Using Hyperspectral Near-Infrared Spectroscopy And Diffuse Correlation Spectroscopy To Monitor The Effects Of Phenylephrine In The Microcirculation, Laura Mawdsley

Electronic Thesis and Dissertation Repository

The microcirculation is the site of oxygen exchange in the body, and little work has been done to determine if different microvascular beds respond similarly to a simultaneous vascular challenge. A hybrid microvascular monitoring device was developed that uses hyperspectral near-infrared spectroscopy and diffuse correlation spectroscopy to simultaneously monitor the brain and skeletal muscle. Experiments were conducted on Sprague Dawley rats (n=6, 156g±6.4g) to discern the effect that phenylephrine (0.1 mL bolus, 10 mg/kg) has on the mean arterial pressure (MAP), hemoglobin concentration, and blood flow in each microvasculature. Hemoglobin concentration increased by 2.1±0.2 mmol in the brain, and decreased …

Hybrid Optical System For Studying The Dynamic Regulation Of Blood Flow/Metabolism In The Adult Brain, Marwan Shahid

Electronic Thesis and Dissertation Repository

Cerebral blood flow (CBF) and oxygen delivery are tightly controlled to meet neuronal energy demands; however, studying dynamic neurovascular coupling in the human brain is challenging due to the lack of methods that can measure rapid changes in CBF and tissue oxygenation. This report presents an in-house-developed hybrid time-resolved near-infrared spectroscopy/diffuse correlation spectroscopy (TR-NIRS/DCS) device and its use to track dynamic CBF and tissue oxygen saturation (StO₂) responses simultaneously with sub-second resolution following a vasodilatory stimulus (i.e., a hypercapnic challenge).

Cerebrovascular reactivity (CVR) experiments were performed on 10 healthy participants (mean age: 27 years) using a computer-controlled gas …