Philosophiae Doctor - PhD (Physiotherapy) / The interaction between impairment and environmental factors impose a certain degree of incapacity on individuals, often undermining their freedom to function. Despite the fact that this disablement may require support services to forestall loss of function, little research has been conducted in Africa and the Sub-Saharan region, more specifically in Kenya, to explore persons with disabilities support services needs and utilization. There is also a paucity of information on predictors of PWDs' use of existing support services. In addition, Kenya lacks a disability policy.

Research within the field of human motion assistive device development, with the purpose of reducing the metabolic cost of daily activities, is seeing the benefits of the exclusive use of passive actuators to store and release energy during the gait cycle. Designs of novel exoskeletons at the University of Ottawa implement the Pneumatic Artificial Muscle (PAM) as the primary method of nonlinear, passive actuation. The PAM is proven as a superior actuator for these devices when compared to the linear mechanical springs used by other researchers. There are, however, challenges regarding PAM pressure loss and the limitation of PAM elongation that have been identified. This thesis aims to develop a hyperelastic tubular soft composite that replicates the distinctive mechanical behaviour of the PAM without the need for internal pressurization. The final soft composite solution was achieved by impregnating a prefabricated polyethylene terephthalate braided sleeve, held at a high initial fibre angle, with a silicone prepolymer. A comprehensive experimental evaluation was performed on numerous prototypes for a variety of customizable design parameters including: initial fibre angle, silicone stiffness, and braided sleeve style. Moreover, two separate analytical models were formulated based on incompressible finite elasticity theory using either a structural model of Holzapfel’s type, or a phenomenological model of Fung’s type. Both models were in good agreement with the experimental data that were collected through a modified extension-inflation test. This research has successfully developed, tested, and validated an innovative soft composite that can achieve specific mechanical properties, such as contraction distance and nonlinear stiffness, for optimal use in human motion assistive devices.

The objective of this study was to investigate the performance of 3 brain-computer interface (BCI) paradigms in an amyotrophic lateral sclerosis (ALS) population (n = 11). Using a repeated-measures design, participants completed 3 BCI conditions: row/column (RCW), checkerboard (CBW), and gray-to-color (CBC). Based on previous studies, it is hypothesized that the CBC and CBW conditions will result in higher accuracy, information transfer rate, waveform amplitude, and user preference over the RCW condition. An offline dynamic stopping simulation will also increase information transfer rate. Higher mean accuracy was observed in the CBC condition (89.7%), followed by the CBW (84.3%) condition, and lowest in the RCW condition (78.7%); however, these differences did not reach statistical significance (P =.062). Eight of the eleven participants preferred the CBC and the remaining three preferred the CBW conditions. The offline dynamic stopping simulation significantly increased information transfer rate (P =.005) and decreased accuracy (P <.000). The findings of this study suggest that color stimuli provide a modest improvement in performance and that participants prefer color stimuli over monochromatic stimuli. Given these findings, BCI paradigms that use color stimuli should be considered for individuals who have ALS.

Objective Current Brain-Computer Interface (BCI) systems typically flash an array of items from grey to white (GW). The objective of this study was to evaluate BCI performance using uniquely colored stimuli. Methods In addition to the GW stimuli, the current study tested two types of color stimuli (grey to color [GC] and color intensification [CI]). The main hypotheses were that in a checkboard paradigm, unique color stimuli will: (1) increase BCI performance over the standard GW paradigm; (2) elicit larger event-related potentials (ERPs); and, (3) improve offline performance with an electrode selection algorithm (i.e., Jumpwise). Results Online results (n = 36) showed that GC provides higher accuracy and information transfer rate than the CI and GW conditions. Waveform analysis showed that GC produced higher amplitude ERPs than CI and GW. Information transfer rate was improved by the Jumpwise-selected channel locations in all conditions. Conclusions Unique color stimuli (GC) improved BCI performance and enhanced ERPs. Jumpwise-selected electrode locations improved offline performance. Significance These results show that in a checkerboard paradigm, unique color stimuli increase BCI performance, are preferred by participants, and are important to the design of end-user applications; thus, could lead to an increase in end-user performance and acceptance of BCI technology.

