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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Investigation into the Stability of Biomedical Grade Silicone and Polyurethane Exposed to Ionizing Radiation

Cooke, Shelley L. 12 September 2018 (has links)
Clinical studies suggest radiation dose and dose rate cause increased failure of medical implants however, little evidence supports this claim and due to the complexity of an in vivo environment, separating variable implants is difficult. Before beginning to understand material changes in vivo, a systematic study of silicone and polyurethane exposed to radiation is needed to verify whether radiation is a major variable contributing to material changes. This research fills a gap within the current literature by investigating low dose therapeutic radiation and varying dose rates at sterilization dose and answers questions on whether radiation in an aqueous environment alone is enough to significantly alter material properties. This is the first research to apply a water environment to therapeutic doses and the first to investigate a range of dose rates for clinical applications. Biomedical grade silicone and polyurethane films will be exposed to both types of radiation in an aqueous environment separately and analyzed for changes. The limited current literature combined with standards for biomedical devices will be used to characterize changes seen in materials. The first strategy used to explore the compliance of biomedical grade polymers employs low doses of therapeutic radiation ranging between 0 Gy and 80 Gy. Analysis of these low doses results in confirming cellular, mechanical and chemical stability of silicone and polyurethane. The second strategy used to investigate silicone and polyurethane exposed materials to 25 kGy (sterilization dose) of gamma irradiation at varying dose rates (3.2 - 833 Gy/min). Results from these studies conclude that varying the dose rate causes slight changes in both materials but not significant enough to alter bulk material properties. In conclusion, the results from this research reveal that both silicone and polyurethane maintain their stability at low doses and varying dose rates of irradiation while in an aqueous environment. This indicates that increased failure rates seen in silicone and polyurethane materials in vivo when exposed to radiation cannot be contributed to radiation alone. With the highly complex environment medical devices are exposed to in vivo, each variable that may contribute to failure should be investigated individually before combining to fully understand the mechanisms of material failure. This study indicates that the environment may play a larger role in material change and there is a need for updates to medical device standards. / PHD / Clinical studies suggest radiation dose and dose rate cause increased failure of medical implants however, little evidence supports this claim and due to the complexity of a human environment, separating factors contributing to failure is difficult. Before beginning to understand material changes, a study of silicone and polyurethane exposed to radiation is needed to verify whether radiation is a major variable contributing to material changes. The results from this research reveal that both silicone and polyurethane maintain their stability at low doses and varying dose rates of irradiation while in water environment. This indicates that increased failure rates seen in silicone and polyurethane materials in clinical settings when exposed to radiation cannot be contributed to radiation alone. With the highly complex environment medical devices are exposed, each factor that may contribute to failure should be investigated individually before combining to fully understand the mechanisms of material failure. This study indicates that the environment may play a larger role in material change and there is a need for updates to medical device standards.
12

Medical devices in Sweden : Industrial structure, production and foreign trade 1985-2002

