No description available.

Through whatever misfortune people have always had the need for artificial limbs. This study questions current thinking in the field of prosthetics, aiming to address the most prevalent issues affecting the amputee today, such as, fit, comfort and practicality, which have an inarguable baring on patient prostheses satisfaction. Through examination, more obscure problems encountered by users were explained, indicating how design issues and methodologies affect the present and future manufacturing process. As a result of this research a development model for the increased effectiveness of prostheses fitrnent and improvements in patient prosthetic satisfaction have been made. This has included suggestions for potential improvements in limb fitting center protocol, patient education and awareness strategies for the assessment of delivered patient needs and requirements Methods implemented during the research consisted of a comprehensive literature review of current infonnation, technical reports and patient satisfaction findings and assessment techniques. 1bis was accompanied with an investigation and evaluation of the prosthetics industry, including limb fitting, patient requirements, product/service shortfalls, rehabilitation technique and patient lifestyle. Additionally interviews and questionnaires with practitioners and users were undertaken aiding the evaluation of patient satisfaction and the identification of potential improvements in artificial limb fitment procedure. The results revealed several areas that deserved more detailed investigation, notably relating to the hypotheses, that the relationship between the levels of fit, comfort and practicality archived within the prostheses has an effect on the patient's satisfaction. Through the examination ofthis main hypothesis one of the most significant factors which emerged was the effect ofthe communication level held between the patient and prosthetist. The results of"this enquiry indicated that improved patient knowledge with respect oftheir situation and an increased ability to accurately relay issues of concern to the prosthetist, facilitated the delivery of satisfactory prostheses, in turn improving its fit, comfort and practicality. In conclusion, previous conjecture as to the limited effectiveness of current prosthetics in re-establishing patients activity levels were assessed, and suggestions generated by the results of patients dissatisfaction with their limbs. These findings facilitated the realisation of new educational, protocol-based methodologies, tools and theories.

Diss. (sammanfattning) Umeå : Univ., 2004. / Härtill 4 uppsatser.

Thesis (Ph. D.)--Biomedical Engineering, Georgia Institute of Technology, 2008. / Committee Chair: Thomas J. Burkholder; Committee Member: Lena H. Ting; Committee Member: Roman O. Grigoriev; Committee Member: Shawn Hochman; Committee Member: T. Richard Nichols.

No description available.

In addition to its intrinsic importance during quiet standing, posture also serves as the background for a wide variety of other critical motor tasks. The hierarchical nature of the motor control system suggests that the different layers may be responsible for different aspects of posture. I tested the hypothesis that spinal reflexes are organized according to optimal principles of stability, control accuracy, and energy. I found that there were no globally stable muscle activation patterns for muscles operating near optimal fiber length, suggesting that the intrinsic viscoelastic properties of muscle are insufficient to provide limb stability. However, for stiffer muscles a stable limb could be created by selectively activating muscles based on their moment-arm joint angle relationships. The optimal organization of length and velocity feedback to control and stabilize the endpoint position of a limb could not be produced from a purely muscle controller, but required neural feedback to improve endpoint performance, reduce energetic cost, and produce greater coordination among joints. I found that while muscles at near optimal fiber length were insufficient to provide limb stability, the length feedback provided by the autogenic stretch reflex was sufficient to stabilize. Length feedback was also sufficient to produce the directional tuning of muscle activity and constrained ground reaction forces as is observed in experiments. These results have implications for controlling powered prosthetic devices, suggesting that subdividing the responsibility for stability among hierarchical control structures will simultaneous improve stability and maneuverability of the devices.

