Pulse Pressure Amplification Case Study

Pulse Pressure Amplification Case Study

Introduction

Pulse pressure amplification (PPamp), the ratio of brachial to aortic pulse pressure, has been found to be an indicator of cardiovascular risk. It has been found to decrease with age. The aim of this case study was to investigate the determinants of the reduction in PPamp with age.

The case study is described in this article.

Reproducing this case study

Requirements

You will need the following to reproduce the case study:

• The pwdb_data_w_aorta_finger_path.mat file, which contains all of the data required for this case study. This file is available for download, and was produced when exporting the database.
• The Matlab ® script for this case study: ppamp_case_study.m
• The Matlab ® script for analysing the pulse wave database: analyse_pwdb.m
• The Matlab ® script for setting the paths for post-processing: setup_paths_for_post_processing.m
• An installation of Matlab ®

Steps

To reproduce the case study:

1. Make a directory in which to store the data and analysis, which will be known as the storage folder. For instance, you might choose: C:/Desktop/PW_studies/
2. Obtain the pwdb_data_w_aorta_finger_path.mat file by either: (i) downloading it (see links here); or (ii) generating it yourself by reproducing the database (NB: this will take a long time).
3. Store pwdb_data_w_aorta_finger_path.mat in a subdirectory of the storage folder named pwdb_#/exported_data/, where # is the number of the database. For instance, this directory might be: C:/Desktop/PW_studies/pwdb_1/exported_data/
4. (This can be skipped if already done previously) Open the setup_paths_for_post_processing.m, and adjust PATHS.storage_folder to the path of the storage folder (such as C:/Desktop/PW_studies/).
5. Open the ppamp_case_study.m script in Matlab ®.
6. Run the script, specifying the number of the PWDB to be analysed (e.g. number 1). The script can be run using a command such as:

ppamp_case_study(1);

7. The plots showing the results of the case study should be saved in C:/Desktop/PW_studies/pwdb_1/case_studies/ . The following plots are relevant to this case study: (i) PPamp_amp_aug, (ii) PPamp_p1, (iii) PPamp_p2, and (iv) PPamp.

In the article describing the results of the case study, we also presented two plots showing how the pressure pulse wave changes as it propagates from the aorta to the finger. These plots can be generated by: 8. Open the analyse_pwdb.m script in Matlab ®. 9. Run the script, specifying the number of the PWDB to be analysed (e.g. number 1). The script can be run using a command such as:

analyse_pwdb(1);

10. The plots showing these results should be saved in C:/Desktop/PW_studies/pwdb_1/analysis/figures . The following plots are relevant to this case study: (i) pw_path_fig_arm_P_young, and (ii) pw_path_fig_arm_P_elderly.