Sidén, Lena-Kajsa January 2003 (has links)
<p>This licentiate thesis uses descriptive, mainly official,Swedish statistics to analyse industrial structure, productionand foreign trade in an industry that is traditionallydifficult to describe in numbers, that of medical devices. Forthe purposes of the thesis, the Swedish Medical Device industryis defined as companies classified in the SE-SIC manufacturingcodes 33101 (medical equipment and instruments, etc), 33102(dental products) and 35430 (invalid vehicles). Also otherbranches contribute, notably parts of SIC 51460 (wholesale inmedical equipment and pharmaceutical goods) and 73103 (medicalresearch and development) although their medical device volumecannot be specified. Additional items have been identified interms of specific product groups rather than as "belonging" toa specific SIC industrial code.</p><p>Taken together, this is considered to correspond reasonablywell to the scope of the field as defined by the Global MedicalDevice Nomenclature (GMDN), a new European standard forclassifying medical devices in a more generic way than do theEuropean Medical Device Directives (or other pieces oflegislation). No quantification according to GMDN can be madeas yet, however, as that requires changing reporting habits inindustry as well as in official statistical classification andnomenclature regimes.</p><p>With the manufacturing code SE-SIC 33101 as main object, thestudy for the first time presents data on the regionaldistribution, size classes of employment, company starting timeand company dynamics, in the form of entries to and exits fromthe code, over a six-year period. The latter analysis includesa follow-up of the "exits", some firms reappearing in otherparts of industry and others disappearing–surprisinglyfew among them being limited companies. Although this industryis comparatively mature, considerable mobility among themid-sized companies is indicated for reasons of real changes or(to some degree) factors inherent in the industrialclassification system. Some structural changes in companies inthe ≥50 employees bracket are identified. It is notedthat American actors, directly or indirectly, are increasinglyinvolved with the medical device industry in Sweden, and that anumber of technology-based companies that were started mostlyin the early eighties have recently reached the 50+ employeelevel.</p><p>The analysis of identifiable production and internationaltrade in medical devices spans a period of 17 years based onofficial statistics following the HS/CN nomenclatures. Adatabase has been built, bottom-up, from the 8-digit CN levelwith production, exports and imports values for close to 100items collected in 12 product groups, for presentation purposesgrouped under three main headings. Compound annual growth ratesfor the latter are presented for three five-year periods1985-2000, showing that Swedish production and exports have hadan overall growth of 10 per cent p.a. This has kept Swedenahead of the international overall growth of 6- 7 per cent p.a.in recent years, products in the main group "Aids&Implants" growing more than 20 per cent p.a. Growth rates inthe most recent five-year period are lower, however. Healthynet exports figures are presented, the figure for 2002nominally representing 40 per cent of the production value incurrent as well as constant prices.</p><p>Production figures are given at industry (local unit) levelas well as at product group level. The product-based figuresidentified for Production 2001 are estimated to SEK 13,3billion, Exports to SEK 13,7 billion and Imports to SEK 9,7billion. Figures for the Apparent Domestic Market arecalculated for the corresponding entities. It is obvious,however, that the statistics do not capture the real productionvalue as exports exceed production both at overall level and inmajor product groups, particularly those on a high systemstechnology level. The situation is not uncommon for a number ofreasons; further, cases in the statistics methodologyliterature confirm that medical instrument-related codes areliable to this phenomenon. Corrections, including adjustmentsof both production and exports values, are possible butdemanding already at one individual 4-digit HS/CN level. This,therefore, must be considered outside the scope of an academicstudy.</p><p>The basic tablework developed for this thesis will be madefreely available to external parties for their own use providedthe author, with contact details, is named as the source.(Processing for commercial purposes is not expected, however.)Any suggestions for improvements are welcomed.</p>
13

Avaliação de dispositivos médicos na percepção do usuário : um estudo de caso com pacientes de hemodiálise

