Oscillometric model

Table of Contents

Arterial pulse, SBD and DBP Arterial pulse over time Cuff pressure

This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details <https://www.gnu.org/licenses/>.

This code was developed by Miodrag Bolic for the book PERVASIVE CARDIAC AND RESPIRATORY MONITORING DEVICES: https://github.com/Health-Devices/CARDIAC-RESPIRATORY-MONITORING

% Changing the path from main_folder to a particular chapter
main_path=fileparts(which('Main_Content.mlx'));
if ~isempty(main_path)
    %addpath(append(main_path,'/Chapter2'))
    cd (append(main_path,'Chapter5/Blood_pressure_signals'))
    addpath(append(main_path,'/Service'))
end
SAVE_FLAG=0; % saving the figures in a file

Arterial pulse, SBD and DBP

Column 1: ECG

Column 2: Arterial blood pressure

Column 3: Cuff pressure with the oscillometric signal

Sampling rate: 250 samples per seconds

Patient conditions: cardiomiopathy

load('BP_data_250Hz.mat')
fs=250;
L=fs*3;
t=1/fs:1/fs:L/fs;
figure
axes('Layer', 'top')
hold on;
[m_sbp,i_sbp]=findpeaks(data(1:L,2),'MinPeakProminence',6,'MinPeakDistance',fs/2 );
[m_dbp_dic,i_dbp_dic]=findpeaks(-data(1:L,2),'MinPeakProminence',0.1,'MinPeakDistance',fs/5 );
hold on, area(t(i_dbp_dic(1):i_dbp_dic(2)),data(i_dbp_dic(1):i_dbp_dic(2),2),'FaceColor','y', "EdgeColor","none")
area(t(i_dbp_dic(3):i_dbp_dic(4)),data(i_dbp_dic(3):i_dbp_dic(4),2),'FaceColor','y',"EdgeColor","none")
area(t(i_dbp_dic(5):i_dbp_dic(6)),data(i_dbp_dic(5):i_dbp_dic(6),2),'FaceColor','y',"EdgeColor","none")
area(t(i_dbp_dic(2):i_dbp_dic(3)),data(i_dbp_dic(2):i_dbp_dic(3),2),'FaceColor','g',"EdgeColor","none")
area(t(i_dbp_dic(4):i_dbp_dic(5)),data(i_dbp_dic(4):i_dbp_dic(5),2),'FaceColor','g',"EdgeColor","none")
area(t(i_dbp_dic(6):L),data(i_dbp_dic(6):L,2),'FaceColor','g',"EdgeColor","none")
ylim([72,135])
plot(t,data(1:L,2))
%plot(t,70*ones(1,length(t)),'k')
xlabel('Time (s)')
ylabel('Arterial blood pressure (mmHg)')
ylim([70,135])
mean(data(1:L,2))
ans = 94.0233

Arterial pulse over time

t=1/fs:1/fs:length(data)/fs;

figure

[m,i]=findpeaks(data(:,2),'MinPeakProminence',6,'MinPeakDistance',fs/2 );

plot(t,data(:,2))

hold on, plot(t(i),m,'o')

[m,i]=findpeaks(-data(:,2),'MinPeakProminence',6,'MinPeakDistance',fs/2 );

hold on, plot(t(i),-m,'*')

xlabel('Time (s)')

ylabel('Arterial blood pressure (mmHg)')

title('Arterial blood pressure with labeled SBP and DBP')

annonation_save('',"Fig5.3.jpg", SAVE_FLAG);

mean(data(:,2))

ans = 99.7460

Cuff pressure

figure

time_int=[10 16; 32 38; 42 48]; % intervals for systolic, MAP and diastolic BP

t=1/fs:1/fs:length(data)/fs;

subplot (2,3,[1,3])

plot(t(1:60*fs),data(1:60*fs,3))

hold on

plot(t(time_int(1,1)*fs:time_int(1,2)*fs),136*ones(1,6*fs+1),'r')

plot(t(time_int(2,1)*fs:time_int(2,2)*fs),110*ones(1,6*fs+1),'k')

plot(t(time_int(3,1)*fs:time_int(3,2)*fs),90*ones(1,6*fs+1),'m')

legend('Cuff pressure', 'Systolic region', 'MAP region','Diastolic region')

xlabel('Time (s)')

ylabel('Pressure (mmHg)')

title('Total pressure')

subplot (2,3,4)

plot(t(time_int(1,1)*fs:time_int(1,2)*fs),data(time_int(1,1)*fs:time_int(1,2)*fs,3),'r')

xlabel('Time (s)')

ylabel('Pressure (mmHg)')

title('Systolic region')

subplot (2,3,5)

plot(t(time_int(2,1)*fs:time_int(2,2)*fs),data(time_int(2,1)*fs:time_int(2,2)*fs,3),'k')

xlabel('Time (s)')

ylabel('Pressure (mmHg)')

title('MAP region')

subplot (2,3,6)

plot(t(time_int(3,1)*fs:time_int(3,2)*fs),data(time_int(3,1)*fs:time_int(3,2)*fs,3),'m')

xlabel('Time (s)')

ylabel('Pressure (mmHg)')

title('Diastolic region')

exportgraphics(gcf,"Fig5.4.jpg", 'Resolution',600)

%Figure 6.17

% plotting=1

% figure

% subplot 311

% if plotting ==1

% %plot(t,P) % and another way is manual integration

% xlabel("Time (s)"), ylabel("Pressure (mmHg)"), title('Arterial pressure')

% xlim([0,20])

% ylim([70,160])

% grid minor

% end

% subplot 312

% if plotting ==1

% %plot(t,omw)

% xlabel("Time (s)"), ylabel("Pressure (mmHg)")

% xlim([0,20])

% title('Total pressure')

% ylim([70,160])

% grid minor

% end

% if plotting ==1

% subplot 313

% %plot(t(peak_ind), omwe)

% xlabel("Time (s)"), ylabel("Pressure (mmHg)")

% xlim([0,20])

% ylim([-5,5])

% title('Oscillometric waveform')

% grid minor

% end

% exportgraphics(gcf,"Fig5.17.jpg", 'Resolution',600)