Dissertations / Theses on the topic 'Prosthetics and orthotics'

Objective: To gather knowledge related to patient satisfaction and mobility with lower limb prosthetic and orthotic devices and to investigate satisfaction with services received. Another purpose of this study is to analyze potential differences between orthotic and prosthetic patients in relation to patient satisfaction and mobility. Design: Cross-sectional study Subjects: 21 participants with a mean age of 58 (SD 16) with an average duration of use of devices of 10 (SD 10) years. 12 out of the 21 participants were orthotic users and 9 were prosthetic users. Methods: Patients were asked to complete two questionnaires, one regarding satisfaction with assistive device and service (QUEST 2.0) and one regarding mobility. Results: Patients mean score regarding satisfaction with assistive device and service were 4.0 (SD 0.8) and 4.2 (SD 1.0) respectively. 91% reported that they had the ability to walk at least 100 meters with their assistive device. The areas where participants experienced most difficulties were walking on uneven ground (70%), walking up and down a hill (57%) and walking on stairs (57%). Conclusion: Overall this study demonstrates that participants were quite satisfied with their assistive device and the service received by the P&O clinic. No statistically significant differences regarding satisfaction with assistive device and service, or mobility, were found between prosthetic and orthotic participants.

The electromyogram (EMG) signal is desired to be used as a control signal for applications such as multifunction prostheses, wheelchair navigation, gait generation, grasping control, virtual keyboards, and gesture-based interfaces [25]. Several research studies have attempted to relate the electromyogram (EMG) activity of the forearm muscles to the mechanical activity of the wrist, hand and/or fingers [41], [42], [43]. A primary interest is for EMG control of powered upper-limb prostheses and rehabilitation orthotics. Existing commercial EMG-controlled devices are limited to rudimentary control capabilities of either discrete states (e.g. hand close/open), or one degree of freedom proportional control [4], [36]. Classification schemes for discriminating between hand/wrist functions and individual finger movements have demonstrated accuracy up to 95% [38], [39], [29]. These methods may provide for increased amputee function, though continuous control of movement is not generally achieved. This thesis considered proportional control via EMG-based estimation of finger forces with the goal of identifying whether multiple degrees of freedom of proportional control information are available from the surface EMG of the forearm. Electromyogram (EMG) activity from the extensor and flexor muscles of the forearm was sensed with bipolar surface electrodes and related to the force produced at the four fingertips during constant-posture, slowly force-varying contractions from 20 healthy subjects. The contractions ranged between 30% maximum voluntary contractions (MVC) extension and 30% MVC flexion. EMG amplitude sampling rate, least squares regularization, linear vs. nonlinear models and number of electrodes used in the system identification were studied. Results are supportive that multiple degrees of freedom of proportional control information are available from the surface EMG of the forearm, at least in healthy subjects. An EMG amplitude sampling frequency of 4.096 Hz was found to produce models which allowed for good EMG amplitude estimates. Least squares regularization with a pseudo-inverse tolerance of 0.055 resulted in significant improvement in modeling results, with an average error of 4.69% MVC-6.59% MVC (maximum voluntary contraction). Increasing polynomial order did not significantly improve modeling results. Results from smaller electrode arrays remained fairly good with as few as six electrodes, with the average %MVC error ranging from 5.13%-7.01% across the four fingers. This study also identified challenges in the current experimental study design and subsequent system identification when EMG-force modeling is performed with four fingers simultaneously. Methods to compensate for these issues have been proposed in this thesis.

