How to upsample an ECG signal and its associated data?

Question

Mibang 2024-6-23

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/2131251-how-to-upsample-an-ecg-signal-and-its-associated-data

编辑： Star Strider 2024-6-24

dataUpsampling.mat

I have an ECG signal which has a sampling frequency of 250 Hz and I want to upsample it to 360 Hz.

The signal has peaks and the indexes of the peaks are also given as "peaks.mat".

The given data is described as follows:

sig.mat: ECG signal whose size is 273010X1, which has 633 peaks as specified in "peaks.mat".

peaks.mat: the sample index where the peaks occur in "sig.mat" and the size is 633X1

So, besides upsampling the signal, how to adjust the indexes of the peaks accordingly?

Thank you,

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Catalytic 2024-6-23

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/2131251-how-to-upsample-an-ecg-signal-and-its-associated-data#answer_1475986

Use interp1 to sample the signals where you want.

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

Answer 2

Star Strider 2024-6-23

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/2131251-how-to-upsample-an-ecg-signal-and-its-associated-data#answer_1475996

Use the resample function to upsample it, since this function is specifically designed for signal processing, and contains an anti-aliasing filter to prevernt spurious frequencies from appearing in the resampled signal.

6 个评论
显示 4更早的评论隐藏 4更早的评论

Star Strider 2024-6-24

在 MATLAB Online 中打开

dataUpsampleTime.mat

Your ‘peaks’ are what I would consider ‘locs’ (indices) in the usual findpeaks terminology.

It is likely not appropriate to use tthe original peak values and locations on a resampled signal. Recalculate everything on the resampled signal instead.

Illustration, with a possible solution —

LD = load('dataUpsampleTime.mat')

LD = struct with fields:

peaks: [2273x1 double] sig: [650000x1 double] tm: [650000x1 double]

peaks = LD.peaks

peaks = 2273x1

77 370 662 946 1231 1515 1809 2044 2402 2706

<mw-icon class=""></mw-icon>

sig = LD.sig;

tm = LD.tm;

Ts = mean(diff(tm))

Ts = 0.0028

% Tsd = std(diff(tm))

Fs = 1/Ts

Fs = 360.0000

[myPks,myLocs] = findpeaks(sig, 'MinPeakProminence',0.5)

myPks = 2274x1

0.8400 0.9400 0.9600 0.8600 0.8200 0.8850 0.9450 0.8750 0.8850 0.8900

<mw-icon class=""></mw-icon>

myLocs = 2274x1

78 371 664 948 1232 1516 1810 2046 2404 2707

<mw-icon class=""></mw-icon>

figure

plot(tm, sig)

hold on

plot(tm(peaks), sig(peaks), 'vr')

plot(tm(myLocs), myPks, '^g')

hold off

grid

xlim([0 25])

sig_filt = highpass(sig, 1.5, Fs, 'ImpulseResponse','iir'); % Filter Out Baseline Variation

[myPks_filt,myLocs_filt] = findpeaks(sig_filt, 'MinPeakProminence',0.5)

myPks_filt = 2275x1

1.0716 1.2052 1.2409 1.1596 1.1284 1.1793 1.2195 1.1486 1.2068 1.1880

<mw-icon class=""></mw-icon>

myLocs_filt = 2275x1

78 371 664 948 1232 1516 1810 2046 2404 2707

<mw-icon class=""></mw-icon>

figure

plot(tm, sig_filt)

hold on

plot(tm(peaks), sig_filt(peaks), 'vr')

plot(tm(myLocs_filt), myPks_filt, '^g')

hold off

grid

xlim([0 25])

I would go back and re-calculate the peak locations and peak values on the resampled signal, as I have done here. Then, use those. (Keep or remove the baseline variation. I provided an approach for tthat if you want to use it.)

.

Mibang 2024-6-24

编辑：Mibang 2024-6-24

Thank you, but your approach is not what I want.

I think I got your helpl enough. Thank you.

Star Strider 2024-6-24

编辑：Star Strider 2024-6-24

在 MATLAB Online 中打开

My pleasure!

What do you want, then?

I’m still not clear on that.

