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.

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:

(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.
Open the export_pwdb.m script in Matlab ® on the host operating system.
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:

Extracting pulse wave parameters

Several parameters are derived from each of the pressure and PPG pulse waves in the database. This is performed in two stages. Firstly, fiducial points are identified on each pulse wave (such as the systolic peak and dicrotic notch). Secondly, features are measured from the positions of the fiducial points (such as the pulse pressure measured between the peak and foot of the pressure wave).

In addition, pulse wave velocities are calculated along several arterial paths.

Extracting haemodynamic parameters

A range of haemodynamic parameters are derived from the commonly measured pulse waves (such as the brachial pressure wave, which is commonly used for assessing blood pressure).

Part of the wider Pulse Wave Database Project