The Web has been a blessing for visually impaired users as with the help of assistive technologies such as screen readers, they can access previously inaccessible information independently. However, for screen reader users, web-based information seeking can still be challenging as web pages are mainly designed for visual interaction. This affects visually impaired users’ perception of theWeb as an information space as well as their experience of search interfaces. The aim of this thesis is therefore to consider visually impaired users’ information seeking behaviour, abilities and interactions via screen readers in the design of a search interface to support complex information seeking. We first conduct a review of how visually impaired users navigate the Web using screen readers. We highlight the strategies employed, the challenges encountered and the solutions to enhance web navigation through screen readers. We then investigate the information seeking behaviour of visually impaired users on the Web through an observational study and we compare this behaviour to that of sighted users to examine the impact of screen reader interaction on the information seeking process. To engage visually impaired users in the design process, we propose and evaluate a novel participatory approach based on a narrative scenario and a dialogue-led interaction to verify user requirements and to brainstorm design ideas. The development of the search interface is informed by the requirements gathered from the observational study and is supported through the inclusion of visually impaired users in the design process. We implement and evaluate the proposed search interface with novel features to support visually impaired users for complex information seeking. This thesis shows that considerations for information seeking behaviour and users’ abilities and mode of interaction contribute significantly to the design of search user interfaces to ensure that interface components are accessible as well as usable.

In an effort to improve mathematics retention and increase assessment scores, the public school district under study implemented Study Island into their Grade 9 algebra program. Study Island is a commercialized web-based program, customized to specific state standards and applied as a supplemental instructional tool. The purpose of this study was to determine the effectiveness of Study Island with general education students and to determine whether the effectiveness of replacing some traditional mathematic instruction with technology was beneficial. The theoretical foundation stemmed from Bloom's work on mastery learning, which holds that children can learn if given the proper environment and tools. The research question investigated algebra students' possible academic growth through the use of Study Island software (N = 56). A nonequivalent pretest-posttest quasi-experimental design was employed to measure student mathematics achievement between students who participated in the technology program (n = 28) and those who did not (n = 28), controlling for preexisting differences in mathematics achievement. The study occurred over a 10-week period, with 90 minutes of daily mathematics instruction. Final results were determined using pre- and postcourse mathematic assessments and by applying analysis of covariance (ANCOVA). Results suggested the use of Study Island had a statistically significant influence on increased mathematic assessment scores. These results support the use of Study Island by the local district to increase mathematics achievement for all students. Implications for positive social change include identifying the effectiveness of a technology treatment, which can contribute to improved student achievement and encourage non-traditional approaches to teaching mathematics.

The goal of this thesis is the kinematic analysis and evaluation of wheelchair mounted robotic arms. More specifically, to address the kinematics of the wheelchair mounted robotic arm (WMRA) with respect to its ability to reach positions commonly required by an assistive device in activities of daily living (ADL). A robotic manipulator attached to a power wheelchair could enhance the manipulation functions of an individual with a disability. In this thesis, a procedure is developed for the kinematic analysis and evaluation of a wheelchair mounted robotic arm. In addition to developing the analytical procedure, the manipulator is evaluated, and design recommendations and insights are obtained. At this time there exist both commercially-available and industrial wheelchair mountable robotic manipulators. The commercially-available manipulators (of which two will be addressed in this research) have been designed specifically for use in rehabilitation robotics. In contrast, industrial robotic manipulators are designed for speed, precision, and endurance. These traits are not required in assistive robots and can actually be dangerous to the operator if mounted onto a wheelchair. Manipulators to be used as WMRAs must be designed specifically for assistive functions in order to be utilized as a wheelchair mounted robotic arm. In an effort to evaluate two commercial manipulators, the procedure for kinematic analysis is applied to each manipulator. Design recommendations with regard to each device are obtained. This method will benefit the researchers by providing a standardized procedure for kinematic analysis of WMRAs that is capable of evaluating independent designs.

