Kyle Cowdrick, MSE

BME PhD Defense Presentation

Date: 2023-04-24
Time: 10:00 AM EST – 11:00AM EST
Location / Meeting Link: Location: Conference Room 302; Emory Children's Center, 2015 Uppergate Dr NE, Atlanta, Georgia 30322 Hybrid Meeting Link: Register in advance for this meeting: https://emory.zoom.us/meeting/register/tJYtc-iprDwjHNyuDPG1kyru1pHXWIJvXG4n After registering, you will receive a confirmation email containing information about joining the meeting.

Committee Members:
Dr. Erin M Buckley PhD (Advisor, Dept. of Biomedical Engineering, Georgia Tech/Emory); Dr. Susan Margulies PhD (Directorate for Engineering, National Science Foundation); Dr. Shella Keilholz PhD (Dept. of Biomedical Engineering, Georgia Tech/Emory); Dr. Deqiang Qiu PhD (Dept. of Radiology, Emory School of Medicine); Dr. Jocelyn Grunwell, MD, PhD (Dept. of Pediatrics, Childrens Healthcare of Atlanta)


Title: Exploring the Translational Clinical Value of Cerebrovascular Reactivity Assessments by Diffuse Correlation Spectroscopy

Abstract:
Cerebrovascular reactivity (CVR), i.e., the ability of cerebral vasculature to dilate or constrict in response to vasoactive stimuli, is a biomarker of vascular health. The available literature suggests CVR quantification may benefit clinical care and consequently, CVR quantification is considered an unmet clinical need. However, the value of addressing this unmet need is not clear. Acknowledging limited investigations exploring the clinical value proposition of bedside CVR assessments, there is a clear gap in existing research seeking to validate new medical technologies that can feasibly quantify CVR in a bedside clinical setting, to identify an underserved patient population that would benefit from such assessments, and to demonstrate that new solutions are able to detect clinically meaningful differences in CVR. This thesis focuses on enhancing the clinical value proposition of CVR assessments by exploring novel experimental approaches to quantify CVR and investigating CVR assessments in a previously unexplored pediatric patient population using an emerging optical neuromonitoring technology termed Diffuse Correlation Spectroscopy (DCS). DCS is an emerging low-cost, noninvasive, and portable optical tool that utilizes near-infrared light to assess cerebral hemodynamics (i.e., cerebral blood flow, cerebrovascular reactivity) at the microvascular length scale. Numerous investigations have explored the potential of DCS as a clinical tool to monitor hemodynamic function in response to disease states or interventions that may adversely disrupt hemodynamic function. To successfully achieve translation of this promising neuromonitoring capability from research concept to routine clinical reality, a convincing value proposition must be established demonstrating the ability of DCS neuromonitoring to detect signs of cerebrovascular dysfunction and provide compelling data showing if on-demand CVR was available to physicians, actionable, timely, and appropriate therapeutic interventions could occur to reverse a CVR abnormality that is itself a determinant of clinical outcome. The overall goal of this work is to explore and enhance the clinical value proposition DCS-mediated CVR assessments in pediatric patients. This work has two primary aims. In Aim #1, I hypothesize that CVR assessed with DCS using more tolerable experimental protocols will agree well with the gold standard hypercapnia challenge. In Aim #2, I hypothesize that children with SCD experience markedly reduced CVR when compared to healthy children in response to a breath hold challenge. The ultimate outcome of this work lends support to the clinical value of DCS-measured CVR assessed in a routine outpatient clinical workflow for a pediatric population with sickle cell disease.