A wheelchair-mounted robotic arm (WMRA) was designed and built to meet the needs of mobility-impaired persons, and to exceed the capabilities of current devices of this type. The mechanical design incorporates DC servo drive, with all actuator hardware at each individual joint, allowing reconfigurable link lengths. It has seven principal degrees of freedom and uses a side mount on a power wheelchair. A simple, scalable control system allows coordinated Cartesian control, and offers expandability for future research, such as coordinated motion with the wheelchair itself. Design payload including gripper is 6 kg, and the total arm mass with controller is 14 kg. These and other design attributes were confirmed through testing on the completed prototype.

Assistive mobile robots, such as intelligent wheelchairs, that can navigate autonomously in response to high level commands from a user can greatly benefit people with cognitive and physical disabilities by increasing their mobility. In this work, we address the problem of safe, comfortable, and customizable motion planning of such assistive mobile robots. We recognize that for an assistive robot to be acceptable to human users, its motion should be safe and comfortable. Further, different users should be able to customize the motion according to their comfort. We formalize the notion of motion comfort as a discomfort measure that can be minimized to compute comfortable trajectories, and identify several properties that a trajectory must have for the motion to be comfortable. We develop a motion planning framework for planning safe, comfortable, and customizable trajectories in small-scale space. This framework removes the limitations of existing methods for planning motion of a wheeled mobile robot moving on a plane, none of which can compute trajectories with all the properties necessary for comfort. We formulate a discomfort cost functional as a weighted sum of total travel time, time integral of squared tangential jerk, and time integral of squared normal jerk. We then define the problem of safe and comfortable motion planning as that of minimizing this discomfort such that the trajectories satisfy boundary conditions on configuration and its higher derivatives, avoid obstacles, and satisfy constraints on curvature, speed, and acceleration. This description is transformed into a precise mathematical problem statement using a general nonlinear constrained optimization approach. The main idea is to formulate a well-posed infinite-dimensional optimization problem and use a conforming finite-element discretization to transform it into a finite-dimensional problem for a numerical solution. We also outline a method by which a user may customize the motion and present some guidelines for conducting human user studies to validate or refine the discomfort measure presented in this work. Results show that our framework is capable of reliably planning trajectories that have all the properties necessary for comfort. We believe that our work is an important first step in developing autonomous assistive robots that are acceptable to human users. / text

Objective: Lifting-seat devices are designed to raise the seat height to reduce biomechanical and neuromuscular demands of a sit-to-stand (STS). The goal of this thesis was to understand how seat height and lifting-seat devices with different mechanisms affect trunk, hip, and knee biomechanics and neuromuscular activity of surrounding muscles, and determine whether the effects are altered by age. Four conditions were tested; 1) no device normal seat height (ND-normal), 2) Seat Assist™ (SA), 3) Power Seat™ (PS), 4) no device raised height (ND-raised). Using a cross-sectional design, two objectives were completed. Objective one compared ND-normal and ND-raised to determine the effects of seat height. Objective two compared ND-raised, PS, SA to determine the effects of lifting-seats. Design: 10 healthy older and 10 healthy younger adults performed five trials of each STS condition. Bilateral lower limb and trunk three-dimensional motion, ground reaction forces and electromyography (EMG) from five muscles were collected.

A brain-machine interface (BMI) uses signals from the brain to control electronic devices. One application of this technology is the control of assistive devices to facilitate movement after paralysis. Ideally, the BMI would identify an intended movement and control an assistive device to produce the desired movement. To implement such a system, it is necessary to identify different movements involving a single limb and users must be able to issue commands at any instant instead of only during specific time windows determined by the BMI itself. A novel processing technique to identify voluntary movements using only four electrodes is presented. Histograms containing the spectral components of intracranial neural signals displaying power changes correlated with movement were unique for each of three movements performed with one limb. Off-line classification of the histograms allowed the identification of the performed movement with an accuracy of 89%. This movement identification system was interfaced with a neuroprosthesis for grasping, fitted to a tetraplegic individual. The user pressed a button triggering the random selection and classification of a brain signal previously recorded intracranially from a different person while performing specific arm movements. Correct identification of the movement triggered grasping functions. Movement identification accuracy was 94% allowing successful operation of the neuroprosthesis. Finally, two BMIs for the real-time asynchronous control of two-dimensional movements were created using a single electrode. One EEG-based system was tested by a healthy participant. A second system was implemented and tested using recordings from an individual undergoing clinical intracranial electrode implantation. The users modulated their 7 Hz-13 Hz oscillatory rhythm through motor imagery. A power decrease below a threshold activated a ``brain-switch''. This switch was coupled with a novel asynchronous control strategy to control a miniature remotely-controlled vehicle as well as a computer cursor. Successful operation of the EEG system required 6 hrs of training. ECoG control was achieved after only 15 minutes. The operation of the BMI was simple enough to allow users to focus on the task at hand rather than on the actual operation of the BMI.

