[PAST EVENT] Denise Erin McKaig, Physics - Final Oral Dissertation Defense [Zoom]
Zoom link: is available upon request. Please email Ellie at [[evwilk]].
Title: Quantitative Analysis of Blood Pressure Waveforms of ICU Patients that Have Experienced a Hemorrhage Event
In the intensive care unit (ICU) of a hospital, patients are monitored continuously, and data from that monitoring are used by doctors daily to understand the present state of the patient. The work of our group seeks to use these signals for predictive monitoring: using the data to predict the future state of the patient, or future clinical episodes This thesis first develops a new algorithm to extract the time between heartbeats from the electrocardiogram. Next, we develop a new method to compute cardiac output (CO -- volume of blood pumped by the heart per unit time) from peripheral blood pressure waveforms. CO is estimated using nine previously proposed algorithms applied to radial blood pressure waveforms and applied to aortic waveforms estimated using three transfer functions. Results are compared with 3966 thermodilution measurements for 440 patients. Predictions based on the various algorithms are combined using linear regression and reduced linear regression methods. These results are compared with the present “gold standard” for cardiac output, the thermodilution method. The best previously-available method gave a mean squared error (MSE) of 0.50 (L/min)2. The new MSE when all predictors are used is 0.44 (L/min)2, a 19% reduction of error. We conclude with a preliminary investigation to see whether measurements of CO can predict when transfusion will be needed.
Denise Erin McKaig was born and grew up in Virginia Beach, VA. She attended James Madison University as a Second Century Scholar. In 2013 she was inducted into the Honor Society of Phi Beta Kappa, and was awarded Outstanding Junior Physics Major. In 2014 she received the Outstanding Senior Physics Major award and graduated Magna cum laude with a B.S. dual majoring in physics and mathematics. In Fall 2014 she began her graduate career at William & Mary. With John Delos as her advisor she has been furthering research into predictive monitoring of patients in the ICU, focusing on analysis of blood pressure waveforms. In Fall 2020 she began teaching as physics faculty at Tidewater Community College. Working simultaneously at TCC and as a graduate student at W&M, she hopes to successfully defend her thesis.