Motor control of any movement task involves the integration of neural, muscular and skeletal systems. This integration must occur throughout the sensorimotor system and focus its efforts on controlling the system endpoint, e.g. the foot during locomotion. A person with a uni-lateral trans-tibial amputation has lost the foot, ankle joint, and muscles crossing those joints, hence the residuum becomes the new terminus of the motor system. The amputee must now adjust to the additional challenges of utilizing a compromised motor system as well as the challenges of controlling an external device, i.e. prosthesis, through the mechanical interface between the residuum and prosthetic socket. The obvious physical and physiologic asymmetries between the sound and amputated limbs are also involved in strategies for locomotion involving kinematic and kinetic asymmetries (Winter&Sienko, 1988). There are many questions as to why these asymmetric locomotor strategies are selected and what factors may be influencing that strategy. Factors influencing a change in locomotor strategy could be related to 1) the central nervous system accounting for the loss of sensorimotor feedback, 2) the altered mechanics of this new human/prosthetic system, or some combination of these factors. Understanding how the human motor system adjusts to the amputation and to the addition of an external mechanical device can provide useful insight into how robust the human control system may be and to adaptations in human motor control. This research uses a group of individuals with a uni-lateral trans-tibial amputation and a group of intact individuals using an Ankle Foot Orthosis (AFO) performing a cycling task to understand the "motor adjustments" necessary to utilize an external device for locomotion. Results of these experiments suggest 1) the motor system does account for the activation-contraction dynamics when coordinating muscle activity post amputation, 2) the motor system also changes joint kinetics and muscle activity, 3) these changes are related to control of the interface between the limb and the external device, and 4) the motor system does not alter kinetic asymmetries when kinematic asymmetries are minimized, contrary to a common practice in rehabilitation (Kapp, 2004). Results suggest that control of the external device, i.e. prosthesis or AFO, via the interface between the limb and the device reflect "motor adjustments" made by the nervous system and may be viewed in the context of tool use. Clinical goals in rehabilitation currently focus on minimizing gait deviations whereas the clinical application of these results suggest these deviations from normal locomotion are motor adjustments necessary to control a tool, i.e. prosthesis, by the motor system. Examining amputee locomotion in the context of tool use changes the clinical paradigm from one designed to minimize deviations to one intended to understand this behavior as related to interface control of the device thereby shifting the focus to improving function of the limb/prosthesis system. Kapp SL. (2004) Atlas amp limb def: surg pros rehab princ. 3rd ed: 385 - 394. Winter&Sienko. (1988) J Biomech, 21: 361 - 367.

This thesis proposes an algorithm that determine the geometry of 3D-printed, custom-designed spring element bands made of thermoplastic elastomer (TPE) for use in a wearable orthotic device to aid in the physical therapy of a human hand exhibiting spasticity after stroke. Each finger of the hand is modeled as a mechanical system consisting of a triple-rod pendulum with nonlinear stiffness at each joint and forces applied at the attachment point of each flexor muscle. The system is assumed quasi-static, which leads to a torque balance between the flexor tendons in the hand, joint stiffness and the design force applied to the fingertip by the 3D-printed spring element. To better understand material properties of the spring element’s material, several tests are performed on TPE specimens printed with different infill geometries, including tensile tests and cyclic loading tests. The data and stress-strain curves for each geometry type are presented, which yield a nonlinear relationship between stress and strain as well as apparent hysteresis. Polynomial curves are used to fit the data, which allows for the band geometry to be designed. A hypothetical hand is presented along with how input measurements might be taken for the algorithm. The inputs are entered into the algorithm, and the geometry of the bands for each finger are generated. Results are discussed, and future work is noted, providing a means for the design of a customized orthotic device.

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.

Existing methods that use a fringe projection technique for orthotic and prosthetic designs produce good results for the trunk and lower limbs; however, the devices used for this purpose are expensive. This thesis investigates the use of an inexpensive passive method involving 3D surface reconstruction from video images taken at multiple views. The design and evaluation methodology, consisting of a number of techniques suitable for orthotic and prosthetic design, is developed. The method that focuses on fitting the reference model (3D model) of an object to the target data (3D data) is presented. The 3D model is obtained by a computer program while the 3D data uses the shape-from silhouette technique in an approximately circular motion.

Powered orthotic devices can be used to restore mobility to the impaired user, and may thereby assist them in daily living tasks. An investigation is performed herein to examine the feasibility of a powered lower-limb orthotic in assisting the sit-to-stand task by 50% of the required torque. Feasibility is considered via simulation. A three-link sit-to-stand model, which is driven by kinematic data, is developed. Models of a Pneumatic Muscle Actuator and a DC motor are used to determine which of the two technologies can make a more appropriate contribution to the sit-to-stand task. Simulation revealed that both the Pneumatic Muscle Actuator and the DC motor are reasonable actuator choices, and neither limited the ability to achieve 50% torque assistance. The ability to assist the task was, however, limited by the ability to derive a control signal for the actuator from the user-orthotic interface. It was concluded that the user-orthotic interface requires further investigation. It was also found that while both actuator technologies are suitable for contributing 50% of the required torque, the Pneumatic Muscle Actuator is preferable due to its ability to scale to greater torques.

Background: To be able to meet social harmony in a continuously globalizing world, intercultural competencies are important to possess as an individual. Thus, it is also important for Certified Prosthetists and Orthotists (CPOs) and other health care providers since they meet many diversities in connection to their work. Aim: The aim of this study is to investigate Danish CPOs’ experience and perception of their intercultural competencies in the treatment of immigrants. Method: This study is a qualitative interview study using a phenomenological approach. Semi-structured interviews are used to collect the data from five CPOs working in Danish clinics. A content analysis, with an inductive approach, is used for the analysis. Findings: From the analysis of the participant interviews, seven sub-categories were found and further divided into three categories: Treatment, work environment, and development of competencies. These contribute to describe the main category and the aim of this study. Conclusion: The Danish CPOs, who participated in this study, experienced that they did not treat immigrants differently than non-immigrants. However, they experienced that some challenges could be connected to the treatment of immigrants, such as communication difficulties, but they all had a perception, that they used specific tools and strategies to accommodate these challenges. Furthermore, they all experienced that their intercultural competencies had improved with experience, but most of them were also interested in further development of their competencies.