This study investigates the effects of intensive remediation in reading and assistive technology skills combined with the use of a computer based text to speech reader in a six-week intensive reading program for junior-age students with reading disabilities. The study reports on the strategies used by the teachers, week-by-week student progress, and the results of a criterion-referenced reading assessment. Other themes include student attitudes towards the technology and barriers to implementation. Findings indicate that a computer based text to speech reader provides significant compensatory support, resulting in improved fluency and comprehension scores. Students using technology were able to access paper and on-line text at a higher level. A model which builds on the work of Dyck and Pemberton (2002) and Edyburn (2004b, 2007) is proposed which provides a theoretical framework to assist schools in decisions about remediation or compensation for struggling readers in primary, junior, intermediate, and senior grades.

Assistive technology, specifically, word prediction software holds great promise in supporting the writing process for students with learning disabilities. This thesis reports on a qualitative study that examined eight students’ self-perceptions as learners and writers using word prediction software. Participants were purposefully recruited from a local Learning Disabilities Association’s listserv located in a mid-sized Eastern Ontario city. Three groups of two to three Grades 4-8 students previously identified with a learning disability, and who were already using word prediction software (e.g. Co-Writer or WordQ), attended a 3-hour session. This session included an instructional workshop, and completion of a short reflective writing task followed by a focus group. Separately, participants’ parents attended a focus group. Data for this study includes focus group responses (student and parent), observations from the workshop, and the written student reflections. Using content analysis, emerging themes from participant responses were analyzed. The main themes from this analysis were: (1) students’ perceptions of having an equal opportunity to participate in academic subjects; (2) increased student self-efficacy; and (3) an ad hoc approach to training and the use of assistive technology software in school. These themes were then linked to relevant literature and a set of recommendations was developed for educators. Recommendations for the future included facilitating increased self-efficacy for students with learning disabilities; reducing the ad hoc approach to teacher education by instituting mandatory courses about students with disabilities in teacher education programs; and increased instruction in the use of assistive technology for parents and teachers. / Thesis (Master, Education) -- Queen's University, 2011-06-27 22:45:11.704

The purpose of this research is twofold: 1) to apply a user-centred approach to examine the usability and acceptability of an on-body ergonomic aid called the Personal Lift Assistive Device (PLAD) in a variety of industrial work environments and 2) to utilize subjective user acceptability data on discomfort, pain and overall PLAD assessment by participants to identify design features that need improvement in the next PLAD iteration. Case studies took place in four different industrial work environments: two distribution centre environments, one retail store environment and one automotive assembly plant environment. These environments were selected to represent different industrial work environments. In total, 20 industrial workers were selected to wear the PLAD and provide their feedback. Results were obtained using subjective questionnaires through verbal and written comments as well as through direct observation of the participants. Three major design changes occurred to the original PLAD iteration tested at the first industrial location. These included: 1) using different stiffness levels of springs for different sizes of individuals in an attempt to decrease discomfort and optimize the effectiveness of the PLAD, 2) an increase in pelvic spacer size and surface area contacting the user’s body to reduce discomfort and 3) modification to the shoulder harness including; shape, dimensions and amount of cushioning to reduce discomfort. Currently, three major design changes were identified and still need to be addressed. These include: 1) reduction of thermal discomfort caused by wearing the PLAD, 2) validation of selecting the appropriate spring stiffness for small, medium and large users of the PLAD (male and female) under various working postures and 3) simplification of the donning and doffing process. Additionally, a simple PLAD spring stiffness sizing chart was created to aid potential manufacturers of the PLAD to select the appropriate spring stiffness for various users of the PLAD. This sizing chart was designed to maintain an average lumbar moment reduction of 15%, while taking discomfort of the shoulders caused by the spring stiffness and overall cost into consideration. / Thesis (Master, Kinesiology & Health Studies) -- Queen's University, 2011-09-28 09:03:01.463

This study investigates the effects of intensive remediation in reading and assistive technology skills combined with the use of a computer based text to speech reader in a six-week intensive reading program for junior-age students with reading disabilities. The study reports on the strategies used by the teachers, week-by-week student progress, and the results of a criterion-referenced reading assessment. Other themes include student attitudes towards the technology and barriers to implementation. Findings indicate that a computer based text to speech reader provides significant compensatory support, resulting in improved fluency and comprehension scores. Students using technology were able to access paper and on-line text at a higher level. A model which builds on the work of Dyck and Pemberton (2002) and Edyburn (2004b, 2007) is proposed which provides a theoretical framework to assist schools in decisions about remediation or compensation for struggling readers in primary, junior, intermediate, and senior grades.

