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.

The physiological energy requirements of prosthetic gait in lower-limb amputees have been observed to be significantly greater than those for able-bodied subjects. However, existing models of energy flow in walking have not been very successful in explaining the reasons for this additional energy cost. Existing mechanical models fail to capture all of the components of energy cost involved in human walking. In this thesis, a new model is developed that estimates the physiological cost of walking for an able-bodied individual; the same cost of walking is then computed using a variation of the model that represents a bi-lateral below-knee amputee. The results indicate a higher physiological cost for the amputee model, suggesting that the model more accurately represents the relative metabolic costs of able-bodied and amputee walking gait. The model is based on a two-dimensional multi-body mechanical model that computes the joint torques required for a specified pattern of joint kinematics. In contrast to other models, the mechanical model includes a balance controller component that dynamically maintains the stability of the model during the walking simulation. This allows for analysis of many consecutive steps, and includes in the metabolic cost estimation the energy required to maintain balance. A muscle stress based calculation is used to determine the optimal muscle force distribution required to achieve the joint torques computed by the mechanical model. This calculation is also used as a measure of the metabolic energy cost of the walking simulation. Finally, an optimization algorithm is applied to the joint kinematic patterns to find the optimal walking motion for the model. This approach allows the simulation to find the most energy efficient gait for the model, mimicking the natural human tendency to walk with the most efficient stride length and speed.

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.

The physiological energy requirements of prosthetic gait in lower-limb amputees have been observed to be significantly greater than those for able-bodied subjects. However, existing models of energy flow in walking have not been very successful in explaining the reasons for this additional energy cost. Existing mechanical models fail to capture all of the components of energy cost involved in human walking. In this thesis, a new model is developed that estimates the physiological cost of walking for an able-bodied individual; the same cost of walking is then computed using a variation of the model that represents a bi-lateral below-knee amputee. The results indicate a higher physiological cost for the amputee model, suggesting that the model more accurately represents the relative metabolic costs of able-bodied and amputee walking gait. The model is based on a two-dimensional multi-body mechanical model that computes the joint torques required for a specified pattern of joint kinematics. In contrast to other models, the mechanical model includes a balance controller component that dynamically maintains the stability of the model during the walking simulation. This allows for analysis of many consecutive steps, and includes in the metabolic cost estimation the energy required to maintain balance. A muscle stress based calculation is used to determine the optimal muscle force distribution required to achieve the joint torques computed by the mechanical model. This calculation is also used as a measure of the metabolic energy cost of the walking simulation. Finally, an optimization algorithm is applied to the joint kinematic patterns to find the optimal walking motion for the model. This approach allows the simulation to find the most energy efficient gait for the model, mimicking the natural human tendency to walk with the most efficient stride length and speed.

While amputee gait has been studied in great detail, the influence of prosthetic foot sagittal and coronal plane stiffness on amputee walking biomechanics is not well understood. In order to investigate the effects of sagittal and coronal plane foot stiffness on amputee walking, a framework for manipulating the stiffness of a prosthetic foot needs to be developed. The sagittal and coronal plane stiffness of a low profile carbon fiber prosthetic foot was manipulated through coupling with selective-laser-sintered prosthetic ankles. The carbon fiber foot provided an underlying non-linear stiffness profile while the ankle modified the overall stiffness of the ankle-foot combination. A design of experiments was performed to determine the effect of four prosthetic ankle dimensions (keel thickness, keel width, space between the ankle top and bottom faces, and the location of the pyramid connection) on ankle-foot sagittal and coronal plane stiffness. Ankles were manufactured using selective laser sintering and statically tested to determine stiffness. Two of the dimensions, space between the ankle top and bottom faces and the location of the pyramid connection, were found to have the largest influence on both sagittal and coronal plane stiffness. A third dimension, keel thickness, influenced only coronal plane stiffness. A number of prosthetic ankle-foot combinations were created that encompassed a range of sagittal and coronal plane stiffness levels that were lower than that of the low profile carbon fiber foot alone. To further test the effectiveness of the framework to manipulate sagittal and coronal plane stiffness, two ankle-foot combinations, one stiffer than the other in the sagittal and coronal planes, were used in a case study analyzing amputee walking biomechanics. Differences in stiffness were large enough to cause noticeable changes in amputee kinematics and kinetics during turning and straight-line walking. Future work will expand the range of ankle-foot stiffness levels that can be created using this framework. The framework will then be used to create ankle-foot combinations to investigate the effect of sagittal and coronal plane stiffness on gait mechanics in a large sample of unilateral transtibial amputees. / text

