Neurocardiovascular research

Brain Blood Flow Measurement in Ageing

This work led by Dr. Ciarán Finucane focuses on the measurement of cerebral perfusion with a view to understanding how changes in brain blood flow effect falls and cognitive function.

An international collaborative study initiated by Dr Ciarán Finucane, and Professor Richard Hughson from the Schlegel Research Institute for Ageing in Waterloo is currently assessing the role of cerebral hypoperfusion in falls risk in retirement villages throughout Ontario Canada. First results indicating that cerebral perfusion abnormalities are common in older adults and are often unidentified by peripheral BP measurements placing individuals at risk of falls.

Most recently in collaboration with colleagues from Falls and Syncope Unit in MISA we have introduced a novel cerebral perfusion measurement system into the clinical environment.

Novel Blood Pressure Measurement Device

Continuous beat-to-beat blood pressure measurement is critical in assessment of age related disorders such as syncope, falls, brain ageing and is critical in the assessment of fast transient changes of blood pressure. However current technologies are expensive, and require significant expertise to operate and interpret and therefore only suited to specialist centres such as MISA.

Our current focus is on developing next generation continuous blood pressure measurement technologies that are cost effective, and user friendly and therefore suitable for broader community adoption.

As part of a new MISA collaborative project between DIT (Product Design and Schools of Electronic and Electrical Engineering) and MPBE initiated in September 2016 we welcomed 2 FYP students from DIT (Karl Martin/Aysha Shah). Both students worked on separate components i.e. product design and electronic engineering perspectives of this project and were co-supervised by Dr. Colm O Kane (DIT), Dr. Ted Burke (DIT), and Dr. Ciarán Finucane (MISA).

The MPBE team in MISA also welcomed Laura Perez Denia to the team in November 2016 as part of her MSc thesis in Bioengineering at TCD under the supervision of Dr. Ciarán Finucane. Laura focussed on a novel system to assess neurocardiovascular instability in young and older adults that is cheaper and more convenient for wider clinical and community use than current technologies based on a novel dynamic oscillometric technology.

Orthostatic Hypotension as a Risk Factor for Injurious Falls in Older Adults

Our team in collaboration with Professor Rose Anne Kenny and team of researchers from TILDA have identified novel neurocardiovascular risk factors for injurious falls in older adults. After standing blood pressure drops. A slow rate of recovery of this blood pressure has been identified as a novel risk for injurious falls and has been recently described in work published in the Journal of the American Geriatric Society with colleagues from TILDA and the University of East Anglia. The importance of this work was also recognised in an accompanying editorial by Professor Lipsitz from Harvard Medical School. These biomarkers are now in regular use in the Falls and Syncope Unit at MISA to inform patient falls risk assessment.

Orthostatic Hypotension, Autonomic Dysfunction and Brain Health

Over the past 10 years collaborative work between Prof Brian Lawlor and Prof Rose Anne Kenny and a number members from the MISA Biomedical Engineering lab has examined relationships between standing blood pressure patterns, autonomic function and cognitive impairment. This work has led to identifying that increases resting heart rate is associated with lower socioeconomic status, heart rate variability is impaired in cognitive decline, and depression with common anti-depressants exaggerating this decline. In addition this work has again highlighted the importance of slow blood pressure recovery following standing and its associations with poorer cognitive function in community dwelling older adults, and a higher rates of transition to dementia.

Cardiovascular Signal Processing

A number of versions of biosignal processing and visualisation software have been developed over the past decade by a number of Biomedical Engineering Lab members. Dr. Ciarán Finucane developed the initial version of the active stand signal processing software which supported rapid analysis of data obtained by a number of clinical studies in MISA and TILDA. More recently version 2 of this software was co-developed by Dr. Chris Soraghan and Dr. Ciarán Finucane to support work in TILDA. This work built upon previous signal processing functionality to include of novel visualisation tool to assist with the analysis of active stand responses and has been was used to analyse active stand blood pressure responses in TILDA.

Active Stand Graphical User Interface

Novel Tests for Vasovagal Syncope

Both Michael Carmody and Michelle Sybring recently conducted an MSc in Biomedical Engineering. Their work focused on the design, development and testing of a novel and convenient test for vasovagal syncope in young and older adults. The developed approach combines physiological measurements made during the active stand test, multiparameter signal processing and advanced data analytics including machine learning algorithms. This work was performed in collaboration with the Falls and Blackout Unit at St. James’s hospital and TILDA and conducted under the supervision of Dr. Ciarán Finucane and Prof. Rose Anne Kenny. This work has recently been presented at a number of international conferences.

Population Normative Blood Pressure Responses to Standing

Work published by our team was a first detailing population reference data on blood pressure and heart rate responses during standing in the leading cardiovascular journal Circulation. This work has highlighted significant age and gender gradients and a broad range of response patterns across individuals. A set of clinical reference charts that can be used by clinical teams were also developed as part of this work.

Normograms – Systolic Blood Pressure (mmHg) – Changes from Supine Values: Men

Systems Physiology – Modelling the Neurocardiovascular System in Fainting and Falls

This work applies the fundamental sciences of mathematical modelling, dynamical systems and non-linear control systems theory to understand the function of neural control systems that regulate cardiovascular activity. This approach serves to inform all aspects of our research theme including hypothesis generation, data analytics and interpretation, medical device design, signal processing and experimental protocol design.

We have developed a comprehensive physiological model of the neurocardiovascular system that enables real-time simulation of blood pressure and heart rate changes during standard clinical tests.

Virtual Cardiovascular System
Simulation of Ventricular and Aortic Pressures

This model has been used:

  • To inform clinical understanding of the etiology of carotid sinus syndrome which is a significant cause of faints and falls in older adults.
  • To enable the identification of novel biomarkers related to impaired neurocardiovascular function which are now used in identifying the risk of future injurious falls in older adults and transition to dementia.
  • To design a convenient medical device for continuous blood pressure measurement in collaboration with colleagues from DIT.