The rationale behind this research originates from the lack of public health care in South Africa. There is an escalation in the number of stroke victims which is a consequence of the increase in hypertension in this urbanising society. This increase results in a growing need for physiotherapists and occupational therapists in this country which is further hindered by the division between urban and rural areas. The exoskeleton device has been formulated to encapsulate methodologies that enable the anthropomorphic integration between a biological and mechatronic limb. The physiotherapeutic mechanism was designed to be portable and adjustable, without limiting the spherical motion and workspace of the human arm. The exoskeleton was portable in the sense that it could be transported geographically and is a complete device allowing for motion in the shoulder, elbow, wrist and hand joints. The avoidance of singularities in the workspace required the implementation of non-orthogonal joints which produces extensive forward kinematics. Traditional geometric or analytical derivations of the inverse kinematics are complicated by the nonorthogonal layout. This hindrance was resolved iteratively via the Damped Least Squares method. The electronic and computer system allowed for professional personnel, such as an occupational therapist or a physiotherapist, to either change an individual joint or a combination of joints angles. A ramp PI controller was established to provide a smooth response in order to simulate the passive therapy motion. / Thesis (M.Sc.Eng)-University of KwaZulu-Natal, Durban, 2011.

<p> Parkinson's disease is a degenerative neurological disease that often impacts older adults, leading to difficulties with transfers, posture, balance, and walking. Approximately half of those with Parkinson's disease develop the symptom of freezing of gait, a condition that makes initiating walking difficult. This leads to loss of independence, fear of falls, injuries, inactivity resulting in social isolation, and increased risk of osteoporosis. Pharmacological therapy provides relief to only some of the neurological symptoms in Parkinson's disease. However, gait, posture, balance, and freezing of gait obtain little benefit from drug treatments. </p><p> Research suggests visual, auditory, and vibratory cueing methods may improve some features of gait. However, visual cueing techniques often require modification of the environment, which is not possible in the community setting. Auditory cueing techniques can be executed with the use of headphones, but this can quickly become a problem, as it becomes a safety concern when it interferes with hearing environmental sounds. Studies of whole body vibration and studies of segment level vibration have demonstrated improvements to walking speed, step duration, step length, and gait variability. However, most studies have only focused on the immediate effects of vibration therapy. </p><p> To assess the impact of vibration as an intervention, we have designed the hard- ware, software, therapy protocol, and conducted a series of studies for this dissertation. The hardware is designed as a segment level device, which can be worn by a user and both provides the vibratory stimulation and measures parameters of gait. We call the device the PDShoe. Three force sensors are embedded into the insole the shoe worn by subjects. Two tactor actuators are placed between the shoe and subject's skin. Upon heel contact with the floor, a tactor placed at the heel begins to vibrate at a predetermined frequency and amplitude. Likewise, when the lateral metatarsal head or hallux of the foot contact the floor, a tactor placed over the metatarsal heads begins to vibrate. Vibration is only provided with the foot is in contact with the floor; this is step synchronized vibration. Data is transferred via a wireless network in real time to a host computer where it is stored for later analysis. Parameters of the vibratory stimulation can be set on the PDShoe from the host computer. Data analysis is performed in a numerical analysis environment, where the time series force data is cut into individual steps. Eight parameters of gait are extracted from each of these steps, providing mean and variability measures for each subject. </p><p> To test the efficacy of step synchronized vibration, we conducted two studies with healthy subjects and four studies with Parkinson's disease subjects. Accuracy and reliability of the device was established and included the use of change point analysis and correlation with the 10-meter Walk Test. Using the PDShoe system without vibratory feedback, we successfully characterized the gait of healthy persons over fifty years old. Subsequently we tested the feasibility, safety, and impact of our step synchronized vibration protocol with healthy subjects. Our protocol was easily implemented, well tolerated, and there were no adverse events. As was expected, no impact from the step synchronized vibration was seen with the healthy subjects. We then performed a feasibility and impact study with Parkinson's disease subjects. Again the protocol was easily implemented, well tolerated, and no adverse events were noted. A difference between pre- and post-intervention clinical scores of the Freezing of Gait Questionnaire, Berg Balance Scale, Timed Up and Go and gait measures of step and stance duration were found. Next, we conducted a clinical study with eight subjects at the All India Institute of Medical Sciences. This study demonstrated that subjects who exhibited the symptom of freezing of gait received the greatest benefit from the step synchronized vibration. These results informed a follow up study on seventeen subjects, all of whom had the symptom of freezing of gait. This last study demonstrated positive improvements in clinical measures of the Freezing of Gait Questionnaire, Berg Balance Scale, Timed Up and Go, Walking Speed, and gait characteristics of step duration, stance duration, swing duration, heel max force timing, and heel contact duration. There is encouraging evidence for further investigation; this data will be used to inform future studies. </p><p> These studies demonstrated the functionality, reliability, validity of the PDShoe device to measure characteristics of gait. Impact was demonstrated in three studies with Parkinson's disease subjects.</p>

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Participants were twelve 70+ kg male strength-trained athletes and one passenger child with a mass of 29 kg. The male participants walked three times over a force plate embedded in an eight metre walkway for each of three conditions: carrying no load, a 29 kg backpack, or a 29 kg passenger. Variables were compared using a repeated measures ANOVA test with a Bonferroni correction. Both load conditions produced compensatory trunk flexion; trunk flexion increased from no load to piggybacking to backpacking. Trunk range of motion was similar for no load and piggybacking, but increased to backpacking. The backpack load caused greater resultant and total magnitude of torque than the passenger load. The trunk extensors dominated with no load and piggybacking and the trunk flexors dominated with backpacking. Many of the significant differences between conditions suggest that piggybacking is biomechanically more similar to natural gait than is backpacking.