For pediatric amputees in developing countries, where characteristically rapid growth of children is compounded by a lack of medical services, maintaining proper socket fit is a challenging but necessary endeavor. A socket design that adjusts for radial and longitudinal growth will allow patients to wear the same socket for a longer period of time saving them the expense of subsequent fittings and hardware. Manufacture of such a socket poses a challenge for contemporary manufacturing processes. Due to its ability to rapidly manufacture complex part geometries, Selective Laser Sintering (SLS) is particularly suited to this application. Several preliminary design concepts for a volume adjustable transtibial SLS prosthetic socket for pediatric amputees in developing countries have been generated. These current design concepts utilize fasteners such as ratchet hooks and threads. Results from design and validation of theoretical models of these fastener concepts are the focus of this thesis. / text

This study is the first to collect and summarize older ethnic Lithuanian city of Vilnius residents and maxillofacial anthropometric data on the dynamics of the overall physical dimensions of age-related dynamics to analyze the factors that influence the physical characteristics and facial anthropometric dimensions of variation. Our maxillofacial study is valuable for anthropologists, dentists, oral and maxillofacial surgeons, plastic surgeons, endocrinologists, geneticists, public health professionals. Our data point to the city of Vilnius Lithuanian nationality elderly population characteristic facial features, it will serve useful data to forensic experts, comprehensively investigating the unknown identity of the person. Purpose The purpose of the study is to examine the 45-year-old and older Vilnius residents of Lithuanian nationality face and some common physical characteristics of aging data, to determine the dependence on the overall health of the mouth and teeth in the social and economic factors. Conclusions 1. Face aging variation general tendency does not differ between the genders of 45-years and older aged Lithuanian ethnic population of Vilnius residents. Vilnius residents face anthropometric data differ significantly across all age and gender groups. Men's facial anthropometric dimensions of data are larger than females. Facial anthropometric data characteristic of the left and right sides shows the asymmetry. 2. Education and chronic diseases have significant... [to full text] / Šiame darbe pirmą kartą surinkti ir apibendrinti vyresnio amžiaus lietuvių tautybės Vilniaus miesto gyventojų veido ir žandikaulių antropomentriniai duomenys, pateikta jų dinamika, nustatyta bendrų fizinių matmenų amžinė dinamika, išanalizuoti veiksniai, darantys įtaką fizinių rodiklių bei veido antropometrinių matmenų kitimui. Šio tyrimo rezultatai atskleidžia žmogaus veido raidos dėsningumus, suteikia informacijos apie Lietuvos gyventojų dantų protezavimo situaciją ir padeda įvertinti požiūrį į burnos sveikatą. Gauti apibendrinti veido ir žandikaulių tyrimo duomenys vertingi antropologams, odontologams, burnos, veido ir žandikaulių chirurgams, plastinės chirurgijos specialistams, endokrinologams, genetikams, visuomenės sveikatos specialistams. Jie atskleidžia Vilniaus miesto vyresnio amžiaus lietuvių tautybės gyventojams būdingus veido bruožus, pasitarnauti tai bus pravartu teismo medicinos ekspertams, kompleksiškai tiriantiems nežinomo asmens tapatybę. Vyresnių nei 45-erių metų amžiaus lietuvių veido antrpometrinių populiacinių tyrimų neatlikta, todėl nėra duomenų, atspindinčių veido senėjimo procesus. Tyrimo tikslas – ištirti 45-erių metų amžiaus ir vyresnių lietuvių tautybės Vilniaus miesto gyventojų veido ir kai kurių bendrų fizinių senėjimo duomenų ypatumus, nustatyti priklausomybę nuo bendros sveikatos būklės, burnos ir dantų būklės socialinių ir ekonominių veiksnių. Išvados: 1. 45-erių metų amžiaus ir vyresnių lietuvių etninės populiacijos Vilniaus miesto... [toliau žr. visą tekstą]

