%function ecg_time;
n=[
    78 -39.5 -70.7 -17 -16.5 -16.5 ...
    -15.0 -15.0 -14.5 -10.0 -3.5 1 -3.5 ...
    -12 -16 -17 -18 -18 -18 -18 ...
    -18 -18 -18 -18 -16.5 -4 9 ...
    19 6.5 -11.0 -17.0 -17 -18 -23 ...
    -18.3 49 ];
Ts=0.004;
Fs=1/Ts;
m=50;
nm=reshape(n'*ones(1,m),1,m*length(n));
nm=nm/(2*max(nm));
ct=Ts:Ts:Ts*length(nm);
subplot(211);
plot(ct,nm);
grid off;
box off;
%xlabel('時間軸t/s');
%ylabel('電壓值V/mV');
%title('心電信號的時域表示');
axis([0 0.5 -0.6 0.6]);
text(0.02,0.52,'心電信號的峰峰值一般為1mV左右');