Effect of catheter motion on ultrasound M-mode images and corresponding velocity profiles: Development and validation of a simulation model

Effect of catheter motion on ultrasound M-mode images and corresponding velocity profiles: Development and validation of a simulation model

De Lat, B.

Dankelman, J. (mentor)
Tuijthof, G.J.M. (mentor)

Mechanical, Maritime and Materials Engineering

BioMechanical Engineering

BME

2014-04-29

Background: An ablation catheter with integrated high-frequency single element ultrasound transducers has been developed by Philips Research, which makes it possible to assess tissue-depth and lesion formation in real-time. The interpretation of the acquired ultrasound M-mode images is difficult due to a combination of cardiac motion and motion of the catheter itself. Objective The aim of this study is to develop and validate a simulation model that includes catheter and tissue motion and use this as a tool to gain insights in the effects of catheter motion on M-mode images and corresponding velocity profiles. Method A 2D simulation model, of a moving catheter with three integrated ultrasound transducers that observe contracting tissue, was developed. Comparison of simulated data with real ultrasound data was performed, among other tests, to validate the 2D simulation model. Validation criteria were based on predefined requirements. The validated simulation model was used to generate seventeen different output datasets varying with the frequency and amplitude of the cardiac \& catheter motion input signals. These datasets were used to analyse the effect of catheter motion on M-mode images and corresponding velocity profiles. Results The validation tests imply that the simulated data can serve as reliable replacements for real ultrasound data. Findings from the analysis of the simulated data suggest that cardiac velocity is underestimated when the catheter angle deviates from its perpendicular state in relation to the tissue and is overestimated when the catheter angle moves back to its perpendicular state. Moreover, when catheter motion dominates over cardiac motion the cardiac velocity may be estimated in the opposite direction as the actual direction of cardiac motion. Conclusion The validation tests insinuate that the simulation model meets the predefined requirements. The simulation increases understanding of the relation between catheter \& cardiac motion in M-mode images. The information that can be derived from an M-mode image can be used to estimate if catheter motion is dominating over cardiac motion. Furthermore, the findings obtained within this study can be used to evaluate if the estimated direction of the velocity of cardiac motion is correct and if the cardiac velocity is under- or overestimated.

catheter ablation
ultrasound
catheter motion
M-mode interpretation
velocity profile

http://resolver.tudelft.nl/uuid:8d3b32c2-3658-4e0d-96ee-99d81e622505

2015-04-29

Student theses

master thesis

(c) 2014 De Lat, B.