Grebin, Sabrina Zanatta January 2016 (has links)
Os dispositivos médicos desempenham um papel crucial na gestão de doenças crônicas, e são utilizados por diferentes usuários, em configurações variadas de ambientes, para o tratamento de diferentes doenças com diferentes níveis de gravidade. Esta dissertação tem por objetivo contribuir na captação, mensuração e análise da percepção do usuário em relação ao uso do dispositivo médico. Como objetivos secundários, tem-se: (i) analisar na literatura abordagens e técnicas de avaliação da usabilidade de dispositivos médicos sob a perspectiva do usuário; (ii) desenvolver e ilustrar, através de um estudo de caso com pacientes de hemodiálise, uma metodologia para avaliação da usabilidade de dispositivos médicos; e (iii) apresentar um procedimento de análise para avaliar a usabilidade de dispositivos médicos na perspectiva do paciente de hemodiálise, identificando quais características do contexto de uso podem afetar esta avaliação. Para atingir os objetivos de pesquisa, a dissertação é composta por três artigos que contemplam cada um dos objetivos mencionados anteriormente. No primeiro artigo foram avaliados 42 estudos, na qual cinco abordagens foram mais comumente utilizadas: entrevista, testes de usabilidade, percurso cognitivo, observação e questionário. Para o segundo e terceiro artigos, um estudo de caso com pacientes de hemodiálise foi conduzido. Questionários estruturados foram aplicados para pacientes em ambientes reais de uso, contendo questões a cerca da percepção de uso (máquina, procedimento e ambiente). No segundo artigo uma metodologia para avaliação centrada no usuário de dispositivos médicos foi proposta. Um fluxo detalhado foi gerado, composto por três etapas: planejamento, estudo de campo e análise dos dados, desdobrados em nove subetapas. No terceiro artigo, duas técnicas estatísticas, a Análise de Variância Multivariada (MANOVA) e Análise Fatorial Exploratória (AFE), foram empregadas para investigar a existência de diferenças nos níveis de satisfação do usuário com os aspectos de uso, além da extração de um menor número de fatores para explicar a satisfação geral do usuário. / Medical devices play a crucial role in chronic disease management, and are used by different users in different environments settings for the treatment of different diseases with different levels of severity. This dissertation aims at contributing to the capture, user perception of measurement and analysis regarding the use of the medical device. As secondary objectives, we have: (i) review the literature approaches and techniques for assessing the usability of medical devices in the user's perspective; (Ii) develop and illustrate through a case study of hemodialysis patients, a methodology for evaluating the usability of medical devices; and (iii) present an analysis procedure to evaluate the usability of medical devices in the hemodialysis patient's perspective, identifying context of use characteristics may affect this assessment. To achieve the research objectives, the dissertation consists of three articles that address each of the objectives mentioned above. In the first article were evaluated 42 studies in which five approaches have been most commonly used: interview, usability testing, cognitive route, observation and questionnaire. For the second and third articles, a case study of hemodialysis patients was conducted. Structured questionnaires were administered to patients in actual use environments, with questions about the perception of use (machine, process and environment). In the second article a methodology to assess user-centric medical device has been proposed. A detailed flow was generated, consisting of three stages: planning, field of study and analysis of the data, broken down into nine sub-steps. In the third article, two technical statistics, Multivariate Analysis of Variance (MANOVA) and exploratory factor analysis (EFA) were employed to investigate the existence of differences in user satisfaction levels with aspects of use, and the extraction of a minor number of factors to explain the overall user satisfaction.
14

Desenvolvimento de sistema de esterilização por plasma a baixa pressão, usando sistema de acoplamento capacitivo e acoplamento indutivo / Development of plasma sterilization system at low pressure, using capacitive and inductively coupling system

