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published_or_final_version / Mechanical Engineering / Master / Master of Philosophy

This thesis describes the successful development and initial evaluation of a proof-of-concept wireless monitoring system for improving the effectiveness and safety of pneumatic compression therapy to help prevent deep vein thrombosis (DVT). In the development, an important objective was to make feasible the practical and commercial deployment of such improved therapy systems in future, by focusing on a cost-effective design and implementation. Over the years, pneumatic compression has been shown to be an effective solution for the prevention of DVT. However, different problems and complications related to the use of commercial pneumatic compression de-vices that typically include automatic pressure controllers and pneumatic compression sleeves have been reported. For example, one study reported a high percentage of improperly applied or nonfunctional pneumatic compression devices in routine usage. Technical problems, non-compliance, and human error were identified as the causes behind the failed therapies. Also, it was reported that dedicated in-service instruction did not improve the proper use of the pneumatic compression controllers and sleeves. In another study, significant unanticipated variations between expected and delivered pneumatic compression therapy were reported: expected therapy delivered only an average of 77.8% of the time during the therapy, and much of the time key values related to the outcome of the therapy were found to have variations great than 10%. Specific hazards have also been reported. For example, one patient developed acute compartment syndrome after wearing a pair of pneumatic compression sleeves with faulty pressure release valves. In another case, epidural analgesia masked a malfunction resulting from a reversed connection between four-way plastic tubing of the sleeves and the controller, exposing a patient to a hazardous pressure of around 300mmHg,blocking all blood flow for a prolonged period of time. Newer models of pneumatic compression sleeves and controllers from various manufacturers claim to improve therapy by, for example, increasing the peak blood flow velocity. However, there is no evidence in the published literature to support such claims. A published review of the literature from1970-2002 reached the conclusion that the most important factors in im-proving therapy with pneumatic compression devices, particularly during and after surgery, were the degree of conformance of delivered therapy to the prescribed therapy, patient compliance, and the appropriateness of the site of compression. The inability to monitor delivered therapy and patient compliance remains a problem in efforts to improve pneumatic compression therapy. The above-described problems were addressed in the successful development of the innovative prototype described in this thesis. This wireless monitoring system should improve the effectiveness and safety of pneumatic compression therapy. Also, innovative aspects of the system design allow for cost-effective integration into existing commercial controllers and sleeves. For example, an innovative and potentially patentable usage and reprocess indicator was developed for pneumatic compression sleeves to significantly improve their safety and to reduce their cost of use per patient.

No description available.

This thesis documents the development of a novel nonlinear controller for servo pneumatic actuators that give good reference tracking at low speed motion, where friction has strong effect to the system behaviors. The design of the nonlinear controller presented in this thesis is based on the formalism of Lyapunov stability theory. The controller is constructed through a dynamical adaptive backstepping-sliding mode control algorithm. The conventional Lyapunov-based control algorithm is often limited by the order of the dynamical system; however, the backstepping design concept allows the control algorithm to be extended to higher order dynamical systems. In addition, the friction is estimated on-line via the Lyapunov-based adaptive laws embedded in the controller; meanwhile, the sliding mode control provides high robustness to the system parameter uncertainties. The simulation results clearly demonstrating the improved system performance (i.e., fast response and the reduced tracking error) are presented. Finally, the integration of the controller with a Lyapunov-based pressure observer reduces the state feedback of the servo pneumatic actuator model to only the piston displacement.

This thesis documents the development of a novel nonlinear controller for servo pneumatic actuators that give good reference tracking at low speed motion, where friction has strong effect to the system behaviors. The design of the nonlinear controller presented in this thesis is based on the formalism of Lyapunov stability theory. The controller is constructed through a dynamical adaptive backstepping-sliding mode control algorithm. The conventional Lyapunov-based control algorithm is often limited by the order of the dynamical system; however, the backstepping design concept allows the control algorithm to be extended to higher order dynamical systems. In addition, the friction is estimated on-line via the Lyapunov-based adaptive laws embedded in the controller; meanwhile, the sliding mode control provides high robustness to the system parameter uncertainties. The simulation results clearly demonstrating the improved system performance (i.e., fast response and the reduced tracking error) are presented. Finally, the integration of the controller with a Lyapunov-based pressure observer reduces the state feedback of the servo pneumatic actuator model to only the piston displacement.