A brain-computer interface (BCI) speller provides non-muscular communication via detection of EEG features. In a non-disabled population, a Checkerboard (CB) stimulus presentation has been shown to improve BCI performance over the standard Row/Column (RC) paradigm. Another improvement is a gray-to-color (CL) paradigm that presents perceptually-salient targets defined by nine unique colors. The current study examines the RC, CB, and CL paradigms in an amyotrophic lateral sclerosis (ALS) population (N = 7). Pilot data suggest improved performance of CB and CL over RC. The results suggest matrices including CB and CL provide more efficient communication and higher user satisfaction in an ALS population.

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Mobility is essential to healthy aging and is closely related to health and overall quality of life. Mobility impairment is an early predictor of disability, and is intimately linked to falling injuries, loss of independence, hospitalization, and mortality. Mobility Assistive Devices (MADs), such as canes, walkers, and wheelchairs, provide support to older adults to improve their balance, coordination, and strength. Despite the acknowledged benefits of MADs for the older adult population research shows that as many as 75% of older adults are non-adherent to prescribed MADs. As non-adherence is a contributing factor to declines in mobility and overall quality of life, it is important to consider the reasoning behind it. Therefore, this doctoral project took a psychosocial perspective and investigated the psychosocial factors that predict non-adherence to MADs among older adults. This study considered a sample of older adult MADs users from long-term care units at the Perley Health Centre in Ottawa with different types of mobility limitations. The study examined the role of psychosocial variables using the Psychosocial Impact of Assistive Devices Scale (PIADS), social support using the Medical Outcomes Study Social Support Survey (MOS-SS), and the demographic variable of sex in the prediction of MADs non-adherence. Predictor variables that were associated with non-adherence in a univariate regression analysis were subsequently entered into a multiple regression analysis. Of the 96 residents invited to participate in the study, 49 gave their consent to participate, and out of this number, 48 completed the study, for a response rate of 51%. The data from the 48 residents (26 females and 22 males), with a mean age of 86.8 (Standard Deviation (SD) = 10.2, age range= 66 - 101), were therefore available for analysis. The most common reported mobility limitations were due to balance problems and leg weakness (29.17% for each). The most common device used was a walker (47.92%), followed by a manual wheelchair (33.33%). No statistical difference was detected between the groups of sexes regarding any of the study variables (P≥0.05). In the univariate regression analysis, the three PIADS subscales, namely, Competence, Adaptability, and Self-esteem, were significantly correlated with non-adherence (p < 0.001). Sex was an insignificant variable, while social support was significantly correlated with Competence, Adaptability, Self-esteem, and non-adherence. In the multiple regression analyses, only Self-esteem showed significant associations (p < 0.05), and the Self-esteem multivariate model explained 43.5 - 54.3% of the variance in non-adherence. This study revealed that the Self-esteem construct, which includes several concepts related to psychological wellbeing, was the only significant predictor of non-adherence among the studied sample of older adults. The theoretical and clinical implications of the findings are subsequently discussed.