INTRODUCTION: Excessive hip adduction (HADD) has been associated with a number of lower extremity overuse injuries, and it has been suggested that it may be the result of reduced strength of the hip abduction musculature. Hip structure has been postulated to influence both hip abduction (HABD) strength and HADD. The purpose of this study was to investigate the relationship between hip structure, HABD strength, and frontal plane kinematics during running. METHODS: Peak isometric HABD strength, lower extremity kinematics, femoral neck-shaft angle (NSA), and pelvis width-femur length (pw-fl) ratio were recorded for 25 female subjects. Pearson correlations (P < .05) were performed between variables. RESULTS: A fair relationship was observed between femoral NSA and HABD strength (r = -.472 P = .017) where an increased NSA was associated with reduced HABD strength. No relationship was observed between HABD strength and frontal plane kinematics or between NSA/pw-fl and frontal plane kinematics. CONCLUSION: Alterations in the femoral NSA have the ability to influence peak isometric hip abduction strength. However, alterations in strength did not result in changes in lower extremity kinematics. Structural deviations at the hip do not appear to influence hip kinematics during running.

<p> This thesis presents the modeling, design, fabrication, and testing of a magnetophoretic bioseparation chip for isolation of biomaterials such as cells, antigens or DNA from their native environment. This microfluidic-based bioseparation device has several unique features, including locally engineered magnetic field gradients and a continuous flow with a buffer switching scheme to improve the performance of the separation process. The overall dimensions of the device are 25 mm by 75 mm by 1 mm. The cell purity was found to increase with increasing the sample flow rate. However, the cell recovery decreases with an increase in the flow rate. A compressive parametric study is performed to investigate the effects of channel height, substrate thickness, magnetic bead size, cell size, flow rate, and the number of beads per cell on the cell separation performance.</p>

<p> Myoelectric control systems (MECs) remain the technological bottleneck in the development of advanced prosthetic hands. MECs should provide a human machine interface that deciphers user intent in real-time and operates effectively in daily life. Current MECs like finite state machines and pattern recognition systems require physiologically inappropriate commands to indicate intent and/or lack effectiveness in a clinical setting. The work of this dissertation aims to develop and validate a novel MEC architecture, namely postural control, in order to supplant the current state of the art MECs and recreate more of the characteristics of the intact limb. Specifically, the development of the postural control systems builds upon previous work based on principal component analysis of human grasping. Novel attributes of the postural control system were then added to the MEC, empirically tested, and validated with able limbed subjects using a virtual hand interface. Further investigation of the postural controller was performed by comparing it to state of the art commercial and research MECs with able limbed subjects using a physical prosthesis during activities of daily living. The dissertation concludes by verifying the increased effectiveness and robustness of the postural controller compared to other MECs when used by persons with transradial limb loss to perform activities of daily living with a physical prosthesis.</p>

The varied impact parameters that characterize an impact to the head have shown to influence the resulting type and severity of outcome injury, both in terms of the dynamic response, and the corresponding deformation of neural tissue. Therefore, when determining head injury risks through event reconstruction, it is important to understand how individual impact characteristics influence these responses. The effect of inbound mass had not yet been documented in the literature. The purpose of this study was to determine the effects of inbound mass on the dynamic impact response and brain tissue deformation. A 50th percentile Hybrid III adult male head form was impacted using a simple pendulum system. Impacts to a centric and a non-centric impact location were performed with six varied inbound masses at a velocity of 4.0 m/s. The peak linear and peak angular accelerations were measured. A finite element model, (UCDBTM) was used to determine brain deformation, namely peak maximum principal strain and peak von Mises stress. Inbound mass produced significant differences for peak linear acceleration for centric (F(5, 24) = 217.55, p=.0005) and non-centric (F(5, 24) = 161.98, p=.0005), and for peak angular acceleration for centric (F(5, 24) = 52.51, p=.0005) and non-centric (F(5, 24) = 4.18, p=.007) impact locations. A change in inbound mass also had a significant effect on peak maximum principal strain for centric (F(5, 24) = 11.04, p=.0005) and non-centric (F(5, 24) = 5.87, p =.001), and for peak von Mises stress for centric (F(5, 24) = 24.01, p=.0005) and non-centric (F(5, 24) = 4.62, p=.004) impact locations. These results indicate the inbound mass of an impact should be of consideration when determining risks and prevention to head and brain injury.