Moreira, Adir Jose 15 September 2006 (has links)
O objetivo deste estudo foi avaliar a eficácia da esterilização por plasma, utilizando como sensor o indicador biológico, esporos deBacillus subtilis. Nesse estudo foram utilizados reatores constituídos de acoplamento capacitivo modo RIE (Reactive Ion Etching) e acoplamento indutivo modo ICP (Inductively Coupled Plasma),sendo esse último classificado em dois tipos, cilíndrico e Planar. A diferença entre esses equipamentos está basicamente na forma de geração do plasma, sendo que no sistema RIE a potência de RF é aplicada nos eletrodos. No sistema ICP cilindrico, a potência é aplicada em uma bobina. No sistema planar que pode ser considerado como um sistema híbrido, a potência de RF é aplicada na bobina e nos eletrodos, fazendo assim com que se obtenha um plasma de alta densidade. Todos os experimentos envolvendo plasma foram desenvolvidos à temperaturas mais baixas quando comparadas com os processos esterilizantes a calor (por volta de 55 ºC), o que garante a possibilidade de aplicação em materiais poliméricos e ópticos (endoscópios, etc.). Os estudos de letalidade dos processos foram realizados utilizando esporos de Bacillus subtilis, veiculados em lamínulas de vidro, os quais foram submetidos a combinações de parâmetros de processo, permitindo a obtenção de dados comparativos quanto a sua letalidade e resistência, e, conseqüentemente, informações quanto à efetividade do processo de esterilização por plasma. Na utilização do sistema RIE os resultados obtidos mostraram-se bastante promissores, quando se utilizou potência de 150 W, pressão de 100 mTorr, vazão de 200 sccm, e tempo de 20 minutos, reduzindo a carga microbiana para próximo de zero nesse intervalo de tempo. Para potência de 100 W, utilizando todos os outros parâmetros, a carga microbiana foi reduzida com tempo de 60 minutos, não sendo este um resultado ideal, porém, ainda aceitável. Para o sistema ICP cilíndrico, os resultados foram também promissores, visto que se conseguiu reduzir a carga microbiana para próximo de zero, com 20 minutos de processo, sob pressão de 330 mTorr, potência de 350 e 400 W, e vazão do gás de 100 sccm. No sistema ICP Planar os resultados também foram muito bons, pois se conseguiu reduzir a carga microbiana para próximo de zero em 12 minutos, utilizando potência de 150 W, pressão de 100 mTorr, e vazão de 200 sccm. Esses resultados alcançados tanto para O2 puro quanto para O2 + H2O2, mostram a possibilidade da aplicação de ambos sistemas na esterilização de materiais hospitalares em geral, sendo entretanto necessários maiores estudos. Os resultados obtidos no trabalho possibilitarão projetar sistemas específicos que podem ser empregados em ambiente hospitalar e em estações de processamento de material cirúrgico. / The objective of this work was to evaluate the effectiveness plasma of the sterilization, using the biological indicators with spore\'s sensors Bacillus subtilis.. For this, the reactors of capacitive constituted of coupling had been used way RIE (Reactive Ion Etching) and inductive coupling was ICP (Inductively Coupled Plasma) which being the last classified in two types, cylindrical and glide. The differences between this equipment are basically in generation of plasma form, being these in systems RIE the RF power is applied in a coil. In the to glide system it can be considered with a hybrid systems, the RF power are applied in the bobbin and the electrodes which make with that it gets a high density of plasma. All the experiments involving plasma had been developed to the temperature near environment (for return of 55º C), which the possibility of application in polymeric and optic materials (the possibility of application in polymeric and optics materials (endoscopies, etc.). The studies of mortality of the process had been carried using the biological indicators constituted with spore\'s sensors Bacillus subtilis, together in blade of glass, which had been subdue the combinations of parameters process, allowing get information comparative such as mortality and resistance, and consequently effectiveness process the of the sterilization information. In the use of RIE systems the results had get showed many promising when it used 150W power, 100 mTorr pressure, 200 sccm leak, 20 minutes time, reducing the microbial load near at zero in this interval time. For 100 W powers, using all the other parameters, microbial load were reduced at 60 minutes times, this results are not being ideal, but can be acceptable. To ICP cylindrical systems, the results had been promising, since it was get to reduce the microbial load near to zero, with 20 minutes of process, under 330 mTorr pressure, 350 e 400 W power and 100 sccm gas leak. In ICP glide systems the results also had been very good, because it was obtained to reduce the microbial load near to zero at 12 minutes, using 150 W power, 100 mTorr pressure and 200 sccm leak. These results reached in such way for 02 pure and to 02 + H202, in general both of the sterilization systems of hospital environment showed the possibility of the application, however was being necessary greater studies. The results will make possible the project of specific systems that can be used in hospital environment and stations of processing of surgical material
15

Desenvolvimento de sistema de esterilização por plasma a baixa pressão, usando sistema de acoplamento capacitivo e acoplamento indutivo / Development of plasma sterilization system at low pressure, using capacitive and inductively coupling system