Made available in DSpace on 2014-07-29T15:29:14Z (GMT). No. of bitstreams: 1 Analise Biomecania da Inicializacao da Marcha de Amputados Transtibiais Protetizados.pdf: 3970642 bytes, checksum: afbedb9e27d84f4cdd22ab374f81a8c5 (MD5) Previous issue date: 2012-03-30 / The amputee patient undergoes several changes after the amputation, not only physical but also emotional and socioeconomic, requiring the use of prosthesis. One of the physical changes that affects the amputee's gait when using your prosthesis ambulation is compromised. The march is the natural way that humans use to move from one location to another. The march is a complex activity because it depends on a series of interactions between the two lower limbs multithreaded and total body mass. Therefore, assessing the impact of the use of prostheses in locomotor through the analysis of strategies for startup of the march transtibial amputees. We evaluated the speed and displacement of the COP, knee and ankle angles of the support member during initialization of the march. For the kinematic analysis was set 34 markers on anatomical landmarks of interest, two AMTI force platforms. For statistical analysis we used the Student t test and correlation between variables. Difference was only statistically significant variables in the knee angle and average speed side. The absence of a flexible ankle joint may result in limitations in the function of the prosthesis. Amputees to achieve an adequate control in propulsion and balance it was necessary to use several strategies to adjust. The prosthesis provided by SUS serves its purpose, which is to provide a walking person. But this improvement in the ankle joint can facilitate the process of walking boot. Another fact of great importance is the frequent evaluation of prosthetic to verify the necessary adjustments of the prosthesis. / O paciente amputado sofre várias alterações após a amputação, não somente físicas, mas também emocionais e socioeconômicas, sendo necessário que a utilização de prótese. Uma das alterações físicas que acomete o amputado é a locomoção quando da utilização de prótese a sua deambulação fica comprometida. A marcha é o meio natural que o ser humano utiliza para se deslocar de um local para outro. A marcha é uma atividade complexa porque depende de uma série de interações entre os dois membros inferiores multissegmentados e a massa total do corpo. Assim sendo, avaliar o impacto da utilização de prótese no aparelho locomotor por meio da análise das estratégias de inicialização da marcha em amputados transtibiais. Foram avaliados a velocidade e deslocamento do COP, ângulos do joelho e tornozelo do membro de apoio durante a inicialização da marcha. Para a análise cinemática foi fixado 34 marcadores em pontos anatômicos de interesse, mais duas plataformas de força AMTI. Para a análise estatística foi utilizado o test t de Student e a correlação entre as variáveis. Foi encontrada diferença estatística somente nas variáveis ângulo do joelho e velocidade médio lateral. A ausência de uma articulação do tornozelo flexível pode resultar em limitações na função da prótese. Os amputados para alcançar um adequado controle na propulsão e equilíbrio houve a necessidade a utilização de várias estratégias de ajustamento. A prótese fornecida pelo SUS atende o seu propósito, que é fornecer uma deambulação ao indivíduo. Porém a melhoria desta na articulação do tornozelo pode facilitar o processo de inicialização da marcha. Outro fato de grande importância é a freqüente avaliação do protetizado a fim de verificar os ajustes necessários da prótese.