A brain-machine interface (BMI) uses signals from the brain to control electronic devices. One application of this technology is the control of assistive devices to facilitate movement after paralysis. Ideally, the BMI would identify an intended movement and control an assistive device to produce the desired movement. To implement such a system, it is necessary to identify different movements involving a single limb and users must be able to issue commands at any instant instead of only during specific time windows determined by the BMI itself. A novel processing technique to identify voluntary movements using only four electrodes is presented. Histograms containing the spectral components of intracranial neural signals displaying power changes correlated with movement were unique for each of three movements performed with one limb. Off-line classification of the histograms allowed the identification of the performed movement with an accuracy of 89%. This movement identification system was interfaced with a neuroprosthesis for grasping, fitted to a tetraplegic individual. The user pressed a button triggering the random selection and classification of a brain signal previously recorded intracranially from a different person while performing specific arm movements. Correct identification of the movement triggered grasping functions. Movement identification accuracy was 94% allowing successful operation of the neuroprosthesis. Finally, two BMIs for the real-time asynchronous control of two-dimensional movements were created using a single electrode. One EEG-based system was tested by a healthy participant. A second system was implemented and tested using recordings from an individual undergoing clinical intracranial electrode implantation. The users modulated their 7 Hz-13 Hz oscillatory rhythm through motor imagery. A power decrease below a threshold activated a ``brain-switch''. This switch was coupled with a novel asynchronous control strategy to control a miniature remotely-controlled vehicle as well as a computer cursor. Successful operation of the EEG system required 6 hrs of training. ECoG control was achieved after only 15 minutes. The operation of the BMI was simple enough to allow users to focus on the task at hand rather than on the actual operation of the BMI.

Aim: The overall aim of this thesis was to generate further knowledge about prosthetic and orthotic services in developing countries. In particular, the thesis focused on patient mobility and satisfaction with prosthetic and orthotic devices, satisfaction with service delivery, and the views of staff regarding clinical practice and education. Methods: Questionnaires, including QUEST 2.0, were used to collect self-reported data from 83 patients in Malawi and 139 patients in Sierra Leone. In addition, 15 prosthetic/orthotic technicians in Sierra Leone and 15 prosthetists/orthotists in Pakistan were interviewed. Results: The majority of patients used their prosthetic or orthotic devices (90% in Malawi, and 86% in Sierra Leone), but half of the assistive devices in use needed repair. Approximately one third of patients reported pain when using their assistive device (40% in Malawi and 34% in Sierra Leone). Patients had difficulties, or could not walk at all, with their prosthetic and/or orthotic device in the following situations; uneven ground (41% in Malawi and 65% in Sierra Leone), up and down hills (78% in Malawi and 75% in Sierra Leone), on stairs (60% in Malawi and 66% in Sierra Leone). Patients were quite satisfied or very satisfied with their assistive device (mean 3.9 in Malawi and 3.7 in Sierra Leone out of 5) and the services provided (mean 4.4 in Malawi and 3.7 in Sierra Leone out of 5), (p<0.001), but reported many problems (418 comments made in Malawi and 886 in Sierra Leone). About half of the patients did not, or sometimes did not, have the ability to access services (71% in Malawi and 40% in Sierra Leone). In relation to mobility and service delivery, orthotic patients and patients using above-knee assistive devices in Malawi and Sierra Leone had the poorest results. In Sierra Leone, women had poorer results than men. The general condition of devices and the ability to walk on uneven ground and on stairs were associated with both satisfaction of assistive devices and service received. Professionals’ views of service delivery and related education resulted in four themes common to Sierra Leone and Pakistan: 1) Low awareness and prioritising of prosthetic and orthotic services; 2) Difficulty managing specific pathological conditions and problems with materials; 3) The need for further education and desire for professional development; 4) Desire for improvements in prosthetic and orthotic education. A further two themes were unique to Sierra Leone; 1) People with disabilities have low social status; 2) Limited access to prosthetic and orthotic services. Conclusion: High levels of satisfaction and mobility while using assistive devices were reported in Malawi and Sierra Leone, although patients experienced pain and difficulties when walking on challenging surfaces. Limitations to the effectiveness of assistive devices, poor comfort, and limited access to follow-up services and repairs were issues that needed to be addressed. Educating prosthetic and orthotic staff to a higher level was considered necessary in Sierra Leone. In Pakistan, prosthetic and orthotic education could be improved by modifying programme content, improving teachers’ knowledge, improving access to information, and addressing issues of gender equality.