O uso de dispositivos assistivos tem sido um importante tema de interesse para pesquisas, em especial por se relacionar com a prevalência de limitações na capacidade funcional, bem como com a fragilidade em idosos. Esses dispositivos podem melhorar a autonomia, reduzir limitações funcionais, melhorar a qualidade de vida, promover melhor adaptação ao meio onde o idoso está inserido e prevenir ou reduzir níveis de fragilidade. Idosos mais velhos (80 anos e mais), residentes no domicílio, podem se beneficiar com o uso de dispositivos assistivos para se manter independentes pelo maior tempo possível. Assim, o objetivo geral deste estudo foi identificar o uso de dispositivos assistivos e sua relação com a capacidade funcional e com a fragilidade em idosos mais velhos residentes no domicílio. Trata-se de um estudo quantitativo do tipo observacional e transversal, realizado com 114 idosos com 80 anos e mais, residentes no município de Ribeirão Preto-SP. O processo de amostragem foi probabilístico, por conglomerados e de duplo estágio. Na coleta de dados, foram feitas entrevistas no domicílio, utilizando um roteiro estruturado de caracterização, Miniexame do Estado Mental, Índice de Katz, Escala de Lawton e Brody, roteiro de problemas de saúde autorreferidos, Escala de Fragilidade de Edmonton e um instrumento elaborado e validado para investigar o uso de dispositivos assistivos. Os dados foram analisados por meio do programa estatístico SAS®9.0, no qual foram gerados análises descritivas e os testes de associação entre as variáveis do estudo. O projeto foi aprovado pelo Comitê de Ética em Pesquisa da Escola de Enfermagem de Ribeirão Preto-USP. Quanto aos resultados, a maioria dos idosos era mulher (69.30%), viúva (57.89%), aposentada (63.16%) e fazia atividade doméstica (61.40%). A idade média foi 85.49 anos e 22.81% dos idosos viviam sozinhos. Os principais problemas de saúde que interferiam no cotidiano foram os problemas de coluna (24.56%) e artrite (18.42%). Ainda da análise descritiva, 79.82% não apresentaram déficit cognitivo, 50% eram independentes nas seis funções das atividades básicas da vida diária (ABVDs), 71.93% tinham dependência parcial nas atividades instrumentais da vida diária (AIVDs), 29.82% não apresentavam fragilidade, 25.44% eram aparentemente vulneráveis e 75.44% faziam uso de, pelo menos, um dispositivo assistivo. Os dispositivos mais usados foram: óculos (45.61%), barras (21.93%) e bengalas (15.79%), sendo que os idosos que mais usavam eram as mulheres (53.51%), na faixa etária de 80 a 89 anos (61.4%), que não tinham companheiro (55.26%) e que residiam com familiares (30.70%). No entanto, nos testes de associação, foram encontradas significâncias estatísticas entre o uso de dispositivos (cadeira de rodas, bengala, andador e óculos) e as ABVDs; uso de dispositivos (cadeira de rodas, bengala e óculos) e as AIVDs; uso de dispositivos (cadeira de rodas, bengala, andador, barras de apoio) e a fragilidade. Concluindo, os dispositivos que se relacionaram com as AVDs e fragilidade foram, predominantemente, aqueles que promovem e/ou auxiliam a mobilidade. Isto sugere que idosos mais velhos domiciliados, em vários níveis funcionais e de fragilidade, utilizam e se beneficiam com os dispositivos assistivos para minimizar a dependência na locomoção e na realização das AVDs / The use of assistive devices has been a major topic of interest for research, especially because it relates with the prevalence of limitations in functional capacity, as well as frailty in the elderly. These devices can improve the autonomy, reduce functional limitations, improve quality of life, better adaptation to the elderly environment and prevent or reduce frailty levels. Resident plder elderly (80 years and over) can benefit from the use of assistive devices to stay independent as long as possible. Thus, the general aim of this study was to identify the use of assistive devices and its relation with functional capacity and frailty in resident older elderly. This is a quantitative observational cross-sectional study performed with 114 elderly aged 80 and over, living in Ribeirão Preto-SP. The sampling was probabilistic, dual- stage clustering. For data collection, interviews were made at home, using a structured script for characterization, the Mini Mental State Examination, the Katz Index, the Lawton and Brody Scale, a script for self-reported health issues, the Edmonton Fragility Scale and an instrument developed and validated to investigate the use of assistive devices. Data were analyzed using the statistical software SAS®9.0 in which the descriptive analyzes and tests of association between the study variables were generated. The project was approved by the Research Ethics Committee of Ribeirão Preto College of Nursing-USP. As for the results, the majority were women (69.30%), widow(ed) (57.89%), retired (63.16%) and performed domestic activities (61.40%). The mean age was 85.49 years, and 22.81% of the elderly lived alone. The main health issues that interfered with daily living were back issues (24.56%) and arthritis (18.42%). Also in the descriptive analysis of the elderly, 79.82% had no cognitive impairment, 50% were independent in the six functions of the basic activities of daily living (BADL), 71.93% had a partial dependence in instrumental activities of daily living (IADL), 29.82% had no frailty, 25.44% were apparently vulnerable and 75.44% used at least one assistive device. The most commonly used devices were: glasses (45.61%), bars (21.93%) and canes (15.79%), and the subjects who most frequently used these devices were women (53.51%), aged 80-89 years (61.4%) who had no partner (55.26%) and lived with family members (30.70%). However, in the tests of association, statistical significance was found between the use of devices (wheelchair, cane, walker and glasses) and BADL; the use of devices (wheelchair, cane and glasses) and IADL; use of devices (wheelchair, cane, walker, grab bars) and frailty. In conclusion, the devices that were related to the ADL and frailty were predominantly those that promote and/or assisted mobility. This suggests that resident older elderly, in various functional and frailty levels, used and benefited from the assistive devices to minimize dependence on locomotion and in the performance of ADLs