Post stroke rehabilitation is effective when a large number of motor repetitions are provided to patients. However, conventional physical therapy or traditional desktop-size robot aided rehabilitation do not provide sufficient number of repetitions due to cost and logistical barriers. Our vision is to realize a wearable and functional hand orthosis that could be used outside of controlled, clinical settings, thus allowing for more training repetitions. Furthermore, if such a device can prove effective for Activities of Daily Living (ADLs) while actively worn, this can incentivize patients to increase its use, further enhancing rehabilitative effects. However, in order to provide such clinical benefits, the device must be completely wearable without obtrusive features, and intuitive to control even for non-experts. In this thesis, we thus focus on wearability, functionality, and intuitive intent detection technology for a novel hand robot, and assess its performance when used both as a rehabilitative device and an assistive tool. A fully wearable device must deliver meaningful manipulation capability in small and lightweight package. In this context, we investigate the capability of single-actuator devices to assist whole hand movement patterns through a network of exotendons. Our prototypes combine a single linear actuator (mounted on a forearm splint) with a network of exotendons (routed on the surface of a soft glove). We investigate two possible tendon network configurations: one that produces full finger extension (overcoming flexor spasticity) and one that combines proximal flexion with distal extension at each finger. In experiments with stroke survivors, we measure the force levels needed to overcome various levels of spasticity and to open the hand for grasping using the first of these configurations, and qualitatively demonstrate the ability to execute fingertip grasps using the second. Our results support the feasibility of developing future wearable devices able to assist a range of manipulation tasks. In order to further improve the wearability of the device, we propose two designs that provide effective force transmission by increasing moment arms around finger joints. We evaluate the designs with geometric models and experiment using a 3D-printed artificial finger to find force and joint angle characteristics of the suggested structures. We also perform clinical tests with stroke patients to demonstrate the feasibility of the designs. The testing supports the hypothesis that the proposed designs efficiently elicit extension of the digits in patients with spasticity as compared to existing baselines. With the suggested transmission designs, the device can deliver sufficient extension force even when the users have increased muscle tone due to fatigue. The vision of an orthotic device used for ADLs can only be realized if the patients are able to operate the device themselves. However, the field is generally lacking effective methods by which the user can operate the device: such controls must be effective, intuitive, and robust to the wide range of possible impairment patterns. The variety of encountered upper limb impairment patterns in stroke patients means that a single sensing modality, such as electromyography, might not be sufficient to enable controls for a broad range of users. To address this significant gap, we introduce a multimodal sensing and interaction paradigm for an active hand orthosis. In our proof-of-concept implementation, EMG is complemented by other sensing modalities, such as finger bend and contact pressure sensors. We propose multimodal interaction methods that utilize this sensory data as input, and show they can enable tasks for stroke survivors who exhibit different impairment patterns. We then assess the performance of the robotic orthosis for two possible roles: as a therapeutic tool that facilitates device mediated hand exercises to recover neuromuscular function, or as an assistive device for use in everyday activities to aid functional use of the hand. 11 chronic stroke (> 2 years) patients with moderate muscle tone (Modified Ashworth Scale ≤ 2 in upper extremity) engage in a month-long training protocol using the orthosis. Individuals are evaluated using standardized outcome measures, both with and without orthosis assistance. The results highlight the potential for wearable and user-driven robotic hand orthoses to extend the use and training of the affected upper limb after stroke. The advances proposed in this thesis have the potential to enable robotic based hand rehabilitation during daily activities (as opposed to isolated hand exercises with limited upper limb engagement) and over extended periods of time, even in a patient’s home environment. Numerous challenges must still be overcome in order to achieve this vision, related to design (compact devices with easier donning/doffing), control (robust yet intuitive intent inferral), and effectiveness (improved functionality in a wider range of metrics). However, if these challenges can be addressed, wearable robotic devices have the potential to greatly extend the use and training of the affected upper limb after stroke, and help improve the quality of life for a large patient population.

Thesis (Ph. D.)--University of Washington, 2005. / Vita. Includes bibliographical references.

In this paper we use multivariate statistical techniques to gain insights into how adaptive gait involving obstacle crossing is regulated in lower-limb amputees compared to able-bodied controls, with the aim of identifying underlying characteristics that differ between the two groups and consequently highlighting gait deficits in the amputees. Eight unilateral trans-tibial amputees and twelve able-bodied controls completed adaptive gait trials involving negotiating various height obstacles; with amputees leading with their prosthetic limb. Spatiotemporal variables that are regularly used to quantify how gait is adapted when crossing obstacles were determined and subsequently analysed using multivariate statistical techniques. There were fundamental differences in the adaptive gait between the two groups. Compared to controls, amputees had a reduced approach velocity, reduced foot placement distance before and after the obstacle and reduced foot clearance over it, and reduced lead-limb knee flexion during the step following crossing. Logistic regression analysis highlighted the variables that best distinguished between the gait of the two groups and multiple regression analysis (with approach velocity as a controlling factor) helped identify what gait adaptations were driving the differences seen in these variables. Getting closer to the obstacle before crossing it appeared to be a strategy to ensure the heel of the lead-limb foot passed over the obstacle prior to the foot being lowered to the ground. Despite adopting such a heel clearance strategy, the lead-foot was positioned closer to the obstacle following crossing, which was likely a result of a desire to attain a limb/foot angle and orientation at instant of landing that minimised loads on the residuum (as evidenced by the reduced lead-limb knee flexion during the step following crossing). These changes in foot placement meant the foot was in a different part of swing at point of crossing and this explains why foot clearance was considerably reduced in amputees. The results highlight that trans-tibial amputees use quite different gait adaptations to cross obstacles compared with controls (at least when leading with their prosthetic limb), indicating they are governed by different constraints; seemingly related to how they land on/load their prosthesis after crossing the obstacle. / Yes