Signal Processing for Ultrasound Diagnosis of Cardiac Output

Lead Research Organisation: Cardiff University
Department Name: Sch of Engineering

Abstract

EPSRC Portfolio: EPSRC Theme: Healthcare Technologies, Challenge: Optimising Treatment/ Optimising care through effective diagnosis, patient-specific prediction and evidence-based intervention, Research areas: Digital signal processing (grow)

Cardiac output is important for diagnosing shock and monitoring the patients' response to therapy at Emergency Departments, and could be measured using advanced non-invasive, stand-alone devices using Continuous Wave Doppler technology. However, despite the growing evidence that measuring cardiovascular haemodynamic parameters is directly linked to the prospects of the patients, monitoring is rarely administered as the procedure requires the involvement of highly-skilled medical professionals.

The procedure involves placing a small device in the suprasternal notch aiming directly down the longitudinal axis at the ascending aorta and across the aortic root. The device transmits continuous wave Doppler ultrasound signal, which is used to calculate the ejection velocity of the blood as it exits the aortic valve. Heart beat is also monitored. This approach, however, is often difficult in all but young and fit individuals, because of restricted and sometimes painful access to the suprasternal notch. For this reason, cardiac output via the pulmonary valve can generally be more conveniently monitored at the left parasternal edge if the device is placed directly anterior to the heart. This is a challenging procedure as it requires (i) accurate transducer and patient positioning, (ii) accurate transducer manipulation, hand movement and pressure control, (iii) abilities to recognise the appearance of the Doppler profile and optimise its characteristics, (iv) an understanding that each patient may need slight variation to the standard approach, and (v) an understanding that suboptimal appearances may occur with low flow states.

The proposed PhD project will contribute to developing a novel, low-cost, non-invasive robotic solution for fine positioning and adjustments of the ultrasound device that will enable the procedure to be administered by individuals with minimal training. This will enable timely and accurate diagnosis and repeated monitoring, therefore improving the choice and reducing the cost of any subsequent intervention, and increasing the likelihood of successful health outcomes.

The project will involve an investigation of how the method is administered in different clinical situations and variable body physique in order to gather experience and to collect required data for the robotic device. Advanced new signal processing algorithms will be developed for recognising the Doppler profile and providing feedback for automatic positioning of the ultrasound device in order to optimise its characteristics.

The positioning of the ultrasound device will be investigated in order to assess the blood flow through the pulmonary valve, and new advanced signal processing algorithms will be developed for recognising the Doppler profile and providing feedback for automatic positioning of the ultrasound device in order to optimise its characteristics. The PhD student will receive training in cross-disciplinary areas including signal processing, ultrasound and cardiac assessment and monitoring.

Publications

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Studentship Projects

Project Reference Relationship Related To Start End Student Name
EP/N509449/1 01/10/2016 30/09/2021
1804840 Studentship EP/N509449/1 01/10/2016 31/03/2020 Jack Latham
 
Title Maximum Frequency Envelope Estimation Method for Doppler Ultrasound 
Description Novel image processing method for extracting the maximum frequency envelope associated with a Doppler ultrasound measurement. The maximum frequency envelope is a useful variable associated with Doppler ultrasound measurements, it can be used to monitor a number of clinical measures, such as cardiac output. 
Type Of Material Physiological assessment or outcome measure 
Year Produced 2018 
Provided To Others? No  
Impact Easy application in research situations, robust in response to poor signal quality. 
 
Title Doppler ultrasound measurements from suprasternal notch, for variety of scan qualities 
Description Database of Doppler ultrasound measurements collected from healthy adult volunteers. 
Type Of Material Database/Collection of data 
Year Produced 2019 
Provided To Others? No  
Impact Database will allow evaluation of features for prediction of scan quality/ ideal scan location, a has potential to for new models to be designed as an outcome. Models will provide feedback with respect to scan quality and scan location. 
 
Description Open day demos 
Form Of Engagement Activity Participation in an open day or visit at my research institution
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact Presented a demo of ongoing work at open days to demonstrate potential projects future students could be involved with.
Year(s) Of Engagement Activity 2018
 
Description Research Presentation 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Postgraduate students
Results and Impact Presentation detailing my ongoing work.
Year(s) Of Engagement Activity 2019
 
Description Symposium and Poster presentations 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Postgraduate students
Results and Impact Oral and poster presentations detailing ongoing and completed work of postgraduate students and teams across universities.
Year(s) Of Engagement Activity 2017
 
Description Symposium with Poster demonstration 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Postgraduate students
Results and Impact Symposium with oral and poster presentations, to spark debate and share ideas.
Year(s) Of Engagement Activity 2018
 
Description University Conference 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Postgraduate students
Results and Impact University conference in which presentations were given detailing different research projects. Presentation competition detailing individuals works.
Year(s) Of Engagement Activity 2018