No description available.

No description available.

The number of Total Glossectomy cases in the United States is seeing an increasing trend as per the Nationwide Inpatient Sample Database. Patients, who have undergone such aggressive surgical procedures, have extensive limitations performing basic oral functions such as swallowing (deglutition), eating and speaking. Current rehabilitation prostheses do little in restoring the functionality of the original tongue. This is true especially in deglutition, which is necessary to transfer a bolus to the esophagus. Such patients need advanced prosthetic devices and through this research, investigations into potential solutions for prosthetic tongues to aid in deglutition were carried out. The process began with an extensive literature review that provided tongue position, motion, and pressure data during the swallowing stages. Several potential designs were considered such as using linkages and pneumatic networks (PneuNets). Based on a decision matrix, PneuNets were adopted as the foundational basis for generating prosthetic designs. Several prototypes were fabricated using Fused Filament Disposition for mold development and silicone Eco-flex 00-30 for actuator development. Each iteration involved tackling several design and manufacturing challenges especially when scaling these actuators from an initial experiment to an anatomical shape and size of a human tongue. A tongue of dimensions 1.8 inches wide, 2.4 inches long and 0.24 inches thick was developed. The PneuNet actuator was powered by a pneumatic system and kinematic data was collected using a tracking software. The data gathered provided validation comparisons between position trends exhibited in the literature. Theoretical deflection models were generated for analyzing the deflection of the front, middle and back sections of the tongue prototype. Details from literature review, design iterations, simulations, validation processes, research challenges and conclusions will be discussed in depth.

This thesis describes the system design of EMG Site, a MATLAB-based application for collection and visualization of surface electromyograms (EMGs) and the real-time control of an upper limb prosthesis, including details pertaining to the design of the software and the graphical user interface (GUI). The application consists of features that aid in the visualization of the collected EMG data and the control of a prosthesis. Visualization of the collected EMG data is handled in one of two ways: an oscilloscope-like view showing the raw EMG data collected with respect to time, or a radial plot showing the processed EMG data collected with respect to the site of EMG data collection on the arm. The control of a hand-wrist prosthesis is primarily regulated through the use of signal processing designed to relate EMG to torque and is visualized in the tracking window - a plotting window showing both a user-control cursor and an either static (or dynamic) computer-controlled target. This thesis concludes with a description of the real-time capabilities of the application regarding both the visualization of the collected EMG data as well as the control of a prosthesis.

The aim of this project was to determine the possible role of the extracellular polymeric substances (EPS) of <I>Staphylococcus epidermidis</I> in biomaterial-centered infections. The first part of the project involved the production, isolation, and characterisation of <I>S.epidermidis</I> EPS. A novel method for the isolation of EPS from complex medium was developed which was able to eliminate the problems associated with contamination of bacterial EPS by medium components. Using this method, samples of EPS were obtained from <I>S.epidermidis</I> ATCC 35984 and clinical isolates. In the second part of the project, studies were carried out in order to determine the effect of EPS-eradicating treatments on (a) the susceptibility of stationary phase planktonic cultures to antibiotics, and (b) the integrity of intact biofilms. Eradication of EPS was achieved by exposure of planktonic stationary phase cultures of a clarithromycin-resistant strain of <I>S.epidermidis</I> (Clar^r No.6) to clarithromycin^*. This antibiotic had no effect on the growth or viability of this strain, however, exposure to clarithromycin resulted in a dose-dependent reduction in the dry weight of EPS obtained (5 μg ml^-1 = 50% reduction, 10 μg ml^-1 = 65% reduction). This result was also achieved with stationary phase cultures of a clarithromycin-sensitive strain of <I>S.epidermidis</I> (16595A). The effect of clarithromycin exposure (EPS eradication) on the subsequent efficacies of the antibiotics teicoplanin, cefuroxime and ciprofloxacin, towards stationary phase planktonic cultures of <I>S.epidermidis</I> Clar^r No.6 was determined by total and viable cell counts. No effect on cell viability was observed for combinations of clarithromycin and teicoplanin or ciprofloxacin. However, the 2 to 3 log reduction in viability that was observed for combinations of clarithromycin and cefuroxime suggested that these two antibiotics may have been working in synergy. ^* Clarithromycin is a macrolide antibiotic which is thought to act on the 50 S ribosomal subunit of bacteria which will then interfere with protein synthesis and in turn lead to inhibition of bacterial growth.

No description available.

No description available.

