Exporting the Database

Introduction

This page describes the steps taken to export the pulse wave database into several different formats to allow researchers to conduct further research using the database. The formats provided are:

• CSV: Comma-Separated Value format
• WFDB: WaveForm DataBase format
• mat: Matlab ® format

Requirements

You will need the following in order to export the database:

• The files produced in the previous two steps extracting data and analysing pulse waves: collated_data.mat, haemodynamic_params.mat, and pulse_wave_params.mat.
• The Matlab ® script for exporting the database: export_pwdb.m
• The Matlab ® script for setting the paths for post-processing: setup_paths_for_post_processing.m
• An installation of Matlab ®

Steps

The process of extracting the simulation data is performed by running export_pwdb.m. To use this script:

1. (This can be skipped if already done previously) Open the setup_paths_for_post_processing.m, and adjust: (i) PATHS.shared_folder to the path of the shared folder; and (ii) PATHS.storage_folder to the path of a folder in which to store the outputs.
2. Open the export_pwdb.m script in Matlab ® on the host operating system.
3. Run the script, specifying the number of the PWDB to be analysed (e.g. number 2). The script can be run using a command such as:

export_pwdb(2);

The script performs the following steps:

Create files containing PWs

Files are created in CSV, WFDB and Matlab ® formats containing PWs at common measurement sites. These are stored in the /exported_data/PWs/ folder.

Create files containing haemodynamic parameters and pulse wave indices

The haemodynamic parameters and pulse wave indices derived from each simulation are stored in the pwdb_haemod_params.csv and pwdb_pw_indices.csv files respectively.

Create files containing the model configurations

The model configurations used to simulate the pulse waves for each virtual subject are stored in:

• pwdb_model_configs.csv: A single file containing the global parameters (such as blood density and heart rate) for each virtual subject.
• geometry: The geometry of each subject's arterial tree is stored in an individual file for each subject (within the /exported_data/geo/ folder).

Create a single Matlab file containing all the data

In addition, a single Matlab file is created which contains all the data extracted from the simulations, called pwdb_data.mat. This is designed to facilitate more advanced analyses requiring multiple pulse waves.