Research Doctorate - Doctor of Philosophy (PhD) / Slug flow dense phase pneumatic conveying can be a most reliable, efficient method for handling a remarkably wide range of dry bulk solids. Models for pressure drop over slugs in the low-velocity slug-flow pneumatic conveying by many researchers only took the force balance into account with the pressure drop. However, the nature of the slug flow pneumatic conveying is discontinuous and seldom becomes steady during the conveying period which requires further investigation. The fundamental understanding to gas/slug interaction in this thesis is that, by being a dynamic system, the faster a slug moves at a speed, the larger the space is left behind the slug. The gas feeding into the conveying system has to fill the increased space first then permeates through the slug and provides a push force on the slug. With gas permeation rate defined by the permeability factor, the derivative of the upstream pressure based on the air mass conservation law has been developed. For a given conveying system, the pressure in the pneumatic conveying system can be solved for steady conditions or numerically simulated for unsteady conditions. Parametric analysis have been conducted for pressure drop factors and found that slug velocity is the major reason causing the pressure fluctuation in the pneumatic conveying system. To verify the pressure drop model, this model has been applied to single slug cases and compared with experimental results for five different bulk materials, showing good results. Three distinct zones, i.e. Fixed Bed Zone, Initial Slug Zone and Reliable Slug Zone, have been found to exist in the relationship between slip velocity and pressure gradient. Lastly this model has also been applied to a multiple slug system under uniform conditions. In all, the fundamental gas pressure/pressure drop model developed in this thesis approaches slug flow conveying from a different viewpoint from the traditional momentum and material stress models developed by previous researchers, and provides a way of assessing the non-steady flow behaviour in granular dense phase pneumatic conveying. This model not only attains a better understanding of slug flow behaviour but also increases the accuracy of predicting the parameters.

Research Doctorate - Doctor of Philosophy (PhD) / Slug flow dense phase pneumatic conveying can be a most reliable, efficient method for handling a remarkably wide range of dry bulk solids. Models for pressure drop over slugs in the low-velocity slug-flow pneumatic conveying by many researchers only took the force balance into account with the pressure drop. However, the nature of the slug flow pneumatic conveying is discontinuous and seldom becomes steady during the conveying period which requires further investigation. The fundamental understanding to gas/slug interaction in this thesis is that, by being a dynamic system, the faster a slug moves at a speed, the larger the space is left behind the slug. The gas feeding into the conveying system has to fill the increased space first then permeates through the slug and provides a push force on the slug. With gas permeation rate defined by the permeability factor, the derivative of the upstream pressure based on the air mass conservation law has been developed. For a given conveying system, the pressure in the pneumatic conveying system can be solved for steady conditions or numerically simulated for unsteady conditions. Parametric analysis have been conducted for pressure drop factors and found that slug velocity is the major reason causing the pressure fluctuation in the pneumatic conveying system. To verify the pressure drop model, this model has been applied to single slug cases and compared with experimental results for five different bulk materials, showing good results. Three distinct zones, i.e. Fixed Bed Zone, Initial Slug Zone and Reliable Slug Zone, have been found to exist in the relationship between slip velocity and pressure gradient. Lastly this model has also been applied to a multiple slug system under uniform conditions. In all, the fundamental gas pressure/pressure drop model developed in this thesis approaches slug flow conveying from a different viewpoint from the traditional momentum and material stress models developed by previous researchers, and provides a way of assessing the non-steady flow behaviour in granular dense phase pneumatic conveying. This model not only attains a better understanding of slug flow behaviour but also increases the accuracy of predicting the parameters.

