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.

Cardiovascular disease (CVD) continues to be the leading cause of death of Canadian women and while treatment for CVD has improved dramatically, women typically fare worse than men with regards to morbidity following cardiac event. Cardiac rehabilitation (CR) is well established as a key intervention in the treatment of coronary artery disease and has been shown to be effective in both men and women. CR remains largely underutilized, especially in women who comprise only 12 – 24% of contemporary CR programs, even though the prevalence of CVD in men and women is similar. The objectives of this pilot trial were to test the feasibility of all procedures, specifically to determine: 1) an estimate of patient recruitment rates, 2) acceptability and feasibility of the intervention and 3) barriers to CR attendance and resources required. Additionally, exploratory research questions were used to determine the effects of telephone coaching on women’s attendance at CR intake appointment, self-efficacy for cardiac exercise and self-efficacy to attend CR. A RCT design enrolled women with CVD referred for CR at a single site in Ontario. Patients were randomized, stratified for age, to either a usual care group or an intervention group. Participants allocated to usual care received a referral to CR. In addition to usual care, women assigned to the intervention group received individualized telephone coaching, designed to support self-management prior to CR intake. Eighty-three patients were approached and 70 consented to participate (usual care n = 36, intervention n = 34). Participants in the intervention group were significantly more likely to attend CR intake (p = 0.048). Participants were highly satisfied with their coaching experience; they found the information provided to be helpful with goal setting, action planning and assisted them in their interactions with their health care providers. Barriers to attendance identified included transportation, health concerns, timing and lack of physician endorsement. Most common resources identified included problem solving support, assistance with communication with physicians and information concerning CR. The evidence obtained from this pilot trial suggests that a telephone coaching intervention designed to enhance self-management is feasible and may improve attendance at CR intake for women following hospital discharge with a cardiac event.

Executive dysfunction can affect community integration in adults with traumatic brain injury (TBI). The Cognitive Orientation to daily Occupational Performance (CO-OP) approach has shown some promise in promoting functional improvements in adults with executive dysfunctions post TBI. However, access to rehabilitation is often limited especially in rural communities. This study aimed to (1) investigate the feasibility of administering the CO-OP approach in a tele-rehabilitation format and (2) examine its impact on community integration and executive dysfunction. A pilot series of 3 case studies was conducted. Participants identified 5 goals; 3 were trained and 2 were untrained to allow examination of transfer. Outcome measures included the Canadian Occupational Performance Measure, the Mayo-Portland Adaptability Inventory-4 Participation Index, and the Dysexecutive Questionnaire. Descriptive analyses demonstrated goal achievement and transfer, suggesting it is feasible to implement the CO-OP approach in a tele-rehabilitation format. Community integration and executive dysfunction behaviours also showed trends towards improvement.

Many patients do not maintain physical activity (PA) post cardiac rehabilitation (CR),however few studies examine a large enough sample over the long-term. Thus, a retrospective cross-sectional study was carried out to examine PA and its correlates 2-6 years post CR; 584 graduates completed a mailed survey (mean+SD age: 69.8+9.8 years, BMI: 27+5.0 kg/m2, 80% male, 41.4+11.6 months since graduation, 36% response rate). PA was assessed using the Physical Activity Scale for the Elderly (PASE, mean+SD: 122.3+75.9). Seventy five percent of participants met Canadian PA guidelines. Greater PA was significantly associated with male sex, younger age, fear of falling, cholesterol control, self-controlled transportation, marital status, full-time work, rural location, higher VO2max, more comorbid conditions, greater perceived health, PA enjoyment, quality of life (QOL), social support, income, and CR staff support. Age,PA enjoyment, QOL, work status, cholesterol control and CR staff were significant in a multivariate model (R2=0.22, F=18.7, p<0.001).

The purpose of this prospective cohort study was to determine the relationships between changes in coping strategies and community integration at 6 and 12 months post traumatic brain injury (TBI). Seventy-one participants were adult significant others (SOs) (family members/friends) of people with TBI. SOs, proxies for TBI patients, completed coping and community integration questionnaire to describe TBI patients’pre-injury status immediately post-injury as baseline information. Followed-up interviewed were completed at 6 and 12 months. Results showed that increased emotional preoccupation coping from baseline to 6 months were significantly associated with decreased productive activities and decreased social integration at 6 months and 12 months and modestly associated with decreased home integration at 12 months. Multivariable regressions showed that changes in emotional preoccupation coping from baseline to 6 months contributed significantly to social integration and productive activities above and beyond demographic factors and injury severity. Implications for cognitive rehabilitation are discussed.

