ECG

Rådata

input_data = jonathanAktivECG.ECGLLRA;
frequency_sampled_at = 512;

plot (input_data)
axis ('tight')
grid on
xlabel('Index of sample')
ylabel('Voltage')
legend('ECG data')
title ('ECG data, unedited')

time = (1:numel(input_data))/frequency_sampled_at;

Filtrera data

lowpass_filtered_ecg = lowpass(input_data,50,frequency_sampled_at);
%plot (lowpass_filtered_ecg)
%axis ('tight')
%grid on

highpass_filtered_ecg = highpass(input_data,0.4,frequency_sampled_at);
plot (highpass_filtered_ecg)
axis ('tight')
grid on
xlabel('Index of sample')
ylabel('Voltage')
legend('ECG data highpass filtered')
title ('ECG data, with highpass filter')

 Räkna ut puls från data
% Koden nedan baseras på https://se.mathworks.com/matlabcentral/fileexchange/68246-visualization-and-analysis-of-an-electrocardiogram-signal?focused=7fbc0610-5e23-435e-a271-ddd80d1065d0&tab=example%

Alternativ 2  (fungerar)
hold off
%Andra sättet att hitta R (förprogrammerad funktion)
%Visar graf där alla peaks hittas
[peaks_2,pos_peaks_2] = findpeaks(highpass_filtered_ecg);
plot(time, highpass_filtered_ecg, 'b', pos_peaks_2/frequency_sampled_at,(peaks_2),'ro')

xlabel('Time (sec)')
ylabel('Voltage (mV)')
axis ('tight')
legend('ECG data highpass filtered', 'Peaks_2 uncut')
title ('ECG data highpass filtered, R peaks, version 2, uncut')


%Visar graf där endast önskade peaks visas, baserat på mätpunktens värde
%och distans till andra peaks
[peaks_2,pos_peaks_2] = findpeaks(highpass_filtered_ecg,'MinPeakDistance',50,'MinPeakHeight',1);
plot(time,highpass_filtered_ecg,'b',pos_peaks_2/frequency_sampled_at,(peaks_2),'ro')

xlabel('Time (sec)')
ylabel('Voltage (mV)')
axis ('tight')
legend('ECG data highpass filtered', 'Peaks_2, cut')
title ('ECG data highpass filtered, R peaks, version 2, cut')

%Results
%First graph of result (shows ECG)
subplot(211)
plot(time,highpass_filtered_ecg,'b',pos_peaks_2/frequency_sampled_at,(peaks_2),'ro')
grid on
axis tight
ylabel ('ECG','fontsize',14)
xlabel ('Time (seconds)', 'fontsize', 14)

%Second of result graphs (shows pulse)
%Jag förstår inte den här, vad händer?
subplot(212)
plot()

%pulsfrekvens f= 1/(pos för peak)*samplingsfrekvens
%standardavvikelse för hjärtfrekvensen
%Dela upp för tidsintervall
grid on
axis tight
ylabel ('Momentous Heart Rate','fontsize',14)
xlabel ('Time (seconds)','fontsize',14)

sgtitle('Results: finding R-peaks and calculating pulse', 'fontsize', 22)

%Beräkning av medelpuls
number_of_R_peaks = length(peaks_2)
time_of_first_R_peak = time(pos_peaks_2(1,1));
time_of_last_R_peak = time(pos_peaks_2(end,1));
time_between_R_peaks = time_of_last_R_peak - time_of_first_R_peak
average_pulse = 60*(number_of_R_peaks)/(time_between_R_peaks)