| PhD Seminar

Name of the Speaker: Jaganathan G (EE21D029)
Guide: Dr. Jayaraj Joseph
Online meeting link: https://meet.google.com/pdn-cgeo-sje
Date/Time: 30th January 2024 (Tuesday), 3:00 PM
Title: Multimodal, multi-vessel assessment for estimation of cardiac function

Abstract

Early detection and prevention of cardiovascular disease (CVD) is paramount for reducing cardiac-related fatalities. Echo-cardiography using ultrasound imaging is the gold standard for early cardiac function screening to assess ejection fraction (EF), stroke volume(SV) and cardiac output (CO), at the left ventricle. However, the need of specialised imaging equipment and trained sonologists in performing the test limits wide spread use in screening, and hence an echo test is often performed after clinical presentation of the disease such as after an angina event. Moreover, the high cost of echocardiography machines and the regulatory constraints such as the PCPNDT ACT, make such imaging systems unsuitable for wide spread screening usage. There is a need for simpler, image-free methods for reliable assessment of cardiac function.

We propose an image-free method for combined assessment of the structure and function of the common carotid artery (CCA) and the jugular vein (JV), to derive estimates of cardiac function, for an initial screening. The carotid artery serves as a gateway to assess left ventricular function, while the jugular vein, originating from the right atria, provides insight into right atrial function, and hence a combined assessment can help in assessing the systemic function of the heart using the CCA and JV as a window to the heart.

We developed a multi-modal probe for simultaneous and synchronized beat-to-beat acquisition of carotid flow velocity and diameter using Continuous Wave Doppler and A-Mode ultrasound. The prototype was developed and tested for feasibility on 25 healthy volunteers. The beat-to-beat variability in carotid diameter was determined to be less than 6%, the carotid diameter and flow velocity waveforms could be captured with a signal-to-noise ratio exceeding 20 dB. We are developing models to estimate cardiac function marker surrogates such as EF, CO and acceleration time (AT) / ejection time (ET) ratio, from the carotid artery flow, diameter, and distension waveforms. Utilizing both in-silico simulations (4374 virtual cases) and in-vivo validation (25 participants), a model was developed to estimate these markers indirectly from the carotid artery. The seminar will also discuss the association between physical activity and carotid arterial stiffness markers in 200 healthy participants (young, middle-aged, elderly), which was studied as part of ongoing research in the lab.