The purpose of this thesis was to analyze factors related to labour market survival and withdrawal behaviour in the profession of Occupational Therapy in Ontario from 1997 to 2006. To provide a portrait of the OT labour market in Ontario overall, and in relation to sector and age, three types of analysis were used: descriptive statistics (including “stay, switch, and leave” analysis), “Stickiness” and “Inflow” analysis, and survival analysis. The largest proportion of OTs worked in the Hospital sector, which had a great ability to retain OTs according to the “Stickiness” analysis. However, when controlling for other variables using survival analysis, none of the sector variables had a significant effect on survival. The youngest and oldest age groups had the highest propensity of leave, due to mobility, family commitments, and retiring (oldest group only). Overall, the profession in Ontario had a strong ability to retain OTs working in the profession during the study period.

Whole-body vibration (WBV) was recently introduced as a potential modality for strengthening bones, and this thesis was set out to investigate whether it plays a role in the prevention of postmenopausal bone loss. First, effects of WBV on bone mineral density (BMD) were systematically evaluated in previous randomized controlled trials (RCTs) in postmenopausal women. Second, a RCT of 202 postmenopausal women with primary osteopenia not on bone medications was conducted to investigate the effects of WBV at 0.3g and 90 Hz versus 0.3g and 30 Hz versus controls on various bone outcomes, as measured by dual-energy x-ray absorptiometry (DXA), high-resolution peripheral quantitative computed tomography (HR-pQCT), and quantitative ultrasound (QUS). In the systematic evaluation of previous RCTs, statistically significant increase in areal BMD (aBMD) at the hip was found in postmenopausal women receiving WBV versus controls, but the effect was small and may have been due to study bias. Also, WBV was not found to influence aBMD at the lumbar spine or volumetric BMD (vBMD) at the distal tibia in the systematic evaluation. In the RCT conducted in this thesis, no statistically significant effects of WBV were found on aBMD at the femoral neck, total hip or lumbar spine, as measured by DXA, or on vBMD or bone structure parameters at the distal tibia or distal radius, as measured by HR-pQCT. Further in this RCT, a statistically significant decrease was observed in QUS attenuation at the calcaneus in women receiving 90 Hz or 30 Hz WBV compared to controls. This may have been due to heel bone or soft tissue damage, although the effect was small and may not be clinically important. In conclusion, this investigation of postmenopausal women did not find clinically relevant benefits of WBV on osteoporotic-prone skeletal sites, including the hip, spine, tibia or radius, while potentially harmful effects on heel bone and/or soft tissue was observed in response to WBV. Thus based on this thesis, WBV is currently not recommended for the prevention of bone loss in community-dwelling postmenopausal women with primary osteopenia.

