<p>Major problems of the Foot Drop treatment are expensive and complex solutions. This work</p><p>presents the performance of a new inexpensive method named as Semi-Active Ankle Foot</p><p>Orthosis (SAAFO). The concept of this approach is to use inexpensive sensors to detect foot step</p><p>movement. The signals from the sensors afterwards will be fed to a control system of SAAFO in</p><p>runtime for a smooth foot movement of a drop foot patient while walking. Different sensors have</p><p>been studied in detail along with comparison to the proposed sensor system and mechanical</p><p>design. The signals from the sensors are used to detect different phases of human walking. These</p><p>sensors are placed at different positions on an orthosis and their signals are studied in detail.</p><p>Experiments have been done in different conditions to get a realistic picture either this assembly</p><p>can be implemented commercially. Signals are plotted and discussed yielding that the human</p><p>walking phases can be easily and accurately detected using inexpensive sensor assembly.</p>

Major problems of the Foot Drop treatment are expensive and complex solutions. This work presents the performance of a new inexpensive method named as Semi-Active Ankle Foot Orthosis (SAAFO). The concept of this approach is to use inexpensive sensors to detect foot step movement. The signals from the sensors afterwards will be fed to a control system of SAAFO in runtime for a smooth foot movement of a drop foot patient while walking. Different sensors have been studied in detail along with comparison to the proposed sensor system and mechanical design. The signals from the sensors are used to detect different phases of human walking. These sensors are placed at different positions on an orthosis and their signals are studied in detail. Experiments have been done in different conditions to get a realistic picture either this assembly can be implemented commercially. Signals are plotted and discussed yielding that the human walking phases can be easily and accurately detected using inexpensive sensor assembly.

Wrist orthoses are the most common upper limb orthoses, being used by thousands of individuals each year to stabilize, immobilize, or support the wrist joint. Wrist orthoses achieve their function by altering the stiffness of the wrist joint (Figure 1-1). However, there is no quantitative understanding of how wrist orthoses affect wrist stiffness, and consequently, wrist orthosis development often relies on feel, intuition, or empirical heuristics rather than a methodical, quantitative approach. Because wrist movement control is dominated by wrist joint stiffness (Charles and Hogan 2011) a quantitative understanding of how wrist orthoses alter the stiffness of the wrist is imperative to the development of improved wrist orthoses with properties tailorable to the needs of the thousands of individuals who use them. In order to begin bridging this gap, our research characterized the stiffness of four common groups of wrist orthosis in two degrees of freedom: flexion-extension (FE) and radioulnar deviation (RUD) which are the degrees of motion most affected by wrist orthoses. We used a wrist robot to measure how twelve orthoses altered the passive wrist stiffness of twenty healthy subjects (three orthoses and five subjects per orthosis group). To perform these measurements we designed a unique wrist-mounting fixture (Figure 3-2) which allows the wrist robot to manipulate the hand inside an orthosis without interfering with orthosis motion (more accurately simulating the actual hand-orthosis interaction). Our results showed that (1) three out of four orthosis groups significantly altered the stiffness of the wrist joint, (2) orthoses in the same group are not generally significantly different than one another, and (3) there are important differences in stiffness between different orthosis groups. An interesting implication of our research is the result that in many cases orthoses with volar stays may be interchanged with orthoses with both volar and dorsal stays without significant changes in orthosis performance (Table 4-2). We anticipate this work will prove fruitful toward the future study of wrist orthoses' effects on wrist movement behavior and the future improvement of wrist orthosis design.

In the United States, more than 18 million people suffer from upper extremity injury. This population is in need of a device both to aid in the completion of activities of daily living (eating and grooming), as well as to provide daily muscular therapy. To assist persons suffering from disabling upper extremity neuromuscular diseases, this thesis concerned the redesign of a powered arm brace from a proof-of-concept design to a more functional, marketable product. The principles of Design for Manufacturability and Assembly (DFMA) were employed as part of the design methodology to create a product that could be scaled into production. Additionally, numerical analyses including Finite Element Analysis (FEA) were completed to prove the both the safety and structural integrity of the orthosis in computer simulations. The design was then successfully tested with marked improvement over the previous design, including a 58% reduction in weight, decreased manufacturing costs, and a significant improvement in functionality and comfort.