Este trabalho apresenta um estudo de caso na indústria de implementos e veículos rodoviários para solução do processo específico de movimentação de veículos e carrocerias rodoviárias nas linhas de montagem. A solução é o desenvolvimento do projeto de uma ferramenta pneumática para atender os parâmetros identificados no processo de movimentação utilizando uma metodologia de projeto. A metodologia adotada é uma composição de modelos sugeridos por autores mostrando uma sequência clara e objetiva do ciclo de vida do projeto, estruturada em quatro fases principais: Projeto Informacional, Projeto Conceitual, Projeto Executivo e Otimização de Projeto. A identificação das informações relevantes ao processo de movimentação dos produtos deu início ao Projeto Informacional. Com a finalidade de conhecer melhor as características dos processos dos potenciais usuários da ferramenta, foram levantadas as características e os parâmetros do processo. Os parâmetros abordam as principais grandezas envolvidas no sistema e suas limitações. Os dados resultantes do levantamento foram analisados gerando uma síntese de todos os parâmetros identificados para o desenvolvimento das próximas fases. No projeto conceitual, houve a evolução da solução através do detalhamento de um conceito, escolhido mediante a proposição de alternativas durante a geração de conceitos. O detalhamento é apresentado através de desenhos, segundo a diretriz de projeto orientado ao computador, com base na estrutura funcional de funcionamento da ferramenta, salientando os principais sistemas e suas configurações. Os dimensionamentos são apresentados no projeto executivo e contemplam dois tipos de análise: a análise cinemática e a análise estrutural do sistema. Na análise cinemática são apresentadas duas propostas de configuração para o motor pneumático que será utilizado na ferramenta. As propostas são expostas através de desenhos de montagem, desenhos explodidos e gráficos dos parâmetros do motor pneumático para cada uma das configurações adotadas. Nesta fase também é mostrada a construção do protótipo. Os resultados do projeto são obtidos através da realização de teste em bancada e em campo para confirmação dos parâmetros estabelecidos. Completando o ciclo de vida do projeto, propõem-se as tendências evolutivas, analisando as possíveis melhorias para a ferramenta. As conclusões do trabalho são baseadas nos resultados apresentados nos testes realizados com a ferramenta, na eficiência da metodologia adotada para o desenvolvimento do projeto e na análise do cumprimento dos objetivos definidos no trabalho. / This paper presents a case study in industry of road road vehicles for solution of the specific handling of road vehicles and truck trailers in assembly lines. The solution is to develop the design of a pneumatic tool to meet the criteria identified in the move process using a design methodology. The methodology used is a composite of models suggested by the authors showed a clear sequence and objective of the life cycle of the project, divided into four main phases: Informational Design, Conceptual Design, Executive Design and Optimization Project. The identification of information relevant to the process of transferring products initiated the Informational Design. In order to better understand the nature of the processes of potential users of the tool has been raised the characteristics and process parameters. The parameters to approach the main quantities involved in the system and its limitations. Data from the survey were analyzed by generating a synthesis of all parameters identified for the development of the next phases. In conceptual design, was the evolution of the solution through the details of a concept, chosen by proposing alternatives for the generation of concepts. The detail is presented through drawings, according to the guideline of design aided computer based functional structure operating the tool, highlighting the major systems and their configurations. The detail is presented in the executive project and includes two types of analysis: kinematic analysis and structural analysis of the system. In the kinematic analysis are presented two proposals for setting for the air motor to be used in the tool. The proposals are exposed through the assembly drawings, exploded drawings and graphics of the parameters of the air motor for each of the configurations adopted. This stage is also shown a prototype. The project results are obtained by performing test bench and field tests to confirm the established parameters. Completing the life cycle of the project, propose to the changing trends, and review possible improvements to the tool. The conclusions of the study are based on the results presented in the tests with the tool, the efficiency of the methodology used to develop the design and analysis of compliance with the defined objectives at work.