碩士
國立臺灣大學
機械工程學研究所
99
The main purpose of this research is to design a set of hip flexion-extension coupling ratio mechanism for paraplegic and HD/HP patients. In clinical experiences, the treatment for paralysis of lower extremities and HD/HP patients is the most challenging issue. Compared with knee joint mechanism, the hip joint needs novel design in priority. The hip mechanism of reciprocating gait orthosis (RGO) can only apply flexion/extension motion. The limitation leads to patients’ compensatory movement. So the mechanism needs to have the ability to adjust higher flexion-extension coupling ratio(FECR) automatically for different phases. First, we use Lagrange equation to establish simple human model. By substituting different initial conditions, the solution can be used to design higher hip coupling ratio mechanism which is better than conventional mechanism. In practical application, we investigate the real coupling ratio and the influence of 1:1 coupling ratio mechanism on normal people by motion analysis method. We find that the abnormal constrain may be one of the main reason of slow walking speed. Finally, we give suggestions for more mature mechanism which can work stably on subjects in the future.

Knee osteoarthritis (OA) is a debilitating disease affecting the entire knee joint by inducing pathological changes to the cartilage and menisci. Currently, the etiology of OA is not completely understood. However, altered gait mechanics, specifically increased joint loading, of OA patients have a clear association with both symptomatic and structural OA progression. Non-surgical intervention tools, such as variable stiffness shoes (VSS), have been developed as a way to decrease loading within the knee joint. However, with external moments being surrogate measures for knee loading, it is unclear if changes in knee moments with the footwear are sufficient to result in a clinical benefit. Therefore, this project’s purpose was to investigate whether a VSS intervention can alter knee joint loading and menisci function in a knee OA population. We used gait analysis, musculoskeletal modeling, and finite element (FE) analysis to determine the effect of VSS on gait mechanics, knee joint contact force, and menisci stress and strain, compared to a control shoe. We found knee moments did not decrease with the VSS intervention. Furthermore, participants who did experience a decrease in knee adduction moment did not always experience a decrease in medial compartment contact force. However, results from our FE modeling of the tibiofemoral joint indicate significant changes in knee joint contact force can influence stress placed on the menisci. Results from this study suggest knee contact forces and tissue stress, not only external moments, should be considered when investigating if VSS can positively impact an OA population.

The ever-changing demands of working life pose considerable challenges to higher education. The literature indicates that traditional forms of university instruction positioned a deficit model of teaching and learning, which is embedded in a logical positivist paradigm, as authoritative in the production of ‘experts’ who possess legitimate knowledge. However, in professional practice, health practitioners often deal with ill-defined problems. If health practitioners are to be prepared properly for their future careers, the development of reflective thinking should be an integral component of professional education courses. The aim of this study was to explore the public narratives on existing teaching and learning practices in higher education, orthotics/prosthetics and psychology, and to examine the authority of these narratives in the unfolding stories of students and the facilitator in a pilot applied psychology course designed for orthotist/prosthetist professionals. There is a paucity of psychological research in orthotic/prosthetic practice and further research in this domain is needed, particularly from a qualitative approach. A story map was used to integrate the methodology of personal experience methods and narrative analysis into one model that represents the voice of public and private narratives in a specific temporality of past, present and future. The analysis of public and private texts revealed the narrative themes of teaching and learning, co-constructing knowledge, reflection-on-practice, disability, community of concern and agency. A critical psychology and social constructionist approach is proposed to facilitate reflective clinical practice in a psychology module for orthotics and prosthetics. In a collaborative learning community, the lived experiences, knowledge, skills, and desires that invited orthotist/prosthetists into this helping field are honoured. In addition, they are encouraged to reflect on the value of professional interventions by using pragmatic criteria of whether an approach fits or is useful for a client, rather than relying on some abstract notion of ‘truth’.
Thesis (PhD (Psychology))--University of Pretoria, 2007.
Psychology
unrestricted