Walking is the most common form of mobility in humans. For lower limb mobility impairments, a common treatment is to prescribe an ankle-foot orthosis (AFO) or brace, which is a passive device designed to resist undesired ankle-foot motion. Recent advances in actuator technology have led to the development of active AFOs (AAFOs). However, these devices are generally too bulky for everyday use and are limited to applications such as gait training for rehabilitation. The aim of this research was to investigate the feasibility of developing a novel Active Ankle-Foot Stabilizer (AAFS). The design criteria were mainly based on the strengths and limitations of existing AFOs. The sagittal plane functional requirements were determined using simulated gait data for elderly individuals and drop foot patients; however, it is intended that the device would be suitable for a wider range of disabilities including ankle sprains. A model of the foot was introduced to modify the moment of a deficient ankle where young healthy adult kinematics and kinetics were assumed. A moment deficit analysis was performed for different gait periods resulting in an AAFS model with two components: a linear rotational spring to modify the ankle joint rotational stiffness, and a torque source. The frontal plane functional requirements for the AAFS were modeled as a linear rotational spring which responded to particular gait events. A novel Variable Rotational Stiffness Actuator (VSRA) AFO was also investigated. It consisted of an actuated spring medial and lateral to the ankle to control sagittal plane ankle stiffness and a passive leafspring posterior to the ankle to control frontal plane ankle stiffness. Due to high forces and profile limitations, a spring and rotation actuator that satisfied the design criteria could not be developed, resulting in an infeasible design. Considering the high forces and moments required by the AAFS, a pneumatic approach was adopted. A novel Airbeam AFO, which consisted of a shank cuff and a foot plate to which airbeams were attached proximally and distally to the ankle, was examined. The joint rotational stiffness of the ankle would be controlled by the inflation of these individual cylindrical airbeams. To satisfy the functional requirements, the airbeam diameters and pressures were too large to meet the design criteria and were unrealistic for a portable device. Finally, a Pneumatic Sock AFO, which proved to best satisfy the functional requirements within the design criteria, was examined. The design consisted of an inner sock worn on the ankle, surrounded by anterior, posterior, medial, and lateral bladders which inflate against outer fabric shells. Although promising, the Pneumatic Sock AFO requires further investigation in regards to manufacturing and behaviour characterization before a functional prototype can be developed. Mechanical test methods to characterize the behaviour of the Pneumatic Sock AFO in the sagittal and frontal planes were developed including the control components required, the configuration of a test rig, and test procedures.

Wearable robotics for assistance and rehabilitation are not yet considered commercially mainstream products, and as a result have not yet seen advanced controls systems and interfaces. Consequently, the available technology is mostly adapted from systems used in parallel technologies, rather than custom applications intended for human use. This study concerns itself with the design and development of a custom control system for a 2-degree of freedom powered upper extremity orthosis capable of driving elbow flexion/extension 135º and humeral rotation 95º . The orthosis has been evaluated for use as both a long-term assistive technology device for persons with disabilities, and as a short-term rehabilitative tool for persons recovering injury. The target demographics for such a device vary in age, cognitive ability and physical function, thus requiring several input parameters requiring consideration. This study includes a full evaluation of the potential users of the device, as well as parameter considerations that are required during the design phase. The final control system is capable of driving each DOF independently or simultaneously, for a more realistic and natural coupled-motion, with proportional control by pulse-width modulation. The dual-axis joystick interface wirelessly transmits to the 1.21 pound control pack which houses a custom microcontroller-driven PCB and 1800 milliamp-hour lithium-ion rechargeable battery capable of delivering 4 hours of running time. Upon integration with the 2 DOF orthosis device, a user may complete full range of motion with up to 5 pounds in their hand in less than 7 seconds, providing full functionality to complete acts of daily living, thus improving quality of life.