Šiame darbe pirmą kartą surinkti ir apibendrinti vyresnio amžiaus lietuvių tautybės Vilniaus miesto gyventojų veido ir žandikaulių antropomentriniai duomenys, pateikta jų dinamika, nustatyta bendrų fizinių matmenų amžinė dinamika, išanalizuoti veiksniai, darantys įtaką fizinių rodiklių bei veido antropometrinių matmenų kitimui. Šio tyrimo rezultatai atskleidžia žmogaus veido raidos dėsningumus, suteikia informacijos apie Lietuvos gyventojų dantų protezavimo situaciją ir padeda įvertinti požiūrį į burnos sveikatą. Gauti apibendrinti veido ir žandikaulių tyrimo duomenys vertingi antropologams, odontologams, burnos, veido ir žandikaulių chirurgams, plastinės chirurgijos specialistams, endokrinologams, genetikams, visuomenės sveikatos specialistams. Jie atskleidžia Vilniaus miesto vyresnio amžiaus lietuvių tautybės gyventojams būdingus veido bruožus, pasitarnauti tai bus pravartu teismo medicinos ekspertams, kompleksiškai tiriantiems nežinomo asmens tapatybę. Vyresnių nei 45-erių metų amžiaus lietuvių veido antrpometrinių populiacinių tyrimų neatlikta, todėl nėra duomenų, atspindinčių veido senėjimo procesus. Tyrimo tikslas – ištirti 45-erių metų amžiaus ir vyresnių lietuvių tautybės Vilniaus miesto gyventojų veido ir kai kurių bendrų fizinių senėjimo duomenų ypatumus, nustatyti priklausomybę nuo bendros sveikatos būklės, burnos ir dantų būklės socialinių ir ekonominių veiksnių. Išvados: 1. 45-erių metų amžiaus ir vyresnių lietuvių etninės populiacijos Vilniaus miesto... [toliau žr. visą tekstą] / This study is the first to collect and summarize older ethnic Lithuanian city of Vilnius residents and maxillofacial anthropometric data on the dynamics of the overall physical dimensions of age-related dynamics to analyze the factors that influence the physical characteristics and facial anthropometric dimensions of variation. Our maxillofacial study is valuable for anthropologists, dentists, oral and maxillofacial surgeons, plastic surgeons, endocrinologists, geneticists, public health professionals. Our data point to the city of Vilnius Lithuanian nationality elderly population characteristic facial features, it will serve useful data to forensic experts, comprehensively investigating the unknown identity of the person. Purpose The purpose of the study is to examine the 45-year-old and older Vilnius residents of Lithuanian nationality face and some common physical characteristics of aging data, to determine the dependence on the overall health of the mouth and teeth in the social and economic factors. Conclusions 1. Face aging variation general tendency does not differ between the genders of 45-years and older aged Lithuanian ethnic population of Vilnius residents. Vilnius residents face anthropometric data differ significantly across all age and gender groups. Men's facial anthropometric dimensions of data are larger than females. Facial anthropometric data characteristic of the left and right sides shows the asymmetry. 2. Education and chronic diseases have significant... [to full text]