A brain computer interface (BCI), which reroutes neural signals from the brain to actuators in a prosthetic or orthotic hand, promises to aid those who suffer from hand motor impairments, such as amputees and victims of strokes and spinal cord injuries. Such individuals can greatly benefit from the return of some of the essential functionality of the hand through the renewed performance of the basic hand movements involved in daily activities. These hand movements include wrist extension, wrist flexion, finger extension, finger flexion and the tripod pinch. The core of this sensorimotor BCI solution lies in the interpretation of the neural information for the five essential hand movements extracted from EEG (electroencephalogram). It is necessary to improve on the interpretation of these EEG signals; hence this research explores the possibility of single-trial EEG discrimination for the five essential hand movements in an offline, synchronous manner. The EEG was recorded from five healthy test subjects as they performed the actual and imagined movements for both hands. The research is then divided into three investigations which respectively attempt to differentiate the EEG for: 1) right and left combinations of the different hand movements, 2) wrist and finger movements on the same hand and 3) the individual five movements on the same hand. A general method is applied to all three investigations. It utilizes independent component analysis (ICA) and time-frequency techniques to extract features based on eventrelated (de)synchronisation (ERD/ERS) and movement-related cortical potentials (MRCP). The Bhattacharyya distance is used for feature reduction and Mahalanobis distance clustering and artificial neural networks are used as classifiers. The best average accuracies of 89 %, 71 % and 57 % for the three respective investigations are obtained using ANNs and features related to ERD/ERS. Along with accuracies around 70 % for a few subjects in the five-movement differentiation investigation, these results indicated the possibility of offline, synchronous differentiation of single-trial EEG for the five essential hand movements. These hand movements can be used in part or in combination as imagined and performed motor tasks for BCIs aimed at controlling prosthetic or orthotic hands.

Dissertação de mestrado integrado em Mechanical Engineering
This project consists of the architecture, design, production, and implementation of a cleaning system applied in a machining centre responsible for the manufacture of accessories with orthotic or prosthetic applications used in the "Padrão Ortopédico" company. Thus, it was necessary to carry out a mechatronic project. Initially, it was necessary to keep in mind a theoretical framework on the subjects to be dealt with during the project. For this purpose, several bibliographies on the theme were studied. The CNC machine to be improved was also intensively investigated in order to get to know it in its entirety and to gather all possible information about it since there were no past records. The result of this process was to point out its weak points and highlight the problem of waste accumulation inside the machine which would have to be solved with a specific hoover. During the construction of the vacuuming system, there were several parameters that had to be taken into consideration. In an initial phase of architecture and design, a model of a cyclone hoover was selected with the suitable relationship between its dimensions. Its constituent parts were also designed and printed three-dimensionally respecting the structure chosen. Before the production of the parts constituting the hoover, its assembly was tested through virtual simulations of computational fluid dynamics. In a final phase of the project, the integration and verification took place at the site defined within the CNC, and it was verified that the system was working. The operation of the hoover occurs without any malfunction. It takes place at the same time as the machine operations, thus resulting in a possible and positive validation and transition of the project. Based on all the work done it is possible to criticise it positively and negatively thus pointing out possible improvements that could be made to the vacuuming system in the future.
Este projeto consiste na arquitetura, conceção, produção e implementação de um sistema de limpeza aplicado a um centro de maquinagem responsável pelo fabrico de acessórios com aplicações ortoprotésicas utilizados na empresa "Padrão Ortopédico". Assim, foi necessário levar a cabo um projeto mecatrónico. Inicialmente é sempre necessário ter em mente um enquadramento teórico sobre os temas a tratar durante o projeto. Para este efeito, foram consultadas várias bibliografias sobre o tema. A máquina CNC, a ser melhorada foi também intensamente investigada a fim de a conhecer na sua totalidade e de recolher todas as informações possíveis sobre a mesma, uma vez que não existiam registos sobre a sua funcionalidade e características. O resultado deste processo foi evidenciar os seus pontos fracos e realçar o problema da acumulação de lixo dentro da máquina, que teria de ser resolvido com um aspirador de pó específico. Durante a construção do sistema de aspiração, houve vários parâmetros que tiveram de ser tomados em consideração. Numa fase inicial de arquitetura e desenho foi selecionado um modelo da relação entre as dimensões de um aspirador de pó do tipo ciclone. As suas partes constituintes foram também concebidas e impressas tridimensionalmente, respeitando o modelo escolhido. Antes da produção das peças que constituem o aspirador de pó, a sua montagem foi testada através de simulações virtuais da dinâmica do fluído computacional. Numa fase final do projeto, a integração e verificação teve lugar no local definido dentro da CNC, constatando-se que o sistema estava operacional. O funcionamento do aspirador de pó também ocorre sem qualquer anomalia de operação. Ocorre ao mesmo tempo que as operações da máquina, resultando assim numa possível e positiva validação e transição do projeto. Com base em todo o trabalho realizado, é possível fazer uma reflexão crítica, valorizando quer aspetos negativos quer positivos apontando, assim, possíveis melhorias que, no futuro, poderiam ser feitas ao sistema de aspiração no futuro.