Master of Science / Department of Kinesiology / Craig A. Harms / In comparison to adults and adolescents, relatively little is known about ventilatory responses of prepubescent children to exercise. Children have smaller airways relative to lung size than adults and ventilate "out of proportion" to metabolic demands of exercise which may render them more susceptible to ventilatory limitations during exercise. It is also not known if there are any sex differences in ventilatory limitations during incremental exercise in children. Therefore, the purpose of this study was to determine the prevalence of ventilatory constraints (expiratory flow limitation, EFL) during incremental exercise to exhaustion in prepubescent (Tanner stage 1) boys and girls. Forty healthy, prepubescent boys (n = 20) and girls (n = 20) with no history of asthma completed baseline pulmonary function and lung volume tests. Subjects then completed an incremental cycle VO[subscript]2max test where workload was increased 10W every 90 sec until exhaustion. RPE, dyspnea ratings, and % EFL were recorded at the end of each exercise stage. EFL was determined by placing the exercising tidal volume loop inside a post-exercise maximal flow volume envelope. Ventilatory and metabolic data were recorded on a breath by breath basis throughout exercise via a metabolic cart. Arterial oxygen saturation was determined via pulse oximetry. Body composition was determined using dual-energy x-ray absorptiometry. Following 15 minutes of recovery, subjects exercised at 105% of their VO[subscript]2max workload until exhaustion to provide confident in the VO[subscript]2max measurement. There were no differences (p>0.05) in anthropometric measures (height, weight) or body composition (lean body mass, percent body fat) measures between boys and girls. At rest, boys had significantly higher lung volumes (TLC, boys = 2.6 + 0.5 L, girls = 2.1 + 0.5 L; FRC, boys = 0.9 + 0.3 L, girls = 0.7 + 0.3 L) and maximal flows (FVC, boys = 2.2 + 0.3 L, girls = 1.9 + 0.4 L; PEF, boys = 3.6 + 0.7 L/sec, girls = 2.9 + 0.6 L/sec; FEV1, boys = 1.9 + 0.2 L/sec, girls = 1.6 + 0.3 L/sec). At maximal exercise, boys had significantly higher VO[subscript]2max (boys = 35.4 + 7.5 ml/kg/min, girls = 29.5 + 6.6 ml/kg/min; boys = 1.2 + 0.2 L/min, girls = 1.0 + 0.2 L/min), VE (boys = 49.8 + 8.8 L/min, girls = 41.2 U+U 8.3 L/min), and VCO[subscript]2 (boys = 1.2 + 0.2 L/min, girls = 0.9 + 0.2 L/min) compared to girls. There were no differences (p>0.05) in VE/VCO2 (boys = 41.1 + 3.9, girls = 43.4 + 5.5), PETCO2 (boys = 35.5 + 2.5 mmHg, girls = 35.7 + 3.2 mmHg) maximal HR (boys = 174.4 + 23.1 bpm; girls = 183.4 + 16.6 bpm), RER (boys = 1.04 + 0.05, 1.03 + 0.08), or SaO2 (boys = 96.7 + 3.4%, girls = 97.7 + 1.3%) which was maintained within 3% of baseline throughout exercise for all subjects. EFL during exercise was present in 19 of 20 boys and 18 of 20 girls. Severity of EFL at VO2max, as judged by % overlap of tidal volume with maximal flow volume envelope, was not different between genders at any time during exercise (at VO[subscript]2max: boys = 58 + 7%, girls = 43 + 8%). There was no significant association between % EFL at VO[subscript]2max and aerobic capacity or total lung volume. A significant relationship existed between % EFL at VO[subscript]2max and the change in end-expiratory lung volume from rest to maximal exercise in boys (r = 0.77) and girls (r = 0.75). In summary, our data suggests that ventilatory constraints in the form of expiratory flow limitation are highly and equally prevalent in prepubescent boys and girls from moderate to maximal exercise which likely leads to an increased work of breathing, but not to decreases in arterial oxygen saturation.

Cognitive impairment in coronary artery disease (CAD) patients can predict poorer quality of life, dementia, and increased mortality. This study aimed to determine the association between long-term cortisol elevations and cognitive function in CAD patients. Participants were recruited at the beginning of a 1 year cardiac rehabilitation program and followed forward. Composite Z-scores were computed from tests measuring memory and executive function at baseline and 1 year. Cortisol deposition (3 months) was measured from a 20 mg, 3 cm hair sample. Analyses of covariance showed less improvement in memory function (F1,50=4.721, p=0.035) but not executive function (F1,49=0.318, p=0.575) in patients dichotomized into a high cortisol group based on a previously established reference range. Prolonged cortisol elevation may be associated with cognitive changes in subjects with CAD.

Cognitive impairment in coronary artery disease (CAD) patients can predict poorer quality of life, dementia, and increased mortality. This study aimed to determine the association between long-term cortisol elevations and cognitive function in CAD patients. Participants were recruited at the beginning of a 1 year cardiac rehabilitation program and followed forward. Composite Z-scores were computed from tests measuring memory and executive function at baseline and 1 year. Cortisol deposition (3 months) was measured from a 20 mg, 3 cm hair sample. Analyses of covariance showed less improvement in memory function (F1,50=4.721, p=0.035) but not executive function (F1,49=0.318, p=0.575) in patients dichotomized into a high cortisol group based on a previously established reference range. Prolonged cortisol elevation may be associated with cognitive changes in subjects with CAD.