Development of Novel and Entirely Non-Invasive High Spatial and High Temporal Resolution Cerebrovascular Monitoring/Imaging Systems

点击翻译按钮获取中文摘要

Control of blood flow to the mammalian brain is regulated by the innate ability of the cerebral blood vessels, termed cerebral autoregulation, allowing for relatively constant flow over a range of systemic arterial pressures. Both the aging process and sex influence autoregulation, with impaired delivery of blood flow and nutrients to the brain causing ongoing secondary damage. This secondary damage takes the form of either deficient blood flow, leading to starvation of brain tissue and eventual new strokes, or as excessive blood flow, leading to swelling and hemorrhage. However, prior literature on the biological influence of aging and sex on cerebral autoregulation is limited. A large contributing factor to the existing knowledge gap, lies in our limited ability to continuously assess cerebral blood vessel function in humans, and characterize its regional differences rapidly and in multiple areas simultaneously. To date, preliminary attempts to characterize cerebral autoregulation in humans and other mammals have relied on intermittent "snap shots" of blood flow, using advanced neuroimaging, or through very focal assessments using biomedical engineering signal processing of data obtained from invasive/noninvasive cerebral monitoring devices. The overarching limitation of these preliminary works, leading to the current knowledge gap, is both the intermittent nature of advanced neuroimaging studies, and the lack of ability to monitor multiple brain regions with current bedside continuous techniques. My program focuses on the development of novel imaging techniques in humans, allowing for continuous rapid assessment of cerebral autoregulation simultaneously in multiple brain areas. The short term aims of my work will employ advanced multichannel near infrared spectroscopy (NIRS) technology, married with entirely noninvasive continuous arterial blood pressure (ABP) monitoring, to derive cerebral autoregulation maps of the entire brain in humans, with high sampling rates at each point. This novel technique will be employed in healthy human populations to allow for both optimization of this technology and the characterization of regional differences in continuously assessed cerebral vessel function across the spectrum of age and sex. Such advances will facilitate bridging the current knowledge gap. Long-term, my program will continue to develop more complex new imaging platforms that are non-invasive, wearable, mobile, with high temporal/spatial resolution, for the comprehensive characterization of mammalian cerebral physiology. Such future aspects of my program will be integration of these continuous novel physiology platforms, with continuous metabolic and electrophysiologic data streams for more comprehensive cerebral physiologic measurement platforms, applied in both large animals and humans. This program will be responsible for training ~3-4 HQP per 5-year DG cycle in the NSE fields of biomedical engineering, big data and signals analysis.