Evaluation of Concavity Compression Mechanism as a Possible Predictor of Shoulder Muscle Fatigue

This study examined the lived experiences of American Muslim principals who serve in public schools post-9/11 to determine whether global events, political discourse, and the media coverage of Islam and Muslims have affected their leadership and spirituality. The aim of the study was to allow researchers and educators to gain an understanding of the adversities that American Muslims principals have experienced post-9/11 and to determine how to address these adversities, particularly through decisions about educational policy and district leadership. A total of 14 American Muslim school leaders who work in public schools post-9/11 across the United States participated in the study, and a phenomenological methodology was used to direct the data collection and coding. Edelman\u27s political spectacle theory served as the theoretical framework for the research. The findings yielded six themes of political climate, role of the media, inferior and foreign: being seen as the other, unconscious fear, spirituality, and education and communication over spectacle. Further, collective guilt and social responsibility emerged as two additional findings. The research suggests that political spectacle and its effects have a large impact on the lives of American Muslim principals, particularly in regard to their leadership and spirituality

Enhancing human metabolic economy in stair climbing via an elastic crutch mechanism

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2011.Cataloged from PDF version of thesis.Includes bibliographical references (p. 77-79).Crutching provides a significant increase in mobility for those with limited walking ability. While level ground walking with crutches has been studied in many different forms, stair climbing is a more energetically taxing activity and the upper arm and shoulder strength required is not always available in weaker or severely injured patients. We posit that the introduction of parallel springs spanning the elbow joint will improve the crutching experience by helping patients attain a metabolic reduction compared to unassisted locomotion. Here, we present a foundation for achieving metabolic reduction with joint-spanning elastic elements. Our approach includes three parts. First, we present an augmented crutch design with an elbow spring that can be modified with different stiffnesses. Second, we put forth a clinical testing protocol in which we measure metabolic economy via the pulmonary gas exchange technique (Vo2avg). Simultaneously recording electromyographic (EMG) signals from the primary active muscles provides a neuromuscular interpretation of the crutching activity not captured by the black-box metabolic techniques. We complete the picture by modeling the energetics of the effective elbow muscle by incorporating empirical measurements of maximum angular velocity achieved under a range of isotonic conditions. The metabolic data exhibits trends consistent with our hypothesis of metabolic reduction; although, more subjects are needed to confirm these results. All subjects reported a feeling of augmentation at the optimal stiffness condition. An analysis of the EMG results show a clear transition in muscle usage patterns from a triceps only power stroke to a combined usage of both triceps and biceps. Where the triceps are maximally active during the non-augmented state, as stiffness increases the biceps become more active and the total activation level drops, suggesting the this shift is at least partially responsible for the observed metabolic reduction. While the model correctly predicts the relative shape of the observed curve, the optimal stiffness predictions are higher than their empirical equivalents. This is most likely due to the extra help the triceps muscles received from active stabilization and power muscles not considered in the model. With a more complete muscular picture one could begin to construct an accurate method of prediction and tuning of optimal stiffness.by Madalyn S. Berns.S.M

Structural integrity of aortic scaffolds decellularized by sonication decellularization system

Sonication decellularization technique has shown effectiveness to remove all the cellular components by the disruption of the cell membranes and removal of the cell debris to prepare the bioscaffolds. However, it is important to confirm whether this technique does not have a detrimental effect on elastin and collagen in bioscaffolds. The objectives of this study are to evaluate the structural integrity of bioscaffolds using histological staining and quantitatively collagen and elastin measurement. Aortic tissues were sonicated in 0.1% SDS for 10 hours at the frequency of 170 kHz with the power output of 15W and washed in Phosphate Buffer Solution (PBS) for 5 days. Then the sonicated aortic tissues were evaluated by Hematoxylin & Eosin (H&E) staining for cell removal analysis, Verhoeff-van Gieson (VVG) staining for visualizing elastin and Picrosirius Red (PSR) staining for visualizing collagen. The collagen and elastic fibres were semi-quantified by ImageJ software. The results showed that sonication decellularization system can remove all the cellular components while maintaining the structural integrity of elastin and collagen on bioscaffolds. This study indicates that sonication decellularization system could remove all cellular components and maintain the structure of the extracellular matrix

On the development of a cybernetic prosthetic hand

The human hand is the end organ of the upper limb, which in humans serves the important function of prehension, as well as being an important organ for sensation and communication. It is a marvellous example of how a complex mechanism can be implemented, capable of realizing very complex and useful tasks using a very effective combination of mechanisms, sensing, actuation and control functions. In this thesis, the road towards the realization of a cybernetic hand has been presented. After a detailed analysis of the model, the human hand, a deep review of the state of the art of artificial hands has been carried out. In particular, the performance of prosthetic hands used in clinical practice has been compared with the research prototypes, both for prosthetic and for robotic applications. By following a biomechatronic approach, i.e. by comparing the characteristics of these hands with the natural model, the human hand, the limitations of current artificial devices will be put in evidence, thus outlining the design goals for a new cybernetic device. Three hand prototypes with a high number of degrees of freedom have been realized and tested: the first one uses microactuators embedded inside the structure of the fingers, and the second and third prototypes exploit the concept of microactuation in order to increase the dexterity of the hand while maintaining the simplicity for the control. In particular, a framework for the definition and realization of the closed-loop electromyographic control of these devices has been presented and implemented. The results were quite promising, putting in evidence that, in the future, there could be two different approaches for the realization of artificial devices. On one side there could be the EMG-controlled hands, with compliant fingers but only one active degree of freedom. On the other side, more performing artificial hands could be directly interfaced with the peripheral nervous system, thus establishing a bi-directional communication with the human brain

A computer-aided study of neuromuscular control in relation to structural properties of the external respiratory apparatus in the cat

Imperial Users onl

Rehabilitation Engineering

Population ageing has major consequences and implications in all areas of our daily life as well as other important aspects, such as economic growth, savings, investment and consumption, labour markets, pensions, property and care from one generation to another. Additionally, health and related care, family composition and life-style, housing and migration are also affected. Given the rapid increase in the aging of the population and the further increase that is expected in the coming years, an important problem that has to be faced is the corresponding increase in chronic illness, disabilities, and loss of functional independence endemic to the elderly (WHO 2008). For this reason, novel methods of rehabilitation and care management are urgently needed. This book covers many rehabilitation support systems and robots developed for upper limbs, lower limbs as well as visually impaired condition. Other than upper limbs, the lower limb research works are also discussed like motorized foot rest for electric powered wheelchair and standing assistance device