MATLAB Answers

Processing EMG data in MATLAB?

157 views (last 30 days)
Tom Nickolay
Tom Nickolay on 25 Feb 2020
Edited: Aquatris on 25 Feb 2020
Hi all,
I am VERY new to MATLAB, so please excuse my ignorance if this is a very novice problem. I am analysing EMG signals, I have imported from my data from xlsx as time (X) and voltage (y).
After extracting data;
set(0, 'defaultFigureToolbar', 'none')
T1_10rm_BS_1 = xlsread('T1_70%_10rm_BS_1.xlsx','Sheet3','A5:E77494');
time = T1_10rm_BS_1(:,1);
BS_RF_1 = T1_10rm_BS_1(:,4);
BS_BF_1 = T1_10rm_BS_1(:,5);
T1_10rm_BS_2 = xlsread('T1_70%_10rm_BS_2.xlsx', 'Sheet4','A5:E78394');
time = T1_10rm_BS_2(:,1);
BS_RF_2 = T1_10rm_BS_2(:,4);
BS_BF_2 = T1_10rm_BS_2(:,5);
running filters;
% Lowpass filter 500Hz
Freq = 1500;
NyqFreq = Freq/2;
Lowpass = 500;
Wn = Lowpass/NyqFreq;
[B,A] = butter (4,Wn,'low');
% run filter
BS_RF_1_low_filtered = filtfilt(B,A,BS_RF_1);
BS_BF_1_low_filtered = filtfilt(B,A,BS_BF_1);
BS_RF_2_low_filtered = filtfilt(B,A,BS_RF_2);
BS_BF_2_low_filtered = filtfilt(B,A,BS_BF_2);
% Highpass filter 10Hz
Highpass = 10;
Wo = Highpass/NyqFreq;
[D,C] = butter (4,Wo,'high');
% run filter
high_pass_BS_RF_1_filtdata = filtfilt(D,C,BS_RF_1_low_filtered);
high_pass_BS_BF_1_filtdata = filtfilt(D,C,BS_BF_1_low_filtered);
high_pass_BS_RF_2_filtdata = filtfilt(D,C,BS_RF_2_low_filtered);
high_pass_BS_BF_2_filtdata = filtfilt(D,C,BS_BF_2_low_filtered);
% Full wave rectification of EMG
filtered_BS_RF_1 = abs(high_pass_BS_RF_1_filtdata);
filtered_BS_BF_1 = abs(high_pass_BS_BF_1_filtdata);
filtered_BS_RF_2 = abs(high_pass_BS_RF_2_filtdata);
filtered_BS_BF_2 = abs(high_pass_BS_BF_2_filtdata);
% Linear envelope (2Hz lowpass)
LP = 2;
Wp = LP/NyqFreq;
[F,E] = butter (4,Wp,'low');
linear_BS_RF_1 = filtfilt(F,E,filtered_BS_RF_1);
linear_BS_BF_1 = filtfilt(F,E,filtered_BS_BF_1);
linear_BS_RF_2 = filtfilt(F,E,filtered_BS_RF_2);
linear_BS_BF_2 = filtfilt(F,E,filtered_BS_BF_2);
and generating my plot (for BS_RF_1);
I am now struggling to try and find the area under the curve for my set of 10 repetitions.
I am looking to define mean activation and peak activation.
All constructive help welcome,


Sign in to comment.

Accepted Answer

Aquatris on 25 Feb 2020
Edited: Aquatris on 25 Feb 2020
I think you are looking for the function cumtrapz, here is the link.


Sign in to comment.

More Answers (0)




Community Treasure Hunt

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

Start Hunting!