Brain-computer interface (BCI) technologies allow users to control external devices through brain activity alone, circumventing the somatic nervous system and the need for overt physical movement. BCIs may potentially benefit individuals with severe neuromuscular disorders who experience significant, and often total, loss of voluntary muscle control (e.g. amyotrophic lateral sclerosis, multiple sclerosis, brainstem stroke). Though a majority of BCI research to date has focused on electroencephalography (EEG) for brain signal acquisition, recently researchers have noted the potential of an optical imaging technology called near-infrared spectroscopy (NIRS) for BCI applications. This thesis investigates the feasibility of a practical, online optical BCI based on conscious modulation of prefrontal cortex activity through the performance of different cognitive tasks, specifically mental arithmetic (MA) and mental singing (MS). The thesis comprises five studies, each representing a step toward the realization of a practical optical BCI. The first study demonstrates the feasibility of a two-choice synchronized optical BCI based on intentional control states corresponding to MA and MS. The second study explores a more user-friendly alternative - a two-choice system-paced BCI supporting a single intentional control state (either MA or MS) and a natural baseline, or "no-control (NC)", state. The third study investigates the feasibility of a three-choice system-paced BCI supporting both MA and MS, as well as the NC state. The fourth study examines the consistency with which the relevant mental states can be differentiated over multiple sessions. The first four studies involve healthy adult participants; in the final study, the feasibility of optical BCI use by a user with Duchenne muscular dystrophy is explored. In the first study, MA and MS were classified with an average accuracy of 77.2% (n=10), while in the second, MA and MS were differentiated individually from the NC state with average accuracies of 71.2% and 62.7%, respectively (n=7). In the third study, an average accuracy of 62.5% was obtained for the MA vs. MS vs. NC problem (n=4). The fourth study demonstrated that the ability to classify mental states (specifically MA vs. NC) remains consistent across multiple sessions (p=0.67), but that there is intersession variability in the spatiotemporal characteristics that best discriminate the states. In the final study, a two-session average accuracy of 71.1% was achieved in the MA vs. NC classification problem for the participant with Duchenne muscular dystrophy.

Introduction: Currently, there are no objective techniques to assess burn depth. An early assessment of burn depth would enable accurate management decisions, which would improve patient outcomes. Near infrared (NIR) technology has shown promise as a non-invasive monitor of oxygenation and perfusion, and its potential to assess the depth of burn injuries has been investigated clinically over the past five years. The purpose of the thesis was to determine the capacity of NIR technology to differentiate acute thermal injuries. Methods: Burn sites (n=5) and control sites (n=5) were created on the dorsum of sixteen animals with brass rods held at constant pressure and heated to 100°C and 37.5°C respectively. NIR data was collected from the burns and control sites pre-burn, immediately post-burn, and 1, 12, 24, 36, 48 and 96 hours after the burn injury. Biopsies of the burn and control sites were acquired at each time point and used to confirm the depth of injury. NIR data was processed for the content of water, oxy-, deoxy- and methemoglobin. Results: Oxyhemoglobin and total hemoglobin decreased as burn depth increased. The proportion of oxy- and deoxyhemoglobin to total hemoglobin showed that the ratio of oxy- to deoxyhemoglobin decreased as burn injury increased. Methemoglobin levels as a ratio of total hemoglobin also showed that as the severity of injury increased the proportion of methemoglobin also increased. Finally, superficial partial thickness injuries (3 s and 12 s) showed early peak levels of water, which rapidly declined towards baseline. The deep partial thickness injuries (20 s and 30 s) do not experience peak levels and retain water over the course of the experiment. The full thickness injuries water levels remain close or below baseline levels throughout the experiment. Conclusion: NIR spectroscopy could distinguish burn depth using water, oxy-, met- and total hemoglobin as separate entities. The presence of methemoglobin in the burn wounds is a novel finding that has not been described previously in burn literature.

Thesis (M.Sc. (Hons.)) -- University of Western Sydney, 2001. / "A thesis submitted in partial fulfilment of the requirements for the degree of Master of Science (Honours), University of Western Sydney, Hawkesbury" Bibliography : leaves 60-66.

Thesis (M.S.)--Oregon State University, 2009. / Printout. Includes bibliographical references (leaves 58-62). Also available on the World Wide Web.

Thesis(M.S.)--Auburn University, 2006. / Abstract. Vita. Includes bibliographic references (p.93-94).

Thesis (M.S.)--Ohio University, November, 2004. / Includes bibliographical references (p. 115-117)

Thesis (M.S.)--Marquette University, 2009. / Jon D. Koch, John P. Borg, James M. Lightstone, Advisors.

Thesis (M.S.)--Ohio University, November, 2004. / Title from PDF t.p. Includes bibliographical references (p. 115-117)

Thesis (Ph.D.)--York University, 2005. Graduate Programme in Physics and Astronomy. / Typescript. Includes bibliographical references (leaves 218-233). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://wwwlib.umi.com/cr/yorku/fullcit?pNR11637

Thesis (M.S.)--University of Texas at Dallas, 2008. / Includes vita. Includes bibliographical references (leaves 63-65)