Prosthetic joint infection with Mycobacterium tuberculosis usually involves the hips or knees and can result from either local reactivation, or less often from hematogenous spread. Predisposing conditions include rheumatoid arthritis, chronic steroid use and pulmonary diseases. The most common symptom at presentation is pain, and the most common physical finding is joint swelling and/or a draining sinus tract. The sedimentation rate is helpful when elevated but is nonspecific, and initial skin testing is only helpful when positive. The diagnosis depends on culture and histologic examination of tissue. Removal of the joint combined with oral antituberculous treatment is necessary when the infection is discovered greater than six weeks post joint replacement. Early diagnosis leads to decreased morbidity. Tuberculous infection of prosthetic joints is a rare disease and its diagnosis depends on a high degree of clinical suspicion.

Prosthetic development recently has focused mainly on myoelectrically controlled electric hands despite a majority of upper extremity amputees actively choosing body powered devices. Myoelectric hands utilize a small electric pulse generated in muscles when flexing as a signal to the hand to close. Finger flexion in these devices is controlled by electromechanical servos, requiring no strength input from the user. Body powered devices use a cable attached to a shoulder harness which causes mechanical closure of the device via tension placed on a control cable by a shoulder shrug motion or arm extension. Outfitting of active duty service personnel has recently tended to follow the electronic hands which have fragile electronics, have a poor response to user input, and are not fit for harsh outdoor environments. This report will detail the current development of a re-design of a custom left hand prosthesis for an active duty Navy SEAL and the transition from electronic controls to full body power function.

To make sense of our unpredictable world, humans use sensory information streaming through billions of peripheral neurons. Uncertainty and ambiguity plague each sensory stream, yet remarkably our perception of the world is seamless, robust and often optimal in the sense of minimising perceptual variability. Moreover, humans have a remarkable capacity for dexterous manipulation. Initiation of precise motor actions under uncertainty requires awareness of not only the statistics of our environment but also the reliability of our sensory and motor apparatus. What happens when our sensory and motor systems are disrupted? Upper-limb amputees tted with a state-of-the-art prostheses must learn to both control and make sense of their robotic replacement limb. Tactile feedback is not a standard feature of these open-loop limbs, fundamentally limiting the degree of rehabilitation. This thesis introduces a modular closed-loop upper-limb prosthesis, a modified Touch Bionics ilimb hand with a custom-built linear vibrotactile feedback array. To understand the utility of the feedback system in the presence of multisensory and sensorimotor influences, three fundamental open questions were addressed: (i) What are the mechanisms by which subjects compute sensory uncertainty? (ii) Do subjects integrate an artificial modality with visual feedback as a function of sensory uncertainty? (iii) What are the influences of open-loop and closed-loop uncertainty on prosthesis control? To optimally handle uncertainty in the environment people must acquire estimates of the mean and uncertainty of sensory cues over time. A novel visual tracking experiment was developed in order to explore the processes by which people acquire these statistical estimators. Subjects were required to simultaneously report their evolving estimate of the mean and uncertainty of visual stimuli over time. This revealed that subjects could accumulate noisy evidence over the course of a trial to form an optimal continuous estimate of the mean, hindered only by natural kinematic constraints. Although subjects had explicit access to a measure of their continuous objective uncertainty, acquired from sensory information available within a trial, this was limited by a conservative margin for error. In the Bayesian framework, sensory evidence (from multiple sensory cues) and prior beliefs (knowledge of the statistics of sensory cues) are combined to form a posterior estimate of the state of the world. Multiple studies have revealed that humans behave as optimal Bayesian observers when making binary decisions in forced-choice tasks. In this thesis these results were extended to a continuous spatial localisation task. Subjects could rapidly accumulate evidence presented via vibrotactile feedback (an artificial modality ), and integrate it with visual feedback. The weight attributed to each sensory modality was chosen so as to minimise the overall objective uncertainty. Since subjects were able to combine multiple sources of sensory information with respect to their sensory uncertainties, it was hypothesised that vibrotactile feedback would benefit prosthesis wearers in the presence of either sensory or motor uncertainty. The closed-loop prosthesis served as a novel manipulandum to examine the role of feed-forward and feed-back mechanisms for prosthesis control, known to be required for successful object manipulation in healthy humans. Subjects formed economical grasps in idealised (noise-free) conditions and this was maintained even when visual, tactile and both sources of feedback were removed. However, when uncertainty was introduced into the hand controller, performance degraded significantly in the absence of visual or tactile feedback. These results reveal the complementary nature of feed-forward and feed-back processes in simulated prosthesis wearers, and highlight the importance of tactile feedback for control of a prosthesis.