En France, plus d’une personne sur dix souffre d’arthrose où le compartiment médial de l’articulation du genou demeure largement affecté. Afin de lutter contre ce fléau qui occasionne des dépenses croissantes dans notre système de santé, l’intégration de traitements non-pharmacologiques et conservateurs dans la prise en charge de cette pathologie est une priorité. De ce fait, les orthèses de décharge pourraient tout à fait répondre à cette nécessité. Malheureusement, au fil des rares prescriptions, force est de constater l’abandon trop rapide de ce type d’appareillage. Majoritairement conçues pour exercer une action mécanique à trois points de pression, les orthèses de décharge sont davantage reconnues pour leur inconfort que pour leurs effets bénéfiques. Etre assis, se tenir debout ou simplement marcher sont autant de situations selon lesquelles l’appareillage devrait être en mesure de s’adapter. Pour autant, les orthèses de décharge exercent, à tort, une seule et même action mécanique continue. Cette dernière est identifiée comme responsable de leur inconfort. Fort de ce constat, ce travail de thèse se penche sur une piste jusqu’alors inexplorée, une action mécanique variable des orthèses de décharge à trois points de pression, garante d’un confort accru dans le but d’améliorer l’alliance thérapeutique. Sur la base de cette idée brevetée, nous verrons à travers ce travail les différentes étapes de validation qui permettent de caractériser un appareillage dynamique, avantageusement comparé aux modèles jusqu’alors proposés. / In France, more than one person out of ten suffers from osteoarthritis, which particularly affects the medial compartment of the knee joint. In order to overcome this issue, which causes increased expenditure in the healthcare system, the integration of non-pharmacological and conservative treatments for the management of this pathology is a priority. As a result, unloader knee braces could fully meet this need. However, few prescriptions and a poor long-term compliance are frequently reported. Usually designed to exert a mechanical action with three-point pressure, unloader knee braces are better known for causing discomfort rather than leading to beneficial effects. Indeed, these braces exert erroneously a continuous mechanical action, which has been identified as responsible for the discomfort. To counteract this problem, equipment should be able to adapt between situations as sitting, standing or walking. Therefore, this thesis focuses on a changeable mechanical action of three-point pressure orthoses, ensuring greater comfort and potentially resulting in improved compliance. According to this idea, this work explores the different stages of validation, which allow to characterize a dynamic unloader knee brace and describe its advantages over the traditional proposed models.

Knee-ankle-foot orthoses (KAFOs) are full leg braces for individuals with knee extensor weakness, designed to support the person during weight bearing activities by preventing knee flexion. KAFOs typically result in an unnatural gait pattern and are primarily used for level ground walking. A novel variable resistance orthotic knee joint was designed and evaluated to address these limitations. This low profile design fits beneath normal clothing. Mechanical and biomechanical testing demonstrated that the design resisted knee motion during stance phase, released the knee joint without restricting the knee’s range of movement, and provided flexion resistance during stair descent. Design modifications and related testing procedures were developed to further improve joint performance and to validate the design prior to testing on individuals with knee extensor weakness.

The Ottawalk-Speed (OWS) orthosis prevents knee collapse in stumble situations. The purpose of this study was to develop a virtual stumble perturbation to measure OWS response to a knee collapse when walking. A new split speed perturbation was developed for the CAREN virtual reality system. This perturbation induced a stumble with increased knee flexion for five able-bodied participants, with either a hopping or stopping recovery strategy. Three knee-ankle-foot orthosis users were subjected to five stumble trials while wearing the OWS. OWS participants used a straight-legged recovery strategy, and extended the knee through recovery weight acceptance. Therefore, the split speed perturbation was not appropriate to measure OWS response to a stumble since knee collapse did not occur. The OWS allowed free knee motion during gait. Further study is required to measure OWS response during a stumble with a knee collapse event.

The Ottawalk-Speed (OWS) orthosis prevents knee collapse in stumble situations. The purpose of this study was to develop a virtual stumble perturbation to measure OWS response to a knee collapse when walking. A new split speed perturbation was developed for the CAREN virtual reality system. This perturbation induced a stumble with increased knee flexion for five able-bodied participants, with either a hopping or stopping recovery strategy. Three knee-ankle-foot orthosis users were subjected to five stumble trials while wearing the OWS. OWS participants used a straight-legged recovery strategy, and extended the knee through recovery weight acceptance. Therefore, the split speed perturbation was not appropriate to measure OWS response to a stumble since knee collapse did not occur. The OWS allowed free knee motion during gait. Further study is required to measure OWS response during a stumble with a knee collapse event.