Staphylococcus epidermidis has emerged in recent years as an important nosocomial pathogen, especially in infections associated with implanted foreign body materials (e.g., prosthetic joints and heart valves) and in individuals with a compromised immune system (e.g., cancer patients and neonates). Although rare, implant infections are long lasting and cause severe suffering for the patient that includes pain and disability and even increased mortality. One aim of the present thesis was to develop and evaluate a genetic method for species identification and simultaneous detection of rifampicin resistance in staphylococci. A second aim was to examine S. epidermidis isolated from prosthetic joint infections (PJIs) and from wrists and nares of healthy individuals regarding their antibiotic susceptibility, biofilm production, virulence factors, and epidemiology. Comparison with phenotypic diagnostics revealed that 8 (16%) of 49 isolates differed in their species identification in favour of the genetic method. In addition, mutations associated with rifampicin resistance, including two not previously reported, were possible to detect in all isolates resistant to rifampicin. Antibiotic susceptibility testing of 61 PJI isolates showed multi-drug resistance in 91%. Furthermore, the results of the synergy testing revealed that no antibiotic combination was significantly better than the others. Hence, the effects that were possible to detect were isolate dependent. To find a method for discriminating between invasive (n=61) and commensal (n=24) isolates of S. epidermidis genotypic and phenotypic characterisations of biofilm production (including the ica and aap genes), antibiotic susceptibility, virulence-related genes (such as agr and ACME) and epidemiology were performed (using multilocus sequence typing [MLST], typing of the staphylococcal chromosome cassette mec [SCCmec] and PhenePlate). Significant differences were found in antibiotic susceptibility, i.e. there was more resistance among invasive isolates. MLST sequence types (ST) ST2 and ST215 dominated the invasive isolates.

Made available in DSpace on 2014-06-11T19:28:58Z (GMT). No. of bitstreams: 0 Previous issue date: 2005Bitstream added on 2014-06-13T18:35:11Z : No. of bitstreams: 1 zaze_ca_me_araca.pdf: 893710 bytes, checksum: 246541052b07b294999b016436174c3a (MD5) / Universidade Estadual Paulista (UNESP) / Este trabalho foi idealizado com o intuito de contribuir para os estudos pertinentes à área da prótese total, e teve como objetivo analisar a alteração da posição relativa dos dentes artificiais em razão do processamento de 40 próteses totais inferiores, obtidas por uma matriz de silicone pré-moldada. Na metodologia, as próteses foram divididas em quatro grupos de 10, que receberam os seguintes tratamentos: Grupo 1 - inclusão em muflas metálicas com muralha de gesso pedra tipo III e polimerização em banho de água quente; Grupo 2 - inclusão em muflas de fibra de vidro com muralha de gesso pedra tipo III e polimerização em microondas; Grupo 3 - inclusão em muflas metálicas com muralha de silicone e polimerização em banho de água quente e Grupo 4 - inclusão em muflas de fibra de vidro com muralha de silicone e polimerização em microondas. Como conclusões, os resultados demonstraram que houve alteração na posição dos dentes artificiais em todas as técnicas de processamento, com o grupo 3 apresentando os melhores resultados seguido dos grupos 4, 2 e 1. / The purpose of this study is to analyze the change in denture tooth position in the fabrication of complete mandibular dentures after different processing techniques. A total of 40 mandibular complete dentures, obtained by a premolded matrix of silicon, were fabricated. There were a total of four groups of complete mandibular dentures. Each group consisted of 10 complete mandibular dentures which were fabricated in the following manner: Group 1 - were processed in a metallic flask using stone plaster type III and polymerized in hot water; Group 2 - were processed in a fiberglass flask using stone plaster type III and polymerized in a microwave; Group 3 - were processed in a metallic flask using silicon and stone plaster type III and polymerized in hot water; Group 4 - were processed in a fiberglass flask using silicon and stone plaster type III and polymerized in a microwave. In conclusion, the results demonstrated that there were alterations in tooth position in all processing techniques. However, Group 3 presented with the least amount of change in tooth positon, followed by Group 4, then Group 2, and finally Group 1 with the most amount of change in tooth position.