Este trabalho apresenta um estudo de caso na indústria de implementos e veículos rodoviários para solução do processo específico de movimentação de veículos e carrocerias rodoviárias nas linhas de montagem. A solução é o desenvolvimento do projeto de uma ferramenta pneumática para atender os parâmetros identificados no processo de movimentação utilizando uma metodologia de projeto. A metodologia adotada é uma composição de modelos sugeridos por autores mostrando uma sequência clara e objetiva do ciclo de vida do projeto, estruturada em quatro fases principais: Projeto Informacional, Projeto Conceitual, Projeto Executivo e Otimização de Projeto. A identificação das informações relevantes ao processo de movimentação dos produtos deu início ao Projeto Informacional. Com a finalidade de conhecer melhor as características dos processos dos potenciais usuários da ferramenta, foram levantadas as características e os parâmetros do processo. Os parâmetros abordam as principais grandezas envolvidas no sistema e suas limitações. Os dados resultantes do levantamento foram analisados gerando uma síntese de todos os parâmetros identificados para o desenvolvimento das próximas fases. No projeto conceitual, houve a evolução da solução através do detalhamento de um conceito, escolhido mediante a proposição de alternativas durante a geração de conceitos. O detalhamento é apresentado através de desenhos, segundo a diretriz de projeto orientado ao computador, com base na estrutura funcional de funcionamento da ferramenta, salientando os principais sistemas e suas configurações. Os dimensionamentos são apresentados no projeto executivo e contemplam dois tipos de análise: a análise cinemática e a análise estrutural do sistema. Na análise cinemática são apresentadas duas propostas de configuração para o motor pneumático que será utilizado na ferramenta. As propostas são expostas através de desenhos de montagem, desenhos explodidos e gráficos dos parâmetros do motor pneumático para cada uma das configurações adotadas. Nesta fase também é mostrada a construção do protótipo. Os resultados do projeto são obtidos através da realização de teste em bancada e em campo para confirmação dos parâmetros estabelecidos. Completando o ciclo de vida do projeto, propõem-se as tendências evolutivas, analisando as possíveis melhorias para a ferramenta. As conclusões do trabalho são baseadas nos resultados apresentados nos testes realizados com a ferramenta, na eficiência da metodologia adotada para o desenvolvimento do projeto e na análise do cumprimento dos objetivos definidos no trabalho. / This paper presents a case study in industry of road road vehicles for solution of the specific handling of road vehicles and truck trailers in assembly lines. The solution is to develop the design of a pneumatic tool to meet the criteria identified in the move process using a design methodology. The methodology used is a composite of models suggested by the authors showed a clear sequence and objective of the life cycle of the project, divided into four main phases: Informational Design, Conceptual Design, Executive Design and Optimization Project. The identification of information relevant to the process of transferring products initiated the Informational Design. In order to better understand the nature of the processes of potential users of the tool has been raised the characteristics and process parameters. The parameters to approach the main quantities involved in the system and its limitations. Data from the survey were analyzed by generating a synthesis of all parameters identified for the development of the next phases. In conceptual design, was the evolution of the solution through the details of a concept, chosen by proposing alternatives for the generation of concepts. The detail is presented through drawings, according to the guideline of design aided computer based functional structure operating the tool, highlighting the major systems and their configurations. The detail is presented in the executive project and includes two types of analysis: kinematic analysis and structural analysis of the system. In the kinematic analysis are presented two proposals for setting for the air motor to be used in the tool. The proposals are exposed through the assembly drawings, exploded drawings and graphics of the parameters of the air motor for each of the configurations adopted. This stage is also shown a prototype. The project results are obtained by performing test bench and field tests to confirm the established parameters. Completing the life cycle of the project, propose to the changing trends, and review possible improvements to the tool. The conclusions of the study are based on the results presented in the tests with the tool, the efficiency of the methodology used to develop the design and analysis of compliance with the defined objectives at work.