how to improve detrending?

1 次查看（过去 30 天）
Explorer
Explorer 2016-2-19
评论： Sibi Ramachandran 2019-2-13
Code:
d=load('CU_Ventricular_Tacharrhythmia\cu01m.mat');
noisyECG_withTrend=d.val(1,:);
subplot(2,1,1), plot(noisyECG_withTrend), grid on,
nnoisyECG_withTrend = noisyECG_withTrend';
t = 1:length(noisyECG_withTrend);
[p,s,mu] = polyfit((1:numel(noisyECG_withTrend))',nnoisyECG_withTrend,6)
f_y = polyval(p,(1:numel(noisyECG_withTrend))',[],mu);
ECG_data = nnoisyECG_withTrend - f_y; % Detrend data
subplot(2,1,2), plot(t,ECG_data); grid on
%ax = axis;
%axis([ax(1:2) -1.2 1.2])
title('Detrended ECG Signal')
xlabel('Samples'); ylabel('Voltage(mV)')
legend('Detrended ECG Signal')
Code Source: http://www.mathworks.com/help/signal/examples/peak-analysis.html
  1 个评论
Explorer
Explorer 2016-2-19
编辑：Explorer 2016-2-19
Basically, I am trying to remove baseline error so that I can extract features like R to R delay and other intervals.

请先登录，再进行评论。

请先登录，再回答此问题。

采纳的回答

Star Strider
Star Strider 2016-2-19
See if this filter does what you want (assuming Fs=256):
Fs = 256;
Fn = Fs/2;
Wp = [1 90]/Fn;
Ws = Wp.*[0.5 1.25];
Rp = 1;
Rs = 20;
[n,Wn] = buttord(Wp,Ws,Rp,Rs);
[b,a] = butter(n,Wn);
[sos,g] = tf2sos(b,a);
figure(1)
freqz(sos, 2048, Fs);
  5 个评论
显示 3更早的评论
Star Strider
Star Strider 2018-10-16
@Evenor —
My code uses functions from the Signal Processing Toolbox. You need to have it installed in order to run my code. You should be able to run it in R2014a.
Sibi Ramachandran
Sibi Ramachandran 2019-2-13
@Star Strider Good morning sir I saw your comments and it helped me to understand the use of these filters. I recently posted a question and I was wondering if you would be able to help me also? Thank you so much!

请先登录，再进行评论。

更多回答（0 个）

类别

在 Help Center 和 File Exchange 中查找有关 Multirate Signal Processing 的更多信息

标签

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by