Adir Jose Moreira 15 September 2006 (has links)
O objetivo deste estudo foi avaliar a eficácia da esterilização por plasma, utilizando como sensor o indicador biológico, esporos deBacillus subtilis. Nesse estudo foram utilizados reatores constituídos de acoplamento capacitivo modo RIE (Reactive Ion Etching) e acoplamento indutivo modo ICP (Inductively Coupled Plasma),sendo esse último classificado em dois tipos, cilíndrico e Planar. A diferença entre esses equipamentos está basicamente na forma de geração do plasma, sendo que no sistema RIE a potência de RF é aplicada nos eletrodos. No sistema ICP cilindrico, a potência é aplicada em uma bobina. No sistema planar que pode ser considerado como um sistema híbrido, a potência de RF é aplicada na bobina e nos eletrodos, fazendo assim com que se obtenha um plasma de alta densidade. Todos os experimentos envolvendo plasma foram desenvolvidos à temperaturas mais baixas quando comparadas com os processos esterilizantes a calor (por volta de 55 ºC), o que garante a possibilidade de aplicação em materiais poliméricos e ópticos (endoscópios, etc.). Os estudos de letalidade dos processos foram realizados utilizando esporos de Bacillus subtilis, veiculados em lamínulas de vidro, os quais foram submetidos a combinações de parâmetros de processo, permitindo a obtenção de dados comparativos quanto a sua letalidade e resistência, e, conseqüentemente, informações quanto à efetividade do processo de esterilização por plasma. Na utilização do sistema RIE os resultados obtidos mostraram-se bastante promissores, quando se utilizou potência de 150 W, pressão de 100 mTorr, vazão de 200 sccm, e tempo de 20 minutos, reduzindo a carga microbiana para próximo de zero nesse intervalo de tempo. Para potência de 100 W, utilizando todos os outros parâmetros, a carga microbiana foi reduzida com tempo de 60 minutos, não sendo este um resultado ideal, porém, ainda aceitável. Para o sistema ICP cilíndrico, os resultados foram também promissores, visto que se conseguiu reduzir a carga microbiana para próximo de zero, com 20 minutos de processo, sob pressão de 330 mTorr, potência de 350 e 400 W, e vazão do gás de 100 sccm. No sistema ICP Planar os resultados também foram muito bons, pois se conseguiu reduzir a carga microbiana para próximo de zero em 12 minutos, utilizando potência de 150 W, pressão de 100 mTorr, e vazão de 200 sccm. Esses resultados alcançados tanto para O2 puro quanto para O2 + H2O2, mostram a possibilidade da aplicação de ambos sistemas na esterilização de materiais hospitalares em geral, sendo entretanto necessários maiores estudos. Os resultados obtidos no trabalho possibilitarão projetar sistemas específicos que podem ser empregados em ambiente hospitalar e em estações de processamento de material cirúrgico. / The objective of this work was to evaluate the effectiveness plasma of the sterilization, using the biological indicators with spore\'s sensors Bacillus subtilis.. For this, the reactors of capacitive constituted of coupling had been used way RIE (Reactive Ion Etching) and inductive coupling was ICP (Inductively Coupled Plasma) which being the last classified in two types, cylindrical and glide. The differences between this equipment are basically in generation of plasma form, being these in systems RIE the RF power is applied in a coil. In the to glide system it can be considered with a hybrid systems, the RF power are applied in the bobbin and the electrodes which make with that it gets a high density of plasma. All the experiments involving plasma had been developed to the temperature near environment (for return of 55º C), which the possibility of application in polymeric and optic materials (the possibility of application in polymeric and optics materials (endoscopies, etc.). The studies of mortality of the process had been carried using the biological indicators constituted with spore\'s sensors Bacillus subtilis, together in blade of glass, which had been subdue the combinations of parameters process, allowing get information comparative such as mortality and resistance, and consequently effectiveness process the of the sterilization information. In the use of RIE systems the results had get showed many promising when it used 150W power, 100 mTorr pressure, 200 sccm leak, 20 minutes time, reducing the microbial load near at zero in this interval time. For 100 W powers, using all the other parameters, microbial load were reduced at 60 minutes times, this results are not being ideal, but can be acceptable. To ICP cylindrical systems, the results had been promising, since it was get to reduce the microbial load near to zero, with 20 minutes of process, under 330 mTorr pressure, 350 e 400 W power and 100 sccm gas leak. In ICP glide systems the results also had been very good, because it was obtained to reduce the microbial load near to zero at 12 minutes, using 150 W power, 100 mTorr pressure and 200 sccm leak. These results reached in such way for 02 pure and to 02 + H202, in general both of the sterilization systems of hospital environment showed the possibility of the application, however was being necessary greater studies. The results will make possible the project of specific systems that can be used in hospital environment and stations of processing of surgical material
16

Contribution to the design of control laws for bilateral teleoperation with a view to applications in minimally invasive surgery.