Braille, as a special written method of communication for the blind, has been globally accepted for years. It gives blind people another chance to learn and communicate more efficiently with the rest of the world. It also makes possible the translation of printed languages into a written language which is recognisable for blind people. Recently, Braille is experiencing a decreasing popularity due to the use of alternative technologies, like speech synthesis. However, as a form of literacy, Braille is still playing a significant role in the education of people with visual impairments. With the development of electronic technology, Braille turned out to be well suited to computer-aided production because of its coded forms. Software based text-to-Braille translation has been proved to be a successful solution in Assistive Technology (AT). However, the feasibility and advantages of the algorithm reconfiguration based on hardware implementation have rarely been substantially discussed. A hardware-based translation system with algorithm reconfiguration is able to supply greater throughput than a software-based system. Further, it is also expected as a single component integrated in a multi-functional Braille system on a chip. / Therefore, this thesis presents the development of a system for text-to-Braille translation implemented in hardware. Differing from most commercial methods, this translator is able to carry out the translation in hardware instead of using software. To find a particular translation algorithm which is suitable for a hardware-based solution, the history of, and previous contributions to Braille translation are introduced and discussed. It is concluded that Markov systems, a formal language theory, were highly suitable for application to hardware based Braille translation. Furthermore, the text-to-Braille algorithm is reconfigured to achieve parallel processing to accelerate the translation speed. Characteristics and advantages of Field Programmable Gate Arrays (FPGAs), and application of Very High Speed Integrated Circuit Hardware Description Language (VHDL) are introduced to explain how the translating algorithm can be transformed to hardware. Using a Xilinx hardware development platform, the algorithm for text-to-Braille translation is implemented and the structure of the translator is described hierarchically.

The loss of memory can have a profound and disabling effect on individuals. People who acquire memory impairments are often unable to live independent lives because they cannot remember what they need to do. In many cases, they rely on family members who live with them. When I carried out ethnographic fieldwork to explore this domain, I observed that individuals with amnesia were surrounded by family members who provided extensive memory support (e.g. reminders). I found that such families very worked closely together to accomplish everyday activities, such as coordinating a family outing or planning a doctor’s appointment. However, these activities were often undermined by family members forgetting. This led me to view memory aids as collaboration technology, rather than as tools that only support an individual’s memory. My dissertation explores this idea and how it can lead to more appropriate designs of assistive technology. To design collaborative assistive technology, I involved persons with amnesia and their family members in a process of participatory design. The design team included six individuals with amnesia, two neuropsychologists, and myself. Five family members were also involved in later stages. This team envisioned the design of a shared calendar application, called Family-Link, that I implemented for Palm mobile devices. I evaluated Family-Link by comparing it to the commercially available Palm Calendar in a six-month study with four families. I found that participants had significantly more shared events when using Family-Link than when using Palm Calendar. Qualitative evidence suggests that Family-Link increased all participants’ awareness of other family members’ schedules, provided caregivers with a greater a sense of security by enabling them to track their family member with amnesia, and reduced the amount of effort that caregivers needed to coordinate. Family-Link also fulfilled the individual needs of persons with amnesia by providing an information storage and retrieval mechanism. However, persons with amnesia and caregivers differed in their opinions about which features were useful. Family-Link can be a particularly important tool for families where members are not co-located throughout the day.

The loss of memory can have a profound and disabling effect on individuals. People who acquire memory impairments are often unable to live independent lives because they cannot remember what they need to do. In many cases, they rely on family members who live with them. When I carried out ethnographic fieldwork to explore this domain, I observed that individuals with amnesia were surrounded by family members who provided extensive memory support (e.g. reminders). I found that such families very worked closely together to accomplish everyday activities, such as coordinating a family outing or planning a doctor’s appointment. However, these activities were often undermined by family members forgetting. This led me to view memory aids as collaboration technology, rather than as tools that only support an individual’s memory. My dissertation explores this idea and how it can lead to more appropriate designs of assistive technology. To design collaborative assistive technology, I involved persons with amnesia and their family members in a process of participatory design. The design team included six individuals with amnesia, two neuropsychologists, and myself. Five family members were also involved in later stages. This team envisioned the design of a shared calendar application, called Family-Link, that I implemented for Palm mobile devices. I evaluated Family-Link by comparing it to the commercially available Palm Calendar in a six-month study with four families. I found that participants had significantly more shared events when using Family-Link than when using Palm Calendar. Qualitative evidence suggests that Family-Link increased all participants’ awareness of other family members’ schedules, provided caregivers with a greater a sense of security by enabling them to track their family member with amnesia, and reduced the amount of effort that caregivers needed to coordinate. Family-Link also fulfilled the individual needs of persons with amnesia by providing an information storage and retrieval mechanism. However, persons with amnesia and caregivers differed in their opinions about which features were useful. Family-Link can be a particularly important tool for families where members are not co-located throughout the day.

