Monitoring brain neurochemistry after brain trauma

Abstract

This thesis investigates the development and implementation of advanced mid-infrared spectroscopic sensors and attenuated total reflection (ATR) fibre optic probes for real-time monitoring of cerebral metabolites in traumatic brain injury (TBI) patients. Through a series of in-vitro and in-vivo studies, this research addresses the critical need for enhanced sensitivity and specificity in brain metabolite monitoring. The integration of these sensors with existing clinical practices promises to aid neurocritical care by through near real-time metabolic data, thereby facilitating timely and effective clinical interventions.

Study I (Chapter 4) confirmed that the EC-QCL MIR sensor can monitor changes in glucose concentrations in–vitro.

Study II (Chapter 5) demonstrated the practical application of integrating the QCL-MIR sensor with microdialysis techniques for continuous monitoring of brain metabolites in a clinical setting, affirming its operational feasibility. Study III (Chapter 6) demonstrated that the improved "second-generation" sensors could quantify pyruvate levels at clinically relevant concentrations, showing significant potential for early detection of secondary brain damage. Study IV (Chapter 7) revealed the potential for ATR fibre optic probes, particularly in the quadruple loop configuration for direct in-situ monitoring of brain metabolites. Study V (Chapter 8) validated a new brain tissue model by characterising the diffusion characteristics of gadolinium-DTPA, thereby supporting its application in subsequent neuro-pharmacokinetic research involving human subjects.

This research advances the field by expanding the capabilities of existing technologies for monitoring cerebral metabolites, providing innovative solutions that address enduring challenges in the treatment and management of TBI.