Delwiche, Thomas 09 December 2009 (has links)
Teleoperation systems have been used in the operating rooms for more than a decade. However, the lack of force feedback in commercially available systems still raises safety issues and forbids surgical gestures like palpation. Although force feedback has already been implemented in experimental setups, a systematic methodology is still lacking to design the control laws. The approach developed in this thesis is a contribution towards such a systematic methodology: it combines the use of disturbance observers with the use of a structured fixed-order controller. This approach is validated by experiments performed on a one degree of freedom teleoperation system. A physical model of this system is proposed and validated experimentally. Disturbance observers allow to compensate friction, which is responsible for performance degradation in teleoperation. Contrary to alternative approaches,they are based on a model of the frictionless mechanical system. This allows to compensate friction with a time varying behavior, which occurs in laparoscopy. Parametric uncertainties in this model may lead to an unstable closed-loop. A kind of "separation principle" is provided to decouple the design of the closed-loop system from the design of the observer. It relies on a modified problem statement and on the use of available robust design and analysis tools. A new metric is proposed to evaluate the performance of friction compensation systems experimentally. This metric evaluates the ability of a compensation system to linearize a motion system, irrespective of the task and as a function of frequency. The observer-based friction compensation is evaluated with respect to this new metric and to a task-based metric. It correctly attenuates the friction in the bandwidth of interest and significantly improves position and force tracking during a palpation task. Structured fixed-order controllers are optimized numerically to achieve robust closed-loop performance despite modeling uncertainty. The structure is chosen among classical teleoperation structures. An efficient algorithm is selected and implemented to design such a controller, which is evaluated for a palpation task. It is compared to a full-order unstructured controller, representative of the design approach that has been used in the teleoperation literature up to now. The comparison highlights the advantages of our new approach: order-reduction steps and counter-intuitive behaviors are avoided. A structured fixed-order controller combined with a disturbance observer is implemented during a needle insertion experiment and allowed to obtain excellent performance.
17

Electrochemical synthesis of electroactive polymers for drugrelease for bio scaffolds.

Almquist, Robert January 2010 (has links)
Stem cell based therapy has the potential to treat several severe diseases; Parkinson’s disease is one well- known example. Transplantation of stem cell derived cells into animal models is unfortunately often associated with tumour formation or- uncontrolled growth of the transplanted cells. One strategy to suppress this tumour formation might be to induce differentiation of these cells, which in turn would prevent them from dividing.   Neuroblastoma tumors are known to demonstrate the complete transition from an undifferentiated state to a completely harmful, differentiated appearance and derived cells can be used as a model for cell differentiation and tumor suppression.   In this Master Thesis’s the conducting polymers PEDOT and PPy, that upon formation can be doped with biologically active compounds which in- turn can be released in a controlled manner through electrical stimulation, were formed together with various drugs (e.g. Methotrexate and Mycophenolic Acid), here shown to have effect on Neuroblastoma cells. Neuroblastoma- derived cell line SH- SY5Y was used as a model system for neuronal differentiation and tumour inhibition. Release profiles of neuroblastoma active drugs following electrical stimulation were evaluated and the effects from electrochemical processes on simultaneously growing SH- SY5Y cells were investigated.   The methods to deposit and release the drugs were based on electropolymerization and electrochemically controlled release, respectively. Controlled release of various drugs and compounds was monitored using Vis- and UV- spectroscopy and on some occasions using HPLC.   The electrochemically controlled release of a biologically inactive compound that can be used as a negative control for electrochemical release in future experiments was shown and that resulting electrochemical processes have negative effects on neuroblastoma cell growth.
18

The Design and Testing of a Less Invasive Dual Plate System for Posterior Spinal Fusion