The ability to differentiate between colours varies from individual to individual. This variation is attributed to factors such as the presence of colour blindness. Colour is used to encode information in information visualizations. An example of such an encoding is categorization using colour (e.g., green for land, blue for water).<p> As a result of the variation in colour differentiation ability among individuals, many people experience difficulties when using colour-encoded information visualizations. These difficulties result from the inability to adequately differentiate between two colours, resulting in confusion, errors, frustration, and dissatisfaction.<p> If a user-specific model of colour differentiation was available, these difficulties could be predicted and corrected. Prediction and correction of these difficulties would reduce the amount of confusion, errors, frustration, and dissatisfaction experienced by users. This thesis presents a model of colour differentiation that is tuned to the abilities of a particular user. To construct this model, a series of judgement tasks are performed by the user. The data from these judgement tasks is used to calibrate a general colour differentiation model to the user. This calibrated model is used to construct a predictor. This predictor can then be used to make predictions about the user's ability to differentiate between two colours.<p> Two participant-based studies were used to evaluate this solution. The first study evaluated the basic approach used to model colour differentiation. The second study evaluated the accuracy of the predictor by comparing its performance to the performance of human participants. It was found that the predictor was as accurate as the human participants 86.3% of the time. Using such a predictor, the colour differentiation abilities of particular users can be accurately modeled.

The ability to differentiate between colours varies from individual to individual. This variation is attributed to factors such as the presence of colour blindness. Colour is used to encode information in information visualizations. An example of such an encoding is categorization using colour (e.g., green for land, blue for water).<p> As a result of the variation in colour differentiation ability among individuals, many people experience difficulties when using colour-encoded information visualizations. These difficulties result from the inability to adequately differentiate between two colours, resulting in confusion, errors, frustration, and dissatisfaction.<p> If a user-specific model of colour differentiation was available, these difficulties could be predicted and corrected. Prediction and correction of these difficulties would reduce the amount of confusion, errors, frustration, and dissatisfaction experienced by users. This thesis presents a model of colour differentiation that is tuned to the abilities of a particular user. To construct this model, a series of judgement tasks are performed by the user. The data from these judgement tasks is used to calibrate a general colour differentiation model to the user. This calibrated model is used to construct a predictor. This predictor can then be used to make predictions about the user's ability to differentiate between two colours.<p> Two participant-based studies were used to evaluate this solution. The first study evaluated the basic approach used to model colour differentiation. The second study evaluated the accuracy of the predictor by comparing its performance to the performance of human participants. It was found that the predictor was as accurate as the human participants 86.3% of the time. Using such a predictor, the colour differentiation abilities of particular users can be accurately modeled.