% LD = load('dataUpsampleTime.mat')

file = websave('dataUpsampleTime.mat','https://www.mathworks.com/matlabcentral/answers/uploaded_files/1721431/dataUpsampleTime.mat');

LD = load(file);

peaks = LD.peaks

peaks = 2273x1

77 370 662 946 1231 1515 1809 2044 2402 2706

<mw-icon class=""></mw-icon>

sig = LD.sig;

tm = LD.tm;

Ts = mean(diff(tm))

Ts = 0.0028

% Tsd = std(diff(tm))

Fs = 1/Ts

Fs = 360.0000

[myPks,myLocs] = findpeaks(sig, 'MinPeakProminence',0.5)

myPks = 2274x1

0.8400 0.9400 0.9600 0.8600 0.8200 0.8850 0.9450 0.8750 0.8850 0.8900

<mw-icon class=""></mw-icon>

myLocs = 2274x1

78 371 664 948 1232 1516 1810 2046 2404 2707

<mw-icon class=""></mw-icon>

figure

plot(tm, sig)

hold on

plot(tm(peaks), sig(peaks), 'vr')

plot(tm(myLocs), myPks, '^g')

hold off

grid

xlim([0 25])

sig_filt = highpass(sig, 1.5, Fs, 'ImpulseResponse','iir'); % Filter Out Baseline Variation

[myPks_filt,myLocs_filt] = findpeaks(sig_filt, 'MinPeakProminence',0.5);

figure

plot(tm, sig_filt)

hold on

plot(tm(peaks), sig_filt(peaks), 'vr')

plot(tm(myLocs_filt), myPks_filt, '^g')

hold off

grid

xlim([0 25])

[sig450,t450] = resample(sig_filt,tm,450)

sig450 = 812500x1

0.0093 0.0105 0.0107 0.0116 0.0128 0.0133 0.0134 0.0169 0.0125 0.0213

<mw-icon class=""></mw-icon>

t450 = 812500x1

0 0.0022 0.0044 0.0067 0.0089 0.0111 0.0133 0.0156 0.0178 0.0200

<mw-icon class=""></mw-icon>

format shortG

myLocs450 = resample(myLocs, 360,450)

myLocs450 = 1820x1

1.0e+00 * 84.705 441.23 809.46 1155.2 1523.7 1858.6 2219.1 2640.5 2994 3354.2

<mw-icon class=""></mw-icon>

myLocs450 = round(myLocs450)

myLocs450 = 1820x1

85 441 809 1155 1524 1859 2219 2640 2994 3354

<mw-icon class=""></mw-icon>

[MyPks450,MyLocs450] = findpeaks(sig450, 'MinPeakProminence',0.5)

MyPks450 = 2275x1

1.0691 1.2059 1.2364 1.1561 1.1356 1.1777 1.2228 1.1528 1.2006 1.184

<mw-icon class=""></mw-icon>

MyLocs450 = 2275x1

97 464 830 1185 1540 1895 2263 2557 3005 3384

<mw-icon class=""></mw-icon>

figure

plot(t450, sig450)

hold on

plot(t450(myLocs450),sig450(myLocs450), 'sr')

plot(t450(MyLocs450),sig450(MyLocs450), 'sg')

hold off

xlim([0 25])

It is simply not possible to resample the location indices as well as the signal, and have the location indices ‘make sense’ in any real way. As I mentioned earlier, find the peaks and locations of the resampled signal after resampl;ing it. Interpolating the data from the original signal to the resampled signal will simply not work. Just use findpeaks on the resampled signal and be done with it.

Notice the difference between the peak locations of the actual resampled signal and the resampled locations of the original signal. That approach just doesn’t work.

.

请先登录，再进行评论。

How to upsample an ECG signal and its associated data?

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

回答（2 个）

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

6 个评论
显示 4更早的评论隐藏 4更早的评论

另请参阅

类别

标签

Community Treasure Hunt

How to upsample an ECG signal and its associated data?

0 个评论 显示 -2更早的评论隐藏 -2更早的评论

回答（2 个）

0 个评论 显示 -2更早的评论隐藏 -2更早的评论

6 个评论 显示 4更早的评论隐藏 4更早的评论

另请参阅

类别

标签

Community Treasure Hunt

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

6 个评论
显示 4更早的评论隐藏 4更早的评论