Quadriceps muscle weakness is a condition that can result from a wide variety of causes, from diseases like polio and multiple sclerosis to injuries of the head and spine. Individuals with weakened quadriceps often have difficulty supplying the knee-extension moments required during common mobility tasks. Existing powered orthoses that provide an assistive knee-extension moment are large and heavy, with power supplies that generally last less than two hours. A new device that provides a knee-extension-assist moment was designed to aid an individual with quadriceps muscle weakness to stand up from a seated position, sit from a standing position, and walk up and down an inclined surface. The knee-extension-assist (KEA) was designed as a modular component to be incorporated into existing knee-ankle-foot-orthoses (KAFO). The KEA consists of three springs that are compressed, as the knee is flexed under bodyweight, by cables that wrap around a sheave at the knee. The KEA returns the stored energy from knee flexion as an extension moment during knee extension. During swing or other non-weight bearing activities, the device is disengaged from the KAFO by decoupling the sheave from the KAFO knee joint, allowing free knee joint motion. A prototype was built and mechanically tested to determine KEA behaviour during loading and extension and to ensure proper KEA function. For biomechanical evaluation, able-bodied subjects used the prototype KEA while performing sit-to-stand, stand-to-sit, ramp ascent, and ramp descent tasks. The KEA facilitated sitting and standing, providing an average of 53 % of the required extension moment for the two participants, which allowed one participant to reduce quadriceps usage by 38 % and the other to perform sit-to-stand in a slower and more controlled manner that was not possible without the KEA. KEA use during ramp gait caused an overall increase in quadriceps activation by 76 %, on average, with use. Future efforts will be made to modify the design to improve functionality, especially for ramp gait, and to reduce device size and weight.

The number of elderly people around the world is growing rapidly. This has led to an increase in the number of people who are seeking assistance and adequate service either at home or in long-term- care institutions to successfully accomplish their daily activities. Responding to these needs has been a burden to the health care system in terms of labour and associated costs and has motivated research in developing alternative services using new technologies. Various intelligent, and non-intelligent, machines and robots have been developed to meet the needs of elderly and people with upper limb disabilities or dysfunctions in gaining independence in eating, which is one of the most frequent and time-consuming everyday tasks. However, in almost all cases, the proposed systems are designed only for the personal use of one individual and little effort to design a multiple-user feeding robot has been previously made. The feeding requirements of elderly in environments such as senior homes, where many elderly residents dine together at least three times per day, have not been extensively researched before. The aim of this research was to develop a machine to feed multiple elderly people based on their characteristics and feeding needs, as determined through observations at a nursing home. Observations of the elderly during meal times have revealed that almost 40% of the population was totally dependent on nurses or caregivers to be fed. Most of those remaining, suffered from hand tremors, joint pain or lack of hand muscle strength, which made utensil manipulation and coordination very difficult and the eating process both messy and lengthy. In addition, more than 43% of the elderly were very slow in eating because of chewing and swallowing problems and most of the rest were slow in scooping and directing utensils toward their mouths. Consequently, one nurse could only respond to a maximum of two diners simultaneously. In order to manage the needs of all elderly diners, they required the assistance of additional staff members. The limited time allocated for each meal and the daily progression of the seniors’ disabilities also made mealtime very challenging. Based on the caregivers’ opinion, many of the elderly in such environments can benefit from a machine capable of feeding multiple users simultaneously. Since eating is a slow procedure, the idle state of the robot during one user’s chewing and swallowing time can be allotted for feeding another person who is sitting at the same table. The observations and studies have resulted in the design of a food tray, and selection of an appropriate robot and applicable user interface. The proposed system uses a 6-DOF serial articulated robot in the center of a four-seat table along with a specifically designed food tray to feed one to four people. It employs a vision interface for food detection and recognition. Building the dynamic equations of the robotic system and simulation of the system were used to verify its dynamic behaviour before any prototyping and real-time testing.

This thesis describes the research, design, and development of a mid-drive wheelchair for use by the elders living independently, in assisted living facilities, and in nursing homes created by a design team at Georgia Tech's Center for Assistive Technology and Environmental Access (CATEA). This wheelchair stands to significantly improve the mobility of elders through better drive wheel placement and design features that could stand to improve their quality of life.

When asked to draw, most people are hesitant because they believe themselves unable to draw well. A human instructor can teach students how to draw by encouraging them to practice established drawing techniques and by providing personal and directed feedback to foster their artistic intuition and perception. This thesis describes the first methodology for a computer application to mimic a human instructor by providing direction and feedback to assist a student in drawing a human face from a photograph. Nine design principles were discovered and developed for providing such instruction, presenting reference media, giving corrective feedback, and receiving actions from the student. Face recognition is used to model the human face in a photograph so that sketch recognition can map a drawing to the model and evaluate it. New sketch recognition techniques and algorithms were created in order to perform sketch understanding on such subjective content. After two iterations of development and user studies for this methodology, the result is a computer application that can guide a person toward producing his/her own sketch of a human model in a reference photograph with step-bystep instruction and computer generated feedback.