%%%%%%检测T波 k4=1; for i=1:aa for i=1:aa xx=SS(i); hold on plot(xx,x2(xx),'r.'); end n=SS(i);cc=-100; for kk=1:55 if n+kk==LL n1=kk; break else n1=55; end end t=1; for j=n+20:n+n1 if cc<x2(j); cc=x2(j); t=j; end end if t~=1 T(k4)=t; k4=k4+1; end end yyy=length(T); if T(yyy)==LL QQ clear P end %检测P波 k3=1; for i=1:aa n=QQ(i);cc=-100; for kk=1:25 if n-kk==0 n1=kk-1; break else n1=25; end end p=1; for j=n-5:-1:n-n1 if cc<x2(j); cc=x2(j); p=j; end end P(k3)=p; k3=k3+1; end yyy=length(T); clear R1 if T(yyy)==LL S1=SS(1:yyy-1) Q1=QQ(1:yyy-1); R1=RR(1:yyy-1); P1=P(1:yyy-1); T1=T(1:yyy-1); clear SS QQ RR P T SS=S1; QQ=Q1; RR=R1; P=P1; T=T1; end figure() plot(x2) for i=1:aa-1 xx=P(i); hold on plot(xx,x2(xx),'y.','Markersize',15); end pause %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %检验T波的下降沿 k5=1; for i=1:length(T) n=T(i);cc=10; for kk=0:40 if n+kk==LL n1=kk; break else n1=40; end end t=1; for j=n+5:n+n1 if cc>x2(j); cc=x2(j); t=j; end end if t~=1 tdown(k5)=t; k5=k5+1; end end %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %检验P波的上升沿和下降沿 %上升沿 k=1; for i=1:length(T) if i==1