Singh, Devin 31 August 2012 (has links)
Spinal fusion is the process by which two or more vertebral levels are joined into a single, solid bone mass in order to restore stability to a spine that has been compromised by trauma, degeneracy or metastasis. Fusion is accomplished through internal hardware positioned anteriorly, posteriorly, or with combined anterior-posterior instrumentation. Since the 1990s the frequency of spinal fusions has been rising, and this trend is expected to continue. Posterior approaches to fusion are most common, primarily consisting of pedicle screw and rod constructs. Despite the high success rate for bony fusion with pedicle screw fixation, this technique poses risks to delicate neurological and vascular structures and is heavily dependent on surgeon expertise. In this thesis, a novel and less invasive posterior spinal hardware system was designed and evaluated, which solely utilizes the spinous processes and laminae of the vertebrae as the point of the bone-implant interface. Morphological and biomechanical studies of the posterior spine were undertaken in order to define important geometric information to guide the design of the proposed hardware and to determine the strength of the posterior elements throughout the spine to assess their ability to support posterior element plating. Utilizing this information, a modular dual plate fusion system was developed for single or multi-level fusion. The system accounts for the native curvature of the spine and can be extended to additional vertebral levels at the time of insertion, or at any later time. Prototypes were manufactured in titanium. Positive biomechanical results were found when the proposed hardware was used as a supplement to anterior instrumentation. Additionally, work focused on 2D-3D registration of neutral CT data with flexion extension x-ray images, was undertaken and shown to yield improved accuracy of important vertebral metrics utilized for clinical assessment of spine stability. This technique is applicable to the evaluation of pathology and kinematics at any level of the spine, including post-fusion adjacent level degeneration. The culmination of this work has resulted in a novel, patent pending posterior element spinal fusion system.
19

The Design and Testing of a Less Invasive Dual Plate System for Posterior Spinal Fusion

Singh, Devin 31 August 2012 (has links)
Spinal fusion is the process by which two or more vertebral levels are joined into a single, solid bone mass in order to restore stability to a spine that has been compromised by trauma, degeneracy or metastasis. Fusion is accomplished through internal hardware positioned anteriorly, posteriorly, or with combined anterior-posterior instrumentation. Since the 1990s the frequency of spinal fusions has been rising, and this trend is expected to continue. Posterior approaches to fusion are most common, primarily consisting of pedicle screw and rod constructs. Despite the high success rate for bony fusion with pedicle screw fixation, this technique poses risks to delicate neurological and vascular structures and is heavily dependent on surgeon expertise. In this thesis, a novel and less invasive posterior spinal hardware system was designed and evaluated, which solely utilizes the spinous processes and laminae of the vertebrae as the point of the bone-implant interface. Morphological and biomechanical studies of the posterior spine were undertaken in order to define important geometric information to guide the design of the proposed hardware and to determine the strength of the posterior elements throughout the spine to assess their ability to support posterior element plating. Utilizing this information, a modular dual plate fusion system was developed for single or multi-level fusion. The system accounts for the native curvature of the spine and can be extended to additional vertebral levels at the time of insertion, or at any later time. Prototypes were manufactured in titanium. Positive biomechanical results were found when the proposed hardware was used as a supplement to anterior instrumentation. Additionally, work focused on 2D-3D registration of neutral CT data with flexion extension x-ray images, was undertaken and shown to yield improved accuracy of important vertebral metrics utilized for clinical assessment of spine stability. This technique is applicable to the evaluation of pathology and kinematics at any level of the spine, including post-fusion adjacent level degeneration. The culmination of this work has resulted in a novel, patent pending posterior element spinal fusion system.
20

Emotionally Meaningful Homecare : Designing for good relationships between patients and devices

Edström, Hampus January 2012 (has links)
Industrial design is an expanding field. Through new research, discussion and explorations the definitions of what designers can and should do is constantly discussed and redefined. The starting point for my master thesis is the investigation of the concept of emotional durability. In other words, I have looked into how designers could create more meaningful relationships between users and products. It concerns product style norms, terminologies for describing relationship types, as well as a product’s meaning to a user. In order to put learning outcomes into practice, this master thesis also involves a design project where I created a proposal for a new rehabilitation product. There is great potential in investigating how meaningful medical devices for the home should be designed. During my design process I try to dig into what it means to design medical products for a home environment. At the same time, I explore how to create emotionally durable experiences for the patients and increase the motivation in their rehabilitation. My proposal is a balance exercising device that introduces a new level of user interaction, which connects back to my research on emotional durability.

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