Pulse Wave Analysis

Pulse Wave Analysis

Introduction

This page describes the steps taken to analyse the simulated pulse waves. Firstly, a range of parameters are derived from each of the pressure and PPG pulse waves using a pulse wave analysis algorithm. Secondly, a range of haemodynamic parameters are derived from the pulse waves.

Requirements

You will need the following in order to analyse the simulated pulse waves:

• A collated_data file containing the PWDB data (produced in the previous step).
• The Matlab ® script for extracting the simulation data: pwdb_pwa.m
• The Matlab ® script for setting the paths for post-processing: setup_paths_for_post_processing.m
• The Matlab ® scripts analysing pulse waves: PulseAnalyse.m and TTAlgorithm
• An installation of Matlab ®

All of the Matlab ® scripts mentioned above are contained within the PWDB code.

Steps

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

1. (This can be skipped if already done when extracting simulation data) 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 pwdb_pwa.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:

pwdb_pwa(2);

The script performs the following steps:

Calculating pulse wave velocities

Pulse wave velocities are calculated along several arterial paths using TTAlgorithm.

Extracting pulse wave parameters

Several parameters are derived from each of the pressure and PPG pulse waves using PulseAnalyse. 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).

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).